Academic literature on the topic 'Antigenic determinants'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Antigenic determinants.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Antigenic determinants"
1
Stephens, R. S., E. A. Wagar, and G. K. Schoolnik. "High-resolution mapping of serovar-specific and common antigenic determinants of the major outer membrane protein of Chlamydia trachomatis." Journal of Experimental Medicine 167, no. 3 (March 1, 1988): 817–31. http://dx.doi.org/10.1084/jem.167.3.817.
Full textAbstract:
The principal surface protein antigen of Chlamydia trachomatis is the major outer membrane protein (MOMP). The MOMP is antigenically complex. Among the 15 serovars of C. trachomatis, mAbs define serovar-, subspecies-, and species-specific determinants on MOMP. The molecular basis of the antigenic diversity of these proteins is reflected in amino acid variable sequence domains. We have mapped the dominant topographic antigenic determinants of MOMP that are defined by mAbs. Using recombinant DNA approaches we have identified the linear distribution of two antigenic domains. One domain contains a serovar-specific determinant and the other contains subspecies- and species-specific determinants. These antigenic domains correspond to two amino acid sequence variable domains. Synthetic peptides were immunogenic and these resolved the serovar-specific determinant within a 14-amino acid peptide. The subspecies- and species-specific determinants were overlapping within a 16-amino acid peptide.
2
Appel, J. R., C. Pinilla, H. Niman, and R. Houghten. "Elucidation of discontinuous linear determinants in peptides." Journal of Immunology 144, no. 3 (February 1, 1990): 976–83. http://dx.doi.org/10.4049/jimmunol.144.3.976.
Full textAbstract:
Abstract Synthetic peptides, made by the method of simultaneous multiple peptide synthesis, were coupled to the protein carrier keyhole limpet hemocyanin and used to raise mAb. Omission and substitution analogs of the original peptides were tested by ELISA to characterize their reactivity with the respective mAb. Linear antigenic determinants were located for 18 different peptides by using omission analogs. The length of the antigenic determinants ranged from 2 to 8 residues, with an average of 6 residues. The three aromatic amino acids, phenylalanine, tryptophan, and tyrosine, the charged hydrophilic amino acids, aspartic acid and lysine, and the neutral amino acid alanine were found to occur most often in the determinant region of the peptides tested, whereas asparagine, cysteine, and histidine occurred the least often. Alanine substitution analogs provided more information than omission analogs by enabling the determination of which side chain groups of the antigenic determinant residues were not critical for binding to the mAb. Detailed, "fingerprint" information about the interaction of the peptide, GASPYPNLSNQQT, and its mAb was obtained by synthesizing a complete series of analogs with individual substitutions for each position of the antigenic determinant, PYPNLS, with the 19 other amino acids. These results suggest that, at the amino acid level, all antigenic determinants of synthetic peptides defined by mAb can be considered discontinuous linear determinants.
3
Stolbikov, A. S., R. K. Salyaev, and N. I. Rekoslavskaya. "A bioinformatics approach for identifying the probable cause of the cross-interaction of antibodies to the antigenic protein HPV16 L1 with the HPV6 L1 protein." Vavilov Journal of Genetics and Breeding 25, no. 7 (December 3, 2021): 787–92. http://dx.doi.org/10.18699/vj21.090.
Full textAbstract:
This paper describes an attempt to analyze, with the aid of bioinformatics resources (programs and databases), the probable cause of the cross-interaction of antibodies against HPV16 L1 with antigenic protein HPV6 L1, which has been revealed in the investigation of the candidate vaccine obtained on the base of a plant expression system (tomato plants). In our opinion, the most likely reason for the cross-interaction of antibodies with antigens of different pathogenic HPV types is the similarity of their antigenic determinants. In this work, the amino acid sequences of HPV16 L1 and HPV6 L1 used for the development of a binary vaccine against cervical cancer and anogenital papillomatosis have been analyzed. For the analysis of antigenic determinants, the programs BepiPred-2.0: Sequential B-Cell Epitope Predictor, DiscoTope 2.0 Server and SYFPEITHI have been used. As a result of the analysis of probable B-cell linear determinants (epitopes), it has been found that in both types of HPV the proteins have approximately the same location and size of linear antigenic determinants; the difference is observed only in the form of small shifts in the size of several amino acid residues. However, there are some differences in the amino acid composition of epitopes; therefore, the possibility for cross-interaction of the antibodies with the antigens due to the similarity of linear antigenic determinants for B-cells is very small. The analysis of potential threedimensional epitopes for B-cells has shown that due to little difference between them the HPV16 L1 and HPV6 L1 proteins have no prerequisites for cross-interaction of the antibodies with the antigens belonging to the two different pathogenic HPV types. The analysis of probable linear epitopes for T-cells has revealed a common antigenic determinant in the two protein sequences. According to the rank made with the SYFPEITHI program, the amino acid sequence AQL(I)FNKPYWL is the second most likely antigenic determinant for T-cells. Meanwhile, the amino acid sequences of this determinant in HPV16 L1 and HPV6 L1 are virtually identical. There is a difference in only one position, but it is not critical due to the similarity of the physicochemical properties of amino acids, for which there is a replacement in the amino acid sequence of antigenic determinants. Consequently, some moderate cross-interaction of the antibodies to HPV16 L1 with the antigens of HPV6 L1 may be expected.
4
Patanjali, S. R., S. U. Sajjan, and A. Surolia. "Erythrocyte-binding studies on an acidic lectin from winged bean (Psophocarpus tetragonolobus)." Biochemical Journal 252, no. 3 (June 15, 1988): 625–31. http://dx.doi.org/10.1042/bj2520625.
Full textAbstract:
An acidic lectin (WBA II) was isolated to homogeneity from the crude seed extract of the winged bean (Psophocarpus tetragonolobus) by affinity chromatography on lactosylaminoethyl-Bio-Gel. Binding of WBA II to human erythrocytes of type-A, -B and -O blood groups showed the presence of 10(5) receptors/cell, with high association constants (10(6)-10(8) M-1). Competitive binding studies with blood-group-specific lectins reveal that WBA II binds to H- and T-antigenic determinants on human erythrocytes. Affinity-chromatographic studies using A-, B-, H- and T-antigenic determinants coupled to an insoluble matrix confirm the specificity of WBA II towards H- and T-antigenic determinants. Inhibition of the binding of WBA II by various sugars show that N-acetylgalactosamine and T-antigenic disaccharide (Thomsen-Friedenreich antigen, Gal beta 1-3GalNAc) are the most potent mono- and di-saccharide inhibitors respectively. In addition, inhibition of the binding of WBA II to erythrocytes by dog intestine H-fucolipid prove that the lectin binds to H-antigenic determinant.
5
Forsyth, IA, A. Hutchings, and GW Butcher. "A panel of monoclonal antibodies to ovine placental lactogen." Journal of Endocrinology 165, no. 2 (May 1, 2000): 435–42. http://dx.doi.org/10.1677/joe.0.1650435.
Full textAbstract:
A panel of 11 rat monoclonal antibodies (mAbs) has been raised to ovine placental lactogen (PL). By competitive enzyme-linked immunoabsorbent assay (ELISA), confirmed by two-site ELISA, the antibodies were shown to recognize six antigenic determinants on the ovine PL molecule, two of which overlap. One antigenic determinant (designated 1) was shared by other members of the prolactin/growth hormone (GH)/PL family in ruminants, humans and rodents. The binding of (125)I-labelled ovine PL to crude receptor preparations from sheep liver (somatotrophic) or rabbit mammary gland (lactogenic) was inhibited by mAbs recognizing antigenic determinants 2-6. Both types of receptor preparation were affected similarly. In the local in vivo pigeon crop sac assay, mAbs directed against determinants 3 and 6 enhanced the biological activity of ovine PL.
6
Wetzler, Meir, M. T. Brady, S. N. J. Siat, S. Kakati, A. W. Block, X. Wang, S. P. Hunger, A. J. Carroll, and S. Ferrone. "Differential Antigenic Profile of High Molecular Weight-Melanoma Associated Antigen (HMW-MAA) Expressed by 11q23-Positive Acute Leukemia: An Immunotherapeutic Target." Blood 106, no. 11 (November 16, 2005): 3261. http://dx.doi.org/10.1182/blood.v106.11.3261.3261.
Full textAbstract:
Abstract The poor clinical response of 11q23-positive [also known as mixed lineage leukemia (MLL)] acute leukemia (AL) to chemotherapy-containing regimens has stimulated interest in developing alternative therapeutic strategies. Among them is immunotherapy. Since no leukemia-specific antigen has been identified in 11q23-positive AL, we are developing an antibody-based immunotherapeutic strategy which targets the HMW-MAA. This antigen, which is a membrane bound proteoglycan, represents an attractive target because of its high expression on the surface of 11q23-positive AL blasts and its restricted distribution in normal tissues. Taking advantage of a unique panel of monoclonal antibodies (mAb) recognizing 7 distinct and spatially distant antigenic determinants, we have analyzed the antigenic profile of HMW-MAA by flow cytometry in samples from 15 adult and 14 pediatric patients with 11q23-positive AL. Our results demonstrate a differential expression of the HMW-MAA antigenic determinants and that their expression pattern correlates with cytogenetic subgroups. Specifically, all the determinants were expressed on 6 adult samples [3 t(11;19)(q23;p13), 2 t(4;11)(q21;q23), and 1 t(10;11)(p12;q23)]. In contrast only 3 determinants were detected on 8 adult samples [3 t(9;11)(p22;q23), and 1 each with t(6;11)(q27;q23), t(11;12)(q23;q13), t(11;14)(q23;p11.2), inv(11)(q21q23.2) and add(11)(q23)]. No antigenic determinant was detected on leukemic cells from the adult patient with t(2;11)(p21;q23). Interestingly, the antigenic profile of HMW-MAA expressed on leukemic cells from pediatric patients was different, since all the determinants were expressed on leukemic cells from 6 t(4;11), 1 t(9;11), 1 t(11;1)(1;13;9)(q23;q25p34;q14.3;p13), 2 t(11;19) and 1 del(11)(q14q23). On the other hand no determinant was detectable on the leukemic cells from 3 children [1 with both t(1;11)(p32;q23) and t(4;11), 1 inv(11)(p15q23) and 1 add(11)(q23)]. Whether the difference in the antigenic profile of HMW-MAA expressed by adult and pediatric 11q23-positive AL cells reflects the different pathogenesis of AL in adults and children remains to be determined. Our data show that the differential expression of antigenic determinants of HMW-MAA on 11q23-positive AL cells does not reflect structural differences in the HMW-MAA expressed by various types of 11q23-positive AL as indicated by the results of Western blotting analysis. Further, the differential expression does not correlate with MLL gene rearrangement, since fluorescent in-situ hybridization (FISH) performed on 15 adult samples detected MLL gene rearrangement in 4 of the 6 samples that express all the determinants and in 6 of the 8 samples that express only 3 determinants. In addition, the pediatric sample with inv(11) that does not express any determinant, has MLL gene rearrangement by FISH. Finally, the differential expression does not correlate with the presence of MLL partial tandem duplication, since it was detected in 1 sample that expresses all the antigenic determinants and in 2 samples that express only 3 determinants. These findings emphasize the need to use more than one HMW-MAA-specific mAb to phenotype 11q23-positive AL and to select patients to be treated with HMW-MAA-specific antibody-based immunotherapy.
7
Maeland, Johan A., Lars Bevanger, and Randi Valsoe Lyng. "Antigenic Determinants of Alpha-Like Proteins of Streptococcus agalactiae." Clinical Diagnostic Laboratory Immunology 11, no. 6 (November 2004): 1035–39. http://dx.doi.org/10.1128/cdli.11.6.1035-1039.2004.
Full textAbstract:
ABSTRACT The majority of group B streptococcus (GBS) isolates express one or more of a family of surface-anchored proteins that vary by strain and that form ladder-like patterns on Western blotting due to large repeat units. These proteins, which are important as GBS serotype markers and as inducers of protective antibodies, include the alpha C (Cα) and R4 proteins and the recently described alpha-like protein 2 (Alp2), encoded by alp2, and Alp3, encoded by alp3. In this study, we examined antigenic determinants possessed by Alp2 and Alp3 by testing of antibodies raised in rabbits, mainly by using enzyme-linked immunosorbent assays (ELISA) and an ELISA absorption test. The results showed that Alp2 and Alp3 shared an antigenic determinant, which may be a unique immunological marker of the Alp variants of GBS proteins. Alp2, in addition, possessed an antigenic determinant which showed specificity for Alp2 and a third determinant which showed serological cross-reactivity with Cα. Alp3, in addition to the determinant common to Alp2 and Alp3, harbored an antigenic site which also was present in the R4 protein, whereas no Alp3-specific antigenic site was detected. These ELISA-based results were confirmed by Western blotting and a fluorescent-antibody test. The results are consistent with highly complex antigenic structures of the alpha-like proteins in a fashion which is in agreement with the recently described structural mosaicism of the alp2 and alp3 genes. The results are expected to influence GBS serotyping, immunoprotection studies, and GBS vaccine developments.
8
Pollard, K. Michael, and Michael G. Cohen. "Predicting Antigenic Determinants of Autoantigens." Autoimmunity 5, no. 4 (January 1990): 265–75. http://dx.doi.org/10.3109/08916939009014711.
Full text
9
Rearden, A. "Evolution of glycophorin A in the hominoid primates studied with monoclonal antibodies, and description of a sialoglycoprotein analogous to human glycophorin B in chimpanzee." Journal of Immunology 136, no. 7 (April 1, 1986): 2504–9. http://dx.doi.org/10.4049/jimmunol.136.7.2504.
Full textAbstract:
Abstract Comparison of human and primate erythrocyte membrane sialoglycoproteins showed that common chimpanzee, dwarf chimpanzee, gorilla, orangutan, and gibbon have major periodic acid Schiff-positive proteins resembling human glycophorin A (GPA) monomer and dimer in electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gels. Immunoperoxidase staining of Western blots with monoclonal antibodies to human GPA showed that these primate bands express some GPA antigenic determinants. A new sialoglycoprotein analogous to human glycophorin B (GPB) was detected in common chimpanzee. Although human MN blood group phenotype results from an amino acid polymorphism of GPA, Western blots showed that in chimpanzee sialoglycoprotein (GPAch) always expresses the M blood group, whereas chimpanzee sialoglycoprotein (GPBch) expresses either the N blood group or a null phenotype. This result explains the detection of M and MN, but not of N, blood group phenotypes in chimpanzee. GPBch has higher apparent m.w. than human GPB, is present in the erythrocyte membrane in greater quantity than human GPB, and contains trypsin cleavage site(s) and the 10F7 determinant (both found on human GPA but not GPB). Expression of human GPA antigenic determinants was consistent with the phylogeny of the hominoid primates; common and dwarf chimpanzee expressed most of the determinants tested, gorilla and orangutan an intermediate number, and gibbon and siamang the least. Of the GPA antigenic determinants examined, the MN blood group determinants were most consistently expressed during evolution of the hominoid primates. The results suggested that variability in expression of GPA antigenic determinants between species was due to both differences in amino acid sequence and glycosylation.
10
Zhang, Hong, Guangwen Wang, Jian Li, Yuchun Nie, Xuanling Shi, Gewei Lian, Wei Wang, et al. "Identification of an Antigenic Determinant on the S2 Domain of the Severe Acute Respiratory Syndrome Coronavirus Spike Glycoprotein Capable of Inducing Neutralizing Antibodies." Journal of Virology 78, no. 13 (July 1, 2004): 6938–45. http://dx.doi.org/10.1128/jvi.78.13.6938-6945.2004.
Full textAbstract:
ABSTRACT Severe acute respiratory syndrome (SARS) is a life-threatening disease caused by a newly identified coronavirus (CoV), SARS-CoV. The spike (S) glycoprotein of CoV is the major structural protein responsible for induction of host immune response and virus neutralization by antibodies. Hence, knowledge of neutralization determinants on the S protein is helpful for designing protective vaccines. To analyze the antigenic structure of the SARS-CoV S2 domain, the carboxyl-terminal half of the S protein, we first used sera from convalescent SARS patients to test the antigenicity of 12 overlapping fragments spanning the entire S2 and identified two antigenic determinants (Leu 803 to Ala 828 and Pro 1061 to Ser 1093). To determine whether neutralizing antibodies can be elicited by these two determinants, we immunized animals and found that both of them could induce the S2-specific antisera. In some animals, however, only one determinant (Leu 803 to Ala 828) was able to induce the antisera with the binding ability to the native S protein and the neutralizing activity to the SARS-CoV pseudovirus. This determinant is highly conserved across different SARS-CoV isolates. Identification of a conserved antigenic determinant on the S2 domain of the SARS-CoV S protein, which has the potential for inducing neutralizing antibodies, has implications in the development of effective vaccines against SARS-CoV.
Dissertations / Theses on the topic "Antigenic determinants"
1
Pang, Ha Sang. "Identification of CD8+ T cell epitopes from HCA661 presented by HLA-A2 molecules /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202006%20PANG.
Full text
2
張紀忠 and Jizhong Zhang. "Conformational antigenic determinants of the HEV CAPSID." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31241360.
Full text
3
Zhang, Jizhong. "Conformational antigenic determinants of the HEV CAPSID /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2207918X.
Full text
4
Beena, T. K. "Antigenic Determinants Of Chicken Riboflavin Carrier Protein: Structural And Functional Aspects." Thesis, Indian Institute of Science, 1994. https://etd.iisc.ac.in/handle/2005/141.
Full textAbstract:
Investigations detailed in this thesis constitute a part of the continuing programme of research undertaken in our laboratory on the riboflavin carrier protein (RCP) with particular reference to identification and synthesis of neutralizing antigenic determinants, design of relevant epitope mimetics with improved immunogenic characteristics and relationship between their secondary structures and immunological properties.
The riboflavin carrier protein is elaborated as a reproductive stratagem to ensure adequate vitamin deposition in the developing oocyte in the chickens. The protein is scrupulously conserved through evolution in terms of physico chemical and immunological characteristics from fish through birds to mammals, including primates. In rodents and subhuman primates immunization with the heteroantigen viz., chicken egg white RCP leads to functional neutralization of the endogenous maternal protein resulting in curtailment of early pregnancy. Thus, the crucial role of RCP in maintenance of pregnancy is established and the protein identified as a potential candidate vaccine for immimocontraception. Further studies with the reduced and carboxymethylated (RCM) RCP as the immunogen reveal that antibodies induced by RCM-RCP are equally effective in bioneutralization of the endogenous protein. So it can be surmised that the native folded structure of RCP is not obligatory for eliciting bioneutralizing antibodies. In an attempt to identify functionally relevant regions of the protein, a panel of monoclonal antibodies (MAbs) have been raised and characterized. One of the MAbs viz., 6J32Ci2 could bring about early fetal resorp-tion when injected to mice with confirmed pregnancies. These results prompted a detail molecular immunological approach to understand underlying mechanisms. The principal aims of the present investigations include: (1) identification of neutralizing epitopes; (2) synthesis of peptidyl sequences incorporating these determinants; (3) an understanding of the structure, antigenic and immunogenic characteristics of these peptides; (4) correlation of conformational and antigenic characteristics; (5) rational design and synthesis of peptide analogs with greater propensity to assume predicted secondary structures; (6) analysis of conformation dependency of peptide antigens and the importance of such conformation in generating an optimal B-cell response; (7) the efficacy of the antibodies elicited by these Peptide antigens in neutralizing endogenous protein with the ultimate aim of designing synthetic vaccines.
Chapter 1 of this thesis deals with a general introduction summarizing the current status of knowledge regarding the chemistry and biology of RCP as well as synthetic peptides as potential immunogens. Chapter 2 outlines details of the experimental procedures adopted. Chapter 3 describes the results of investigations on the C-terminal fragment (residues 200-219) of cRCR The main consideration in selecting this sequence for the design of a potential peptide-based vaccine relied on the epitopic specificity of the neutralizing MAb 6S2C12. Epitope mapping using the Pepscan method revealed that the monoclonal antibody recognizes a core sequence corresponding to residues 203-210 of the cRCP. A 21-residue synthetic peptide (C-21) comprising this epitope was synthesized and antibodies elicited to the peptide conjugated to two different carriers, namely diphtheria toxoid and purified protein derivative (PPD) for T-cell help. In both active and passive immunoneutralization experiments, the peptide specific neutralizing antibodies interfered with the biological function of the protein and hence either protected from pregnancy or caused early fetal resorption in rodents as well as in sub-human primates. The conforma-tional properties of the peptide in aqueous buffers were analyzed from circular dichroism which revealed the absence of any ordered structure in the native C-21 peptide. Theoretical predictions of secondary structure suggested a propensity for an t*-helical structure for this fragment in the native protein. Therefore, influence of the helix-promoting solvent, vizM 2,2,2,trifluroethanol (TFE) on the C-21 peptide was investigated. Addition of TFE resulted in spectral changes with negative bands at 208 and 222 nm and a positive band at 190 rim which are typical of an a-helix.
To gain more information on the conformational characteristics of this peptide, it was considered worthwhile to stabilize the native peptide in an a-helical conformation based on simple rational design principles. Towards this end, four analogs of the parent peptide were synthesized and helix stabilization was sought to be achieved by introducing either salt bridges or back-bone conformational constraints such as by incorporating a-amino isobutyric acid at appropriate positions. In all the analogs, the core sequence, recognised by the neutralizing MAb 6B2C12 was maintained intact to ensure induction of antibodies capable of recognizing the native protein. CD spectral analysis of the analog peptides indicated that all the engineered peptides had varying degrees of enhanced helicities as compared to the parent peptide. The immunogenicity of each analog was studied by to the relevant peptide-diphtheria toxoid conjugates and analyzing their reactivities with the native protein by direct and competitive ELISA. The results revealed that these engineered conformational analogs axe highly immunogenic eliciting high titers of anti-protein antibodies. The relative affinities of these antibodies to bind cRCP were investigated. The antibodies to peptide analogs had higher affinities for the native protein and a positive correlation was found between the helical content of the peptide antigen in question and the relative affinity of corresponding antibody. The antibodies directed to all the peptide analogs could block the function of RCP resulting in early embryonic resorption when administered to pregnant mice. An interesting pattern of immunological cross-reactivity has been observed with the native and designed peptides. Antibodies raised to constrained helical analogs could bind the C-21 peptide which is structurally flexible. In contrast, the antibodies raised to the flexible native peptide antigen were inefficient in recognizing the structured peptides. The ability of all the peptide antibody to bind the native protein has been interpreted in terms of a conformationally flexible C-terminus region in cRCP.
Chapter 4 details investigations on a 21-residue peptide (N- 21) from the N-terminiis (4-24) of the protein. Selection of this peptidyl sequence relied on theoretical prediction of potential sequential determinants on RCP other than at C-terminus as well as on the outcome of immunoneutralisation experiments using antibodies to egg yolk RCP which lacks the relevant C-terminal determinants. The structure of this peptide in solution was analyzed by two dimensional NMR and CD. NMR experiments revealed the presence of two structured regions in the peptide. Diagnostic nuclear Overhauser effects characteristics of reverse turns or short frayed helical segments over residues 3-9 and 18-21 of the peptide were obtained. CD spectra showed the presence of a strong, negative band at 204 nm over a wide range of solvent conditions, a feature which has been interpreted in terms of a "polyproline Il-like" segment encompassing residues 11-16 which corresponds to an interesting (X-Pro)^ repeat in the N-21 sequence.
Specific antibodies were generated to this peptide as a conjugate with diphtheria toxoid. Administration of the antipeptide antibodies could neutralize the protein in vivo as demonstrated by early embryonic loss in pregnant mice. In limited experiments the antipeptide antibodies showed propensity to protect bonnet monkeys from pregnancy over a few consecutive ovulatory cycles when titres are maintained elevated by periodic boosting. To address the relationship between peptide structures and antigenicity, epitope mapping of this antipeptide antibodies as well- as the polyclonal antibodies to native RCP was undertaken using the Pepscan method. The results reveal that antigenic regions correspond well to conformationally well-defined elements of structure with the polyproline II-like segment being a common antigenic determinant on both the peptide and the native protein. These observations are suggestive of the involvement of both the N and C-terminal regions of RCP in terms of its binding to putative plasma membrane receptors.
5
Beena, T. K. "Antigenic Determinants Of Chicken Riboflavin Carrier Protein: Structural And Functional Aspects." Thesis, Indian Institute of Science, 1994. http://hdl.handle.net/2005/141.
Full textAbstract:
Investigations detailed in this thesis constitute a part of the continuing programme of research undertaken in our laboratory on the riboflavin carrier protein (RCP) with particular reference to identification and synthesis of neutralizing antigenic determinants, design of relevant epitope mimetics with improved immunogenic characteristics and relationship between their secondary structures and immunological properties.
The riboflavin carrier protein is elaborated as a reproductive stratagem to ensure adequate vitamin deposition in the developing oocyte in the chickens. The protein is scrupulously conserved through evolution in terms of physico chemical and immunological characteristics from fish through birds to mammals, including primates. In rodents and subhuman primates immunization with the heteroantigen viz., chicken egg white RCP leads to functional neutralization of the endogenous maternal protein resulting in curtailment of early pregnancy. Thus, the crucial role of RCP in maintenance of pregnancy is established and the protein identified as a potential candidate vaccine for immimocontraception. Further studies with the reduced and carboxymethylated (RCM) RCP as the immunogen reveal that antibodies induced by RCM-RCP are equally effective in bioneutralization of the endogenous protein. So it can be surmised that the native folded structure of RCP is not obligatory for eliciting bioneutralizing antibodies. In an attempt to identify functionally relevant regions of the protein, a panel of monoclonal antibodies (MAbs) have been raised and characterized. One of the MAbs viz., 6J32Ci2 could bring about early fetal resorp-tion when injected to mice with confirmed pregnancies. These results prompted a detail molecular immunological approach to understand underlying mechanisms. The principal aims of the present investigations include: (1) identification of neutralizing epitopes; (2) synthesis of peptidyl sequences incorporating these determinants; (3) an understanding of the structure, antigenic and immunogenic characteristics of these peptides; (4) correlation of conformational and antigenic characteristics; (5) rational design and synthesis of peptide analogs with greater propensity to assume predicted secondary structures; (6) analysis of conformation dependency of peptide antigens and the importance of such conformation in generating an optimal B-cell response; (7) the efficacy of the antibodies elicited by these Peptide antigens in neutralizing endogenous protein with the ultimate aim of designing synthetic vaccines.
Chapter 1 of this thesis deals with a general introduction summarizing the current status of knowledge regarding the chemistry and biology of RCP as well as synthetic peptides as potential immunogens. Chapter 2 outlines details of the experimental procedures adopted. Chapter 3 describes the results of investigations on the C-terminal fragment (residues 200-219) of cRCR The main consideration in selecting this sequence for the design of a potential peptide-based vaccine relied on the epitopic specificity of the neutralizing MAb 6S2C12. Epitope mapping using the Pepscan method revealed that the monoclonal antibody recognizes a core sequence corresponding to residues 203-210 of the cRCP. A 21-residue synthetic peptide (C-21) comprising this epitope was synthesized and antibodies elicited to the peptide conjugated to two different carriers, namely diphtheria toxoid and purified protein derivative (PPD) for T-cell help. In both active and passive immunoneutralization experiments, the peptide specific neutralizing antibodies interfered with the biological function of the protein and hence either protected from pregnancy or caused early fetal resorption in rodents as well as in sub-human primates. The conforma-tional properties of the peptide in aqueous buffers were analyzed from circular dichroism which revealed the absence of any ordered structure in the native C-21 peptide. Theoretical predictions of secondary structure suggested a propensity for an t*-helical structure for this fragment in the native protein. Therefore, influence of the helix-promoting solvent, vizM 2,2,2,trifluroethanol (TFE) on the C-21 peptide was investigated. Addition of TFE resulted in spectral changes with negative bands at 208 and 222 nm and a positive band at 190 rim which are typical of an a-helix.
To gain more information on the conformational characteristics of this peptide, it was considered worthwhile to stabilize the native peptide in an a-helical conformation based on simple rational design principles. Towards this end, four analogs of the parent peptide were synthesized and helix stabilization was sought to be achieved by introducing either salt bridges or back-bone conformational constraints such as by incorporating a-amino isobutyric acid at appropriate positions. In all the analogs, the core sequence, recognised by the neutralizing MAb 6B2C12 was maintained intact to ensure induction of antibodies capable of recognizing the native protein. CD spectral analysis of the analog peptides indicated that all the engineered peptides had varying degrees of enhanced helicities as compared to the parent peptide. The immunogenicity of each analog was studied by to the relevant peptide-diphtheria toxoid conjugates and analyzing their reactivities with the native protein by direct and competitive ELISA. The results revealed that these engineered conformational analogs axe highly immunogenic eliciting high titers of anti-protein antibodies. The relative affinities of these antibodies to bind cRCP were investigated. The antibodies to peptide analogs had higher affinities for the native protein and a positive correlation was found between the helical content of the peptide antigen in question and the relative affinity of corresponding antibody. The antibodies directed to all the peptide analogs could block the function of RCP resulting in early embryonic resorption when administered to pregnant mice. An interesting pattern of immunological cross-reactivity has been observed with the native and designed peptides. Antibodies raised to constrained helical analogs could bind the C-21 peptide which is structurally flexible. In contrast, the antibodies raised to the flexible native peptide antigen were inefficient in recognizing the structured peptides. The ability of all the peptide antibody to bind the native protein has been interpreted in terms of a conformationally flexible C-terminus region in cRCP.
Chapter 4 details investigations on a 21-residue peptide (N- 21) from the N-terminiis (4-24) of the protein. Selection of this peptidyl sequence relied on theoretical prediction of potential sequential determinants on RCP other than at C-terminus as well as on the outcome of immunoneutralisation experiments using antibodies to egg yolk RCP which lacks the relevant C-terminal determinants. The structure of this peptide in solution was analyzed by two dimensional NMR and CD. NMR experiments revealed the presence of two structured regions in the peptide. Diagnostic nuclear Overhauser effects characteristics of reverse turns or short frayed helical segments over residues 3-9 and 18-21 of the peptide were obtained. CD spectra showed the presence of a strong, negative band at 204 nm over a wide range of solvent conditions, a feature which has been interpreted in terms of a "polyproline Il-like" segment encompassing residues 11-16 which corresponds to an interesting (X-Pro)^ repeat in the N-21 sequence.
Specific antibodies were generated to this peptide as a conjugate with diphtheria toxoid. Administration of the antipeptide antibodies could neutralize the protein in vivo as demonstrated by early embryonic loss in pregnant mice. In limited experiments the antipeptide antibodies showed propensity to protect bonnet monkeys from pregnancy over a few consecutive ovulatory cycles when titres are maintained elevated by periodic boosting. To address the relationship between peptide structures and antigenicity, epitope mapping of this antipeptide antibodies as well- as the polyclonal antibodies to native RCP was undertaken using the Pepscan method. The results reveal that antigenic regions correspond well to conformationally well-defined elements of structure with the polyproline II-like segment being a common antigenic determinant on both the peptide and the native protein. These observations are suggestive of the involvement of both the N and C-terminal regions of RCP in terms of its binding to putative plasma membrane receptors.
6
Choukri, Sam. "Selection of malaria-specific epitopes from random peptide libraries /." free to MU campus, to others for purchase, 1999. http://wwwlib.umi.com/cr/mo/fullcit?p9962513.
Full text
7
Serafin, Ina Loretta. "Epitope mapping of the dengue 3 envelope protein." Thesis, Queensland University of Technology, 1999.
Find full text
8
Smyrnis, Elie Mario. "The generation of monoclonal antibodies to neural cell type-specific antigenic determinants." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28399.
Full textAbstract:
Somatic cell hybridization techniques were used to produce a panel of anti-neural cell monoclonal antibody-secreting murine hybridomas.
Whole living cultures of bovine oligodendrocytes were used to inject (intra-splenically and without adjuvants) Balb/C mice with a total of 2.0 to 2.5 x 10⁶ oligodendrocytes. Polyethylene glycol was subsequently used to fuse these sensitized splenic lymphocytes to the murine NS-1 myeloma cell line. After fusion, supernatants were screened immunocytochemically using murine neural cell cultures. Initial screening identified a total of 17 clones, each of which primarily labelled a surface antigen specific to galactocerebroside-positive oligodendrocytes; as demonstrated by double-immunostaining characterization. The monoclonal antibodies were determined to be of either the IgM class or IgG[sub 2b] subclass. Moreover, these antibodies recognized protein bands possessing an
apparent molecular weight of 29,000 and/or 59,000 Da on Western blots of homogenized bovine oligodendrocytes. This may, therefore, represent immunolabelling of a previously unrecognized surface constituent of oligodendrocytes.
Culture supernatants from a second separate fusion experiment involving an intrasplenic injection with 20 μg of SDS-PAGE subfractionated human newborn brain particulate fraction were tested using first, an ELISA, and subsequently, indirect immunofluorescence microscopy. Screening demonstrated 2 clones which produced antibodies immunoreactive to an astrocyte subclass (glial fibrillary acidic protein-positive cells) found only in cultures of newborn murine brain. These antibodies were determined to be of an IgM class and were shown to specifically reactivity with electroblots of a protein constituent of whole newborn brain particulate fraction having an apparent molecular weight of 50,000 Da.Medicine, Faculty of
Pathology and Laboratory Medicine, Department of
Graduate
9
Grace, Christopher. "Diagnostically significant antigens of Treponema pallidum subsp. pallidum : identification, serological efficacy, and characterisation of the major antigenic determinants." Thesis, Open University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311861.
Full text
10
Otali, Dennis. "The combined effect of formalin fixation and individual steps in tissue processing on immunorecognition." Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2008r/otali.pdf.
Full textBooks on the topic "Antigenic determinants"
1
E, Sercarz Eli, ed. Antigenic determinants and immune regulation. Basel: Karger, 1989.
Find full text
3
B, Wisdom G., ed. Peptide antigens: A practical approach. Oxford: I.R.L.Press, 1994.
Find full text
4
Schenkel-Brunner, Helmut. Human blood groups: Chemical and biochemical basis of antigen specificity. Wien: Springer-Verlag, 1995.
Find full text
5
Schenkel-Brunner, Helmut. Human blood groups: Chemical and biochemical basis of antigen specificity. 2nd ed. Wien: Springer, 2000.
Find full text
6
Éva, Rajnavölgyi, ed. Synthetic peptides in the search for B- and T-cell epitopes. Austin, Tex: R.G. Landes Co., 1994.
Find full text
7
Binek, Marian. Mapowanie i określanie mitogenności epitopów gronkowcowej enterotoksyny B. Warszawa: Wydawn. SGGW-AR, 1991.
Find full text
8
Fred, Brown, and Crumpton M. J, eds. Immune recognition of protein antigens: Proceedings of a Royal Society Discussion Meeting held on 6 and 7 July 1988. London: Royal Society, 1989.
Find full text
9
Kwapinski, George. The immunochemistry of man. Malabar, Fla: Krieger Pub. Co., 1991.
Find full text
10
Ulrich, Reineke, and Schutkowski Mike, eds. Epitope mapping protocols. 2nd ed. New York: Humana Press, 2009.
Find full textBook chapters on the topic "Antigenic determinants"
1
Goodman, Joel W. "Modelling Determinants for Recognition by B Cells and T Cells." In Antigenic Determinants and Immune Regulation, 1–22. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318820.
Full text
2
Bluestone, Jeffrey A., and Terry Potter. "T Cell Clones and Monoclonal Antibodies: Immunologic Probes of Major Histocompatibility Complex Class I Molecules (Part 1 of 2)." In Antigenic Determinants and Immune Regulation, 23–35. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318822.
Full text
3
Bluestone, Jeffrey A., and Terry Potter. "T Cell Clones and Monoclonal Antibodies: Immunologic Probes of Major Histocompatibility Complex Class I Molecules (Part 2 of 2)." In Antigenic Determinants and Immune Regulation, 36–48. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318823.
Full text
4
McKean, David J. "Structural Requirements for Class II Molecule Recognition by Antibodies and T Cell Antigen Receptors (Part 1 of 2)." In Antigenic Determinants and Immune Regulation, 49–66. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318824.
Full text
5
McKean, David J. "Structural Requirements for Class II Molecule Recognition by Antibodies and T Cell Antigen Receptors (Part 2 of 2)." In Antigenic Determinants and Immune Regulation, 67–84. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318825.
Full text
6
Kapp, Judith A., and Phyllis Jonas Whiteley. "Insulin-Determinant Recognition by Helper and Suppressor T cells." In Antigenic Determinants and Immune Regulation, 85–100. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318826.
Full text
7
Fritz, Robert B., and Dale E. McFarlin. "Encephalitogenic Epitopes of Myelin Basic Protein." In Antigenic Determinants and Immune Regulation, 101–25. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318828.
Full text
8
Cohen, Jeffrey A., William V. Williams, David B. Weiner, and Mark I. Greene. "Molecular Aspects of Ligand Interaction with Somatic and Immune Receptors: Insights from Studies of the Mammalian Reoviruses (Part 1 of 2)." In Antigenic Determinants and Immune Regulation, 126–41. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318829.
Full text
9
Cohen, Jeffrey A., William V. Williams, David B. Weiner, and Mark I. Greene. "Molecular Aspects of Ligand Interaction with Somatic and Immune Receptors: Insights from Studies of the Mammalian Reoviruses (Part 2 of 2)." In Antigenic Determinants and Immune Regulation, 142–56. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318830.
Full text
10
Mitchison, N. A. "Suppression of the Response to Murine Alloantigens: Four-Cell-Type Clusters, Function-Flipping and Idiosyncratic Responses." In Antigenic Determinants and Immune Regulation, 157–68. Basel: KARGER, 1989. http://dx.doi.org/10.1159/000318831.
Full textConference papers on the topic "Antigenic determinants"
1
Nomura, S., H. Nagata, N. Sone, K. Oda, T. Kokawa, and K. Yasunaga. "ANALYSIS OF PLATELET ANTIGENS FOR ANTI-PLATELET ANTIBODIES IN ITP USING FLOW CYTOMETRY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644582.
Full textAbstract:
Idiopathic thrombocytopenic purpura (ITP) is a syndrome caused by circulating antibodies reactive with the platelet membrane. The antigenic specificity of these antibodies is unknown. We have characterized new monoclonal antibodies that react with a determinant specific to GP Ib and GP Ib- Ia complex, and used flow cytometry to investigate platelets in ITP for antigenic determinants to which autoantibodies are directed. Forty cases of ITP were analyzed in detail by the platelet suspension immunofluorescence test(PSIFT) of von dem Borne et al. The monoclonal antibodies used were 5 against GP Ib-Ia complex (NNKY1-32, NNKY2-5, NNKY2-6, NNKY2-11, NNKY2-18) and 2 against GP lb (NNKY5-4, NNKY5-5). The reactivity of monoclonal antibodies was inhibited by the presence of autoantibody on platelets in some ITP patients. Differences in inhibition were found not only between monoclonal antibodies but also between cases.These results suggest that some ITP patients have circulating antibodies to GP Ib or GP II b - Ia, and that heterogeneous antibodies are present on platelets. Moreover, the presence of these autoantibodies may aggravate or initiate a bleeding tendency.
2
FAUVEL-LAFEVE, F., and Y. J. LEGRAND. "IMMUNOCHEMICAL IDENTIFICATION OF A THROMBOSPONDIN -LIKE ANTIGEN IN ARTERIAL THROMBOGENIC MICROFIBRILS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643823.
Full textAbstract:
The biochemical structure of arterial microfibrils (MFS) is unknown. Presently, the most probable hypothesis is that elastin associated MFS contain several antigenic determinants with MW varying between 31 and 200 KD.From our previous studies we know that MFS extracted by 6 M GuCl contain a major glycoprotein with a 128 KD MV (GP128). GP 128 is essential for the reactivity of MFS towards blood platelets but due tc the high insolubility of the extracted material it was not possible to isolate and study this GP 128. We have used immunoblotting to determine if MFS contain determinants recognized by antibodies against connective tissue glycoproteins such as fibronectin, type VI collagen or anti-platelet thrombospondin (TSP). 'The results showed that MFS do not contain fibronectin or type VI collagen but that anti-TSP IgG reacted with GP 128. Furthermore, the Fab fragments from anti-TSP IgG inhibited platelet aggregation induced by MFS but not by collagen or ADP . In a second step,to raise antibodies against GP 128, we prepared blots from entire MFS, the nitrocellulose band corresponding to GP 128 was cut, dissolved in DMSO, and wrs injected to rabbits. Such obtained antibodies recognized only GP 128 in arterial MFS and also TSP in a platelet lysate confirming that GP 128 and TSP have a common antigenic structure. IgG from anti-GP 128 inhibit platelet aggregation induced by MFS but not by collagen or ADP. Previously reported observations showed that tissue TSP and endothelial cells derived GP 128 have a similar affinity for chromatography supports and have the same effect on platelet-MFS interactions. All these results led us to propose that TSP, GP 128, and MFS recognize a common determinant on platelet membrane. This assumption would be strenghened if GP 128 indeed is derived from tissue TSP.
3
Binnema, D. J., and G. Dooijewaard. "INVOLVEMENT OF FACTOR XII (F XII) AND PREKALLIKREIN (PKK) IN THE ACTIVATION OF UROKINASE (UK)-RELATED PROTEINS IN HUMAN PLASMA." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643297.
Full textAbstract:
Recently it has been shown that in human plasma two types of UK-related proteins occur: Type I, plasma UK, with UK-related antigenic determinants directly accessible to anti-UK antibodies and Type II with UK-related antigenic determinants which become accessible only after SDS treatment and separation of polypeptides on PAGE. In this study we compared the molecular and enzymic properties of the two types in: 1. plasma activated by dextran sulphate (DXS) euglobulin precipitation, 2. plasma that was not activated and 3. plasma deficient in F XII, depleted in PKK and subsequently activated by DXS. ACA 34 gel chromatography, SDS PAGE, fibrin underlay zymography and immunoblotting were used. Results:Conclusions: 1. The UK-related subunits of T1 and TII are active when cleaved, but relatively inactive in the single-chain form. 2. The presence of F XII and PKK is indispensable for activation of TII, but not for that of TI; TII contributes to the F Xll-de-pendent plasminogen activator activity reported earlier, TI to the F Xll-independent part. 3. Activation of TI by DXS with no F XII and PKK present impairs the formation of the 150,000 form. 4. The specific activity of TII is rather low, but its concentration in plasma (not shown) is at least ten times that of TI.
4
Poon, M.-C., K.-S. Chow, S. Low, and G. D. Sinclair. "DIFFERENTIAL RESPONSES OF DIFFERENT FACTOR VIII MOLECULAR FORMS TO THROMBIN AND EDTA." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644039.
Full textAbstract:
Prevailing data suggest that activation of factor VIII (VIII) results in the enzymatic cleavage of the molecule into two chains bound by Ca++. When Ca++ becomes critically involved is not clear. We have investigated this process by studying the relationship of thrombin activation of VIII and the EDTA enhancement of VIII antigen (VIII:Ag). VIII:Ag was assayed by a specific and sensitive (<0.7 mU/ml) ELISA using microtiter plates coated with human anti-VIII IgG and probed with a mouse monoclonal antibody to VIII:Ag. Unlike VIII activities, plasma VIII:Ag levels detected by this ELISA were found to be relatively constant during in vitro thrombin activation. However, in the presence of EDTA (at pH 7.0), the apparent VIII:Ag values were enhanced by 1.6-1.8 fold. Sera devoid of VIII activity, on the contrary, already had VIII:Ag values about 1.6-fold higher than the corresponding plasma values, and the raised serum VIII:Ag values could not be further enhanced in the presence of EDTA. Fractionation of VIII from cryoprecipitates by aminohexyl-agarose chromatography in buffers containing Ca++ and protease inhibitors revealed the heterogeneous nature of VIII molecules. The different VIII fractions showed differential responses to activation by thrombin, and VIII:Ag enhancement by EDTA. Thrombin activation studies showed that the earlier fractions were most activatable, with the thrombin activatability falling progressively with successive fractions. When EDTA enhancement of VIII:Ag was studied, the reverse was observed: the enhancement increased progressively with successive fractions. Thus, aminohexyl-agarose chromatography resulted in fractionation of VIII into a continuous spectrum of molecular forms. We postulate that the earlier eluting fractions contained mainly "native" molecules which responded maximally to thrombin and minimally to EDTA. Subsequent fractions contained mainly the "active" form of VIII which responded minimally to thrombin but maximally to EDTA. The enhancement of VIII:Ag by EDTA is likely due to the removal of Ca++ with exposure of additional antigenic determinants. Our data suggest that Ca-^ participates mainly in the conformation of "active" VIII molecules. In serum, the molecule had been degraded with maximum exposure of the antigenic determinants, so that EDTA had no further enhancement effect.
5
Tomaslni, B. R., and D. F. Mosher. "PREFERENTIAL RECOGNITION OF VITRONECTIN (S-PR0TEIN) BY A MONOCLONAL ANTIBODY UPON INTERACTION WITH THROMBIN, ANTITHROMBIN AND GLYCOSAMINOGLYCANS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643634.
Full textAbstract:
V1tronect1n/S-Prote1n (VN/SP) is a glycoprotein present at a concentration of 200-400 ug/ml 1n plasma and serum. It has been shown to promote cel 1-substratum adhesion and to act as an Inhibitor of the membrane attack complex of complement and of the inactivation of thrombin by antithrombin III in the presence of low levels of heparin. We have previously shown that VN/SP binds more avidly to heparln-agarose and to a monoclonal antibody (MaVN/SP)-Sepharose column when present 1n serum rather than 1n plasma. In order to examine the possibility of a serum-induced conformational change, we utilized, 1n this study, an Indirect enzyme-linked Immunosorbent system to test for the exposure of new antigenic determinants. When MaVN/SP was Incubated with plasma or serum, recognition of VN/SP 1n serum was approximately 50 fold greater than recognition of VN/SP in plasma. Since VN/SP has been shown to Interact strongly with the thromb1n-ant1thrombin complex, we examined the antigenicity of VN/SP when Incubated with thrombin and antithrombin 1n the presence and absence of heparin. Incubation of VN/SP with heparin promoted a 2.5-fold Increase 1n recognition by MaVN/SP. When MaVN/SP was Incubated with thromb1n-ant1thrombin but not thrombin or antithrombin alone, recognition was Increased by 7-fold 1n the absence of heparin and by 32-fold 1n the presence of heparin. This differential recognition of VN/SP was not observed with a second monoclonal antibody raised originally against S-Prote1n. Treatment of VN/SP with various glycosaminoglycans and polysaccharides demonstrated the following relative potencies for Induction of the partial antigenic change: dextran sulfate>fucoidan>heparin> dermatan suIfate>hyaluronic acid. No effect was detected upon Incubation of VN/SP with keratan sulfate, heparan sulfate or chondroltln sulfate. These data suggest a conformational change Induced by thrombin-antlthrombin which may allow VN/SP to Interact more avidly with other molecules such as heparin. The physiological role of this putative conformational change is under investigation.
6
Nugent, Diane. "IDENTIFICATION OF ANTIPLATELET ANTIBODY IDIOTYPlSS ASSOCIATED WITH GLYCOPROTEIN Ib SPECIFICITY, PRESENT IN ITP PLASMA AND PRODUCED BY HUMAN HYBRIDOMAS FROM ITP SPLEEN CELL FUSIONS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644758.
Full textAbstract:
Platelet membrane glycoproteins (GP) express anumber of antigenic determinants important in theetiology of autoimmune thrombocytopenia. Sensitization to GPIb, although not the most frequent cause of ITP, leads to a particularly severe form ofthe disease. We have identified a number of casesof ITP in which GPIb bears the relevant immunogen. Using GPIb-specific autoantibodies isolated from the plasma of one such patient, we have produced a number of rabbit polyclonal and murine monoclonal anti-idiotypic antibodies. These antibodies recognize an idiotype expressed on the IgM antibody of this patient as well as IgG or IgM antibodies from several other patients with ITP, all of which can be shown to bind specifically to GPIb. Statistical analysis of a series of plasmas from normal individuals and thrombocytopenic patients demonstrated that there is a very strong correlation between the presence of the idiotype and GPIb reactivity, (p < 0.00001). These anti-idiotypic antibodies are useful for the detection and characterization of GPIb-specific antibodies in the sera of patients with a clinically severe form of ITP. The classification of patients bearing this idiotype in their plasma may be useful in predicting disease outcome, thus identifying a group of ITP patients in whom more aggressive therapeutic regimens may be indicated. The use of these reagents and the development of human B lymphoblastoid cell lines producing monoclonal anti-GPIb antibodies will serve to elucidate the clonal origin and cellular regulation of autoantibody production in this disease
7
Saundry, R. H., S. Khumprayoon, and G. F. Savidge. "THE IDENTIFICATION OF A NOVEL FACTOR X ACTIVATOR ACTIVITY IN Mg2+ - ANTICOAGULATED PLASMA." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643293.
Full textAbstract:
Mg2+ anticoagulated PPP (20mM MgCl2) was applied at RT to a Zn2+ immobilised biscarboxymethylamino Sepharose 4B column and eluted with 20mM Tris, 20mM MgCl2, 2.5mM CaCl2 0.15M NaCl buffer pH 7.4. Following collection of the wash-through fractions, bound proteins were developed through application of linear (0 to 35mM) imidazole gradients.All fractions were screened for F.II, V, IX, X, vWF:Ag, Protein C, Fg, Fn and 2-macroglobulin by ELISA, VIII:Ag by IRMA, and VIII:C by both 1-stage and 2-stage bioassay methods. VIIIrAg (60-90% yield), vWF:Ag (100%), VIII:C 1-stage activity (35%), Fn (> 60%), Fg (> 80%), V (50%) and a2-macroglobulin (> 70%) were located only in the gradient fractions. Two distinct peaks demonstrated shortening of the 2-stage VIII:C assay:- one co-eluting with the 1-stage VIII:C activity and another major peak in the wash-through fractions where antigenic determinants of F.II, IX, X and part of the protein C were located and partially resolved from each other. Only F.II.-Ag co-eluted with the “ 2-stage VIII:C” activity. Similar observations were found in Mg2+ -anticoagulated severe Haemophilia A plasma and in citrated PPP developed with 20mM MgCl2, 20mM Tris buffer. A1(0H)3 treatment abolished the activity from citrate -, but not from Mg2+ -anticoagulated plasma.The relevant fractions showed no activities in F.V, VII, VIII:C, IX or X 1-stage bioassays. They did not clot Fg and did not contain detectable Xa or Ila as assessed by S-2222, S-2238 or S-2288. Following incubation with specific antisera against IgG, II, V, VII:Ag, X, protein C, a- and g- lipoproteins, and plasminogen only anti-II inhibited this "2-stage VIII:C" activity. 2-stage VIII:C assays depend upon Ca2+ -dependent generation of Xa. Since the activity in the wash-through fractions could not be ascribed to VIII, Xa, or Ila the results would indicate the presence of a hitherto undescribed Factor X activator activity.
8
Ruan, C., X. Du, H. Wan, X. Hu, X. Xi, and P. Li. "CHARACTERIZATION OF THE FIBRINOGEN BINDING SITES USING MONOCLONAL ANTIBODIES TO HOMAN PLATELET MEMBRANE GLYCOPROTEINS IIb/IIIa*." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643700.
Full textAbstract:
Two new murine monoclonal antibodies, SZ-21 and SZ-22, (both IgG1 subclass), were produced by the hybridoma technique using washed human platelets as the immunogen. Both SZ-21 and SZ-22 reanted specifically with normal platelets and megakaryocytes but not with Glanzmann's thrombasthenic platelets which lack the membrane glycoprotein(GP)IIb/IIIa complex. Platelets from 10 normal donors bound 64,500±20,300(x+SD) SZ-21 molecules/platelet with KD4.4±1.5nM and 61,000±19,900 SZ-22 molecules/platelet with KD18.8±6.7nM respectively.Affinity chromatography confirmedthat SZ-21 and SZ-22 reacted with theGPIIb/IIIa complex. SZ-21 inhibited the platelet aggregation and secretioninduced by collagen, arachidonic acidand thrombin,and the second wave of aggregation in response to ADP, adrenaline and ristocetin. The fibrinogen binding to human platelets induced by ADP, arachidonic acid and PAF was also inhibited by SZ-21. But SZ-22 hado effects on platelet aggregation andfibrinogen binding. Western blot analyses indicated that SZ-21reanted with GPIIIa and that SZ-22 bound to GPIIb. When the protein was reduced by 2-mercaptoethand, SZ-22 reacted with the enchain of GPIIb, but SZ-21 lost its ability of binding to GPIIIa, suggested that the antigenic determinants of SZ-21 depended on the integrity ofthe intra αchain disulfide bond of GPIIIa. On chymotrypsin treated platelets,the epitope for SZ-21wasidentified on a 66 KD membrane-bound fragment of GPIIIa. The appearanceofthe 66 KD fragment was related withthechymotrypsin-mediated fibrinogen binding and aggregation. However the prolonged treatment with chymotrypsin reduced the platelet aggregation, which coincided with the appearance of the 66KD fragment, a product of thefurther hydrolysis of the 66KD fragment.These results suggested that the domainbetween the 66KD and 60KD fragments of GPIIIa might be essential for the maintenance of the fibrinogen binding sites.* Supported by the Science fund of the Chinese Academy of Sciences ( project No.82-172 ) and the National Science fund of China ( project No.3860713 ).
9
Santoso, S., Y. Shibata, V. Kiefel, and C. Mueller-Eckhardt. "IDENTIFICATION OF YUK(b) ALLOANTIGEN ON PLATELET GLYCOPROTEIN IIIa*." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643528.
Full textAbstract:
Neonatal alloimmune thrombocytopenic purpura (NATP) is caused by IgG platelet alloantibodies (ab), produced by the mother and directed against antigens present on the platelets of the child. The specificity of the platelet-specific ab is anti-Pl(Al) in the majority of cases. Other specificities, i.e. anti-Pl(E2), anti-Bak(a), anti-Pen, and anti-Pl(A2) have also been found. Recently, Shibata et al (1986) have described a new platelet antigen system Yuk(a)/Yuk(b) involved in NATP. The Yuk(a) and Yuk(b) antigens are not expressed on thromb-asthenic platelets indicating that these antigens do exiŞt on glycoprotein (GP) lib and/or Ilia. In order to investigate the molecular localization of these antigens, we studied the interaction of anti-Yuk(b) purified ab with membrane components of platelets using immunoblot procedure and compared their immunochemical behaviour with that of other platelet specific ab (anti-Pl(A 1), -Lek(a), -Bak(a)).In the absence of disulfide reduction Yuk(b) ab reacted with an antigen of molecular weight (mol wt) 92 kDa with an electrophoretic mobility identical to GP Ilia. An identical result was obtained for P1(A1) ab. In contrast, the Bak(a) ab as well as Lek(a) ab detected an antigen of mol wt 134 kDa which comigrated with GP lib. After reduction with 2-mercaptoethanol binding of anti-Pi(Al) and anti-Yuk(b) was not observed. To further localize the Yuk(b) antigen on GP Ilia, immunoblotting experiments were performed with anti-Pl(Al) and anti-Yuk(b) of chymotrypsin treated platelets. While anti-Pl(Al) bound to GP IIIa and a 68 kDa component, anti-Yuk(b) bound only to GP IIIa when the platelets had been treated for 45 min with chymotrypsin.This discrepancy became even more pronounced by prolonged treatment of platelets (225 min) in that the reactivity of anti-Yuk(b) was entirely abolished, whereas binding of anti-Pl(Al) shifted completely from the 92 kDa to the 68 kDa component. Thus, unlike the P1(A1) antigen, the Yuk(b) determinant either resides on the 30 kDa fragment of GP Ilia or it is destroyed by chymotrypsin treatment.
10
Church, W., T. Messier, P. Howard, J. Amiral, D. Meyer, and K. Mam. "A SHARED EPITOPE ON HUMAN PROTEIN C, FACTOR X, FACTOR VII, AND PROTTOBIN DEFINED BY A MONOCLONAL ANTIBODY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643937.
Full textAbstract:
A monoclonal antibody prepared against hunan protein C (HPC) was found to react with several other vitamin K-dependent blood proteins. Using a competitive inhibition solid-phase radioinminoassay with HPC, binding of 125I-HPC to the antibody was inhibited by purified prothrombin, Factor X, and Factor VII in addition to protein C. Other vitamin K-dependent proteins including Factor IX, protein S, and bone-GLA protein did not compete for binding of 125I-HPC to the antibody. The effect of calciun ion on the binding of antibody to 125I-HPC was examined in a solid-phase imnunoassay system with the antibody bound to rabbit anti-mouse inminoglobulin adsorbed to microtiter plates. In the presence of 5 mM calciun ion, radiolabeled protein C did not bind to the antibody; radiolabeled protein C did bind, however, in the presence of 5 nM EDTA suggesting that the epitope is expressed only after removal of calciun ion. The antibody bound to prothrombin and to decarboxylated prothrombin after adsorption of the antigens onto nitrocellulose indicating that the presence of GLA was not required for antibody binding. Iimunoblotting of proteins which were reduced, the peptides separated by SDS-PAGE, and transferred to nitrocellulose showed that the antibody reacts with a determinant found on the light chains of protein C and Factor X and with prothrombin Fragment 1. Comparison of the protein sequences of protein C light chain, Factor X light chain, Factor VII, and prothrombin Fragment 1 identified a segment of amino acid sequence that is highly conserved in all four proteins and might contain the antigenic site. The monoclonal antibody thus defines an antigenic determinant which is masked by calcium ion and is found on the surface of several related, yet different coagulation proteins. This antibody should prove useful in understanding the evolutionary relationships amongst the vitamin K-dependent proteins and also in understanding the effect of calcium ion on the structure of protein C, Factor X, prothrombin, Factor VII and possibly other related proteins. (Supported by NIH grant MHLBI HL35058)
Reports on the topic "Antigenic determinants"
1
Evans, Donald L., Avigdor Eldar, Liliana Jaso-Friedmann, and Herve Bercovier. Streptococcus Iniae Infection in Trout and Tilapia: Host-Pathogen Interactions, the Immune Response Towards the Pathogen and Vaccine Formulation. United States Department of Agriculture, February 2005. http://dx.doi.org/10.32747/2005.7586538.bard.
Full textAbstract:
The objectives of the BARD proposal were to determine the mechanisms of nonspecific cytotoxic cells (NCC) that are necessary to provide heightened innate resistance to infection and to identify the antigenic determinants in Streptococcus iniae that are best suited for vaccine development. Our central hypothesis was that anti-bacterial immunity in trout and tilapia can only be acquired by combining "innate" NCC responses with antibody responses to polysaccharide antigens. These Objectives were accomplished by experiments delineated by the following Specific Aims: Specific aim (SA) #1 (USA) "Clone and Identify the Apoptosis Regulatory Genes in NCC"; Specific aim #2 (USA)"Identify Regulatory Factors that Control NCC Responses to S. iniae"; Specific aim #3 (Israel) "Characterize the Biological Properties of the S. iniae Capsular Polysaccharide"; and Specific aim #4 (Israel) "Development of an Acellular Vaccine". Our model of S. iniae pathogenesis encompassed two approaches, identify apoptosis regulatory genes and proteins in tilapia that affected NCC activities (USA group) and determine the participation of S.iniae capsular polysaccharides as potential immunogens for the development of an acellular vaccine (Israel group). We previously established that it was possible to immunize tilapia and trout against experimental S. difficile/iniaeinfections. However these studies indicated that antibody responses in protected fish were short lived (3-4 months). Thus available vaccines were useful for short-term protection only. To address the issues of regulation of pathogenesis and immunogens of S. iniae, we have emphasized the role of the innate immune response regarding activation of NCC and mechanisms of invasiveness. Considerable progress was made toward accomplishing SA #1. We have cloned the cDNA of the following tilapia genes: cellular apoptosis susceptibility (CAS/AF547173»; tumor necrosis factor alpha (TNF / A Y 428948); and nascent polypeptide-associated complex alpha polypeptide (NACA/ A Y168640). Similar attempts were made to sequence the tilapia FasLgene/cDNA, however these experiments were not successful. Aim #2 was to "Identify Regulatory Factors that Control NCC Responses to S. iniae." To accomplish this, a new membrane receptor has been identified that may control innate responses (including apoptosis) of NCC to S. iniae. The receptor is a membrane protein on teleost NCC. This protein (NCC cationic antimicrobial protein-1/ncamp-1/AAQ99138) has been sequenced and the cDNA cloned (A Y324398). In recombinant form, ncamp-l kills S. iniae in vitro. Specific aim 3 ("Characterize the Biological Properties of the S.iniae Capsular Polysaccharide") utilized an in- vitro model using rainbow trout primary skin epithelial cell mono layers. These experiments demonstrated colonization into epithelial cells followed by a rapid decline of viable intracellular bacteria and translocation out of the cell. This pathogenesis model suggested that the bacterium escapes the endosome and translocates through the rainbow trout skin barrier to further invade and infect the host. Specific aim #4 ("Development of an Acellular Vaccine") was not specifically addressed. These studies demonstrated that several different apoptotic regulatory genes/proteins are expressed by tilapia NCC. These are the first studies demonstrating that such factors exist in tilapia. Because tilapia NCC bind to and are activated by S. iniae bacterial DNA, we predict that the apoptotic regulatory activity of S. iniae previously demonstrated by our group may be associated with innate antibacterial responses in tilapia.
2
Bercovier, Herve, Raul Barletta, and Shlomo Sela. Characterization and Immunogenicity of Mycobacterium paratuberculosis Secreted and Cellular Proteins. United States Department of Agriculture, January 1996. http://dx.doi.org/10.32747/1996.7573078.bard.
Full textAbstract:
Our long-term goal is to develop an efficient acellular vaccine against paratuberculosis based on protein antigen(s). A prerequisite to achieve this goal is to analyze and characterize Mycobacterium paratuberculosis (Mpt) secreted and cellular proteins eliciting a protective immune response. In the context of this general objective, we proposed to identify, clone, produce, and characterize: the Mpt 85B antigen and other Mpt immunoreactive secreted proteins, the Mpt L7/L12 ribosomal protein and other immunoreactive cellular proteins, Mpt protein determinants involved in invasion of epithelial cells, and Mpt protein antigens specifically expressed in macrophages. Paratuberculosis is still a very serious problem in Israel and in the USA. In the USA, a recent survey evaluated that 21.6% of the dairy herd were infected with Mpt resulting in 200-250 million dollars in annual losses. Very little is known on the virulence factors and on protective antigens of Mpt. At present, the only means of controlling this disease are culling or vaccination. The current vaccines do not allow a clear differentiation between infected and vaccinated animals. Our long-term goal is to develop an efficient acellular paratuberculosis vaccine based on Mpt protein antigen(s) compatible with diagnostic tests. To achieve this goal it is necessary to analyze and characterize secreted and cellular proteins candidate for such a vaccine. Representative Mpt libraries (shuttle plasmid and phage) were constructed and used to study Mpt genes and gene products described below and will be made available to other research groups. In addition, two approaches were performed which did not yield the expected results. Mav or Mpt DNA genes that confer upon Msg or E. coli the ability to invade and/or survive within HEp-2 cells were not identified. Likewise, we were unable to characterize the 34-39 kDa induced secreted proteins induced by stress factors due to technical difficulties inherent to the complexity of the media needed to support substantial M. pt growth. We identified, isolated, sequenced five Mpt proteins and expressed four of them as recombinant proteins that allowed the study of their immunological properties in sensitized mice. The AphC protein, found to be up regulated by low iron environment, and the SOD protein are both involved in protecting mycobacteria against damage and killing by reactive oxygen (Sod) and nitrogen (AhpC) intermediates, the main bactericidal mechanisms of phagocytic cells. SOD and L7/L12 ribosomal proteins are structural proteins constitutively expressed. 85B and CFP20 are both secreted proteins. SOD, L7/L12, 85B and CFP20 were shown to induce a Th1 response in immunized mice whereas AphC was shown by others to have a similar activity. These proteins did not interfere with the DTH reaction of naturally infected cows. Cellular immunity provides protection in mycobacterial infections, therefore molecules inducing cellular immunity and preferentially a Th1 pathway will be the best candidate for the development of an acellular vaccine. The proteins characterized in this grant that induce a cell-mediated immunity and seem compatible with diagnostic tests, are good candidates for the construction of a future acellular vaccine.
3
Sordillo, Lorraine, Don Wojchowski, Gary Perdew, Arthur Saran, and Gabriel Leitner. Identification of Staphylococcus aureaus Virulence Factors Associated with Bovine Mastitis. United States Department of Agriculture, February 2001. http://dx.doi.org/10.32747/2001.7574340.bard.
Full textAbstract:
Staphylococcus aureus is a major cause of mastitis in dairy cattle. The organism is able to adhere to and penetrate mammary epithelium, forming deep seated abscesses that result in chronic infections. This study was based on the observation that certain genotypes of S. aureus are isolated more frequently from field cases of bovine mastitis than others and the most prevalent genotypes of S. aureus have an increased ability to resist neutrophil phagocytosis and killing compared to the rare variants. It was hypothesized that these predominating genotypes differentially express virulence factors that allow them to overcome or suppress essential host defense mechanisms and successfully colonize mammary parenchyma. The overall objective of this study was to determine the mechanisms by which predominating S. aureus genotypes were able to resist mammary gland defense mechanisms. The following specific aims were accomplished to address the overall objectives of this project: 1. Analyze and compare cell surface and secreted protein profiles of common and rare S. aureus genotypes isolated from field cases of bovine mastitis. 2. Purify and sequence selectively synthesized proteins unique to the most prevalent genotypes of S. aureus . 3. Determine the in vitro effects of isolated proteins on essential host defense mechanisms. Results from each specific aim showed that these redominating genotypes differentially express factors that may allow them to overcome or suppress essential host defense mechanisms and successfully colonize mammary parenchyma. Using complementary approaches, both the US and Israeli teams identified differentially expressed S. aureus factors that were positively correlated with virulence as determined by the ability to modify host immune cell responses and increase disease pathogenesis. Several candidate virulence factors have ben identified at both the molecular (US team) and protein (Israeli team) levels. Components of the phosphotransferase system were shown to be differentially expressed in prevalent strains of S. aureus and to modify the growth potential of these strains in a milk microenvironment. Evidence provided by both the Israeli and US teams also demonstrated a potential role of Staphylococcal enterotoxins in the pathogenesis of mastitis. Certain enterotoxins were shown to directly affect neutrophil bactericidal activities which can profoundly affect the establishment of new intramammary infections. Other evidence suggests that S. aureus superantigens can suppress mammary defenses by enhancing lymphoid suppressor cell activity. Collectively, these data suggest that unique factors are associated with predominating S. aureus genotypes that can affect in vitro and in vivo virulence as related to the pathogenesis of bovine mastitis. The potential development of a subunit mastitis vaccine which incorporates only relevant antigenic determinants has not been investigated in depth. Experiments outlined in this proposal has identified putative virulence factors which contribute to the pathogenesis of S. aureus mastitis and which may be used to formulate an efficacious subunit mastitis vaccine. Results from these studies may lead to the development of new methods to prevent this costly disease, providing a viable alternative to less effective mastitis control procedures based on chemotherapy.