Academic literature on the topic 'Antibody Dependent Enhancement'
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Journal articles on the topic "Antibody Dependent Enhancement"
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Wen, Jieqi, Yifan Cheng, Rongsong Ling, Yarong Dai, Boxuan Huang, Wenjie Huang, Siyan Zhang, and Yizhou Jiang. "Antibody-dependent enhancement of coronavirus." International Journal of Infectious Diseases 100 (November 2020): 483–89. http://dx.doi.org/10.1016/j.ijid.2020.09.015.
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Thomas, Sandra, Jade B. Redfern, Brett A. Lidbury, and Suresh Mahalingam. "Antibody-dependent enhancement and vaccine development." Expert Review of Vaccines 5, no. 4 (August 2006): 409–12. http://dx.doi.org/10.1586/14760584.5.4.409.
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Gras, G., T. Strub, D. Dormont, Jacques Homsy, Masatoshi Tateno, and JayA Levy. "ANTIBODY-DEPENDENT ENHANCEMENT OF HIV INFECTION." Lancet 331, no. 8597 (June 1988): 1285–86. http://dx.doi.org/10.1016/s0140-6736(88)92106-x.
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Burke, Donald S., and Srisakul Kliks. "Antibody‐Dependent Enhancement in Dengue Virus Infections." Journal of Infectious Diseases 193, no. 4 (February 15, 2006): 601–3. http://dx.doi.org/10.1086/499282.
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Nakayama, Eri, Daisuke Tomabechi, Keita Matsuno, Noriko Kishida, Reiko Yoshida, Heinz Feldmann, and Ayato Takada. "Antibody-Dependent Enhancement of Marburg Virus Infection." Journal of Infectious Diseases 204, suppl_3 (November 2011): S978—S985. http://dx.doi.org/10.1093/infdis/jir334.
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Kurane, I., B. J. Mady, and F. A. Ennis. "Antibody-dependent enhancement of dengue virus infection." Reviews in Medical Virology 1, no. 4 (December 1991): 211–21. http://dx.doi.org/10.1002/rmv.1980010405.
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Takada, Ayato, Heinz Feldmann, Thomas G. Ksiazek, and Yoshihiro Kawaoka. "Antibody-Dependent Enhancement of Ebola Virus Infection." Journal of Virology 77, no. 13 (July 1, 2003): 7539–44. http://dx.doi.org/10.1128/jvi.77.13.7539-7544.2003.
Full textAbstract:
ABSTRACT Most strains of Ebola virus cause a rapidly fatal hemorrhagic disease in humans, yet there are still no biologic explanations that adequately account for the extreme virulence of these emerging pathogens. Here we show that Ebola Zaire virus infection in humans induces antibodies that enhance viral infectivity. Plasma or serum from convalescing patients enhanced the infection of primate kidney cells by the Zaire virus, and this enhancement was mediated by antibodies to the viral glycoprotein and by complement component C1q. Our results suggest a novel mechanism of antibody-dependent enhancement of Ebola virus infection, one that would account for the dire outcome of Ebola outbreaks in human populations.
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Meyer, Keith, Malika Ait-Goughoulte, Zhen-Yong Keck, Steven Foung, and Ranjit Ray. "Antibody-Dependent Enhancement of Hepatitis C Virus Infection." Journal of Virology 82, no. 5 (December 19, 2007): 2140–49. http://dx.doi.org/10.1128/jvi.01867-07.
Full textAbstract:
ABSTRACT Hepatitis C virus (HCV) often causes a persistent infection associated with hypergammaglobulinemia, high levels of antiviral antibody and circulating immune complexes, and immune complex disease. We previously reported that only a limited neutralizing activity to vesicular stomatitis virus or HCV pseudotype is generated in animals immunized with recombinant HCV envelope proteins and chronically infected HCV patient sera. Interestingly, when some of these neutralizing sera were diluted into a range of concentrations below those that reduced virus plaque number, an increase in pseudotype plaque formation was observed. Purified HCV E2-specific human monoclonal antibodies were used to further verify the specificity of this enhancement, and one- to twofold increases were apparent on permissive Huh-7 cells. The enhancement of HCV pseudotype titer could be inhibited by the addition of a Fc-specific anti-human immunoglobulin G Fab fragment to the virus-antibody mixture prior to infection. Treatment of cells with antibody to Fc receptor I (FcRI) or FcRII, but not FcRIII, also led to an inhibition of pseudotype titer enhancement in an additive manner. Human lymphoblastoid cell line (Raji), a poor host for HCV pseudotype infection, exhibited a four- to sixfold enhancement of pseudotype-mediated cell death upon incubation with antibody at nonneutralizing concentrations. A similar enhancement of cell culture-grown HCV infectivity by a human monoclonal antibody was also observed. Taken together, antibodies to viral epitopes enhancing HCV infection need to be taken into consideration for pathogenesis and in the development of an effective vaccine.
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Billings, Lora, Amy Fiorillo, and Ira B. Schwartz. "Vaccinations in disease models with antibody-dependent enhancement." Mathematical Biosciences 211, no. 2 (February 2008): 265–81. http://dx.doi.org/10.1016/j.mbs.2007.08.004.
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Eaton, Heather E., Emily Penny, and Craig R. Brunetti. "Antibody dependent enhancement of frog virus 3 infection." Virology Journal 7, no. 1 (2010): 41. http://dx.doi.org/10.1186/1743-422x-7-41.
Full textDissertations / Theses on the topic "Antibody Dependent Enhancement"
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Willey, Suzanne. "Antibody-dependent enhancement of HIV-1 infection." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1445149/.
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Antibody-dependent enhancement (ADE) is the process by which virus-specific antibodies enhance entry or replication of a virus, leading to increased infection and the potential to exacerbate disease progression or severity. In terms of HIV infection, ADE could make the difference between an ineffective vaccine and a dangerous one. There is also the possibility that ADE affects disease progression in natural infection. Here, one aspect of ADE, complement-mediated ADE (C'-ADE), was investigated in detail. An assay was developed to study C'-ADE in both R5- and X4-tropic HIV-1 strains in the context of early, primary infection and vaccination. A CD4+ T cell line was used for these studies which expressed the complement receptor 2 (CR2) and HIV-1 co-receptors CXCR4 and CCR5. C'-ADE in primary infection was investigated using serum samples collected longitudinally from infected individuals from as early as 12 days post onset of primary symptoms. When tested against autologous viruses isolated early after infection, C'-ADE was detected in 9 out of 10 patients. In some cases this was potent enough to produce increases in infection greater than 100-fold. Later virus isolates that evolved to escape antibody neutralisation were enhanced by sera that neutralised early virus. Competition studies carried out with neutralising and enhancing IgG showed neutralisation to be the dominant activity. Enhancing, but not neutralising, activity of patient sera was detected against heterologous primary isolates. Post-vaccination C'-ADE was investigated using sera from volunteers vaccinated with a monomeric gpl20 vaccine from a dual-tropic HIV-1 strain. Sera from vaccinees enhanced infection of the vaccine virus strain but did not neutralise it. Neutralisation was seen for an X4 virus strain, MN, and individuals that produced the most potent neutralisation against MN also produced the most potent enhancement of the vaccine strain. CR2-mediated increased attachment of opsonised viruses to the target cell was shown to be the principle mechanism of C'-ADE. The use of a CR2 cytoplasmic tail mutant showed that receptor signalling was not necessary for C'-ADE. Results from these studies show that antibodies that appear to be non-neutralising in neutralisation assay systems can actually have dramatic effects on virus infection in a different context. These new findings are considered in relation to existing knowledge on neutralisation and ADE of HIV.
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Leung, Hiu-lan Nancy, and 梁曉灡. "Mechanism of antibody-dependent enhancement in severe acute respiratory syndrome coronavirus infection." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B47327066.
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Severe lymphopenia is a clinical feature of Severe Acute Respiratory Syndrome
(SARS) patients. However, lymphocytes do not express receptor for SARS-CoV,
neither the widely accepted viral receptor angiotensin converting enzyme 2 (ACE2)
nor the putative receptors Dendritic Cell- and Liver/lymph-Specific Intercellular
adhesion molecule-3-Grabbing Non-integrin (DC-SIGN and L-SIGN). Our group
previously showed in vitro that, SARS-CoV Spike pseudotyped particles (SARSCoVpp)
could infect human B cells only when inoculated in presence of anti-SARSCoV
Spike immune serum. Such observations raised concerns about the possible
occurrence of antibody-dependent enhancement (ADE) of infection, a phenomenon
during which a virus bounded by antibodies could gain entry into cells through
mechanisms involving complement receptors or Fc receptors. Recently, we have
demonstrated the participation of the human Fc gamma receptor II (hFcγRII)
molecules in granting SARS-CoV an opportunity to infect human immune cells.
The aim of this study was to decipher the molecular mechanism leading to antibodymediated,
FcγRII-dependent infection of immune cells by SARS-CoV. By using
transduction experiment, I highlighted that different members of the hFcγRII family
(namely hFcγRIIA, hFcγRIIB1 and hFcγRIIB2) could confer susceptibility to ADE of
SARS-CoVpp infection. I further demonstrated that purified anti-viral
immunoglobulin G, but not other soluble factor(s) from heat-inactivated immune
serum, was the determinant for occurrence of ADE infection. Additionally, with the
development of a cell-cell fusion assay, I illustrated that in contrast to the ACE2-
dependent pathway, ADE infection did not occur at the plasma membrane, but rather
require internalization of virus/antibodies immune complexes by the target cells. In
line with this hypothesis, my results using a panel of FcγRII-expressing mutants
demonstrated that binding of immune complexes to cell surface FcγRII was a
prerequisite but was not sufficient to trigger ADE infection. In these experiments,
only FcγRII signaling-competent constructions conferred susceptibility to ADE of
SARS-CoVpp infection.
Altogether my results point toward a role of the anti-SARS-CoV Spike IgG in vitro in
granting SARS-CoV an opportunity to infect cells bearing signaling-competent
FcγRII receptors. If further confirmed, such observations could have implications for
understanding SARS-CoV tropism and SARS pathogenesis, as well as warrant for
careful design of SARS vaccines and immunotherapy based on anti-viral antibodies.published_or_final_version
Microbiology
Master
Master of Philosophy
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Nikin-Beers, Ryan Patrick. "Mathematical Modeling of Dengue Viral Infection." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/48594.
Full textAbstract:
In recent years, dengue viral infection has become one of the most widely-spread mosquito-borne diseases in the world, with an estimated 50-100 million cases annually, resulting in 500,000 hospitalizations. Due to the nature of the immune response to each of the four serotypes of dengue virus, secondary infections of dengue put patients at higher risk for more severe infection as opposed to primary infections. The current hypothesis for this phenomenon is antibody-dependent enhancement, where strain-specific antibodies from the primary infection enhance infection by a heterologous serotype. To determine the mechanisms responsible for the increase in disease severity, we develop mathematical models of within-host virus-cell interaction, epidemiological models of virus transmission, and a combination of the within-host and between-host models. The main results of this thesis focus on the within-host model. We model the effects of antibody responses against primary and secondary virus strains. We find that secondary infections lead to a reduction of virus removal. This is slightly different than the current antibody-dependent enhancement hypothesis, which suggests that the rate of virus infectivity is higher during secondary infections due to antibody failure to neutralize the virus. We use the results from the within-host model in an epidemiological multi-scale model. We start by constructing a two-strain SIR model and vary the parameters to account for the effect of antibody-dependent enhancement.Master of Science
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Williams, Kelley J. "Silver Nanoparticles Inhibit the Binding and Replication of Dengue Virus." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1431880664.
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Chih-YuanKuo and 郭芝源. "Antibody-dependent enhancement of coxsackievirus B3 infection." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/06387823099071872709.
Full textAbstract:
碩士國立成功大學
微生物及免疫學研究所
98
Coxsackievirus B3 (CVB3) belongs to the human enterovirus B of Picornaviridae. CVB3 is associated with severe neonatal diseases, including myocarditis, hepatitis, encephalitis, and pancreatitis. Antibody-dependent enhancement (ADE) infection has been reported in several viruses and has been shown to contribute to disease severity. To understand the relationships between CVB3 and ADE, the in vitro model of CVB3 infection through ADE mechanism were established using the human neutrophil cell line HL-60, the mouse macrophage cell line J774.1 and the mouse hepatocyte cell line AML12. The viral titer was significantly enhanced in HL-60 cells at the concentration 3.29-52.66 μg/ml of commercial human immunoglobulin IgG, and in J774.1 cells at the concentration of 0.118-1.88 μg/ml and in AML12 cells at the concentration of 0.12-0.94 μg/ml of mouse anti-CVB3 IgG. Besides, using FcγR blocking antibody FcγRI (CD64), FcγRII (CD32), FcγRIII (CD16), we found anti-FcγRII and anti-FcγRIII could inhibit viral titer in HL-60 cells, anti-FcγRII/III and anti-FcγRI could inhibit viral titer in J774.1 cells. Furthermore, CVB3 infection via ADE can enhance some inflammatory cytokines expression, including interleukin 10 (IL-10), IL-12p70, tumour necrosis factor (TNF), Interferon γ (IFN-γ). The ADE phenomenon also found in J774.1 cells at the concentration of 0.002-0.037 μg/ml of anti-CVB1 IgG with CVB3. To further investigate CVB3 ADE mechanism in vivo, 3-day-old ICR mice were pretreated with various concentrations of anti-CVB3 mouse antiserum IgG 24 hours before infection subcutaneously. The highest death rate of mice was found at concentration of 0.94 μg/ml of anti-CVB3 IgG on the six days post-infection. Moreover, elevation level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) by ADE was observed 2 to 6 days post-infection. Histopathologically, mice infected by ADE also revealed enhanced hepatocyte damage and neutrophil infiltration than control. Furthermore, TNF and IFN-γ peaked on day 2 but IL-6 and IL-10 surged later on day 10 in ADE mice. The viral titer revealed markedly enhanced in liver and heart on day 2 of ADE mice than control. Moreover, pregnant ICR mice were pretreated with various concentrations of anti-CVB3 mouse antiserum IgG. Then, 3-day-old suckling mice were injected with CVB3. The highest mortality rate of suckling mice was found at the concentration of 7.52 μg/ml of anti-CVB3 IgG. In conclusion, our studies demonstrated that the ADE mechanism play an important role in pathogenesis of CVB3 infection by attenuating cytokines expression.
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Chen, Yi-Chun, and 陳逸純. "Antibody-dependent enhancement of enterovirus 71 infection." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/89756298994796824442.
Full textAbstract:
碩士國立成功大學
微生物及免疫學研究所
97
Enterovirus 71 (EV71) belongs to the Human enterovirus A of Picornaviridae. Hand-foot-and-mouth disease and herpangina are the most common clinical features of EV71 infection; however, some patients are complicated with brainstem encephalitis, pulmonary edema, pulmonary hemorrhage, and cardiopulmonary failure. Inflammatory cytokines and chemokines play an important role of EV71 infection. Antibody-dependent enhancement (ADE) infection has been reported in various viruses and has been shown to contribute to disease severity. An in vitro system of EV71 infection through ADE mechanism was established using the human monocytic cell line THP-1. The percentage of EV71-infected cells was significantly enhanced at the concentration (1000-4000 μg/ml) of commercial human immunoglobulin added to THP-1, in comparison with virus-infected cell line without adding commercial human immunoglobulin. EV71 infection was able to enhance the transcription of several inflammatory mediators, including interleukin (IL)-6, IL-8, IL-10, interferon (IFN)-β, tumour necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1, IFN-γ inducible protein (IP)-10 and monokine induced by IFN-γ (MIG) via ADE. To further investigate EV71 ADE mechanism in vivo, 6-day-old ICR mice were pretreated with various dilution of anti-EV71 mouse antiserum or anti-EV71 IgG 24 hours before intraperitoneal infection. We found that mice significantly showed aggravated clinical symptoms and increased death at concentration of 1：2-12 of anti-EV71 IgG on the 14 days. Histopathologically, anti-EV71 IgG-added mice also revealed enhanced neuronal and muscular damage than control. Furthermore increased levels of several cytokines and chemokines (IFN-γ, TNF-α, MCP-1) were detected in the sera of anti-EV71 antiserum-added mice. In conclusion, our results demonstrated that the ADE mechanism may involve in the EV71 pathogenesis and contribute to enhance inflammation and tissue damage.
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Yang, Yu-Ching, and 楊育靜. "Anti-preM antibody mediated antibody-dependent enhancement in dengue virus infecton." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/24401547786236819221.
Full textAbstract:
碩士國立成功大學
微生物及免疫學研究所
92
Dengue virus (DEN) can cause either self-limited mild disease of dengue fever (DF), or severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). It is well known that children with secondary infection of a different serotype of dengue virus will cause more severe DHF/DSS that might be fatal. Antibody-dependent enhancement of infection (ADE) is widely accepted to be central to the development of these clinical entites. When the virus is bonded by sub-neutralizing or non-neutralizing antibodies from previous infection, the complex can be captured by Fc gamma receptor-bearing cells via the Fc portion of the immunoglobulins, and then enhances the viral entrance and replication. However, the mechanism responsible for this ADE phenomenon has not been clearly defined. In order to characterize it, we have set up an in vitro infectious model to study the role of enhancing antibodies on DEN infection. Because autoantibodies were found in DHF/DSS patients and B cell could support the DEN replication, we first chose a human B lymphoma, BJAB, as a model. The DEN serotype 2 (DEN2)-infected BJAB expressed dengue viral non-structural protein 1 (NS1), envelope protein（E） and core protein post infection that could be detected by flow cytometer. Infectious viral particles were detected by plaque assay in the culture supernatant. DEN2 not only replicated in BJAB cells but also activated them to up-regulate activation markers, including CD70 and CD86. A sub-neutralizing titer (1:6000) of heterologous DEN3-immune serum was able to enhance DEN2 infection in BJAB cells. Furthermore, a panel of hybridomas secreting antibodies recognizing different DEN2 antigens was infected by DEN2. Surprisingly, only those hybridomas secreting anti-DEN precursor membrane protein (anti-preM) antibodies could be infected. This implicates that anti-preM antibody may mediate the ADE. Indeed, the infection of DEN2 on Fc receptor-bearing cells, such as DC2.4 cell line and other non-permissible hybridoma, was enhanced at least 10 fold in the presence of anti-preM antibody. Anti-preM antibodies mediated enhancement could also be demonstrated on non-Fc receptor-bearing cells, such as BHK and A549. This enhancement was not found for anti-E antibodies. These studies can help us understand the characteristics of enhancing antibody, although its mechanism and biological significance need further investigation.
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Eichen, Eva. "Antibody dependent enhancement: a model for understanding congenital Zika syndrome." Thesis, 2018. https://hdl.handle.net/2144/32971.
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This literature review will discuss Zika virus and the salient research on antibody dependent enhancement and how this mechanism may lead to congenital defects. Specific objectives include: the mechanism of antibody dependent enhancement, Zika and dengue virus pathogenesis, placenta pathophysiology, and how changes in viral virulence may play a role the pathogenesis of neurologic congenital defects seen in infants infected with Zika virus in utero.
While some cohort studies have examined the relationship between prior dengue immunity, Zika virus infection in pregnancy, and effects on neonatal outcomes further prospective studies using large cohorts and more detailed lab testing and imaging is essential to better understand this relationship. A proposed study enrolling a large cohort of women in the 6th- 8th week of pregnancy from Northeastern Brazil will seek to further describe what additional risk dengue immunity may pose in the context of Zika virus. This risk is essential to understand, as Zika and Dengue viruses co-circulate in many regions of the world. Furthermore, participants in the proposed study will undergo bi-weekly screening for Zika virus through laboratory and ultrasound testing until their delivery. Infants will then have full neurologic testing and MRI scanning for the following year after birth to characterize any congenital defects. Neonates born to mothers with prior dengue immunity who contract Zika virus during pregnancy will be compared to neonates not exposed to Zika virus in utero. This experiment will illuminate the associated risk and evidence of ADE occurring with prior dengue immunity and Zika virus infection during pregnancy. Results from this study will not only help define risks of congenital defects with Zika virus, it will inform vaccine research and elucidate challenges in the administration of the current tetravalent dengue vaccine.
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Huang, Kao-Jean, and 黃國珍. "Dengue Virus Infection: Antibody Dependent Enhancement and Autoantibody-associated Pathogenesis." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/00630988998628166481.
Full textAbstract:
博士國立成功大學
基礎醫學研究所
93
Dengue virus, a re-emerging infectious agent, may cause endemic dengue fever in tropical and sub-tropical region worldwide. Its transmission was relied on the domestic mosquito, Ades egypti or Ades albopictus, and there are four dengue serotypes existing in the world. The disease spectrum after dengue virus infection includes self-limited dengue fever (DF) and more complicated forms as dengue hemorrhagic fever or dengue shock syndrome (DHF/DSS). Two important characteristics of severe DHF/DSS are thrombocytopenia and plasma leakage (hemorrhage), but the mechanism underlying DHF/DSS remains elusive. The antibody-dependent enhancement (ADE) hypothesis proposed by Dr. Halstead has governed the dengue research and vaccine development for many years. Although this theory explains the linking of the in vitro ADE effect and the bimodal age-incidence pattern of DHF/DSS, the factors participating in the hemorrhagic process are not identified yet. The aberrant immune status of dengue patients was evident with the transient CD4/CD8 ratio inversion at day 6-10 after fever onset and the expression of early activation marker, CD69 on both CD4 and CD8 cells. The appearance of bandemia, monocytosis and atypical lymphocytosis reflects the early depletion of these blood cells and the later hematopoietic generation of them. The impairment of PHA-stimulated T lymphocyte proliferation at the acute stage was correlated with the deficiency of monocytes in the peripheral blood. Massive cytokine production, such as IL-6 and IFN-g were detectable in the sera of patients from DHF children, DHF infants and DHF adults. The IL-6 expression was earlier than IFN-g, which was followed by IL-10. In order to investigate the immunopathogenesis of DHF/DSS, we developed a murine model for dengue infection in A/J mice. Dengue viral genomes could be detected in the blood (day 2) and the tissues of brain and liver (week 2 or 3) post dengue virus infection. Infectious viral particles were reisolated from those tissues. Interestingly, this murine model will develop transient thrombocytopenia in either primary or secondary infection. The anti-platelet antibodies (both IgM and IgG isotypes) were induced as early as day 4 post-infection. Furthermore, dengue viral antigens could be detected in the peripheral blood mononuclear cells (PBMCs) of DHF children at the acute stage. Monocytes have long been thought as an important target for dengue virus and play a role in the ADE phenomenon. A flow cytometric method was established for the quantification of dengue virus-infected cells and was applied to study the ADE mechanisms. This method was comparable to the conventional plaque assay method, but with more simple, accuracy and timesaving. The ADE phenomenon was demonstrated when B cell line (BJAB) or primary PBMCs were infected by dengue in the presence of diluted dengue immune serum. Anti-dengue monoclonal antibodies (mAbs) generated from dengue 2 virus-infected mice were used to study the ADE effect. Anti-dengue structure mAbs (anti-E or anti-prM mAbs), not anti-non-structure mAb (anti-NS1 mAb), were capable of enhancing dengue virus infection dose-dependently on the Fcg receptor-bearing cells, including P388D1, DC2.4 and K562. This ADE effect depends on the presence of whole anti-dengue immunoglobulins and the expression of the Fcg receptors on target cells. Surprisingly, anti-prM not anti-E mAb preferentially enhance dengue virus infection of B hybridomas and the cells without Fcg receptors, such as BHK and A549. The epitope peptide recognized by anti-prM mAb was mapped as M3, which is located at the a.a.53-67 of the prM protein nearby the prM/M cleavage junction. This M3 peptide could specifically block the anti-prM Ab-mediated ADE effect in a dose dependent manner. The anti-M3 human antibodies were detected in clinical dengue patient sera and could also mediate the ADE infection. The mechanism of anti-prM mAb mediated- ADE effect on non-Fcg R cells was that the anti-prM mAbs bind to BHK or A549 cell surface membrane proteins and bridge the viruses to the putative dengue virus receptors, thus enhancing dengue virus infection. Molecular mimicry mechanism may participate in dengue virus infection, and anti-platelet or anti-endothelial cell autoantibodies have been detected in dengue patients’ sera. Monoclonal antibodies from dengue virus- infected mice could also bind to platelets or endothelial cells. Most anti-platelet mAbs (with different platelet-binding profile) cross-react to dengue viral NS1 antigens, and some anti-NS1, anti-E and anti-prM mAbs cross-react to endothelial cells or lymphocytes. In the presence of complement or activated monocytes, these mAbs may mediate complement-dependent cytotoxicity or antibody-dependent cellular phagocytosis. One autoantigen candidate, heat shock protein 60 (HSP60), for anti-prM mAb was identified on the surface of BHK, A549 and endothelial cells. Collectively, dengue virus can infect more cells in secondary infection by the ADE effect, and infected cells will release more viral antigens to stimulate the immune system to produce more anti-dengue antibodies as well as the high level cytokines, such as IL-6, IFN-g. By the molecular mimicry mechanism, the increased anti-dengue antibodies (anti-E, anti-prM or anti-NS1 antibodies) will cross-react with self-antigens expressed on platelets, endothelial cells or even lymphocytes. In the aberrant immune response, activated lymphocytes will secret lots of cytokines, which may activate monocytes and polymorphonuclear (PMN) cells. Activated phagocytes might engulf or impair the antibody-bound cells and then cause thrombocytopenia and plasma leakage. This autoantibody -associated pathogenic mechanism integrating the ADE theory, activated T cell responses, cytokine storming, macrophage activation responses and autoimmunity will be the basis of DHF immunopathogenesis and provide a guide for future dengue vaccine development.
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Tsung-TingTsai and 蔡宗婷. "Regulation of Interleukin-10 Production in Antibody-Dependent Enhancement of Dengue Virus Infection." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/08662128255413598452.
Full textAbstract:
博士國立成功大學
基礎醫學研究所
103
Dengue virus (DENV) infection is a global and aggressive mosquito-borne infectious disease which causes both dengue fever and dengue hemorrhagic fever. Unfortunately, there are no effective vaccines and therapeutic antiviral drugs for clinical use. Accumulated clinical evidence shows that DENV infection induces a high level of anti-inflammatory cytokine interleukin (IL)-10 in patients with severe dengue hemorrhagic fever and dengue shock syndrome as compared with those with mild dengue fever. It is important that the intrinsic antibody-dependent enhancement (ADE) of infection causes higher production of IL-10 which promotes viral replication; however, the underlying molecular mechanisms of IL-10 regulation are still unclear. This study is aimed at investigating the pathogenic role and regulatory mechanism of IL-10 production during ADE of DENV infection. First, I established an in vitro model of ADE infection and discovered that the presence of monoclonal anti-envelope (E) antibody increased the infectivity of DENV in human monocytic THP-1 cells. The effects of ADE were further studied by determining protein expression and transcriptional activation of IL-10. We previously demonstrated that DENV infection induces IL-10 production by deactivating glycogen synthase kinase (GSK)-3β in a sequential protein kinase A (PKA)- and phosphoinositide (PI) 3-kinase/PKB-regulated manner. Under ADE infection, DENV not only caused a significant increase in PI3K and PKA activities, but also induced phosphorylation of PKB at Ser473 and GSK-3β at Ser9. Silencing cAMP response element-binding protein (CREB) decreased IL-10 production. Pharmacological inhibition of spleen tyrosine kinase (Syk), PI3K, and PKA reduced IL-10 production has been confirmed following ADE of DENV infection. Moreover, inhibiting Syk also decreased ADE-induced phosphorylation of PKB at Ser473, GSK-3β at Ser9, and CREB at Ser133, indicating Syk may act upstream of PI3K/PKB/GSK-3β/CREB pathway for ADE-induced IL-10 production. The heat-inactivated DENV was unable to induce IL-10 production in THP-1 cells, whereas ultraviolet-deactivated DENV induced IL-10 production normally. The knockdown of C-type lectin superfamily member 5 (CLEC5A) expression in THP-1 cells showed a significant decrease in IL-10 production after DENV infection. The viral load which is not serotype affected the IL-10 response. Regarding ADE-enhanced IL-10/ suppressor of cytokine signaling 3 (SOCS3) expression may interfere with the antiviral response, results showed that genetically and pharmacologically inhibiting IL-10 signaling (including CREB, Syk, PI3K, PKA, and CLEC5A) significantly retarded DENV replication and NS4B expression no matter whether it is with or without ADE of DENV infection. These results show that IL-10 is beneficial for DENV replication and the target IL-10 may be a potential antiviral treatment.
Book chapters on the topic "Antibody Dependent Enhancement"
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Kulkarni, Ruta. "Antibody-Dependent Enhancement of Viral Infections." In Dynamics of Immune Activation in Viral Diseases, 9–41. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-1045-8_2.
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Halstead, Scott B. "Dengue Antibody-Dependent Enhancement: Knowns and Unknowns." In Antibodies for Infectious Diseases, 249–71. Washington, DC, USA: ASM Press, 2015. http://dx.doi.org/10.1128/9781555817411.ch15.
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Bastug, Aliye, and Hurrem Bodur. "SARS-CoV-2 Infection and Antibody-Dependent Enhancement." In Understanding COVID-19: The Role of Computational Intelligence, 101–13. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-74761-9_5.
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Dimmock, Nigel J. "Antibody-Dependent Enhancement of Infectivity by Neutralizing Antibody: Fc and Complement Receptors." In Current Topics in Microbiology and Immunology, 30–31. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-77849-0_8.
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Hober, Didier, Famara Sane, Karena Riedweg, Rachel Desailloud, and Anne Goffard. "Antibody-Dependent Enhancement of Coxsackievirus-B Infection: Role in the Pathogenesis of Type 1 Diabetes." In Diabetes and Viruses, 325–35. New York, NY: Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4614-4051-2_30.
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Porterfield, James S. "Antibody-Dependent Enhancement of Viral Infectivity." In Advances in Virus Research Volume 31, 335–55. Elsevier, 1986. http://dx.doi.org/10.1016/s0065-3527(08)60268-7.
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"Dengue Antibody-Dependent Enhancement: Knowns and Unknowns." In Antibodies for Infectious Diseases, 249–71. American Society of Microbiology, 2015. http://dx.doi.org/10.1128/microbiolspec.aid-0022-2014.
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Halstead, Scott B. "Neutralization and Antibody-Dependent Enhancement of Dengue Viruses." In Advances in Virus Research, 421–67. Elsevier, 2003. http://dx.doi.org/10.1016/s0065-3527(03)60011-4.
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Beatriz Borges Silva, Isaura, Renato Kaylan Alves de Oliveira França, Jacyelly Medeiros Silva, Andrea Queiroz Maranhão, and Carlos Roberto Prudencio. "Phage Display as a Strategy to Obtain Anti-flavivirus Monoclonal Antibodies." In Dengue Fever in a One Health Perspective. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.93076.
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Arbovirus of the Flaviviridae family represents an issue worldwide, particularly because it can lead to serious illness and death in some countries. There is still a great complexity in obtaining effective therapies and specific and sensitive diagnostic tests, due to the high antigenic similarity between them. This similarity may account for antibodies cross reactivity which has positive and negative consequences for the course of infectious diseases. Among dengue virus (DENV) serotype infections, the cross-reactivity can increase virus replication and the risk of a severe disease by a mechanism known as an antibody-dependent enhancement (ADE). The search for serological biomarkers through monoclonal antibodies (MAbs) that identify unique viral regions can assist in the differential detection, whereas the development of recombinant antibodies with a neutralizing potential can lead to the establishment of efficacious treatments. The Phage Display methodology emerged as one of the main alternatives for the selection of human MAbs with high affinity for a specific target. Therefore, this technology can be a faster alternative for the development of specific diagnostic platforms and efficient and safe treatments for flavivirus infections. In this context, we propose for this chapter a discussion about Phage Display as a strategy to obtain MAbs for DENV and other flaviviruses.
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Puerta-Guardo, Henry, Scott B. Biering, Eva Harris, Norma Pavia-Ruz, Gonzalo Vázquez-Prokopec, Guadalupe Ayora-Talavera, and Pablo Manrique-Saide. "Dengue Immunopathogenesis: A Crosstalk between Host and Viral Factors Leading to Disease: PART II - DENV Infection, Adaptive Immune Responses, and NS1 Pathogenesis." In Dengue Fever in a One Health Perspective. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.93551.
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Severe disease is associated with serial infection with DENV of different serotypes. Thus, primary DENV infections normally cause asymptomatic infections, and secondary heterotypic infections with a new DENV serotype potentially increase the risks of developing severe disease. Despite many proposed hypotheses trying to explain it, the exact immunological mechanism leading to severe dengue disease is unknown. In turn, severe manifestations are believed to be a consequence of the combinations of many immunopathogenic mechanisms involving viral and host factors leading to increased pathogenesis and disease. Of these mechanisms, the adaptive immune response has been proposed to play a critical role in the development of severe dengue manifestations. This includes the effect of non-neutralizing but enhancing antibodies produced during primary infections, which results in enhanced-DENV infection of Fc-γ-receptor-expressing cells (e.g. monocytes and macrophages) during DENV heterotypic exposure in a phenomenon called antibody-dependent enhancement (ADE); the increased activation of memory T cells during secondary infections, which has low affinity for the current infecting serotype and high affinity for a past infection with a different serotype known as the original antigenic sin; the unbalanced production of pro-inflammatory cytokines that have a direct effect on vascular endothelial cells resulting in plasma leak in a phenomenon known as cytokine storm; and the excessive activation of the complement system that causes exacerbated inflammatory responses, increasing disease severity. In addition to the adaptive immune responses, a secreted viral factor known as the nonstructural protein 1 (NS1) has been recently proposed as the missing corner piece of the DENV pathogenesis influencing disease. This Part II of the chapter will discuss the interplay between the distinct host adaptive immune responses and viral factors that together contribute to the development of DENV pathogenesis and severe disease.
Conference papers on the topic "Antibody Dependent Enhancement"
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BILLINGS, LORA, IRA B. SCHWARTZ, and LEAH B. SHAW. "THE DYNAMICS OF ANTIBODY DEPENDENT ENHANCEMENT IN MULTI-STRAIN DISEASES WITH VACCINATION." In Proceedings of the 2008 Conference on FACM'08. WORLD SCIENTIFIC, 2008. http://dx.doi.org/10.1142/9789812835291_0005.
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Bertino, Erin M., Jeffrey S. Rose, Christina Wu, Tanios Bekaii-Saab, Panayiotis S. Savvides, Richard M. Goldberg, Miguel Villalona, et al. "Abstract A76: Enhancement of cetuximab-induced antibody-dependent cellular cytotoxicity with lenalidomide in advanced solid tumors: A Phase I trial." In Abstracts: AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics--Oct 19-23, 2013; Boston, MA. American Association for Cancer Research, 2013. http://dx.doi.org/10.1158/1535-7163.targ-13-a76.
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Meusburger, S., R. Beckmann, J. Wojta, and B. R. Binder. "RELATION OP FIBRIN STIMULATION OF tPA MEDIATED PLASMINOGEN ACTIVATION AND FIBRIN BINDING TOWARDS FIBRONEKTIN AS REVEALED BY A MONOCLONAL ANTIBODY (MAB) AGAINST FCB-2 FIBRINOGEN FRAGMENTS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644403.
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Fibrin binds to the finger domain of fibronektin via the C-terminal end of the chain and it was reported previously by us that in a fluid phase assay fibronektin inhibits fibrin enhancement of plasminogen activation by tPA. However, other have shown that tPA binds to fibronectin thereby possibly mediating enhanced matrix bound plasmin formation. In the present study we tried to further characterize the interaction between fibronectin and fibrin in regard to fibrin dependent enhancement of plasminogen activation by tPA. For fibrin binding to fibronectin we have developed an ELISA system using fibronectin coated plates and antibodies against fibrin(ogen) to quantify bound fibrin. For determination of plasminogen activation we used a coupled spectrophotometric fluid phase assay with Glu-plasminogen as substrate and H-D-Val-Leu-Lys-pNA to quantify the formed plasmin. Fibrin binding to coated fibronectin was linear between 500ng and 1 mg/ml for fibrin monomers (reptilase), FCB-2 fragments and thrombin (3.3 U/ml) treated fibrinogen, respectively. A monoclonal antibody directed against the FCB-2 fibrinogen fragment which also could be shown to recognize fibirn but not fibrinogen did not recognize fibronectin bound fibrin and inhibited also the fibrin stimulatory effect on plasminogen activation indicating that the epitope against which the antibody is directed is closely related to both the fibronectin binding site and the site involved in t-PA stimulation.
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Sakata, Y., J. Mimuro, and Y. koike. "PLASMA-CLOT LYSIS INDUCED BY MONOCLONAL ANTIBODY AGAINST α2-PLASMIN INHIBITOR." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643789.
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A Monoclonal antibody (MCA) against α2-plasmin inhibitor α2-Pl) designated as JTP-1 inhibited antiplasmin act ivity and complex formation of a2-PI with plasmin. By using this MCA we tried to observe plasma-clot lysis (CL) in vitro and to estimate the level of total fibrinolytic capacity in plasma. As reported previously (Blood 55: U83, 1980) spontaneous CL is a striking feature of the plasma derived from a patient with α2-PI deficiency. We showed that this abnormally increased fibrinolysis was solely due to the deficiency of α2-PI. However, the contribution of plasminogen activator (PA) and its inhibitor to this specific patient' plasma -CL has been under discussion. Therefore, to test whether similar CL can be found in normal plasma without an addition of PA, plasma clots were made after incubation of plasma from normal volunteers containing 125i fibrinogen with various concentration of JTP-1, and fibrinolysis was measured by counting the soluble radioactivity. The addition of JTP-1 to plasma led to a dose-dependent enhancement of the soluble 125i fragment-release from the clot. However, JTP-1 had no effect on a2-PI-deficient plasma-CL. Other anti-a2-PI MCAs whose epitopes were not involved in the reactive site of a2-PI had no effect on CL and rabbit anti-mouse immunoglobulin IgG neutralized this JTP-l-inducing CL completely. Immunodepletion of tissue PA (tPA) or plasminogen from plasma decreased the rate of CL but that of prourokinase did not. To determine the role of PA inhibitor (PAl) released from platelets (pits) in the regulation of CL in vitro, plasma clots were made from pits poor plasma (PPP) and pits rich plasma (PRP), and CL was observed in the presence of JTP-1. There was almost no difference of the lysis time between PPP clot and PRP clot, although plasma clot from pregnant woman was lysed slowly. These results strongly suggest that endogenous t-PA in plasma is still functionally active after blood collection and CL is mainly prevented by a2-PI in vitro.-plasmin inhibitor (a2-Pl) designated as JTP-1 inhibited antiplasmin act ivity and complex formation of a2-PI with plasmin. By using this MCA we tried to observe plasma-clot lysis (CL) in vitro and to estimate the level of total fibrinolytic capacity in plasma. As reported previously (Blood 55: U83, 1980) spontaneous CL is a striking feature of the plasma derived from a patient with a2-PI deficiency. We showed that this abnormally increased fibrinolysis was solely due to the deficiency of a2-PI. However, the contribution of plasminogen activator (PA) and its inhibitor to this specific patient' plasma -CL has been under discussion. Therefore, to test whether similar CL can be found in normal plasma without an addition of PA, plasma clots were made after incubation of plasma from normal volunteers containing 125i fibrinogen with various concentration of JTP-1, and fibrinolysis was measured by counting the soluble radioactivity. The addition of JTP-1 to plasma led to a dose-dependent enhancement of the soluble 125i fragment-release from the clot. However, JTP-1 had no effect on a2-PI-deficient plasma-CL. Other anti-a2-PI MCAs whose epitopes were not involved in the reactive site of a2-PI had no effect on CL and rabbit anti-mouse immunoglobulin IgG neutralized this JTP-l-inducing CL completely. Immunodepletion of tissue PA (tPA) or plasminogen from plasma decreased the rate of CL but that of prourokinase did not. To determine the role of PA inhibitor (PAl) released from platelets (pits) in the regulation of CL in vitro, plasma clots were made from pits poor plasma (PPP) and pits rich plasma (PRP), and CL was observed in the presence of JTP-1. There was almost no difference of the lysis time between PPP clot and PRP clot, although plasma clot from pregnant woman was lysed slowly. These results strongly suggest that endogenous t-PA in plasma is still functionally active after blood collection and CL is mainly prevented by a2-PI in vitro.-plasmin inhibitor (a2-Pl) designated as JTP-1 inhibited antiplasmin act ivity and complex formation of a2-PI with plasmin. By using this MCA we tried to observe plasma-clot lysis (CL) in vitro and to estimate the level of total fibrinolytic capacity in plasma. As reported previously (Blood 55: U83, 1980) spontaneous CL is a striking feature of the plasma derived from a patient with α2-PI deficiency. We showed that this abnormally increased fibrinolysis was solely due to the deficiency of a2-PI. However, the contribution of plasminogen activator (PA) and its inhibitor to this specific patient' plasma -CL has been under discussion. Therefore, to test whether similar CL can be found in normal plasma without an addition of PA, plasma clots were made after incubation of plasma from normal volunteers containing 125i fibrinogen with various concentration of JTP-1, and fibrinolysis was measured by counting the soluble radioactivity. The addition of JTP-1 to plasma led to a dose-dependent enhancement of the soluble 125i fragment-release from the clot. However, JTP-1 had no effect on a2-PI-deficient plasma-CL. Other anti-a2-PI MCAs whose epitopes were not involved in the reactive site of a2-PI had no effect on CL and rabbit anti-mouse immunoglobulin IgG neutralized this JTP-l-inducing CL completely. Immunodepletion of tissue PA (tPA) or plasminogen from plasma decreased the rate of CL but that of prourokinase did not. To determine the role of PA inhibitor (PAl) released from platelets (pits) in the regulation of CL in vitro, plasma clots were made from pits poor plasma (PPP) and pits rich plasma (PRP), and CL was observed in the presence of JTP-1. There was almost no difference of the lysis time between PPP clot and PRP clot, although plasma clot from pregnant woman was lysed slowly. These results strongly suggest that endogenous t-PA in plasma is still functionally active after blood collection and CL is mainly prevented by α2-PI in vitro.
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Fraser, Kathryn A., Takashi Kangas, Ross B. Fulton, Steven M. Leonardo, Ben Harrison, Yumi Yokoyama, Nandita Bose, Jeremy R. Graff, Mark Uhlik, and Keith B. Gorden. "Abstract 3767: Imprime PGG, a soluble yeast b-glucan PAMP, enhancement of anti-tumor responses in combination with tumor targeting antibody is highly dependent on NK cell killing." In Proceedings: AACR Annual Meeting 2018; April 14-18, 2018; Chicago, IL. American Association for Cancer Research, 2018. http://dx.doi.org/10.1158/1538-7445.am2018-3767.
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Lund-Hansen, T., and L. C. Peterson. "COMPARISON OF ENZYMATIC PROPERTIES OF HUMAN PLASMA FVIIa AND HUMAN RECOMBINANT FVIIa." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643787.
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Human plasma FVIIa (pFVIIa) and human recombinant FVIIa (rFVIIa) were both purified by immune adsorption chromatography using a calcium dependent monoclonal antibody. The FVII obtained is highly purified and contains only trace contaminants as revealed by SDS-PAGE and reverse phase HPLC chromatography. FVII was fully activated during the purification procedure. A FVIIa activity assay has been developed in microplates using human FX as a substrate and methoxycarbonyl-D-cyclohexal-alanyl-glycyl-arginine-pNA as a chromogenic substrate for the FXa generated. The assay was linear at FVIIa concentrations between 0.5 and 10 nM. The concentration of the chromogenic substrate was 0.5 mM. A pH optimum at about 8 was found. An apparent Km=0.2 μM for FX was found for both pFVIIa and rFVIIa.The results suggest that the kinetics of human FX activation by pFVIIa and rFVIIa are identical. The FVIIa activity was found to be calcium dependent with maximal activity at about 0.25 mM, while the activities at 1 and 2 mM were 20% and 3%, respectively. When rabbit brain extract is used, the well-known dramatic enhancement effect of thromboplastin could be demonstrated with both FVII preparations. Also this reaction is calcium-dependent; however, the profile of the curve is distinctly different. Poly-D-lysine (MW 160,000) was found to enhance the FVIIa activity in a concentration dependent manner. Maximum stimulation (fivefold) was obtained at a concentration of about 10 mg/l.
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Haber, Edgar, Marchall T. Runge, Christoph Bode, Betsy Branscomb, and Janet Schnee. "ANTIBODY TARGETED FIBRINOLYSIS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643723.
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Chemical conjugates of fibrin-specificantibodies and plasminogen activators. Urokinase or tPA were linked covalently toamonoclonal antibody specific for the amino terminus of the beta chain of human fibrin (59D8) by means of the unidirectionalcross-linking reagent SPDP. The fibrinolytic potency of the conjugates at equal amidolytic activities was compared to the native plasminogen activators in an assay measuring lysis of 1251-fibrin monomer covalently linked to Sepharose CL-4B. Urokinase was least potent, tPA exhibited a 10fold increase in fibrinolysis whereas both the urokinase and tPA antibody conjugates and a urokinase-Fab conjugate were 250fold more potent than urokinase and 25 fold more potent than tPA. Enhanced fibrinolysis was fully inhibited by b peptide indicating its dependence on antigen binding. In a plasma assay conjugates of tPA orUK to antibody produced a 3.2- to 4.5-fold enhancement in clot lysis in human plasma over that of the respective unconjugated plasminogen activator. However, the UK-59D8 conjugate was only as potent as tPAalone. Antibody-conjugated tPA or UK consumed less fibrinogen, alpha 2-antiplasminand plasminogen than did the unconjugatedactivators, at equipotent thrombolytic concentrations. In a quantitative rabbit thrombolysis model, the activity of the purified conjugate was compared with that oftPA alone and that of a conjugate betweentPA and a digoxin-specific monoclonal antibody. After correction for spontaneous lysis, tPA-59D8 was shown to be 2.8 to,9.6times more potent than tPA alone. Unconjugated tPA and tPA-digoxin were equipotent.At equivalent thrombolytic concentrations, tPA-59D8 degraded less fibrinogen and consumed less alpha 2-antiplasmin than did tPA alone. These results suggest that tPA can be efficiently directed to the site of a thrombus by conjugation to an antifibrin monoclonal antibody, resulting in both more potent and more selective thrombolysis.A recombinant fusion protein comprising a fibrin-specific antibody site and theB chain of tPA. The rearranged 59D8 heavychain gene was cloned and combined in theexpression vector pSV2gpt withsequence coding for a portion of the Gamma 2b constant region and the catalytic beta chain of t-PA. This construct was transfected into heavy chain loss variant cells derived from the 59D8 hybridoma. Recombinant protein was purified by affinitychromatography and analyzed with Western blots. These revealed a 65-kD heavy chain-t-PA fusion protein that is secreted in association with the 59D8 light chain in the form of a 170-kD disulfide linked dimer. A chromogenic substrate assay showed the fusion protein to have 70 percent of the peptidolytic activity of native t-PA and to activate plasminogen as efficiently as t-PA. In a competitive binding assay, reconstituted antibody was shown to have a binding profile similar to that of native 59D8. Thus by recombinant techniques we have produced a novel hybrid protein capable of high affinity fibrin binding andplasminogen activation.Chemical conjugates between a fibrin-specific and a tPA-specific antibody. A heteroantibody duplex (duplex) with specificities for both tPA and fibrin was synthesized by conjugating iminothiolane-modified anti-tPA monoclonal antibody (TCL8) toantifibrin antibody 59D8. Addition of both duplex and tPA to a plasma clot assay gave more lysis (200 units produced 23.1 lysis; 400 units, 29.5 lysis) than did tPAalone (200 units, 1.8% lysis; 400 units,19% lysis). Despite increased potency associated with duplex addition, fibrinogen and alpha-2-antiplasmin levels at equal tPA concentrations did not differ. Thus, itis possible to concentrate tPA (added separately) to the site of a thrombus in plasma using a heteroantibody duplex with specificities for both tPA and fibrin.Biosynthetically produced heteroduplexantibodies that are both fibin and tPA-specific. The bispecific antibodies were prepared in two ways. First, polyethylene glycol-mediated fusions were performed with two different hybridoma cell lines: anti-fribrin b chain producer, 59D8 and anti-tPA producer, TCL8. TCL8 cells were selected for HPRT-minus variants and then fused with TK-deficient 59D8 cells. One cell line, F36.23, possessed both anti-human fibrin and anti-human t-PA immunoreactivities. A second method yielded another bispecific antibody, F32.1. This cell line was selected after fusing TCL8 (HPRT-minus) cells with spleen cells from a mouseimmunized with a fibrin-like peptide corresponding to the amino terminus of fibrinalpha-chains. Affinity-purified F32.1 andF36.23 retained anti-fibrin and anti-t-PAactivity and enhanced fibrinolytic potency of tPA by a factor of 10.