scholarly journals Extract of Nippostrongylus brasiliensisStimulates Polyclonal Type-2 Immunoglobulin Response by Inducing De Novo Class Switch

2000 ◽  
Vol 68 (9) ◽  
pp. 4913-4922 ◽  
Author(s):  
Humphrey N. Ehigiator ◽  
Andrew W. Stadnyk ◽  
Timothy D. G. Lee
Keyword(s):  
B Cells ◽  
De Novo ◽  
Immunoglobulin E ◽  
T Cell Response ◽  
In Vitro Cultures ◽  
Interleukin 4 ◽  
Nippostrongylus Brasiliensis ◽  
Class Switch

ABSTRACT Infection with the nematode parasite Nippostrongylus brasiliensis induces a pronounced type-2 T-cell response that is associated with marked polyclonal immunoglobulin E (IgE) and IgG1 production in mice. To examine the differential roles of the infection and products produced by nematodes, we investigated a soluble extract of N. brasiliensis for the ability to mediate this type-2 response. We found that the extract induced a marked increase in IgE and IgG1 levels, similar to that induced by the infection. The extract did not affect the level of IgG2a in serum, showing that the effect was specific to IgE and IgG1 (type-2-associated immunoglobulin) rather than inducing a nonspecific increase in all immunoglobulin isotypes. This response was also associated with increased interleukin-4 production in vitro. These results confirm that the extract, like infection, is a strong inducer of polyclonal type-2 responses and a reliable model for investigating the regulation of nematode-induced responses. The extract induced the production of IgG1 when added to in vitro cultures of lipopolysaccharide-stimulated B cells. This provides evidence for the induction of class switch. It did not induce upregulation of IgG1 in naive (unstimulated) B cells or expand B cells in in vitro cultures. Analysis of DNA from the spleens of mice treated with the extract by digestion-circularization PCR demonstrated a marked increase in the occurrence of γ1 switch region gene recombination in the cells in vivo. These results provide strong evidence that soluble worm products are able to mediate the marked polyclonal γ1/ɛ response and that infection is not required to mediate this response. Furthermore, these data provide evidence that the soluble nematode extract induces this effect by causing de novo class switch of B cells and not by an expansion of IgG1 B cells or an increase in antibody production by IgG1 plasma cells.

Cultured Human B Cell APCs Expanded Using Il-4 and CD40 Ligand Preferentially Promote a Type 2 T Cell Response to Alloimmune Stimulation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2668-2668
Author(s):  
Abdul Tawab ◽  
Yoshiyuki Takahashi ◽  
Childs Richard ◽  
Kurlander J. Roger
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Response ◽  
Cd40 Ligand ◽  
T Cell Response ◽  
Ifn Γ

Abstract In vitro stimulation of human peripheral blood B cells with recombinant IL-4 and CD40 ligand (CD40L) markedly increases their expression of MHC and costimulatory molecules, thus enhancing antigenic peptide presentation to T cells. Because these cells proliferate extensively in vitro (unlike monocytes or dendritic cells), they represent a promising and convenient reagent for the generation and maintenance of antigen-specific T cells for use in a variety of experimental or therapeutic settings. However, the impact of this type of B cell APC on cytokine production by responder T cells has hitherto not been examined. To address this issue, we stimulated normal human T cells with either allogeneic B cells (generated in vitro) or with MNCs obtained from the same donor. After 7 days, T cells were washed and re-challenged with the same APCs. The resulting alloreactive cytokine response was measured using quantitative ELISPOT methods and expressed as the frequencies of IFN-γ, IL-4, and IL-5 producing cells per thousand responder cells added. B cell- and MNC-primed cell lines both produced vigorous lymphokine responses, but B cell-stimulated T cells consistently produced more IL-5 spots (mean of 265 vs. 98/1000 responders, p<0.002) and fewer IFN-γ spots (163 vs 386/1000 cells, p<0.005) than MNC-stimulated cells. Further, the ratio of IFN-γ to IL-5 spots was almost ten-fold lower in B cell-stimulated cultures compared to MNC-induced cultures (0.67 vs. 5.2, p<0.001). ELISPOT studies assessing the ratio of IFN-γ to IL-4 spots and ELISA assays comparing IFN-γ and IL-5 levels from culture supernatants demonstrated the same pattern of marked type 2 skewing by B cells. This pattern was unaffected by the presence of anti-IL-4 antibody suggesting type 2 skewing was not mediated by IL-4. Cytokine skewing produced by B cells or MNC could be partially reversed by swapping MNC and B cells during re-stimulation on day 7, but this plasticity was markedly reduced after 3 (weekly) cycles of B cell or MNC re-stimulation in vitro. Type 2 skewing by B cells was enhanced when monocytes were removed from responder T cell populations by either depleting CD14+ positive cells or by positive selection of T cells prior to stimulation. In contrast, type 2 polarization could be prevented using recombinant IL-12. Not all cells of B-cell origin share the same propensity to type 2 skewing observed with IL-4/CD40L-stimulated B cells; under identical conditions, EBV-transformed B cells stimulated alloimmune T cells to produce a strong type 1 cytokine response comparable to that produced by MNCs. In summary, IL-4/CD40L-stimulated B cells strongly promote a type 2 T cell response during primary alloimmune challenge; this skewing can become fixed after repeated B cell stimulation. Investigators using these cells as APC should be aware of this potential phenomenon, particularly during primary T cell responses. It is also important to consider the factors described above that may exacerbate or ameliorate this effect.

scholarly journals ILC2s regulate adaptive Th2 cell functions via PD-L1 checkpoint control

2017 ◽  
Vol 214 (9) ◽  
pp. 2507-2521 ◽  
Author(s):  
Christian Schwartz ◽  
Adnan R. Khan ◽  
Achilleas Floudas ◽  
Sean P. Saunders ◽  
Emily Hams ◽  
...  
Keyword(s):  
T Cell Response ◽  
Lymphoid Cells ◽  
Th2 Cells ◽  
Nippostrongylus Brasiliensis ◽  
Checkpoint Control ◽  
T Helper ◽  
Inhibitor Molecule ◽  
Cell Functions

Group 2 innate lymphoid cells (ILC2s) are important effector cells driving the initiation of type 2 immune responses leading to adaptive T helper 2 (Th2) immunity. Here we show that ILC2s dynamically express the checkpoint inhibitor molecule PD-L1 during type 2 pulmonary responses. Surprisingly, PD-L1:PD-1 interaction between ILC2s and CD4+ T cells did not inhibit the T cell response, but PD-L1–expressing ILC2s stimulated increased expression of GATA3 and production of IL-13 by Th2 cells both in vitro and in vivo. Conditional deletion of PD-L1 on ILC2s impaired early Th2 polarization and cytokine production, leading to delayed worm expulsion during infection with the gastrointestinal helminth Nippostrongylus brasiliensis. Our results identify a novel PD-L1–controlled mechanism for type 2 polarization, with ILC2s mediating an innate checkpoint to control adaptive T helper responses, which has important implications for the treatment of type 2 inflammation.

scholarly journals Transcriptional Repression of Stat6-Dependent Interleukin-4-Induced Genes by BCL-6: Specific Regulation of Iɛ Transcription and Immunoglobulin E Switching

1999 ◽  
Vol 19 (10) ◽  
pp. 7264-7275 ◽  
Author(s):  
Miera B. Harris ◽  
Chih-Chao Chang ◽  
Michael T. Berton ◽  
Nika N. Danial ◽  
Jandong Zhang ◽  
...  
Keyword(s):  
B Cells ◽  
Target Genes ◽  
Germ Line ◽  
Immunoglobulin E ◽  
Interleukin 4 ◽  
Target Sequence ◽  
Class Switching ◽  
Mobility Shift ◽  
Specific Regulation

ABSTRACT The BCL-6 proto-oncogene encodes a POZ/zinc-finger transcription factor that is expressed in B cells and a subset of CD4+ T cells within germinal centers. Recent evidence suggests that BCL-6 can act as a sequence-specific repressor of transcription, but the target genes for this activity have not yet been identified. The binding site for BCL-6 shares striking homology to the sites that are the target sequence for the interleukin-4 (IL-4)-induced Stat6 (signal transducers and activators of transcription) signaling molecule. Electrophoretic mobility shift assays demonstrate that BCL-6 can bind, with different affinities, to several DNA elements recognized by Stat6. Expression of BCL-6 can repress the IL-4-dependent induction of immunoglobulin (Ig) germ line ɛ transcripts, but does not repress the IL-4 induction of CD23 transcripts. Consistent with the role of BCL-6 in modulating transcription from the germ line ɛ promoter, BCL-6−/−mice display an increased ability to class switch to IgE in response to IL-4 in vitro. These animals also exhibit a multiorgan inflammatory disease characterized by the presence of a large number of IgE+ B cells. The apparent dysregulation of IgE production is abolished in BCL-6−/− Stat6−/− mice, indicating that BCL-6 regulation of Ig class switching is dependent upon Stat6 signaling. Thus, BCL-6 can modulate the transcription of selective Stat6-dependent IL-4 responses, including IgE class switching in B cells.

scholarly journals B Cell Receptor–independent Stimuli Trigger Immunoglobulin (Ig) Class Switch Recombination and Production of IgG Autoantibodies by Anergic Self-Reactive B Cells

2003 ◽  
Vol 197 (7) ◽  
pp. 845-860 ◽  
Author(s):  
Tri Giang Phan ◽  
Michelle Amesbury ◽  
Sandra Gardam ◽  
Jeffrey Crosbie ◽  
Jhagvaral Hasbold ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Systemic Infection ◽  
Cell Receptor ◽  
Gene Replacement ◽  
B Cell Receptor ◽  
Interleukin 4 ◽  
Isotype Switching ◽  
Class Switch

In both humans and animals, immunoglobulin (Ig)G autoantibodies are less frequent but more pathogenic than IgM autoantibodies, suggesting that controls over Ig isotype switching are required to reinforce B cell self-tolerance. We have used gene targeting to produce mice in which hen egg lysozyme (HEL)-specific B cells can switch to all Ig isotypes (SWHEL mice). When crossed with soluble HEL transgenic (Tg) mice, self-reactive SWHEL B cells became anergic. However, in contrast to anergic B cells from the original nonswitching anti-HEL × soluble HEL double Tg model, self-reactive SWHEL B cells also displayed an immature phenotype, reduced lifespan, and exclusion from the splenic follicle. These differences were not related to their ability to Ig class switch, but instead to competition with non-HEL–binding B cells generated by VH gene replacement in SWHEL mice. When activated in vitro with B cell receptor (BCR)-independent stimuli such as anti-CD40 monoclonal antibody plus interleukin 4 or lipopolysaccharide (LPS), anergic SWHEL double Tg B cells proliferated and produced IgG anti-HEL antibodies as efficiently as naive HEL-binding B cells from SWHEL Ig Tg mice. These results demonstrate that no intrinsic constraints to isotype switching exist in anergic self-reactive B cells. Instead, production of IgG autoantibodies is prevented by separate controls that reduce the likelihood of anergic B cells encountering BCR-independent stimuli. That bacteria-derived LPS could circumvent these controls may explain the well-known association between autoantibody-mediated diseases and episodes of systemic infection.

Impaired Ig class switch in mice deficient for the X-linked lymphoproliferative disease gene Sap

Blood ◽  
2005 ◽  
Vol 106 (6) ◽  
pp. 2069-2075 ◽  
Author(s):  
Umaima Al-Alem ◽  
Cuiling Li ◽  
Nathalie Forey ◽  
Francis Relouzat ◽  
Marie-Claude Fondanèche ◽  
...  
Keyword(s):  
B Cells ◽  
Natural Killer ◽  
Viral Infections ◽  
Immunoglobulin E ◽  
Lymphoproliferative Disease ◽  
Interleukin 4 ◽  
Barr Virus ◽  
Epstein Barr ◽  
Deficient Mice

Abstract X-linked lymphoproliferative disease (XLP) is characterized by abnormal immune responses to Epstein-Barr virus attributed to inactivating mutations of the SAP gene. Previous studies showed immunoglobulin E (IgE) deficiency and low serum IgG levels in Sap-deficient mice before and after viral infections, which are associated with impaired CD4+ T-helper function. In the present work, we find that signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) is expressed in B cells and this expression is down-regulated after stimulation with lipopolysaccharide (LPS) and interleukin 4 (IL-4). We demonstrate that B cells from Sap-deficient mice exhibit reduced IgG and IgA production in vitro. This impairment correlates with decreased circular transcript levels of Iα, Iγ2a, Iγ2b, and Iγ3 after stimulation, which indicate a defective Ig switch recombination in Sap-deficient B cells. While XLP is believed to cause defects in T, natural killer T (NKT), and natural killer (NK) cells, our results indicate that B cells are also affected. (Blood. 2005;106:2069-2075)

scholarly journals Stereotypic neutralizing VH antibodies against SARS-CoV-2 spike protein receptor binding domain in COVID-19 patients and healthy individuals

2021 ◽  
pp. eabd6990
Author(s):  
Sang Il Kim ◽  
Jinsung Noh ◽  
Sujeong Kim ◽  
Younggeun Choi ◽  
Duck Kyun Yoo ◽  
...  
Keyword(s):  
B Cells ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
De Novo ◽  
Binding Domain ◽  
Host Cells ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Healthy Individuals

Stereotypic antibody clonotypes exist in healthy individuals and may provide protective immunity against viral infections by neutralization. We observed that 13 out of 17 patients with COVID-19 had stereotypic variable heavy chain (VH) antibody clonotypes directed against the receptor-binding domain (RBD) of SARS-CoV-2 spike protein. These antibody clonotypes were comprised of immunoglobulin heavy variable (IGHV)3-53 or IGHV3-66 and immunoglobulin heavy joining (IGHJ)6 genes. These clonotypes included IgM, IgG3, IgG1, IgA1, IgG2, and IgA2 subtypes and had minimal somatic mutations, which suggested swift class switching after SARS-CoV-2 infection. The different immunoglobulin heavy variable chains were paired with diverse light chains resulting in binding to the RBD of SARS-CoV-2 spike protein. Human antibodies specific for the RBD can neutralize SARS-CoV-2 by inhibiting entry into host cells. We observed that one of these stereotypic neutralizing antibodies could inhibit viral replication in vitro using a clinical isolate of SARS-CoV-2. We also found that these VH clonotypes existed in six out of 10 healthy individuals, with IgM isotypes predominating. These findings suggest that stereotypic clonotypes can develop de novo from naïve B cells and not from memory B cells established from prior exposure to similar viruses. The expeditious and stereotypic expansion of these clonotypes may have occurred in patients infected with SARS-CoV-2 because they were already present.

scholarly journals Tumor-Released Survivin Induces a Type-2 T Cell Response and Decreases Cytotoxic T Cell Function, in Vitro

2012 ◽  
Vol 6 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Jessica M. S. Jutzy ◽  
Salma Khan ◽  
Malyn May Asuncion-Valenzuela ◽  
Terry-Ann M. Milford ◽  
Kimberly J. Payne ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
Cell Function ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
T Cell Function

scholarly journals B lymphocyte binding to E- and P-selectins is mediated through the de novo expression of carbohydrates on in vitro and in vivo activated human B cells.

1994 ◽  
Vol 94 (4) ◽  
pp. 1585-1596 ◽  
Author(s):  
A A Postigo ◽  
M Marazuela ◽  
F Sánchez-Madrid ◽  
M O de Landázuri
Keyword(s):  
B Cells ◽  
B Lymphocyte ◽  
De Novo ◽  
Human B Cells

scholarly journals Mapping of a Functional Recombination Motif that Defines Isotype Specificity for μ→γ3 Switch Recombination Implicates NF-κB p50 as the Isotype-specific Switching Factor

2004 ◽  
Vol 199 (5) ◽  
pp. 617-627 ◽  
Author(s):  
Amy L. Kenter ◽  
Robert Wuerffel ◽  
Carmen Dominguez ◽  
Ananth Shanmugam ◽  
Hongmei Zhang
Keyword(s):  
B Cells ◽  
Binding Site ◽  
Class Switch Recombination ◽  
Interleukin 4 ◽  
Specific Factor ◽  
Wild Type ◽  
Class Switch ◽  
Activation Induced Deaminase ◽  
Necessary And Sufficient

Ig class switch recombination (CSR) requires expression of activation-induced deaminase (AID) and production of germline transcripts to target S regions for recombination. However, the mechanism of CSR remains unclear. Here we show that an extrachromosomal S plasmid assay is AID dependent and that a single consensus repeat is both necessary and sufficient for isotype-specific CSR. Transfected switch substrates specific for μ→γ3 and μ→γ1 are stimulated to switch with lipopolysaccharide (LPS) alone or LPS and interleukin-4, respectively. An Sγ3/Sγ1 substrate containing only three Sγ3-associated nucleotides reconstituted LPS responsiveness and permitted mapping of a functional recombination motif specific for μ→γ3 CSR. This functional recombination motif colocalized with a binding site for NF-κB p50, and p50 binding to this site was previously established. We show a p50 requirement for plasmid-based μ→γ3 CSR using p50-deficient B cells. Switch junctions from p50-deficient B cells showed decreased lengths of microhomology between Sμ and Sγ3 relative to wild-type cells, indicating a function for p50 in the mechanics of CSR. We note a striking parallel between the affects of p50 and Msh2 deficiency on Sμ/Sγ3 junctions. The data suggest that p50 may be the isotype-specific factor in μ→γ3 CSR and epistatic with Msh2.

scholarly journals CD1c but neither CD1a nor CD1b molecules are expressed on normal, activated, and malignant human B cells: identification of a new B-cell subset

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 241-247 ◽  
Author(s):  
D Delia ◽  
G Cattoretti ◽  
N Polli ◽  
E Fontanella ◽  
A Aiello ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
De Novo ◽  
Cell Subset ◽  
Ultrastructural Level ◽  
Cytoplasmic Staining ◽  
Clear Cut ◽  
Hodgkin's Lymphomas

Abstract The CD1 cluster of monoclonal antibodies (MoAbs) CD1a, CD1b, and CD1c, identifies molecules that are differentially expressed on hematopoietic and nonhematopoietic tissues. Our earlier finding that the mantle zone (MZ) but not the germinal center (GC) of normal lymph nodes (LN) is CD1c+, CD1a-, and CD1b- prompted us to further investigate the expression of these molecules on normal, activated, and malignant B cells. We report that blood and spleen contain CD1c+ B cells that account for 49% +/- 20.4% (mean +/- SD) and 50.9% +/- 4.4% of the total B cell population, respectively. CD1a- and CD1b-specific MoAbs are unreactive with both B and T cells; these latter are CD1c- as well. When CD1c+ and CD1c- B cells are activated in vitro, the CD1c molecule is upregulated in the former subset and induced de novo in the latter. Conversely, activated blood T cells remain CD1c-. Neither CD1a nor CD1b molecules are detected on activated T and B lymphocytes. At ultrastructural level, the CD1c+ B cells exhibit distinctive features, namely, condensed chromatin with or without a nucleolus and a unique cluster of cytoplasmic vesicles and organelles; the number of nucleolated cells is higher in the spleen (95%) than in the tonsil (40%) or blood (5%). These findings further confirm the similarity between blood and MZ B cells. The CD1c expression assessed on 27 B-cell chronic lymphocytic leukemias (B-CLL) and 46 B non-Hodgkin's lymphomas (B-NHL) was detected on 41% and 32% of cases, respectively; the latter comprised four follicular and 11 diffuse histotypes. The Burkitt's lymphomas were CD1c-negative. The B-cell neoplasms were all CD1a- and, except for four with a weak cytoplasmic staining, all CD1b- as well. The clear-cut CD1c distribution in normal LN (MZ+, GC-) contrasted with the evidence that some B-NHL cells of GC origin (eg, follicular with predominantly small cleaved cells) were CD1c+. Overall, the finding that CD1c expression is restricted to a fraction of B cells present in lymphoid organs and in peripheral blood indicates that CD1c is a powerful marker for the identification and dissection of B-cell subsets whose functional properties can now be evaluated.

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