scholarly journals α4-integrin deficiency in B cells does not affect disease in a T-cell–mediated EAE disease model

2019 ◽  
Vol 6 (4) ◽  
pp. e563
Author(s):  
Rehana Z. Hussain ◽  
Petra D. Cravens ◽  
William A. Miller-Little ◽  
Richard Doelger ◽  
Valerie Granados ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Adoptive Transfer ◽  
Lymphoid Organs ◽  
Pathogenic Role ◽  
Genetic Ablation ◽  
Secondary Lymphoid Organs ◽  
The Brain

ObjectiveThe goal of this study was to investigate the role of CD 19+ B cells within the brain and spinal cord during CNS autoimmunity in a peptide-induced, primarily T-cell–mediated experimental autoimmune encephalomyelitis (EAE) model of MS. We hypothesized that CD19+ B cells outside the CNS drive inflammation in EAE.MethodsWe generated CD19.Cre+/− α4-integrinfl/fl mice. EAE was induced by active immunization with myelin oligodendrocyte glycoprotein peptide (MOGp35-55). Multiparameter flow cytometry was used to phenotype leukocyte subsets in primary and secondary lymphoid organs and the CNS. Serum cytokine levels and Ig levels were assessed by bead array. B-cell adoptive transfer was used to determine the compartment-specific pathogenic role of antigen-specific and non–antigen-specific B cells.ResultsA genetic ablation of α4-integrin in CD19+/− B cells significantly reduced the number of CD19+ B cells in the CNS but does not affect EAE disease activity in active MOGp35-55-induced disease. The composition of B-cell subsets in the brain, primary lymphoid organs, and secondary lymphoid organs of CD19.Cre+/− α4-integrinfl/fl mice was unchanged during MOGp35-55-induced EAE. Adoptive transfer of purified CD19+ B cells from CD19.Cre+/− α4-integrinfl/fl mice or C57BL/6 wild-type (WT) control mice immunized with recombinant rMOG1-125 or ovalbumin323-339 into MOGp35-55-immunized CD19.Cre+/− α4-integrinfl/fl mice caused worse clinical EAE than was observed in MOGp35-55-immunized C57BL/6 WT control mice that did not receive adoptively transferred CD19+ B cells.ConclusionsObservations made in CD19.Cre+/− α4-integrinfl/fl mice in active MOGp35-55-induced EAE suggest a compartment-specific pathogenic role of CD19+ B cells mostly outside of the CNS that is not necessarily antigen specific.

scholarly journals Sphingosine-1-Phosphate Receptor Type 4 (S1P4) Is Differentially Regulated in Peritoneal B1 B Cells upon TLR4 Stimulation and Facilitates the Egress of Peritoneal B1a B Cells and Subsequent Accumulation of Splenic IRA B Cells under Inflammatory Conditions

2021 ◽  
Vol 22 (7) ◽  
pp. 3465
Author(s):  
Janik Riese ◽  
Alina Gromann ◽  
Felix Lührs ◽  
Annabel Kleinwort ◽  
Tobias Schulze
Keyword(s):  
B Cells ◽  
B Cell ◽  
Peritoneal Cavity ◽  
Lymphoid Organs ◽  
Receptor Expression ◽  
Inflammatory Conditions ◽  
Sphingosine 1 Phosphate ◽  
Secondary Lymphoid Organs

Background: Gram-negative infections of the peritoneal cavity result in profound modifications of peritoneal B cell populations and induce the migration of peritoneal B cells to distant secondary lymphoid organs. However, mechanisms controlling the egress of peritoneal B cells from the peritoneal cavity and their subsequent trafficking remain incompletely understood. Sphingosine-1-phosphate (S1P)-mediated signaling controls migratory processes in numerous immune cells. The present work investigates the role of S1P-mediated signaling in peritoneal B cell trafficking under inflammatory conditions. Methods: Differential S1P receptor expression after peritoneal B cell activation was assessed semi‑quantitatively using RT-PCR in vitro. The functional implications of differential S1P1 and S1P4 expression were assessed by transwell migration in vitro, by adoptive peritoneal B cell transfer in a model of sterile lipopolysaccharide (LPS)‑induced peritonitis and in the polymicrobial colon ascendens stent peritonitis (CASP) model. Results: The two sphingosine-1-phosphate receptors (S1PRs) expressed in peritoneal B cell subsets S1P1 and S1P4 are differentially regulated upon stimulation with the TLR4 agonist LPS, but not upon PMA/ionomycin or B cell receptor (BCR) crosslinking. S1P4 deficiency affects both the trafficking of activated peritoneal B cells to secondary lymphoid organs and the positioning of these cells within the functional compartments of the targeted organ. S1P4 deficiency in LPS-activated peritoneal B cells results in significantly reduced numbers of splenic innate response activator B cells. Conclusions: The S1P-S1PR system is implicated in the trafficking of LPS-activated peritoneal B cells. Given the protective role of peritoneal B1a B cells in peritoneal sepsis, further experiments to investigate the impact of S1P4-mediated signaling on the severity and mortality of peritoneal sepsis are warranted.

scholarly journals Human Dendritic Cells Skew Isotype Switching of CD40-activated Naive B Cells towards IgA1 and IgA2

1997 ◽  
Vol 185 (11) ◽  
pp. 1909-1918 ◽  
Author(s):  
Jérôme Fayette ◽  
Bertrand Dubois ◽  
Stéphane Vandenabeele ◽  
Jean-Michel Bridon ◽  
Béatrice Vanbervliet ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Culture Conditions ◽  
Lymphoid Organs ◽  
Cell Growth And Differentiation ◽  
Secondary Lymphoid Organs

Within T cell–rich areas of secondary lymphoid organs, interdigitating dendritic cells recruit antigen-specific T cells that then induce B cells to secrete Igs. This study investigates the possible role(s) of dendritic cells in the regulation of human B cell responses. In the absence of exogenous cytokines, in vitro generated dendritic cells (referred to as Dendritic Langerhans cells, D-Lc) induced surface IgA expression on ∼10% of CD40-activated naive sIgD+ B cells. In the presence of IL-10 and TGF-β, a combination of cytokines previously identified for its capacity to induce IgA switch, D-Lc strongly potentiated the induction of sIgA on CD40-activated naive B cells from 5% to 40–50%. D-Lc alone did not induce the secretion of IgA by CD40-activated naive B cells, which required further addition of IL-10. Furthermore, D-Lc skewed towards the IgA isotype at the expense of IgG, the Ig production of CD40-activated naive B cells cultured in the presence of IL-10 and TGF-β. Importantly, under these culture conditions, both IgA1 and IgA2 were detected. In the presence of IL-10, secretion of IgA2 by CD40-activated naive B cells could be detected only in response to D-Lc and was further enhanced by TGF-β. Collectively, these results suggest that in addition to activating T cells in the extrafollicular areas of secondary lymphoid organs, human D-Lc also directly modulate T cell–dependent B cell growth and differentiation, by inducing the IgA isotype switch.

scholarly journals Dendritic Cells Enhance Growth and Differentiation of CD40-activated B Lymphocytes

1997 ◽  
Vol 185 (5) ◽  
pp. 941-952 ◽  
Author(s):  
Bertrand Dubois ◽  
Béatrice Vanbervliet ◽  
Jérome Fayette ◽  
Catherine Massacrier ◽  
Cees Van Kooten ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Lymphoid Organs ◽  
Secondary Lymphoid Organs

After antigen capture, dendritic cells (DC) migrate into T cell–rich areas of secondary lymphoid organs, where they induce T cell activation, that subsequently drives B cell activation. Here, we investigate whether DC, generated in vitro, can directly modulate B cell responses, using CD40L-transfected L cells as surrogate activated T cells. DC, through the production of soluble mediators, stimulated by 3- to 6-fold the proliferation and subsequent recovery of B cells. Furthermore, after CD40 ligation, DC enhanced by 30–300-fold the secretion of IgG and IgA by sIgD− B cells (essentially memory B cells). In the presence of DC, naive sIgD+ B cells produced, in response to interleukin-2, large amounts of IgM. Thus, in addition to activating naive T cells in the extrafollicular areas of secondary lymphoid organs, DC may directly modulate B cell growth and differentiation.

scholarly journals THU0053 CONTRIBUTION OF DEFECTIVE NON-APOPTOTIC FAS SIGNALING TO IMMUNE DYSREGULATION IN AUTOIMMUNE LYMPHOPROLIFERATIVE SYNDROME (ALPS)

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 238.3-238
Author(s):  
J. Staniek ◽  
T. Kalina ◽  
G. Andrieux ◽  
M. Boerries ◽  
I. Janowska ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Signaling Pathway ◽  
Germinal Center ◽  
Lymphoid Organs ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Fas Signaling ◽  
Secondary Lymphoid Organs

Background:ALPS patients show impaired generation of humoral memory for T independent antigens whereas they generate memory for self-antigens due to impaired FAS-dependent removal of autoreactive germinal center B cells. It is known that FAS signaling via caspase activation results in cell apoptosis. However, FAS ligation may also initiate or modulate non-apoptotic signaling as shown for example by its ability to activate NF-κB. Recent data implicate a regulatory role of FAS in the modulation of mTOR signaling in ALPS double-negative T cells. Moreover, a recently described C194V FAS mutation disturbs its post-translational modification leading to impaired apoptosis induction while non-apoptotic signalling is still intact. Consequently, C194V FAS protects from the autoimmune phenotype in the murine ALPS system. This supports the view that FAS may prevent autoimmunity with other mechanisms than inducing apoptosis.Objectives:We hypothesize that FAS mutations impair this modulatory signaling, leading to hyper-activation of B cells. Therefore we aim to investigate non apoptotic FAS signaling in B cells derived from healthy individuals and ALPS patients.Methods:We studied resting and activated B cells in ALPS patients in presence or absence of FAS ligand by flow cytometry analysing relevant molecules to the CD40 signaling pathway. We used mass cytometry to perform functional phenotyping of B cells isolated from secondary lymphoid organs. Proteomic studies were performed to identify potential signaling circuits and RNA sequencing to study the consequences of FAS signaling on B cell fate.Results:In CD40L activated B cells, FAS signaling results in specific modulation of the mTOR signaling pathway. This modulation is absent in ALPS derived B cells. In line with these data germinal center B cells and plasmablast from secondary lymphoid organs of ALPS patients show hyperactive mTOR signaling pathway. Proteomic studies identify a circuit that links FAS to the phosphatase PTEN via DAXX and the deubiquitinase USP7.Conclusion:We describe a new role of FAS in the regulation of B cell activation. Defects in FAS signaling in ALPS contribute to dysregulation of the mTOR signaling pathway and disturbed B cell development.Disclosure of Interests:None declared

scholarly journals Germinal center B cell development has distinctly regulated stages completed by disengagement from T cell help

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ting-ting Zhang ◽  
David G Gonzalez ◽  
Christine M Cote ◽  
Steven M Kerfoot ◽  
Shaoli Deng ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
B Cell Differentiation ◽  
B Cell Maturation ◽  
Germinal Center B Cell ◽  
T Cell Help ◽  
Dose Dependent

To reconcile conflicting reports on the role of CD40 signaling in germinal center (GC) formation, we examined the earliest stages of murine GC B cell differentiation. Peri-follicular GC precursors first expressed intermediate levels of BCL6 while co-expressing the transcription factors RelB and IRF4, the latter known to repress Bcl6 transcription. Transition of GC precursors to the BCL6hi follicular state was associated with cell division, although the number of required cell divisions was immunogen dose dependent. Potentiating T cell help or CD40 signaling in these GC precursors actively repressed GC B cell maturation and diverted their fate towards plasmablast differentiation, whereas depletion of CD4+ T cells promoted this initial transition. Thus while CD40 signaling in B cells is necessary to generate the immediate precursors of GC B cells, transition to the BCL6hi follicular state is promoted by a regional and transient diminution of T cell help.

scholarly journals Antiviral Protection and Germinal Center Formation, But Impaired B Cell Memory in the Absence of CD19

1998 ◽  
Vol 188 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Thomas Fehr ◽  
Robert C. Rickert ◽  
Bernhard Odermatt ◽  
Jürgen Roes ◽  
Klaus Rajewsky ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Antibody Responses ◽  
B Cell Activation ◽  
Protein Antigens ◽  
Cell Memory ◽  
B Cell Memory

Coligation of CD19, a molecule expressed during all stages of B cell development except plasmacytes, lowers the threshold for B cell activation with anti-IgM by a factor of 100. The cytoplasmic tail of CD19 contains nine tyrosine residues as possible phosphorylation sites and is postulated to function as the signal transducing element for complement receptor (CR)2. Generation and analysis of CD19 gene–targeted mice revealed that T cell–dependent (TD) antibody responses to proteinaceous antigens were impaired, whereas those to T cell–independent (TI) type 2 antigens were normal or even augmented. These results are compatible with earlier complement depletion studies and the postulated function of CD19. To analyze the role of CD19 in antiviral antibody responses, we immunized CD19−/− mice with viral antigens of TI-1, TI-2, and TD type. The effect of CD19 on TI responses was more dependent on antigen dose and replicative capacity than on antigen type. CR blocking experiments confirmed the role of CD19 as B cell signal transducer for complement. In contrast to immunization with protein antigens, infection of CD19−/− mice with replicating virus led to generation of specific germinal centers, which persisted for >100 d, whereas maintenance of memory antibody titers as well as circulating memory B cells was fully dependent on CD19. Thus, our study confirms a costimulatory role of CD19 on B cells under limiting antigen conditions and indicates an important role for B cell memory.

CD40 Ligand Activation Alters B Cell Migration to Secondary Lymphoid Organs.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 935-935
Author(s):  
Yvonne A. Efebera ◽  
Tahamtan Ahmadi ◽  
Amanda Flies ◽  
David H. Sherr
Keyword(s):  
B Cells ◽  
Lymph Nodes ◽  
B Cell ◽  
Cd40 Ligand ◽  
Lymphoid Organs ◽  
Cell Populations ◽  
Secondary Lymphoid Organs ◽  
Activated B Cells

Abstract Background: An increased understanding of the requirements for antigen presentation has encouraged development of cell-based cancer vaccines. Trials using dendritic cells (DC) as antigen presenting cells (APC) for immunotherapy of several malignancies have shown considerable success. However, the difficulty in generating large numbers of DC required for these immunizations has led to the search for alternative APC. One such candidate is the CD40 ligand (CD40L)-activated B cell, populations of which can readily be expanded in vitro. To be an effective vehicle for antigen presentation to T cells, CD40L-activated B cells must be capable of migrating to secondary lymphoid organs. Therefore, CD40L-activated B cell migration following subcutaneous or intravenous injection was evaluated. Methods: Splenic B cells from GFP transgenic mice were activated with CD40L + IL-4 and expanded in vitro prior to i.v. or s.c. injection of 3–4 x 107 into C57BL/6 mice. Recipient mice were sacrificed 2 hrs or 1–14 days thereafter and the percentage of GFP+/B220+ B cells quantified in spleens and lymph nodes by flow cytometry. Localization of these cells within lymphoid organs was determined by immunohistochemistry. In some experiments, activated C57BL/6 B cells were labeled with carboxy fluorescein succinimidyl ester (CFSE) to evaluate cell growth in vivo. Results: Murine B cell populations were readily expanded by culture on CD40L-transfected L cells in the presence of IL-4. CD40L-activated B cells expressed high levels of CD80, CD86, and LFA-1 but decreased levels of L-selectin relative to naive cells. Following i.v. injection, activated B cells were detected in spleens and lymph nodes within 1 day. Peak concentrations of activated B cells were noted in spleens and lymph nodes on days 7 (4.8% of injected cells) and 10 (1.25% of injected cells) respectively, suggesting expansion of the activated B cell population in vivo. Naive B cells injected i.v. were detected within 1 day but their number declined precipitously thereafter. Following s.c. injection, peak levels of CD40L-activated B cells were noted on day 5 (spleens) and day 7 (lymph nodes). As determined by immunohistochemistry, both CD40L-activated and naïve B cells injected i.v. appeared in B cell regions of spleens and lymph nodes. While the kinetics of accumulation of CD40L-activated B cells injected s.c. or i.v. were similar, s.c. injected CD40L-activated B cells homed to the T cell regions of spleens and lymph nodes. CFSE experiments indicated that these activated B cells continue to grow in vivo. In contrast, naïve B cells injected s.c. only appeared in B cell regions. Conclusion: CD40L-activated B cell populations can readily be expanded in vitro, CD40L-activated B cells migrate to secondary lymphoid organs even when injected s.c., activated B cell populations expand in vivo, and s.c. injected, CD40L-activated B cells preferentially home to T cell regions of secondary lymphoid organs. These results suggest that this effective APC may serve as an important vehicle for delivery and presentation of exogenous (e.g. tumor) antigens to T cells in vivo.

The Proto-Oncogene LRF Is Essential for Normal Mature B Cell Development and Germinal Center Formation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1788-1788
Author(s):  
Nagisa Sakurai ◽  
Manami Maeda ◽  
Sung-UK Lee ◽  
Julie Teruya-Feldstein ◽  
Takahiro Maeda
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Cell Stage ◽  
Transitional B Cells ◽  
Notch Pathways ◽  
Secondary Lymphoid Organs

Abstract LRF (Leukemia/Lymphoma Related Factor, also known as Pokemon, FBI-1, OCZF and ZBTB7a) was originally identified as an interaction partner of the oncoprotein BCL6. LRF can act as a proto-oncogene by repressing the tumor suppressor ARF and cooperates with BCL6 in MEF (mouse embryonic fibroblasts) immortalization. It is highly expressed in human Non-Hodgkin Lymphoma (NHL) cases, in the pathogenesis of which BCL6 is known to be involved (Maeda et al. Nature 2005). Inducible inactivation of the LRF gene in mouse Hematopoietic Stem Cells (HSCs) results in complete block of early B cell development at the HSC/progenitor stages and concomitant development of double positive (DP) T cells in the bone marrow (BM) (Maeda et al. Science 2007). While these findings clearly illustrate key roles of LRF in normal and malignant B cell development, it is not fully identified as to which B cell stages LRF is required during normal B cell development. To elucidate the role of LRF in B cells in vivo, we established and characterized B cell-specific LRF conditional knockout (KO) mice. We took advantage of mb-1 Cre knock-in mice, in which Cre expression is restricted to the B cells after the ProB cell stage. B cell compartments in the BM (PreProB, ProB, PreB and immatureB) are grossly normal in LRFF/ Fmb1-Cre mice. The LRF gene was efficiently eliminated in BM CD19+ B cells revealed by quantitative real-time PCR assay. Furthermore, LRF protein was not detected in purified CD19+ B cells, but seen in CD19-non-B cells, confirming the specific inactivation of the LRF gene in B cells. Thus, despite its critical role at the HSC/progenitor stages, LRF was found to be dispensable for the survival of normal BM B cells. These findings are consistent with the fact that GSI treatment (Maeda et al. Science 2007) or Notch1 loss (Lee and Maeda, unpublished) rescues the defects in early B cell development seen in LRFF/FMx1-Cre+ mice. Notch signaling is necessary for the transitional B cells to commit to the marginal zone B cells (MZB). Inactivation of the component of the Notch pathways in mice results in no MZB development. On the contrary, deletion of the MINT/SHARP gene, a suppressor of Notch signaling, leads to increase of MZB cells and concomitant reduction of follicular B (FOB) cells, indicating that Notch induces MZB cell fate at the transitional B cell stage. Given that LRF is a potent Notch suppressor at the HSC/progenitor stages, we hypothesized that LRF opposes Notch pathway in mature B cells as well. To test this hypothesis, we characterized mature B cell development in LRFF/Fmb1-Cre mice. While transitional B cells were largely unaffected in LRFF/Fmb1-Cre mice, we observed a slight but statistically significant reduction of follicular (FO) B cells (B220+CD19+AA4.1-CD1d-CD23+) and concomitant increase of MZB cells (B220+CD19+AA4.1-CD1d+CD23-) as seen in MINT/SHARP knockout mice. Thus, LRF may also oppose Notch pathways at the branching point for the FOB vs. MZB fate decision. Finally, to determine the role of LRF in Germinal Center (GC) formation in vivo, we characterized secondary lymphoid organs of LRFF/Fmb1-Cre mice after antigen stimulation. Both spleen and Peyer’s Patches were analyzed two weeks after immunization with Chicken Gamma Globulin (NP-CGG). While a GC reaction was robustly induced in control mice upon immunization, GC formation was significantly impaired in LRFF/Fmb1-Cre mice as revealed by immuno-histochemical analysis (IHC) and FACS. Only few GC cells (B220+CD19+FAS+CD38-PNA+) were observed in spleens, and the absolute numbers of GC cells were drastically reduced in LRFF/Fmb1-Cre mice. Residual LRF-deficient GC B cells were mostly negative for CXCR4, which is predominantly expressed in proliferating centroblasts within GCs, suggesting that LRF-deficient GC B cells may have defects in cellular proliferation in response to antigen stimuli. Our data indicates that LRF plays key roles in mature B cell development in the secondary lymphoid organs, but dispensable for the maintenance of early BM B cells.

scholarly journals Specific fibroblastic niches in secondary lymphoid organs orchestrate distinct Notch-regulated immune responses

2014 ◽  
Vol 211 (11) ◽  
pp. 2265-2279 ◽  
Author(s):  
Nicolas Fasnacht ◽  
Hsin-Ying Huang ◽  
Ute Koch ◽  
Stéphanie Favre ◽  
Floriane Auderset ◽  
...  
Keyword(s):  
B Cells ◽  
Lymphoid Organs ◽  
T Cell Differentiation ◽  
Tissue Architecture ◽  
Lineage Specification ◽  
Marginal Zone B Cells ◽  
Genetic Ablation ◽  
Follicular Helper ◽  
Follicular Helper T Cell ◽  
Secondary Lymphoid Organs

Fibroblast-like cells of secondary lymphoid organs (SLO) are important for tissue architecture. In addition, they regulate lymphocyte compartmentalization through the secretion of chemokines, and participate in the orchestration of appropriate cell–cell interactions required for adaptive immunity. Here, we provide data demonstrating the functional importance of SLO fibroblasts during Notch-mediated lineage specification and immune response. Genetic ablation of the Notch ligand Delta-like (DL)1 identified splenic fibroblasts rather than hematopoietic or endothelial cells as niche cells, allowing Notch 2–driven differentiation of marginal zone B cells and of Esam+ dendritic cells. Moreover, conditional inactivation of DL4 in lymph node fibroblasts resulted in impaired follicular helper T cell differentiation and, consequently, in reduced numbers of germinal center B cells and absence of high-affinity antibodies. Our data demonstrate previously unknown roles for DL ligand-expressing fibroblasts in SLO niches as drivers of multiple Notch-mediated immune differentiation processes.

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