Artículos de revistas: "Identification de jet b"

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Beluffi, Camille. "b jet Identification in CMS". Nuclear and Particle Physics Proceedings 273-275 (abril de 2016): 2491–93. http://dx.doi.org/10.1016/j.nuclphysbps.2015.09.435.

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Abazov, V. M., B. Abbott, M. Abolins, B. S. Acharya, M. Adams, T. Adams, E. Aguilo et al. "b-Jet identification in the D0 experiment". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 620, n.º 2-3 (agosto de 2010): 490–517. http://dx.doi.org/10.1016/j.nima.2010.03.118.

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3

Buzatu, A. "Real-time b-jet identification in ATLAS". Journal of Physics: Conference Series 513, n.º 1 (11 de junio de 2014): 012004. http://dx.doi.org/10.1088/1742-6596/513/1/012004.

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4

Nguyen, Matthew. "b-jet Identification in PbPb Collisions with CMS". Nuclear Physics A 904-905 (mayo de 2013): 705c—708c. http://dx.doi.org/10.1016/j.nuclphysa.2013.02.112.

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5

Abazov, V. M., B. Abbott, B. S. Acharya, M. Adams, T. Adams, J. P. Agnew, G. D. Alexeev et al. "Improved b quark jet identification at the D0 experiment". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 763 (noviembre de 2014): 290–303. http://dx.doi.org/10.1016/j.nima.2014.04.087.

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6

Chabert, Eric. "b-jet identification at High Level Trigger in CMS". Journal of Physics: Conference Series 608 (22 de mayo de 2015): 012041. http://dx.doi.org/10.1088/1742-6596/608/1/012041.

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7

Mochizuki, Kazuya. "b-jet identification algorithms and performance in the ATLAS experiment". Nuclear and Particle Physics Proceedings 273-275 (abril de 2016): 2536–38. http://dx.doi.org/10.1016/j.nuclphysbps.2015.09.450.

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8

Ellison, J., A. Kernan y D. Smith. "Simulation of b-jet identification in a non-magnetic detector". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 302, n.º 2 (abril de 1991): 227–40. http://dx.doi.org/10.1016/0168-9002(91)90406-g.

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9

Coccaro, A. "Track reconstruction and b-jet identification for the ATLAS trigger system". Journal of Physics: Conference Series 368 (21 de junio de 2012): 012034. http://dx.doi.org/10.1088/1742-6596/368/1/012034.

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10

Freeman, J., W. Ketchum, J. D. Lewis, S. Poprocki, A. Pronko, V. Rusu y P. Wittich. "An artificial neural network based b jet identification algorithm at the CDF experiment". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 663, n.º 1 (enero de 2012): 37–47. http://dx.doi.org/10.1016/j.nima.2011.10.024.

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11

YAMAMOTO, Hiroshi, Kaori IKEBATA, Yusuke YASUDA, Ikumi TAMURA y Norihisa TATARAZAKO. "Case Study of Toxicity Identification Evaluation (TIE) Applied to the Selected Factory Effluents in Tokushima, Japan ". Journal of Environmental Chemistry 25, n.º 1 (2015): 11–17. http://dx.doi.org/10.5985/jec.25.11.

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12

Freeman, J., T. Junk, M. Kirby, Y. Oksuzian, T. J. Phillips, F. D. Snider, M. Trovato, J. Vizan y W. M. Yao. "Introduction to HOBIT, a b-jet identification tagger at the CDF experiment optimized for light Higgs boson searches". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 697 (enero de 2013): 64–76. http://dx.doi.org/10.1016/j.nima.2012.09.021.

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13

van den Eijnden, J., N. Degenaar, T. D. Russell, R. Wijnands, A. Bahramian, J. C. A. Miller-Jones, J. V. Hernández Santisteban et al. "A new radio census of neutron star X-ray binaries". Monthly Notices of the Royal Astronomical Society 507, n.º 3 (21 de julio de 2021): 3899–922. http://dx.doi.org/10.1093/mnras/stab1995.

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ABSTRACT We report new radio observations of a sample of 36 neutron star (NS) X-ray binaries, more than doubling the sample in the literature observed at current-day sensitivities. These sources include 13 weakly magnetized (B < 1010 G) and 23 strongly magnetized (B ≥ 1010 G) NSs. 16 of the latter category reside in high-mass X-ray binaries, of which only two systems were radio-detected previously. We detect four weakly and nine strongly magnetized NSs; the latter are systematically radio fainter than the former and do not exceed LR ≈ 3 × 1028 erg s−1. In turn, we confirm the earlier finding that the weakly magnetized NSs are typically radio fainter than accreting stellar-mass black holes. While an unambiguous identification of the origin of radio emission in high-mass X-ray binaries is challenging, we find that in all but two detected sources (Vela X-1 and 4U 1700-37) the radio emission appears more likely attributable to a jet than the donor star wind. The strongly magnetized NS sample does not reveal a global correlation between X-ray and radio luminosity, which may be a result of sensitivity limits. Furthermore, we discuss the effect of NS spin and magnetic field on radio luminosity and jet power in our sample. No current model can account for all observed properties, necessitating the development and refinement of NS jet models to include magnetic field strengths up to 1013 G. Finally, we discuss jet quenching in soft states of NS low-mass X-ray binaries, the radio non-detections of all observed very-faint X-ray binaries in our sample, and future radio campaigns of accreting NSs.

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Tumasyan, Armen, Wolfgang Adam, Janik Walter Andrejkovic, Thomas Bergauer, Suman Chatterjee, Marko Dragicevic, Alberto Escalante Del Valle et al. "A new calibration method for charm jet identification validated with proton-proton collision events at √s = 13 TeV". Journal of Instrumentation 17, n.º 03 (1 de marzo de 2022): P03014. http://dx.doi.org/10.1088/1748-0221/17/03/p03014.

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Abstract Many measurements at the LHC require efficient identification of heavy-flavour jets, i.e. jets originating from bottom (b) or charm (c) quarks. An overview of the algorithms used to identify c jets is described and a novel method to calibrate them is presented. This new method adjusts the entire distributions of the outputs obtained when the algorithms are applied to jets of different flavours. It is based on an iterative approach exploiting three distinct control regions that are enriched with either b jets, c jets, or light-flavour and gluon jets. Results are presented in the form of correction factors evaluated using proton-proton collision data with an integrated luminosity of 41.5 fb-1 at √s = 13 TeV, collected by the CMS experiment in 2017. The closure of the method is tested by applying the measured correction factors on simulated data sets and checking the agreement between the adjusted simulation and collision data. Furthermore, a validation is performed by testing the method on pseudodata, which emulate various mismodelling conditions. The calibrated results enable the use of the full distributions of heavy-flavour identification algorithm outputs, e.g. as inputs to machine-learning models. Thus, they are expected to increase the sensitivity of future physics analyses.

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Wardle, J. F. C. "Magnetic Fields in AGN". International Astronomical Union Colloquium 164 (1998): 97–103. http://dx.doi.org/10.1017/s0252921100044717.

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AbstractWe review VLBI polarization results. In particular, we discuss the a) “shock in jet paradigm”, b) the orientation of the magnetic field in jets as a function of optical identification, c) rotation measure and Faraday dispersion measurements as a probe of the narrow line region, and d) future directions of polarization observations. Results we emphasize are i) there is still a strong correlation between optical L/C ratio or EW and magnetic field orientation in the jets of blazars, even for high redshift weak-lined objects, ii) observed rotation measures are much smaller than expected from the properties of the NLR, except for some CSS sources. Also iii) a faint boundary layer or sheath (with a parallel magnetic field) has been observed around the jet of the weak-lined blazar 1055+018, and iv) circular polarization has been detected for the first time in the jets of 3C 84 and 3C 279.

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KODAMA, Kazuko, Shigeru SUZUKI y Yoshiyuki HARADA. "Separation and Identification of Paraben Conjugates in Human Urine by Liquid Chromatography/tandem Mass Spectrometry Combining Precursor Ion Scan and Accurate Mass Analysis ". Journal of Environmental Chemistry 27, n.º 1 (2017): 1–8. http://dx.doi.org/10.5985/jec.27.1.

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17

Su, Yu-wen, Alexandra Flemming, Thomas Wossning, Elias Hobeika, Michael Reth y Hassan Jumaa. "Identification of a Pre-BCR Lacking Surrogate Light Chain". Journal of Experimental Medicine 198, n.º 11 (24 de noviembre de 2003): 1699–706. http://dx.doi.org/10.1084/jem.20031428.

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SLP-65−/− pre-B cells show a high proliferation rate in vitro. We have shown previously that λ5 expression and consequently a conventional pre-B cell receptor (pre-BCR) are essential for this proliferation. Here, we show that pre-B cells express a novel receptor complex that contains a μ heavy chain (μHC) but lacks any surrogate (SL) or conventional light chain (LC). This SL-deficient pre-BCR (SL−pre-BCR) requires Ig-α for expression on the cell surface. Anti-μ treatment of pre-B cells expressing the SL−pre-BCR induces tyrosine phosphorylation of substrate proteins and a strong calcium (Ca2+) release. Further, the expression of the SL−pre-BCR is associated with a high differentiation rate toward κLC-positive cells. Given that B cell development is only partially blocked and allelic exclusion is unaffected in SL-deficient mice, we propose that the SL−pre-BCR is involved in these processes and therefore shares important functions with the conventional pre-BCR.

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YAMAZAKI, Hideo, Masanobu ISHIDA, Hideki MATSUI, Hitoshi NAGANUMA y Moto TAKAKUSAKI. "Assessment of Lead Pollution and Identification of the Contamination Source of Gas Station Site Soil ". Journal of Environmental Chemistry 25, n.º 3 (2015): 129–37. http://dx.doi.org/10.5985/jec.25.129.

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Ingold, Karine, Adrian Zumsteg, Aubry Tardivel, Bertrand Huard, Quynh-Giao Steiner, Teresa G. Cachero, Fang Qiang et al. "Identification of proteoglycans as the APRIL-specific binding partners". Journal of Experimental Medicine 201, n.º 9 (25 de abril de 2005): 1375–83. http://dx.doi.org/10.1084/jem.20042309.

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B cell activating factor of the tumor necrosis factor (TNF) family (BAFF) and a proliferation-inducing ligand (APRIL) are closely related ligands within the TNF superfamily that play important roles in B lymphocyte biology. Both ligands share two receptors—transmembrane activator and calcium signal–modulating cyclophilin ligand interactor (TACI) and B cell maturation antigen (BCMA)—that are predominantly expressed on B cells. In addition, BAFF specifically binds BAFF receptor, whereas the nature of a postulated APRIL-specific receptor remains elusive. We show that the TNF homology domain of APRIL binds BCMA and TACI, whereas a basic amino acid sequence (QKQKKQ) close to the NH2 terminus of the mature protein is required for binding to the APRIL-specific “receptor.” This interactor was identified as negatively charged sulfated glycosaminoglycan side chains of proteoglycans. Although T cell lines bound little APRIL, the ectopic expression of glycosaminoglycan-rich syndecans or glypicans conferred on these cells a high binding capacity that was completely dependent on APRIL's basic sequence. Moreover, syndecan-1–positive plasma cells and proteoglycan-rich nonhematopoietic cells displayed high specific, heparin-sensitive binding to APRIL. Inhibition of BAFF and APRIL, but not BAFF alone, prevented the survival and/or the migration of newly formed plasma cells to the bone marrow. In addition, costimulation of B cell proliferation by APRIL was only effective upon APRIL oligomerization. Therefore, we propose a model whereby APRIL binding to the extracellular matrix or to proteoglycan-positive cells induces APRIL oligomerization, which is the prerequisite for the triggering of TACI- and/or BCMA-mediated activation, migration, or survival signals.

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Tangye, Stuart G., Yong-Jun Liu, Gregorio Aversa, Joseph H. Phillips y Jan E. de Vries. "Identification of Functional Human Splenic Memory B Cells by Expression of CD148 and CD27". Journal of Experimental Medicine 188, n.º 9 (2 de noviembre de 1998): 1691–703. http://dx.doi.org/10.1084/jem.188.9.1691.

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Memory B cells isolated from human tonsils are characterized by an activated cell surface phenotype, localization to mucosal epithelium, expression of somatically mutated immunoglobulin (Ig) variable (V) region genes, and a preferential differentiation into plasma cells in vitro. In spleens of both humans and rodents, a subset of memory B cells is believed to reside in the marginal zone of the white pulp. Similar to tonsil-derived memory B cells, splenic marginal zone B cells can be distinguished from naive follicular B cells by a distinct cell surface phenotype and by the presence of somatic mutations in their Ig V region genes. Although differences exist between human naive and memory B cells, no cell surface molecules have been identified that positively identify all memory B cells. In this study, we have examined the expression of the receptor-type protein tyrosine phosphatase CD148 on human B cells. CD148+ B cells present in human spleen exhibited characteristics typical of memory B cells. These included an activated phenotype, localization to the marginal zone, the expression of somatically mutated Ig V region genes, and the preferential differentiation into plasma cells. In contrast, CD148− B cells appeared to be naive B cells due to localization to the mantle zone, the expression of surface antigens typical of unstimulated B cells, and the expression of unmutated Ig V region genes. Interestingly, CD148+ B cells also coexpressed CD27, whereas CD148− B cells were CD27−. These results identify CD148 and CD27 as markers which positively identify memory B cells present in human spleen. Thus, assessing expression of these molecules may be a convenient way to monitor the development of memory B cell responses in immunocompromised individuals or in vaccine trials.

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Descatoire, Marc, Sandra Weller, Sabine Irtan, Sabine Sarnacki, Jean Feuillard, Sébastien Storck, Anne Guiochon-Mantel et al. "Identification of a human splenic marginal zone B cell precursor with NOTCH2-dependent differentiation properties". Journal of Experimental Medicine 211, n.º 5 (14 de abril de 2014): 987–1000. http://dx.doi.org/10.1084/jem.20132203.

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Mouse splenic marginal zone precursors (MZPs) differentiate into marginal zone B (MZB) cells under a signaling pathway involving Notch2 and its ligand, delta-like 1 ligand (Dll1). We report the identification of an MZP subset in the spleen of young children. These MZPs differentiate into MZ-like B cells in vitro in the presence of OP9 cells expressing human DLL1, as demonstrated by the up-regulation of classical MZB cell markers. A set of diagnostic genes discriminating IgM+IgD+CD27+ blood and splenic MZB cells from switched B cells was identified (up-regulation of SOX7, down-regulation of TOX, COCH, and HOPX), and their expression during the induction assay mirrored the one of MZB cells. Moreover, Alagille patients with a NOTCH2 haploinsufficiency display a marked reduction of IgM+IgD+CD27+ B cells in blood, whereas their switched memory B cells are not affected. Altogether, these results argue in favor of the existence of a rodent-like MZB cell lineage in humans.

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van den Berg, T. K., J. J. Brevé, J. G. Damoiseaux, E. A. Döpp, S. Kelm, P. R. Crocker, C. D. Dijkstra y G. Kraal. "Sialoadhesin on macrophages: its identification as a lymphocyte adhesion molecule." Journal of Experimental Medicine 176, n.º 3 (1 de septiembre de 1992): 647–55. http://dx.doi.org/10.1084/jem.176.3.647.

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In this study we present evidence that the mouse and rat sialoadhesin (originally named sheep erythrocyte receptor) on macrophages can function as a lymphocyte adhesion molecule. Lymphocytes were shown to bind to the splenic marginal zone, and lymph node subcapsular sinus and medulla in a frozen section assay. Selective depletion experiments showed that binding was mediated by macrophages. Adhesion was blocked by preincubation of the sections with monoclonal antibodies against mouse or rat sialoadhesin. Binding was temperature dependent, divalent cation independent, and involved sialic acid residues on the lymphocyte, as it could be inhibited by prior neuraminidase treatment or addition of the ganglioside GD1a. Binding to sialoadhesin was confirmed using the purified receptor and was observed among T cells, T blasts, B cells, and B blasts. Isolated macrophages or dendritic cells showed little binding. Sialoadhesin provides the first example of a macrophage-restricted lymphocyte adhesion molecule.

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Li, Li, Xin Zhang, Sharlotte Kovacic, Andrew J. Long, Karen Bourque, Clive R. Wood y Yong Sung Choi. "Identification of a Human Follicular Dendritic Cell Molecule That Stimulates Germinal Center B Cell Growth". Journal of Experimental Medicine 191, n.º 6 (20 de marzo de 2000): 1077–84. http://dx.doi.org/10.1084/jem.191.6.1077.

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The initial interaction between B cells and follicular dendritic cells (FDCs) appears to be essential for germinal center (GC) formation. To identify molecules regulating this interaction, we generated FDC-staining monoclonal antibodies (mAbs) and screened them for their ability to block FDC-mediated costimulation of growth and differentiation of CD40-stimulated B cells. Using one of the inhibitory mAbs, 8D6, we expression cloned the cDNA encoding the 8D6 antigen (Ag) from a human FDC line, HK. The 8D6 Ag is a novel protein of 282 amino acids that is expressed abundantly on FDCs. Monolayers of COS cells transiently transfected with the 8D6 Ag cDNA stimulate B cell growth. The mAb 8D6 blocks the costimulatory function completely. The inhibitory activity of the mAb 8D6 was demonstrated to be due to an inhibition of cell cycle progression of CD40 ligand–stimulated GC B cells. In addition, the mAb 8D6 inhibits the growth of a lymphoma of GC origin, L3055, which depends on FDCs or HK cells for its growth. These findings suggest that the primary function of FDCs in the GC is to stimulate B cell growth. An FDC signal molecule, 8D6 Ag, may be an important molecule to mediate this function.

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Rahayuwati, Sat, Purnama Hidayat y Sri Hendrastuti Hidayat. "Variasi morfologi puparium Bemisa tabaci (Gennadius) (Hemiptera: Aleyrodidae) pada berbagai inang dan ketinggian tempat dari daerah endemik penyakit kuning cabai di Wilayah Sundaland". Jurnal Entomologi Indonesia 17, n.º 2 (14 de septiembre de 2020): 61. http://dx.doi.org/10.5994/jei.17.2.61.

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Bemisia tabaci (Gennadius) is one of polyphagous whitefly that has been known as gemini virus vector. The identification of B. tabaci is carried out based on pupal case or puparium of red eye fouth stage. The morphological variation of B. tabaci puparium leads to the difficulties on species identification. This research was aimed to study the morphological variations of B. tabaci puparium that has been found in various host plants at various altitude. Samples of B. tabaci puparium were obtained from Sundaland endemic area of pepper yellow curl disease virus endemic areas including West Sumatra, West Java, Central Java, East Java, Bali, South Kalimantan. Slides-mounted were made from puparium and then identification was carried out to species. Observations have been conducted on B. tabaci puparial size, puparial shape, number of elongated dorsal setae, and caudal setae size. Canonical correlation analysis was applied to determine the factors that affected the puparium morphological variation. Based on the results, there were four variations of puparium: oval, oval with 1–2 indentations, oval with more than 3 indentations, and sea shell shapes. The variation observed on dorsal setae number, puparial shape, and size of B. tabaci were supposed due to the induction of trichomes on the leaves surface. Puparium variations were affected by host plants instead of altitude.

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van Zelm, Menno C., Tomasz Szczepański, Mirjam van der Burg y Jacques J. M. van Dongen. "Replication history of B lymphocytes reveals homeostatic proliferation and extensive antigen-induced B cell expansion". Journal of Experimental Medicine 204, n.º 3 (20 de febrero de 2007): 645–55. http://dx.doi.org/10.1084/jem.20060964.

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The contribution of proliferation to B lymphocyte homeostasis and antigen responses is largely unknown. We quantified the replication history of mouse and human B lymphocyte subsets by calculating the ratio between genomic coding joints and signal joints on kappa-deleting recombination excision circles (KREC) of the IGK-deleting rearrangement. This approach was validated with in vitro proliferation studies. We demonstrate that naive mature B lymphocytes, but not transitional B lymphocytes, undergo in vivo homeostatic proliferation in the absence of somatic mutations in the periphery. T cell–dependent B cell proliferation was substantially higher and showed higher frequencies of somatic hypermutation than T cell–independent responses, fitting with the robustness and high affinity of T cell–dependent antibody responses. More extensive proliferation and somatic hypermutation in antigen-experienced B lymphocytes from human adults compared to children indicated consecutive responses upon additional antigen exposures. Our combined observations unravel the contribution of proliferation to both B lymphocyte homeostasis and antigen-induced B cell expansion. We propose an important role for both processes in humoral immunity. These new insights will support the understanding of peripheral B cell regeneration after hematopoietic stem cell transplantation or B cell–directed antibody therapy, and the identification of defects in homeostatic or antigen-induced B cell proliferation in patients with common variable immunodeficiency or another antibody deficiency.

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Pani, G., M. Kozlowski, J. C. Cambier, G. B. Mills y K. A. Siminovitch. "Identification of the tyrosine phosphatase PTP1C as a B cell antigen receptor-associated protein involved in the regulation of B cell signaling." Journal of Experimental Medicine 181, n.º 6 (1 de junio de 1995): 2077–84. http://dx.doi.org/10.1084/jem.181.6.2077.

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Recent data implicating loss of PTP1C tyrosine phosphatase activity in the genesis of the multiple hemopoietic cell defects found in systemic autoimmune/immunodeficient motheaten (me) and viable motheaten (mev) mice suggest that PTP1C plays an important role in modulating intracellular signaling events regulating cell activation and differentiation. To begin elucidating the role for this cytosolic phosphatase in lymphoid cell signal transduction, we have examined early signaling events and mitogenic responses induced by B cell antigen receptor (BCR) ligation in me and mev splenic B cells and in CD5+ CH12 lymphoma cells, which represent the lymphoid population amplified in motheaten mice. Despite their lack of functional PTP1C, me and mev B cells proliferated normally in response to LPS. However, compared with wild-type B cells, cells from the mutant mice were hyperresponsive to normally submitogenic concentrations of F(ab')2 anti-Ig antibody, and they exhibited reduced susceptibility to the inhibitory effects of Fc gamma IIRB cross-linking on BCR-induced proliferation. Additional studies of unstimulated CH12 and wild-type splenic B cells revealed the constitutive association of PTP1C with the resting BCR complex, as evidenced by coprecipitation of PTP1C protein and phosphatase activity with BCR components and the depletion of BCR-associated tyrosine phosphatase activity by anti-PTP1C antibodies. These results suggest a role for PTP1C in regulating the tyrosine phosphorylation state of the resting BCR complex components, a hypothesis supported by the observation that PTP1C specifically induces dephosphorylation of a 35-kD BCR-associated protein likely representing Ig-alpha. In contrast, whereas membrane Ig cross-linking was associated with an increase in the tyrosine phosphorylation of PTP1C and an approximately 140-kD coprecipitated protein, PTP1C was no longer detected in the BCR complex after receptor engagement, suggesting that PTP1C dissociates from the activated receptor complex. Together these results suggest a critical role for PTP1C in modulating BCR signaling capacity, and they indicate that the PTP1C influence on B cell signaling is likely to be realized in both resting and activated cells.

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Jamieson, C., F. Mauxion y R. Sen. "Identification of a functional NF-kappa B binding site in the murine T cell receptor beta 2 locus." Journal of Experimental Medicine 170, n.º 5 (1 de noviembre de 1989): 1737–43. http://dx.doi.org/10.1084/jem.170.5.1737.

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We have identified a sequence in the TCR beta 2 locus that is homologous to the kappa B site in the Ig kappa light chain enhancer. This element, TCR beta-B, is located in the vicinity of previously identified T cell-specific DNase1 hypersensitive sites. Transfection analysis shows that a 60-bp fragment encompassing this site is preferentially active in T cells stimulated with phorbol esters or the HTLV-1 tax gene product compared with a B cell line that constitutively expresses NF-kappa B. Our results provide the first evidence for transcriptional regulatory sequences residing within the J beta 2-C beta 2 intron and suggest the possible involvement of these sequences in modulation of TCR beta gene expression upon cellular activation.

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Nitschke, Lars, Helen Floyd, David J. P. Ferguson y Paul R. Crocker. "Identification of CD22 Ligands on Bone Marrow Sinusoidal Endothelium Implicated in CD22-dependent Homing of Recirculating B Cells". Journal of Experimental Medicine 189, n.º 9 (3 de mayo de 1999): 1513–18. http://dx.doi.org/10.1084/jem.189.9.1513.

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CD22 is a B cell–specific transmembrane protein known to function as a negative regulator of B cell signaling. It has also been implicated in cell adhesion through recognition of α2,6-linked sialic acids on glycans of target cells. Previous studies showed that CD22-deficient mice had a strongly reduced population of mature recirculating B cells in the bone marrow despite normal B cell development. Using a soluble recombinant form of the receptor (CD22-Fc), we demonstrate here that sialylated ligands for CD22 are expressed on sinusoidal endothelial cells of murine bone marrow but not on endothelial cells in other tissues examined. Injection of CD22-Fc revealed that the CD22 ligands in the bone marrow were accessible to the circulation. Treatment of mice with either CD22-Fc or affinity-purified anti-CD22 antibody led to an ∼50% reduction in mature recirculating B cells in the bone marrow without affecting numbers in the spleen. Finally, consistent with the notion that CD22 is a homing receptor, we show that compared with wild-type mice, CD22-deficient animals have a lower number of immunoglobulin M–secreting plasma cells in the bone marrow.

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Mårtensson, Inga-Lill, Fritz Melchers y Thomas H. Winkler. "A Transgenic Marker for Mouse B Lymphoid Precursors". Journal of Experimental Medicine 185, n.º 4 (17 de febrero de 1997): 653–62. http://dx.doi.org/10.1084/jem.185.4.653.

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Three lines of transgenic mice have been generated which express human CD25 under the control of the 722-base pair region located immediately 5′ of the precursor (pre)–B cell–specific λ5 gene. All three strains express human CD25 in parallel to endogenous λ5 on pre–B cells, but not on mature B lymphocytes or other blood cell lineages. High expression of human CD25 on B lineage cells of transgenic mice has allowed the identification of a new B220+CD19−λ5+ precursor of the B220+CD19+λ5+ c-kit+ pre-BI cells. Both types of precursors are clonable on stromal cells in the presence of interleukin-7. The CD19− precursors have a sizeable part of their immunoglobulin heavy chain gene loci in germline configuration, while the CD19+ pre–BI cells are predominantly DJH rearranged. The results indicate that random integration of the 722-bp 5′ region of the λ5 gene into the mouse genome confers tissue and differentiation stage–specific expression of a transgene.

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Descatoire, Marc, Sandra Weller, Sabine Irtan, Sabine Sarnacki, Jean Feuillard, Sébastien Storck, Anne Guiochon-Mantel et al. "Identification of a human splenic marginal zone B cell precursor with NOTCH2-dependent differentiation properties". Journal of Experimental Medicine 211, n.º 5 (5 de mayo de 2014): 1005. http://dx.doi.org/10.1084/jem.2013220304222014c.

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Can-Vargas, Xareni, Natalia Barboza, Eric J. Fuchs y Eduardo J. Hernández. "Spatial Distribution of Whitefly Species (Hemiptera: Aleyrodidae) and Identification of Secondary Bacterial Endosymbionts in Tomato Fields in Costa Rica". Journal of Economic Entomology 113, n.º 6 (19 de octubre de 2020): 2900–2910. http://dx.doi.org/10.1093/jee/toaa215.

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Abstract In Costa Rica, tomato (Solanum lycopersicum Linnaeus) Linnaeus (Solanales: Solanaceae) is one of the crops most severely affected by the whiteflies (Hemiptera: Aleyrodidae) Trialeurodes vaporariorum (Westwood) and the Bemisia tabaci (Gennadius) species complex. The objective of this study was to monitor the spatial distribution and diversity of these species and to detect the presence of secondary bacterial endosymbionts in individuals collected in areas of intensive tomato production. In total, 628 whitefly individuals were identified to the species level using restriction analysis (PCR-RFLP) of a fragment of the mitochondrial cytochrome C oxidase I gene (mtCOI). Trialeurodes vaporariorum was the predominant species, followed by B. tabaci Mediterranean (MED). Bemisia tabaci New World (NW) and B. tabaci Middle East-Asia Minor 1 (MEAM1) were present in lower numbers. The mtCOI fragment was sequenced for 89 individuals and a single haplotype was found for each whitefly species. Using molecular markers, the 628 individuals were analyzed for the presence of four endosymbionts. Arsenophonus Gherna et al. (Enterobacterales: Morganellaceae) was most frequently associated with T. vaporariorum, whereas Wolbachia Hertig (Rickettsiales: Anaplasmataceae) and Rickettsia da Rocha-Lima (Rickettsiales: Rickettsiaceae) were associated with B. tabaci MED. This study confirmed that B. tabaci NW has not been completely displaced by the invasive species B. tabaci MED and B. tabaci MEAM1 present in the country. An association was found between whitefly species present in tomato and certain secondary endosymbionts, elevation was the most likely environmental factor to affect their frequency.

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Faust, E. A., D. C. Saffran, D. Toksoz, D. A. Williams y O. N. Witte. "Distinctive growth requirements and gene expression patterns distinguish progenitor B cells from pre-B cells." Journal of Experimental Medicine 177, n.º 4 (1 de abril de 1993): 915–23. http://dx.doi.org/10.1084/jem.177.4.915.

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Long-term bone marrow cultures have been useful in determining gene expression patterns in pre-B cells and in the identification of cytokines such as interleukin 7 (IL-7). We have developed a culture system to selectively grow populations of B lineage restricted progenitors (pro-B cells) from murine bone marrow. Pro-B cells do not grow in response to IL-7, Steel locus factor (SLF), or a combination of the two. c-kit, the SLF receptor, and the IL-7 receptor are both expressed by pro-B cells, indicating that the lack of response is not simply due to the absence of receptors. Furthermore, SLF is not necessary for the growth of pro-B cells since they could be expanded on a stromal line derived from Steel mice that produces no SLF. IL-7 responsiveness in pre-B cells is associated with an increase in n-myc expression and is correlated with immunoglobulin (Ig) gene rearrangements. Although members of the ets family of transcription factors and the Pim-1 kinase are expressed by pro-B cells, n-myc is not expressed. Pro-B cells maintain Ig genes in the germline configuration, which is correlated with a low level of recombination activating genes 1 and 2 (Rag-1 and 2) mRNA expression, but high expression of sterile mu and terminal deoxynucleotidyl transferase. Pro-B cells are unable to grow separated from the stromal layer by a porous membrane, indicating that stromal contact is required for growth. These results suggest that pro-B cells are dependent on alternative growth signals derived from bone marrow stroma and can be distinguished from pre-B cells by specific patterns of gene expression.

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Akatsuka, Yoshiki, Tetsuya Nishida, Eisei Kondo, Mikinori Miyazaki, Hirohumi Taji, Hiroatsu Iida, Kunio Tsujimura et al. "Identification of a Polymorphic Gene, BCL2A1, Encoding Two Novel Hematopoietic Lineage-specific Minor Histocompatibility Antigens". Journal of Experimental Medicine 197, n.º 11 (27 de mayo de 2003): 1489–500. http://dx.doi.org/10.1084/jem.20021925.

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We report the identification of two novel minor histocompatibility antigens (mHAgs), encoded by two separate single nucleotide polymorphisms on a single gene, BCL2A1, and restricted by human histocompatibility leukocyte antigen (HLA)-A*2402 (the most common HLA-A allele in Japanese) and B*4403, respectively. Two cytotoxic T lymphocyte (CTL) clones specific for these mHAgs were first isolated from two distinct recipients after hematopoietic cell transplantation. Both clones lyse only normal and malignant cells within the hematopoietic lineage. To localize the gene encoding the mHAgs, two-point linkage analysis was performed on the CTL lytic patterns of restricting HLA-transfected B lymphoblastoid cell lines obtained from Centre d'Etude du Polymorphisme Humain. Both CTL clones showed a completely identical lytic pattern for 4 pedigrees and the gene was localized within a 3.6-cM interval of 15q24.3–25.1 region that encodes at least 46 genes. Of those, only BCL2A1 has been reported to be expressed in hematopoietic cells and possess three nonsynonymous nucleotide changes. Minigene transfection and epitope reconstitution assays with synthetic peptides identified both HLA-A*2402– and B*4403-restricted mHAg epitopes to be encoded by distinct polymorphisms within BCL2A1.

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Kabelitz, D. y P. Conradt. "Identification of CD2-/CD3+ T cells in fetal human tissue." Journal of Experimental Medicine 168, n.º 5 (1 de noviembre de 1988): 1941–46. http://dx.doi.org/10.1084/jem.168.5.1941.

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From 1 to 23% of fetal human spleen or thymus cells (from the 20th to 24th week of gestation) were found to display a previously unrecognized CD2-/CD3+ phenotype. IL-2-dependent, long-term clones of CD2-/3+ T cells did not react with a panel of anti-CD2 mAbs and did not form rosettes with sheep erythrocytes. These results show that (a) significant numbers of CD2-/3+ T cells are present in fetal human spleen and/or thymus; and (b) in contrast to the widely accepted view, expression of CD2 is not a prerequisite for the expression of the CD3 molecular complex on human T cells.

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Koning, F., A. M. Kruisbeek, W. L. Maloy, S. Marusic-Galesic, D. M. Pardoll, E. M. Shevach, G. Stingl, R. Valas, W. M. Yokoyama y J. E. Coligan. "T cell receptor gamma/delta chain diversity." Journal of Experimental Medicine 167, n.º 2 (1 de febrero de 1988): 676–81. http://dx.doi.org/10.1084/jem.167.2.676.

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The TCR-gamma and -delta chains of six murine hybridomas were compared by one-dimensional SDS-PAGE and two-dimensional NEPHGE/SDS-PAGE analysis. This allowed the identification of three distinct gamma chains (gamma a, gamma b, and gamma c) and three distinct delta chains (delta a, delta b, and delta c). Four gamma/delta chain combinations (gamma a delta a, gamma b delta b, gamma b delta c, and gamma c delta a) were observed. These results indicate that multiple forms of the delta chain are expressed and suggest that the delta chains are encoded for by an Ig-like rearranging gene. This delta chain polymorphism significantly enhances the potential diversity of TCR-gamma/delta, which may be of importance for a better understanding of the putative ligand(s) recognized by this receptor.

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Wöhner, Miriam, Hiromi Tagoh, Ivan Bilic, Markus Jaritz, Daniela Kostanova Poliakova, Maria Fischer y Meinrad Busslinger. "Molecular functions of the transcription factors E2A and E2-2 in controlling germinal center B cell and plasma cell development". Journal of Experimental Medicine 213, n.º 7 (3 de junio de 2016): 1201–21. http://dx.doi.org/10.1084/jem.20152002.

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E2A is an essential regulator of early B cell development. Here, we have demonstrated that E2A together with E2-2 controlled germinal center (GC) B cell and plasma cell development. As shown by the identification of regulated E2A,E2-2 target genes in activated B cells, these E-proteins directly activated genes with important functions in GC B cells and plasma cells by inducing and maintaining DNase I hypersensitive sites. Through binding to multiple enhancers in the Igh 3′ regulatory region and Aicda locus, E-proteins regulated class switch recombination by inducing both Igh germline transcription and AID expression. By regulating 3′ Igk and Igh enhancers and a distal element at the Prdm1 (Blimp1) locus, E-proteins contributed to Igk, Igh, and Prdm1 activation in plasmablasts. Together, these data identified E2A and E2-2 as central regulators of B cell immunity.

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Kee, Barbara L. y Cornelis Murre. "Induction of Early B Cell Factor (EBF) and Multiple B Lineage Genes by the Basic Helix-Loop-Helix Transcription Factor E12". Journal of Experimental Medicine 188, n.º 4 (17 de agosto de 1998): 699–713. http://dx.doi.org/10.1084/jem.188.4.699.

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The transcription factors encoded by the E2A and early B cell factor (EBF) genes are required for the proper development of B lymphocytes. However, the absence of B lineage cells in E2A- and EBF-deficient mice has made it difficult to determine the function or relationship between these proteins. We report the identification of a novel model system in which the role of E2A and EBF in the regulation of multiple B lineage traits can be studied. We found that the conversion of 70Z/3 pre-B lymphocytes to cells with a macrophage-like phenotype is associated with the loss of E2A and EBF. Moreover, we show that ectopic expression of the E2A protein E12 in this macrophage line results in the induction of many B lineage genes, including EBF, IL7Rα, λ5, and Rag-1, and the ability to induce κ light chain in response to mitogen. Activation of EBF may be one of the critical functions of E12 in regulating the B lineage phenotype since expression of EBF alone leads to the activation of a subset of E12-inducible traits. Our data demonstrate that, in the context of this macrophage line, E12 induces expression of EBF and together these transcription factors coordinately regulate numerous B lineage–associated genes.

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Murn, Jernej, Olivier Alibert, Ning Wu, Simon Tendil y Xavier Gidrol. "Prostaglandin E2 regulates B cell proliferation through a candidate tumor suppressor, Ptger4". Journal of Experimental Medicine 205, n.º 13 (15 de diciembre de 2008): 3091–103. http://dx.doi.org/10.1084/jem.20081163.

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B cell receptor (BCR) signaling contributes to the pathogenesis of B cell malignancies, and most B cell lymphomas depend on BCR signals for survival. Identification of genes that restrain BCR-mediated proliferation is therefore an important goal toward improving the therapy of B cell lymphoma. Here, we identify Ptger4 as a negative feedback regulator of proliferation in response to BCR signals and show that its encoded EP4 receptor is a principal molecule conveying the growth-suppressive effect of prostaglandin E2 (PGE2). Stable knockdown of Ptger4 in B cell lymphoma markedly accelerated tumor spread in mice, whereas Ptger4 overexpression yielded significant protection. Mechanistically, we show that the intrinsic activity of Ptger4 and PGE2–EP4 signaling target a similar set of activating genes, and find Ptger4 to be significantly down-regulated in human B cell lymphoma. We postulate that Ptger4 functions in B cells as a candidate tumor suppressor whose activity is regulated by PGE2 in the microenvironment. These findings suggest that targeting EP4 receptor for prostaglandin may present a novel strategy for treatment of B cell malignancies.

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Seifert, Marc y Ralf Küppers. "Molecular footprints of a germinal center derivation of human IgM+(IgD+)CD27+ B cells and the dynamics of memory B cell generation". Journal of Experimental Medicine 206, n.º 12 (16 de noviembre de 2009): 2659–69. http://dx.doi.org/10.1084/jem.20091087.

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The origin of IgM+CD27+ B lymphocytes with mutated IgV genes, which account for ∼20% of human peripheral blood (PB) B cells, is controversially discussed. A generation in a primary diversification pathway, in T cell–independent immune responses, or in T cell–dependent germinal center (GC) reactions has been proposed. We show here that IgM+IgD+CD27+ and IgM+IgD−/lowCD27+ B cell subsets carry, like class-switched memory B cells, mutations in the Bcl6 gene as a genetic trait of a GC experience. Moreover, the identification of PB IgM+IgD+CD27+ B cells clonally related to GC-derived IgG+ memory B cells with shared and distinct IgV gene mutations demonstrates the GC origin also of the former subset. These findings provide genetic evidence for a GC derivation of somatically mutated IgM+ B cells and indicate that adult humans harbor a large population of IgM+IgD+ post-GC memory B cells. Furthermore, the analysis revealed that a highly diverse and often very large population of memory B cells is generated from a given GC B cell clone, and that (preferentially IgM) memory B cells are generated already early in the GC reaction. This provides novel insights into the dynamics of GC reactions and the generation of a memory B cell repertoire.

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Napolitano, M., K. B. Seamon y W. J. Leonard. "Identification of cell surface receptors for the Act-2 cytokine." Journal of Experimental Medicine 172, n.º 1 (1 de julio de 1990): 285–89. http://dx.doi.org/10.1084/jem.172.1.285.

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We have identified cell surface receptors for Act-2, a secreted protein expressed upon activation of T cells, B cells, and monocytes. Although 125I-Act-2 showed little, if any, specific binding to resting peripheral blood lymphocytes (PBL) receptors were readily detected on PHA/PMA-activated PBL and a variety of cell lines including MT-2, HL60, DMSO differentiated HL60, HeLa, and K562 cells. The equilibrium dissociation constant (Kd) is 3-12 nM for MT-2, K562, and PBL activated with PHA/PMA for 40-80 h. We have also identified a rabbit polyclonal antiserum that can block Act-2 binding to its receptors. The ability to detect specific Act-2 receptors and the development of a blocking antiserum should prove valuable in efforts to molecularly clone the Act-2 receptor and to dissect the biological actions of Act-2.

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Lederman, S., M. J. Yellin, A. Krichevsky, J. Belko, J. J. Lee y L. Chess. "Identification of a novel surface protein on activated CD4+ T cells that induces contact-dependent B cell differentiation (help)." Journal of Experimental Medicine 175, n.º 4 (1 de abril de 1992): 1091–101. http://dx.doi.org/10.1084/jem.175.4.1091.

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CD4+ T lymphocytes provide contact-dependent stimuli to B cells that are critical for the generation of specific antibody responses in a process termed T helper function. The surface structures on activated CD4+ T cells that mediate this function are not fully known. We previously reported the isolation of a functionally unique subclone of the Jurkat leukemic T cell line (D1.1) that constitutively expressed contact-dependent helper effector function. To identify T cell surface molecules that mediate contact-dependent T helper function, a monoclonal antibody (mAb), designated 5c8, was generated that inhibits D1.1-mediated B cell activation and immunoprecipitates a novel 30-kD protein structure from surface-iodinated D1.1 cells. Normal CD4+ T cells express 5c8 antigen (Ag) transiently 5-6 h after activation by phorbol myristate acetate and phytohemagglutinin with maximal expression 5-6 h after activation and absence of expression by 24 h. In contrast, neither resting nor activated CD8+ T cells express 5c8 Ag. In functional studies, mAb 5c8 inhibits the ability of fixed, activated CD4+ T cells to induce B cell surface CD23 expression. In addition, mAb 5c8 inhibits the ability of CD4+ T cells to direct terminal B cell differentiation driven by pokeweed mitogen. Taken together, these data suggest that 5c8 Ag is a novel, activation-induced surface T cell protein that is involved in mediating a contact-dependent element of the helper effector function of CD4+ T lymphocytes.

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Pujiastuti, Yulia, Chandra Irsan, Siti Herlinda, Laila Kartini y Eka Yulistin. "Keanekaragaman dan pola keberadaan lalat buah (Diptera: Tephritidae) di Provinsi Sumatera Selatan". Jurnal Entomologi Indonesia 17, n.º 3 (11 de diciembre de 2020): 125. http://dx.doi.org/10.5994/jei.17.3.125.

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Fruit flies attack mostly on fruit vegetables and fresh consumed fruit. Symptoms of damage is decaying of fruit surface resulting to fruit falling. Data on the diversity of fruit fly species in South Sumatra and their patterns of presence have not been widely reported. The aim of the research was to study diversity and presence patterns of fruit flies based on the host and trap. The research was conducted using a survey method in 9 cities and districts in South Sumatra Province. Fruit flies were collected by collecting infected fruit and using traps containing cue lure (CL) and methyl eugenol (ME). There were 24 types of plants observed, including fruit, vegetables, and fruit for consumption. Fruit flies identification was carried out by observing external morphological characteristics. The identification resulted 18 species in which CL and ME trap 10 and 7 species, respectively. One species (Bactrocera latrifons) did not trapped in both traps. Among 18 species, 7 of them were obtained from fruit collections. The type of attractant affected species diversity and number of fruit flies caught. B. latifrons was only found in fruit rearing. The altitude of observation area affected fruit flies diversity. All species were found in the lowlands, except B. ascitus, B. cilifera, and B. latrifons. In the moderate lands and highlands, the number of fruit fly species found was less than in the lowlands.

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Kanamori, T., H. Inoue, Y. Iwata, Y. Ohmae y T. Kishi. "In Vivo Metabolism of 4-Bromo-2,5-dimethoxyphenethylamine (2C-B)in the Rat: Identification of Urinary Metabolites". Journal of Analytical Toxicology 26, n.º 2 (1 de marzo de 2002): 61–66. http://dx.doi.org/10.1093/jat/26.2.61.

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44

Laidlaw, Brian J., Timothy H. Schmidt, Jesse A. Green, Christopher D. C. Allen, Takaharu Okada y Jason G. Cyster. "The Eph-related tyrosine kinase ligand Ephrin-B1 marks germinal center and memory precursor B cells". Journal of Experimental Medicine 214, n.º 3 (31 de enero de 2017): 639–49. http://dx.doi.org/10.1084/jem.20161461.

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Identification of germinal center (GC) B cells is typically reliant on the use of surface activation markers that exhibit a wide range of expression. Here, we identify Ephrin-B1, a ligand for Eph-related receptor tyrosine kinases, as a specific marker of mature GC B cells. The number of Ephrin-B1+ GC B cells increases during the course of an immune response with Ephrin-B1+ GC B cells displaying elevated levels of Bcl6, S1pr2, and Aicda relative to their Ephrin-B1– counterparts. We further identified a small proportion of recently dividing, somatically mutated Ephrin-B1+ GC B cells that have begun to down-regulate Bcl6 and S1pr2 and express markers associated with memory B cells, such as CD38 and EBI2. Transcriptional analysis indicates that these cells are developmentally related to memory B cells, and likely represent a population of GC memory precursor (PreMem) B cells. GC PreMem cells display enhanced survival relative to bulk GC B cells, localize near the edge of the GC, and are predominantly found within the light zone. These findings offer insight into the significant heterogeneity that exists within the GC B cell population and provide tools to further dissect signals regulating the differentiation of GC B cells.

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Jacewicz, M., H. Clausen, E. Nudelman, A. Donohue-Rolfe y G. T. Keusch. "Pathogenesis of shigella diarrhea. XI. Isolation of a shigella toxin-binding glycolipid from rabbit jejunum and HeLa cells and its identification as globotriaosylceramide." Journal of Experimental Medicine 163, n.º 6 (1 de junio de 1986): 1391–404. http://dx.doi.org/10.1084/jem.163.6.1391.

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A glycolipid that specifically binds shigella toxin was isolated from both HeLa cells and rabbit jejunal mucosa and identified as globotriaosylceramide (Gb3) by its identical mobility on HPTLC to authentic erythrocyte Gb3. Toxin also bound to a band tentatively identified as alpha-hydroxylated Gb3. In addition, toxin bound to P1 antigen present in group B human erythrocyte glycolipid extracts. The common feature of the three binding glycolipids is a terminal Gal alpha 1----4Gal disaccharide linked beta 1----4 to either Glc or GlcNAc. Globoisotriaosylceramide, which differs from Gb3 only in possessing a Gal alpha 1----3Gal terminal disaccharide, and LacCer, which lacks the terminal Gal residue of Gb3, were incapable of binding the toxin. Binding was shown to be mediated by the B subunit by the use of isolated toxin A and B subunits and monoclonal subunit-specific antibodies. Gb3-containing liposomes competitively inhibited the binding of toxin to HeLa cell monolayers but did not inhibit toxin-induced cytotoxicity. These studies show an identical carbohydrate-specific glycolipid receptor for shigella toxin in gut and in HeLa cells. The toxin B subunit that mediates this binding has also been shown to recognize a glycoprotein receptor with different sugar specificity. Thus, we have demonstrated that the same small (Mr 6,500) B subunit polypeptide has two distinctive carbohydrate-specific binding sites. The Gal alpha 1----4Gal disaccharide of the glycolipid toxin receptor is also recognized by the Gal-Gal pilus of uropathogenic E. coli. This suggests the possibility that the pilus and toxin B subunit contain homologous sequences. If this is true, it may be possible to use the purified Gal-Gal pilus to produce toxin-neutralizing antibodies.

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Pon, Robert A., Michele Lussier, Qing-Ling Yang y Harold J. Jennings. "N-Propionylated Group B Meningococcal Polysaccharide Mimics a Unique Bactericidal Capsular Epitope in Group B Neisseria meningitidis". Journal of Experimental Medicine 185, n.º 11 (2 de junio de 1997): 1929–38. http://dx.doi.org/10.1084/jem.185.11.1929.

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The N-propionylated group B meningococcal polysaccharide (NPrGBMP) mimics a unique protective epitope on the surface of group B meningococci (GBM) and Escherichia coli K1. Using a series of monoclonal antibodies (mAbs) induced by the NPrGBMP–monomeric tetanus toxoid (TT) conjugate vaccine it was demonstrated that mAbs having specificities for both extended and conventional short segments of the NPrGBMP were formed, but only the former were bactericidal, and/or gave passive protection against live challenge by GBM. The failure of mAbs specific for short epitopes to protect was further established when (NeuPr)4–TT was used as the vaccine. Of all the mAbs produced that were specific for short internal segments of the NPrGBMP, none were protective, despite the fact that most of them cross-react with the GBM capsular polysaccharide. In contrast, most of the protective mAbs produced by NPrGBMP– TT did not recognize the group B meningococcal polysaccharide (GBMP) unless it was present in its aggregated high molecular weight form. The bactericidal epitope mimicked by the NPrGBMP was shown to be ubiquitous in the capsule of both GBM and E. coli K1 using immunogold labeling techniques and, because of its unique properties, its identification could be significant in the development of a comprehensive conjugate vaccine against group B meningococcal meningitis. This is because most known human α(2–8)-polysialic acid self-antigens can be accommodated in 30–50 α(2–8)-linked sialic acid residues, which is roughly equivalent to an 11-kD length of the GBMP. It has been hypothesized that the formation of the protective epitope on the surface of GBM is due to the interaction of helical segments of the GBMP with another molecule and that the protective epitope is mimicked by the NPrGBMP. Support for the above hypothesis is provided by the fact that the protective NPrGBMP epitope has a similar unusual length dependency to that of the GBMP epitope.

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Biancone, L., M. A. Bowen, A. Lim, A. Aruffo, G. Andres y I. Stamenkovic. "Identification of a novel inducible cell-surface ligand of CD5 on activated lymphocytes." Journal of Experimental Medicine 184, n.º 3 (1 de septiembre de 1996): 811–19. http://dx.doi.org/10.1084/jem.184.3.811.

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CD5 is a 67-kD glycoprotein that is expressed on most T lymphocytes and on a subset of mature B cells. Although its physiologic function is unknown, several lines of evidence suggest that CD5 may play a role in the regulation of T cell activation and in T cell-antigen presenting cell interactions. Using a CD5-immunoglobulin fusion protein (CD5Rg, for receptorglobulin) we have uncovered a new CD5 ligand (CD5L) expressed on the surface of activated splenocytes. Stimulation of murine splenocytes with anti-CD3 and anti-CD28 antibodies induce transient expression of CD5L on B lymphocytes that lasts for approximately 72 h. Binding of CD5Rg to activated splenocytes is trypsin resistant and independent of divalent cations. However, it is pronase sensitive and dependent on N-linked glycosylation of CD5, since treatment of CD5Rg with PNGaseF on N-glycanase completely abrogates its ability to bind activated splenocytes. It addition to splenocytes, CD5L is expressed on activated murine T cell clones. Immunoprecipitation, antibody, and recombinant protein blocking studies indicate that CD5L is distinct from CD72, which has been proposed to be a CD5 ligand. To determine whether CD5-CD5L interaction might play a role in vivo, we tested the effect of CD5Rg in a murine model of antibody-mediated membranous glomerulonephritis. Injection of CD5Rg was found to abrogate development of the disease. Taken together, our results help identify a novel ligand of CD5 and propose a role for CD5 in the regulation of immune responses.

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Guo, Y., Y. Wu, S. Shinde, M. S. Sy, A. Aruffo y Y. Liu. "Identification of a costimulatory molecule rapidly induced by CD40L as CD44H." Journal of Experimental Medicine 184, n.º 3 (1 de septiembre de 1996): 955–61. http://dx.doi.org/10.1084/jem.184.3.955.

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The interaction between CD40 ligand and CD40 is critical for activation of T and B cells in vivo. We have recently demonstrated that this interaction rapidly induces a novel costimulatory activity distinct from B7 and independent of CD28. To study the molecular basis of the costimulatory activity, we have produced a novel monoclonal antibody, TM-1, that binds an 85-kilodalton costimulatory molecule rapidly induced by CD40L. Expression cloning reveals that TM-1 binds CD44H. CD44H expressed on Chinese hamster ovary cells has potent costimulatory activity for clonal expansion of T cells isolated from both wild-type mice and these with a targeted mutation of CD28. Thus, CD44H costimulates T cell proliferation by a CD28-independent mechanism. These results revealed that CD44H is a costimulatory molecule rapidly induced by CD40L.

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Beisner, Daniel R., Petra Langerak, Albert E. Parker, Carol Dahlberg, Francella J. Otero, Sue E. Sutton, Laurent Poirot et al. "The intramembrane protease Sppl2a is required for B cell and DC development and survival via cleavage of the invariant chain". Journal of Experimental Medicine 210, n.º 1 (24 de diciembre de 2012): 23–30. http://dx.doi.org/10.1084/jem.20121072.

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B cell development requires tight regulation to allow for the generation of a diverse repertoire while preventing the development of autoreactive cells. We report, using N-ethyl-N-nitrosourea (ENU)–induced mutagenesis, the identification of a mutant mouse (chompB) with a block in early B cell development. The blockade occurs after the transitional 1 (T1) stage and leads to a decrease in mature B cell subsets and deficits in T cell–dependent antibody responses. Additionally, chompB mice have decreases in myeloid dendritic cells (DCs). The mutation was mapped to the intramembrane protease signal peptide peptidase-like 2a (Sppl2a), a gene not previously implicated in immune cell development. Proteomic analysis identified the invariant chain (CD74) as a key substrate of Sppl2a and suggests that regulated intramembrane proteolysis of CD74 by Sppl2a contributes to B cell and DC survival. Moreover, these data suggest that modulation of Sppl2a may be a useful therapeutic strategy for treatment of B cell dependent autoimmune disorders.

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Poon-King, R., J. Bannan, A. Viteri, G. Cu y J. B. Zabriskie. "Identification of an extracellular plasmin binding protein from nephritogenic streptococci." Journal of Experimental Medicine 178, n.º 2 (1 de agosto de 1993): 759–63. http://dx.doi.org/10.1084/jem.178.2.759.

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Examination of the extracellular products of nephritis(+) and nephritis(-) group A streptococci revealed the presence of a 46-kD protein secreted by nephritogenic strains that binds to human plasmin. Immunological data revealed that this protein, called nephritis plasmin binding protein (NPBP), is not related to group A streptokinase nor to a recently described streptococcal dehydrogenase protein. The binding of human plasmin to this protein can be blocked by epsilon-amino caproic acid, indicating the importance of lysine groups in the binding process. Mutanolysin extracts of cell walls from these nephritogenic strains probed with anti-NPBP antibody were negative for cell wall-bound NPBP. Serological data with acute poststreptococcal glomerulonephritis (APSGN) and acute rheumatic fever sera indicated that the protein reacts preferentially with APSGN sera. Amino acid sequence analysis and immunological reactivity suggest NPBP is the streptococcal pyrogenic exotoxin B precursor, also previously described as zymogen (streptococcal proteinase precursor). The secretion of both group A streptokinase and a secreted plasmin binding protein in the same nephritogenic strain raises an intriguing hypothesis of the mechanisms of action of this protein in APSGN.

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