Intersection of the complement and immune systems: a signal transduction complex of the B lymphocyte-containing complement receptor type 2 and CD19.

The complement system augments the humoral immune response, possibly by a mechanism that involves the B lymphocyte membrane receptor, CR2, which binds the C3dg fragment of C3 and triggers several B cell responses in vitro. The present study demonstrates that CR2 associates with a complex of membrane proteins that may mediate signal transduction by ligated CR2. Monoclonal antibodies to CR2 immunoprecipitated from digitonin lysates of Raji B lymphoblastoid cells a membrane complex containing CR2, approximately equimolar amounts of CD19, which is a member of the immunoglobulin superfamily, and three unidentified components: p130, p50, and p20. The complex, which was immunoprecipitated also with anti-CD19, could be dissociated by Nonidet P-40, accounting for its absence in previous studies of CR2. Expression of recombinant CR2 and CD19 in K562 erythroleukemia cells led to formation of a complex that contained not only these two proteins but also p130, p50, and p20, and another component, p14. These unidentified components of the CR2/CD19 complex coimmunoprecipitated with CD19 and not with CR2 from singly transfected cells, indicating primary association with the former. CD19 replicated the capacity of CR2 to interact synergistically with mIgM for increasing free intracellular Ca2+, suggesting that the complex mediates this function of CR2. Therefore, CR2 associates directly with CD19 to become a ligand-binding subunit of a pre-existing signal transduction complex of the B cell that may be representative of a family of membrane protein complexes. This interaction between the complement and immune systems differs from that between immunoglobulin and Clq by involving membrane rather than plasma proteins, and by having complement involved in the afferent phase of the immune response.

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Attenuation of Apoptosis Underlies B Lymphocyte Stimulator Enhancement of Humoral Immune Response

Journal of Experimental Medicine ◽

10.1084/jem.192.7.953 ◽

2000 ◽

Vol 192 (7) ◽

pp. 953-964 ◽

Cited By ~ 313

Author(s):

Richard K.G. Do ◽

Eunice Hatada ◽

Hayyoung Lee ◽

Michelle R. Tourigny ◽

David Hilbert ◽

...

Keyword(s):

Immune Response ◽

T Cell ◽

B Cells ◽

B Cell ◽

Cell Survival ◽

B Lymphocyte ◽

Humoral Immune ◽

B Cell Survival ◽

B Lymphocyte Stimulator

B lymphocyte stimulator (BLyS) is a newly identified monocyte-specific TNF family cytokine. It has been implicated in the development of autoimmunity, and functions as a potent costimulator with antiimmunoglobulin M in B cell proliferation in vitro. Here we demonstrate that BLyS prominently enhances the humoral responses to both T cell–independent and T cell–dependent antigens, primarily by attenuation of apoptosis as evidenced by the prolonged survival of antigen-activated B cells in vivo and in vitro. BLyS acts on primary splenic B cells autonomously, and directly cooperates with CD40 ligand (CD40L) in B cell activation in vitro by protecting replicating B cells from apoptosis. Moreover, although BLyS alone cannot activate the cell cycle, it is sufficient to prolong the survival of naive resting B cells in vitro. Attenuation of apoptosis by BLyS correlates with changes in the ratios between Bcl-2 family proteins in favor of cell survival, predominantly by reducing the proapoptotic Bak and increasing its prosurvival partners, Bcl-2 and Bcl-xL. In either resting or CD40L-activated B cells, the NF-κB transcription factors RelB and p50 are specifically activated, suggesting that they may mediate BLyS signals for B cell survival. Together, these results provide direct evidence for BLyS enhancement of both T cell–independent and T cell–dependent humoral immune responses, and imply a role for BLyS in the conservation of the B cell repertoire. The ability of BLyS to increase B cell survival indiscriminately, at either a resting or activated state, and to cooperate with CD40L, further suggests that attenuation of apoptosis underlies BLyS enhancement of polyclonal autoimmunity as well as the physiologic humoral immune response.

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Monoclonal antibodies to the 140,000 mol wt glycoprotein of B lymphocyte membranes (CR2 receptor) initiates proliferation of B cells in vitro

Blood ◽

10.1182/blood.v66.4.824.bloodjournal664824 ◽

1985 ◽

Vol 66 (4) ◽

pp. 824-829

Author(s):

BS Wilson ◽

JL Platt ◽

NE Kay

Keyword(s):

Monoclonal Antibodies ◽

B Cells ◽

B Cell ◽

Peripheral Blood ◽

B Lymphocyte ◽

Human Peripheral Blood ◽

Raji Cell ◽

Lymphoid Cells ◽

Humoral Immune

Several mouse monoclonal IgG antibodies (AB1, AB2, AB3, and AB5) were developed that reacted with a 140,000 mol wt glycoprotein on the surface of cultured RAJI B lymphoid cells. The antibodies reacted with purified normal human peripheral blood B cells and CLL Ig+ B cells and showed specific germinal center and mantle zone staining in tissue sections of secondary lymphoid organs. Immunodepletion studies using 125I surface-labeled Raji cell membrane antigens demonstrated that the antigen identified by AB5 is the same 140,000 mol wt glycoprotein detected by anti-B2 that has recently been shown to react with the C3d fragment or CR2 receptor. (Iida et al: J Exp Med 158:1021, 1983). Addition of the AB series and anti-B2 monoclonal antibodies to cultures of purified human peripheral blood B cells resulted in the uptake of 3H- thymidine at two to six times background control levels provided that irradiated autologous T cells were added to the culture. Stimulation was not evoked by other monoclonal antibodies to B cell surface molecules (ie, B1, BA-1, BA-2, and HLA-DR). Pepsin-generated F(ab')2 fragments of anti-CR2 antibodies were essentially as effective as the intact IgG molecule in stimulating B cells. Induction of B cell proliferation by antibody binding to CR2 suggests that the C3d receptor may have an integral role in regulation of humoral immune response.

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Monoclonal antibodies to the 140,000 mol wt glycoprotein of B lymphocyte membranes (CR2 receptor) initiates proliferation of B cells in vitro

Blood ◽

10.1182/blood.v66.4.824.824 ◽

1985 ◽

Vol 66 (4) ◽

pp. 824-829 ◽

Cited By ~ 53

Author(s):

BS Wilson ◽

JL Platt ◽

NE Kay

Keyword(s):

Monoclonal Antibodies ◽

B Cells ◽

B Cell ◽

Peripheral Blood ◽

B Lymphocyte ◽

Human Peripheral Blood ◽

Raji Cell ◽

Lymphoid Cells ◽

Humoral Immune

Abstract Several mouse monoclonal IgG antibodies (AB1, AB2, AB3, and AB5) were developed that reacted with a 140,000 mol wt glycoprotein on the surface of cultured RAJI B lymphoid cells. The antibodies reacted with purified normal human peripheral blood B cells and CLL Ig+ B cells and showed specific germinal center and mantle zone staining in tissue sections of secondary lymphoid organs. Immunodepletion studies using 125I surface-labeled Raji cell membrane antigens demonstrated that the antigen identified by AB5 is the same 140,000 mol wt glycoprotein detected by anti-B2 that has recently been shown to react with the C3d fragment or CR2 receptor. (Iida et al: J Exp Med 158:1021, 1983). Addition of the AB series and anti-B2 monoclonal antibodies to cultures of purified human peripheral blood B cells resulted in the uptake of 3H- thymidine at two to six times background control levels provided that irradiated autologous T cells were added to the culture. Stimulation was not evoked by other monoclonal antibodies to B cell surface molecules (ie, B1, BA-1, BA-2, and HLA-DR). Pepsin-generated F(ab')2 fragments of anti-CR2 antibodies were essentially as effective as the intact IgG molecule in stimulating B cells. Induction of B cell proliferation by antibody binding to CR2 suggests that the C3d receptor may have an integral role in regulation of humoral immune response.

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Wiskott-Aldrich syndrome protein deficiency leads to reduced B-cell adhesion, migration, and homing, and a delayed humoral immune response

Blood ◽

10.1182/blood-2004-03-1003 ◽

2005 ◽

Vol 105 (3) ◽

pp. 1144-1152 ◽

Cited By ~ 91

Author(s):

Lisa Westerberg ◽

Malin Larsson ◽

Samantha J. Hardy ◽

Carmen Fernández ◽

Adrian J. Thrasher ◽

...

Keyword(s):

Immune Response ◽

B Cells ◽

B Cell ◽

Humoral Immune Response ◽

Wiskott Aldrich Syndrome ◽

Humoral Immune ◽

Germinal Center Reaction ◽

Syndrome Protein ◽

Deficient Mice

Abstract The Wiskott-Aldrich syndrome protein (WASp) is mutated in the severe immunodeficiency disease Wiskott-Aldrich syndrome (WAS). The function of B cells and the physiologic alterations in WAS remain unclear. We show that B cells from WAS patients exhibited decreased motility and had reduced capacity to migrate, adhere homotypically, and form long protrusions after in vitro culture. WASp-deficient murine B cells also migrated less well to chemokines. Upon antigen challenge, WASp-deficient mice mounted a reduced and delayed humoral immune response to both T-cell–dependent and –independent antigens. This was at least in part due to deficient migration and homing of B cells. In addition, the germinal center reaction was reduced in WASp-deficient mice. Thus, WASp is crucial for optimal B-cell responses and plays a pivotal role in the primary humoral immune response.

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The effect of carbohydrate moiety structure on the immunoregulatory activity of lactoferrin in vitro

Cellular & Molecular Biology Letters ◽

10.2478/s11658-014-0196-2 ◽

2014 ◽

Vol 19 (2) ◽

Cited By ~ 7

Author(s):

Michał Zimecki ◽

Jolanta Artym ◽

Maja Kocięba ◽

Maria Duk ◽

Marian Kruzel

Keyword(s):

Immune Response ◽

In Vitro Models ◽

Immunoglobulin Superfamily ◽

Glycan Structure ◽

Bovine Lactoferrin ◽

Mouse Splenocytes ◽

Humoral Immune ◽

Sialic Acid Receptors ◽

Complex Glycan

AbstractThe aim of this study was to evaluate the immunoregulatory effects of recombinant human lactoferrin (rhLF) in two in vitro models: (1) the secondary humoral immune response to sheep erythrocytes (SRBC); and (2) the mixed lymphocyte reaction (MLR). We compared the non-sialylated glycoform of rhLF as expressed by glycoengineered Pichia pastoris with one that was further chemically sialylated. In an earlier study, we showed that sialylated rhLF could reverse methotrexate-induced suppression of the secondary immune response of mouse splenocytes to SRBC, and that the phenomenon is dependent on the interaction of lactoferrin (LF) with sialoadhesin (CD169). We found that the immunorestorative activity of sialylated rhLF is also dependent on its interaction with the CD22 antigen, a member of the immunoglobulin superfamily that is expressed by B lymphocytes. We also demonstrated that only sialylated rhLF was able to inhibit the MLR reaction. MLR was inhibited by bovine lactoferrin (bLF), a glycoform that has a more complex glycan structure. Desialylated bLF and lactoferricin, a bLF-derived peptide devoid of carbohydrates, did not express such inhibitory activity. We showed that the interaction of LF with sialic acid receptors is essential for at least some of the immunoregulatory activity of this glycoprotein.

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Role of CXCL5 in Regulating Chemotaxis of Innate and Adaptive Leukocytes in Infected Lungs Upon Pulmonary Influenza Infection

Frontiers in Immunology ◽

10.3389/fimmu.2021.785457 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lei Guo ◽

Nan Li ◽

Zening Yang ◽

Heng Li ◽

Huiwen Zheng ◽

...

Keyword(s):

Immune Response ◽

Influenza Virus ◽

Virus Infection ◽

B Cell ◽

B Lymphocyte ◽

Influenza Infection ◽

Influenza Virus Infection ◽

Neutrophil Infiltration ◽

Cell Immune Response

Respirovirus such as influenza virus infection induces pulmonary anti-viral immune response, orchestration of innate and adaptive immunity restrain viral infection, otherwise causes severe diseases such as pneumonia. Chemokines regulate leukocyte recruitment to the inflammation site. One chemokine CXCL5, plays a scavenging role to regulate pulmonary host defense against bacterial infection, but its role in pulmonary influenza virus infection is underdetermined. Here, using an influenza (H1N1) infected CXCL5-/- mouse model, we found that CXCL5 not only responds to neutrophil infiltration into infected lungs at the innate immunity stage, but also affects B lymphocyte accumulation in the lungs by regulating the expression of the B cell chemokine CXCL13. Inhibition of CXCL5-CXCR2 axis markedly induces CXCL13 expression in CD64+CD44hiCD274hi macrophages/monocytes in infected lungs, and in vitro administration of CXCL5 to CD64+ alveolar macrophages suppresses CXCL13 expression via the CXCL5-CXCR2 axis upon influenza challenge. CXCL5 deficiency leads to increased B lymphocyte accumulation in infected lungs, contributing to an enhanced B cell immune response and facilitating induced bronchus-associated lymphoid tissue formation in the infected lungs during the late infection and recovery stages. These data highlight multiple regulatory roles of CXCL5 in leukocyte chemotaxis during pulmonary influenza infection.

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Plasmodium vivax Cell-Traversal Protein for Ookinetes and Sporozoites: Naturally Acquired Humoral Immune Response and B-Cell Epitope Mapping in Brazilian Amazon Inhabitants

Frontiers in Immunology ◽

10.3389/fimmu.2017.00077 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 8

Author(s):

Rodrigo Nunes Rodrigues-da-Silva ◽

Isabela Ferreira Soares ◽

Cesar Lopez-Camacho ◽

João Hermínio Martins da Silva ◽

Daiana de Souza Perce-da-Silva ◽

...

Keyword(s):

Immune Response ◽

B Cell ◽

Plasmodium Vivax ◽

Humoral Immune Response ◽

Epitope Mapping ◽

Cell Epitope ◽

Brazilian Amazon ◽

Humoral Immune ◽

B Cell Epitope

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Fetal liver pro-B and pre-B lymphocyte clones: expression of lymphoid-specific genes, surface markers, growth requirements, colonization of the bone marrow, and generation of B lymphocytes in vivo and in vitro

Molecular and Cellular Biology ◽

10.1128/mcb.12.2.518-530.1992 ◽

1992 ◽

Vol 12 (2) ◽

pp. 518-530

Author(s):

R Palacios ◽

J Samaridis

Keyword(s):

B Cell ◽

B Lymphocytes ◽

Stromal Cells ◽

B Lymphocyte ◽

Germ Line ◽

Fetal Liver ◽

Rag 1 ◽

B Cell Precursors

We describe here the development and characterization of the FLS4.1 stromal line derived from 15-day fetal liver of BALB/c embryos and defined culture conditions that efficiently support the cloning and long-term growth of nontransformed B-220+ 14-day fetal liver cells at two stages of B-cell development, namely, pro-B lymphocytes (immunoglobulin [Ig] genes in germ line configuration) and pre-B cells (JH-rearranged genes with both light-chain Ig genes in the germ line state). All B-cell precursor clones require recombinant interleukin-7 (rIL-7) and FLS4.1 stromal cells for continuous growth in culture, but pro-B lymphocyte clones can also proliferate in rIL-3. None proliferate in rIL-1, rIL-2, rIL-4, rIL-5, rIL-6, or leukemia inhibitory factor. FLS4.1 stromal cells synthesize mRNA for Steel factor but not for IL-1 to IL-7; all pro-B and pre-B clones express c-Kit, the receptor for Steel factor, and a c-Kit-specific antibody inhibits the enhanced proliferative response of fetal liver B-220+ B-cell precursors supported by FLS4.1 stromal cells and exogenous rIL-7 but does not affect that promoted by rIL-7 alone. Northern (RNA) blot analysis of the expression of the MB-1, lambda 5, Vpre-B, c mu, RAG-1, and RAG-2 genes in pro-B and pre-B clones show that transcription of the MB-1 gene precedes IgH gene rearrangement and RNA synthesis from c mu, RAG-1, RAG-2, lambda 5, and Vpre-B genes. All clones at the pre-B-cell stage synthesize mRNA for c mu, RAG-1, and RAG-2 genes; transcription of the lambda 5 and Vpre-B genes seems to start after D-to-JH rearrangement in B-cell precursors, indicating that the proteins encoded by either gene are not required for B-cell progenitors to undergo D-to-JH gene rearrangement. These findings mark transcription of the MB-1 gene as one of the earliest molecular events in commitment to develop along the B-lymphocyte pathway. Indeed, both pro-B and pre-B clones can generate in vitro and in vivo B lymphocytes but not T lymphocytes; moreover, these clones do not express the CD3-gamma T-cell-specific gene, nor do they have rearranged gamma, delta, or beta T-cell antigen receptor genes.

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Babesia bovis RON2 contains conserved B-cell epitopes that induce an invasion-blocking humoral immune response in immunized cattle

Parasites & Vectors ◽

10.1186/s13071-018-3164-2 ◽

2018 ◽

Vol 11 (1) ◽

Cited By ~ 5

Author(s):

Mario Hidalgo-Ruiz ◽

Carlos E. Suarez ◽

Miguel A. Mercado-Uriostegui ◽

Ruben Hernandez-Ortiz ◽

Juan Alberto Ramos ◽

...

Keyword(s):

Immune Response ◽

B Cell ◽

Humoral Immune Response ◽

Babesia Bovis ◽

B Cell Epitopes ◽

Humoral Immune

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In vitro immunization approach to generate specific murine monoclonal IgG antibodies

10.1101/2020.11.24.393728 ◽

2020 ◽

Author(s):

Sophia Michelchen ◽

Burkhard Micheel ◽

Katja Hanack

Keyword(s):

Monoclonal Antibodies ◽

Legionella Pneumophila ◽

B Lymphocyte ◽

Laboratory Animals ◽

Igg Antibody ◽

Simplified Approach ◽

Humoral Immune ◽

Viral Coat

AbstractGenerating monoclonal antibodies to date is a time intense process requiring immunization of laboratory animals. The transfer of the humoral immune response into in vitro settings shortens this process and circumvents the necessity of animal immunization. However, orchestrating the complex interplay of immune cells in vitro is very challenging. We aimed for a simplified approach focusing on the protagonist of antibody production: the B lymphocyte. We activated purified murine B lymphocytes in vitro with combinations of antigen and stimuli. Within ten days of culture we induced specific IgM and IgG antibody responses against a viral coat protein. Permanently antibody-producing hybridomas were generated. Furthermore we used this method to induce a specific antibody response against Legionella pneumophila. We thus established an effective protocol to generate monoclonal antibodies in vitro. By overcoming the necessity of in vivo immunization it may be the first step towards a universal strategy to generate antibodies from various species.

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