scholarly journals B cell–derived IL-27 promotes control of persistent LCMV infection

2022 ◽  
Vol 119 (3) ◽  
pp. e2116741119
Author(s):  
Isaraphorn Pratumchai ◽  
Jaroslav Zak ◽  
Zhe Huang ◽  
Booki Min ◽  
Michael B. A. Oldstone ◽  
...  

Recent studies have identified a critical role for B cell–produced cytokines in regulating both humoral and cellular immunity. Here, we show that B cells are an essential source of interleukin-27 (IL-27) during persistent lymphocytic choriomeningitis virus (LCMV) clone 13 (Cl-13) infection. By using conditional knockout mouse models with specific IL-27p28 deletion in B cells, we observed that B cell–derived IL-27 promotes survival of virus-specific CD4 T cells and supports functions of T follicular helper (Tfh) cells. Mechanistically, B cell–derived IL-27 promotes CD4 T cell function, antibody class switch, and the ability to control persistent LCMV infection. Deletion of IL-27ra in T cells demonstrated that T cell–intrinsic IL-27R signaling is essential for viral control, optimal CD4 T cell responses, and antibody class switch during persistent LCMV infection. Collectively, our findings identify a cellular mechanism whereby B cell–derived IL-27 drives antiviral immunity and antibody responses through IL-27 signaling on T cells to promote control of LCMV Cl-13 infection.

1989 ◽  
Vol 170 (5) ◽  
pp. 1477-1493 ◽  
Author(s):  
R H DeKruyff ◽  
T Turner ◽  
J S Abrams ◽  
M A Palladino ◽  
D T Umetsu

We have analyzed in detail the precise requirements for the induction of human IgE synthesis using several experimental approaches with purified B cells and well-characterized alloantigen-specific CD4+ T cell clones expressing different profiles of lymphokine secretion. Using these clones under cognate conditions in which the B cells expressed alloantigens recognized by the cloned T cells, we have confirmed that IL-4 is required for the induction of IgE synthesis, but we have clearly demonstrated that IL-4 by itself is not sufficient. With several cloned CD4+ T cell lines, including an IL-4-producing clone that could not induce IgE synthesis, and cloned T cells pretreated with cyclosporin A to inhibit lymphokine synthesis, we showed that Th cell-B cell interactions are necessary for IgE synthesis, and that low molecular weight B cell growth factor (LMW-BCGF) and IL-4, in combination, are lymphokines of major importance in the induction of IgE synthesis. Together our results indicate that optimal induction of an IgE-specific response requires the exposure of B cells to a particular complex of signals that include (a) a signal(s) involving Th-B cell interaction that primes B cells to receive additional signals from soluble lymphokines, (b) a specific B cell proliferative signal provided by LMW-BCGF, and (c) a specific B cell differentiation signal provided by IL-4.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 693-693
Author(s):  
Krystalyn E Hudson ◽  
Jeanne Hendrickson ◽  
Chantel M Cadwell ◽  
Neal N Iwakoshi ◽  
James C. Zimring

Abstract Abstract 693 Introduction: Breakdown of humoral tolerance to red blood cell (RBC) antigens can result in autoimmune hemolytic anemia (AIHA), a severe and potentially fatal disease. The pathogenesis of AIHA is poorly understood. To investigate the baseline biology of tolerance to self-antigens expressed on RBCs, we utilized a murine transgenic mouse with RBC-specific expression of a model antigen consisting of a triple fusion protein of hen egg lysozyme (HEL), ovalbumin (Ova), and human blood group molecule Duffy; HEL-OVA-Duffy (HOD mouse). Methods: Wild-type C57BL/6 (B6) mice or HOD mice (on a B6 background) were immunized with HEL/CFA or OVA/CFA to test immune responses to antigens contained within HOD. Some animals were immunized with peptides as opposed to whole protein. Anti-HOD antibodies were quantified by indirect immunofluorescence using HOD RBCs as targets. Anti-HEL IgG was quantified by ELISA and anti-HEL secreting B cells were enumerated by ELISPOT. CD4+ T cell responses were assessed by tetramer staining and tetramer pull-down assays using I-Ab-OVA-329-337/326-334. T cell tolerance was specifically broken by adoptive transfer of OT-II CD4+ T cells into HOD mice (OT-II T cells recognize OVA323-339 presented by I-Ab). Effects of HOD antigen expression on B cell development were evaluated by crossing the HOD mouse with an anti-HEL BCR knockin mouse (SwHEL mouse) that is capable of normal class switching. Results: Immunization of B6 mice with OVA/CFA induced high titer antibodies reactive with HOD RBCs; in contrast, no anti-HOD was detected in HOD mice immunized with OVA/CFA. Similarly, no anti-HEL was detected in HOD mice immunized with HEL/CFA, whereas wild-type B6 mice had high anti-HEL titers (p<0.05). These data demonstrate overall humoral tolerance to the HOD antigen. Using pull-down assays, OVA-tetramer reactive T cells were detected in both B6 and HOD mice, with similar endogenous frequencies (mean numbers are 40 and 53 T cells, respectively; at least 6 mice analyzed), suggesting that central tolerance did not eliminate HOD reactive T cells. However, upon immunization with OVA peptide, B6 but not HOD mice had a detectable expansion of OVA-tetramer reactive CD4+ T cells, indicating that peripheral tolerance was preventing HOD autoreactive CD4+ T cells from participating in an immune response. To assess B cell tolerance to the HOD antigen, T cell tolerance was circumvented through adoptive transfer or OTII splenocytes (specific for the OVA323-339 peptide) into HOD mice. Anti-HEL autoantibodies were detected in HOD mice but not control B6 mice (p<0.001). Antibody production correlated with a 10–20 fold increase of anti-HEL antibody secreting cells, as determined by ELISPOT. Autoantibody production in HOD mice was not due to passenger B cells from the OTII donor, an artifact of excess CD4+ T cell number, or bystander activation as no autoantibodies were observed upon adoptive transfer with OTIIs on a Rag knockout background, irrelevant CD4+ T cells from SMARTA mice, or activated CD4+ T cells from TCR75 mice. To test the effects of HOD antigen expression on development of autoreactive B cells, HOD mice were crossed with SwHEL BCR transgenic mice (that express anti-HEL) and the F1 mice were analyzed. HEL-reactive B cells were visualized using multimeric HEL conjugated to allophycocyanin. In HOD-SwHEL+ mice, approximately 46±14% of immature bone marrow B cells were reactive with HEL, compared to 15±12% in HOD+SwHEL+ mice (p=0.043, 3 independent experiments, 5 mice total). Conclusions: These data demonstrate that tolerance to an RBC specific antigen is complete in the CD4+ T cell, but not the B cell compartment. CD4+ T cell tolerance appears to be more an effect of peripheral tolerance than central deletion, as OVA-tetramer reactive CD4+ T cells were visible in HOD mice but did not activate upon immunization with their cognate antigen. In contrast, while the HODxSwHEL F1 mice demonstrate that some B cell tolerance to HOD occurs, the induction of autoantibodies by introducing CD4+ autoreactive T cells (OT-II) demonstrates that B cell tolerance to the HOD antigen is incomplete in HOD mice. Together, these data suggest that a breakdown in T cell tolerance is all that is required for the pathogenesis of AIHA. As the T cell tolerance appears not to be deletional, it is predicted that environmental factors leading to a breakdown in peripheral tolerance of CD4+ T cells would be sufficient to induce AIHA. Disclosures: Zimring: Immucor Inc,: Research Funding.


2003 ◽  
Vol 198 (7) ◽  
pp. 1011-1021 ◽  
Author(s):  
Mark Y. Sangster ◽  
Janice M. Riberdy ◽  
Maricela Gonzalez ◽  
David J. Topham ◽  
Nicole Baumgarth ◽  
...  

Contact-mediated interactions between CD4+ T cells and B cells are considered crucial for T cell–dependent B cell responses. To investigate the ability of activated CD4+ T cells to drive in vivo B cell responses in the absence of key cognate T–B interactions, we constructed radiation bone marrow chimeras in which CD4+ T cells would be activated by wild-type (WT) dendritic cells, but would interact with B cells that lacked expression of either major histocompatibility complex class II (MHC II) or CD40. B cell responses were assessed after influenza virus infection of the respiratory tract, which elicits a vigorous, CD4+ T cell–dependent antibody response in WT mice. The influenza-specific antibody response was strongly reduced in MHC II knockout and CD40 knockout mice. MHC II–deficient and CD40-deficient B cells in the chimera environment also produced little virus-specific immunoglobulin (Ig)M and IgG, but generated a strong virus-specific IgA response with virus-neutralizing activity. The IgA response was entirely influenza specific, in contrast to the IgG2a response, which had a substantial nonvirus-specific component. Our study demonstrates a CD4+ T cell–dependent, antiviral IgA response that is generated in the absence of B cell signaling via MHC II or CD40, and is restricted exclusively to virus-specific B cells.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3847-3847
Author(s):  
Patricia E. Zerra ◽  
Seema R. Patel ◽  
Connie M. Arthur ◽  
Kathryn R. Girard-Pierce ◽  
Ashley Bennett ◽  
...  

Abstract Background: While red blood cell (RBC) transfusion can be beneficial, exposure to allogeneic RBCs can result in the development of RBC alloantibodies that can make it difficult to obtain compatible RBCs for future transfusions. Aside from phenotype matching protocols, no strategy currently exists that is capable of preventing RBC alloimmunization following therapeutic transfusion. As RBC alloantigens represent diverse determinants capable of driving distinct immune pathways, common immunological nodes must be identified in order to successfully prevent RBC alloimmunization against a variety of different alloantigens. Recent results demonstrate that marginal zone (MZ) B cells mediate anti-KEL antibody formation in the complete absence of CD4 T cells. However, whether MZ B cells similarly regulate RBC alloantibody formation against other RBC alloantigens remains unknown. As a result, we examined the role of MZ B cells and CD4 T cells in the development of RBC alloantibodies following exposure to the HOD (hen egg lysozyme, ovalbumin and duffy) antigen. Methods: Each recipient was transfused with HOD or KEL RBCs following either MZ B cell or CD4 T cell depletion using a cocktail of MZ B cell (anti-CD11a and anti-CD49d) or anti-CD4 depleting antibody, 4 and 2 days prior to transfusion. Control groups received isotype control injections in parallel. MZ B cell deficient (CD19cre/+ X Notch2flx/flx) and CD4 T cell deficient (MHC class II knockout) recipients were also used to examine the role of MZ B cells and CD4 T cells, respectively. Serum collected on days 5 and 14 post-transfusion was evaluated for anti-HOD or anti-KEL antibodies by incubating HOD or KEL RBCs with serum, followed by detection of bound antibodies using anti-IgM and anti-IgG and subsequent flow cytometric analysis. Evaluation of antibody engagement and overall survival of HOD or KEL RBCs was accomplished by labeling RBCs with the lipophilic dye, DiI, prior to transfusion, followed by examination for bound antibody and RBC clearance on days 5 and 14 post-transfusion by flow cytometry. Results: Similar to the ability of MZ B cell depletion to reduce anti-KEL antibody formation following KEL RBC exposure, depletion of MZ B cells significantly reduced anti-HOD IgM and IgG antibodies following HOD RBC transfusion. In contrast, injection of recipients with isotype control antibodies in parallel failed to prevent alloantibody formation following HOD or KEL RBC transfusion. Similar results were obtained following HOD or KEL RBC transfusion into recipients genetically deficient in MZ B cells. In contrast, although MZ B cells were required for HOD and KEL RBC-alloantibody formation, manipulation of CD4 T cells differentially impacted the ability of each antigen to induce alloantibodies. While transfusion of HOD or KEL RBCs resulted in robust IgM alloantibodies in the absence of CD4 T cells, depletion or genetic elimination of CD4 T cells significantly inhibited anti-HOD IgG antibody formation, while failing to impact IgG anti-KEL antibody formation. Consistent with this, while manipulation of CD4 T cells protected HOD RBCs from antibody deposition and subsequent RBC clearance, this same approach failed to similarly protect KEL RBCs following transfusion. In contrast, depletion of MZ B cells not only prevented detectable alloantibody production, but also completely protected HOD or KEL RBCs from antibody deposition and subsequent RBC clearance. Conclusion: These results suggest that while MZ B cells mediate a robust IgM antibody response following either KEL or HOD antigen exposure, MZ B cells appear to possess the capacity to orchestrate unique downstream IgG responses through CD4 T cell dependent and independent pathways contingent on target alloantigen. As a result, while manipulation of CD4 T cells may prevent alloantibody formation against some antigens, targeting this immune population inadequately prevents RBC alloantibody formation against all RBC antigens. As chronic transfusion therapy exposes recipients to a wide variety of alloantigens, these results suggest that MZ B cells may represent a central initiating node that governs RBC alloimmunization against a variety of RBC alloantigens, and may therefore serve as a useful target in preventing alloantibody formation in chronically transfused individuals. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4535-4535
Author(s):  
Yongxia Wu ◽  
Steven D Schutt ◽  
Ryan P Flynn ◽  
Mengmeng Zhang ◽  
Hung D Nguyen ◽  
...  

Abstract Chronic graft-versus-host disease (cGVHD) remains to be a major cause of mortality and morbidity after allogeneic hematopoietic cell transplantation (allo-HCT). cGVHD is characterized as autoimmune-like fibrosis and antibody production, mediated by pathogenic T and B cells. Through producing pro-inflammatory cytokines, CD4 T cells are the driving force of cGVHD. Donor B cells augment the pathogenesis of cGVHD not only by acting as antigen-presenting cells (APCs) and promoting CD4 T-cell expansion and survival, but also by producing autoantibodies. microRNA (miR)-17-92 has been shown to regulate T-cell immunity including allogeneic, anti-viral, and anti-tumor responses. Recently, miR-17-92 was found to act together with Bcl-6 to promote the differentiation of Follicular help T (Tfh) cells. Furthermore, B-cell deficiency of miR-17-92 impairs IgG2c production. Since Tfh differentiation and antibody production are required for the development of cGVHD, we hypothesize that miR-17-92 contributes to the pathogenesis of cGVHD by promoting pathogenic T- and B-cell responses. By using Cre-loxp system, we generated B6 mice with conditional deficiency of miR-17-92 in T cells (CD4cre), B cells (CD19cre), or both (CD4CD19cre). aGVHD to cGVHD transition model (B6 to BALB/c) was utilized to test the effects of individual and combinational deficiency of miR-17-92 in T and/or B cells in the development of cGVHD. BALB/c mice were lethally irradiated and transferred with splenocytes plus BM cells derived from CD4cre, CD19cre or CD4CD19cre miR-17-92flox/flox B6 mice. WT B6 (Cre- miR-17-92flox/flox) mice were used as control donors. A significantly reduction of GVHD mortality was observed only in the recipients with CD4CD19cre grafts, but not with CD4cre or CD19cre grafts. Deficiency of miR-17-92 in donor T or B cells indeed improved the clinical manifestation of cGVHD, but the deficiency in both T and B cells showed further improvement, indicating the additive role of miR-17-92 in T and B cells in the pathogenesis of cGVHD. Mechanistically, deficiency of miR-17-92 in T cells resulted in the reduction of Tfh generation (Fig. A), germinal center (GC) B-cell and plasma cell differentiation, and the expression of MHC-II and CD86 on donor B cells in recipient spleens. Furthermore, deficiency of miR-17-92 in B cells significantly reduced the levels of total IgG and IgG2c in recipient serum (Fig. A). These data suggest that miR-17-92 contributes to both T- and B-cell differentiation and function, which is required for the development of cGVHD. To extend our findings, we used a bronchiolitis obliterans cGVHD model (B6 to B10.BR). Recipient mice were pre-conditioned and received either BM alone from WT or CD19cre B6 mice, or BM plus purified T cells from WT or CD4cre B6 mice. Deficiency of miR-17-92 in T cells or BM-derived B cells resulted in significant improvement in pulmonary functions in recipient mice, as demonstrated by a decrease in resistance and elastance and an increase in compliance (Fig. B). Consistently, we found that miR-17-92 promoted Tfh and GC B-cell differentiation (Fig. B), while inhibiting differentiation of T follicular regulatory cells in recipient spleens 60 days after allo-HCT. For translational purpose, we tested whether inhibition of miR-17-92 could ameliorate cGVHD using locked nucleic acid (LNA) antagomirs specific for miR-17 or miR-19, key members in this microRNA cluster. In a SLE cGVHD model (DBA2 to BALB/c), administration of anti-miR-17, but not anti-miR-19, significantly suppressed the incidence of proteinuria and the severity of clinical manifestation by inhibiting donor splenocyte expansion, expression of costimulatory molecules on donor B cells, and differentiation of GC B cells and plasma cells (Fig. C). In addition, systemic delivery of anti-miR-17 significantly improved skin cGVHD by restraining IL-17 producing CD4 T-cell infiltration in skin-draining lymph nodes in a scleroderma-cGVHD model (B10.D2 to BALB/c). Taken together, the current work reveals that miR-17-92 is required for T- and B-cell differentiation and function, and thus for the development of cGVHD. Furthermore, pharmacological inhibition of miR-17 represents a potential therapeutic strategy for the control of cGVHD after allo-HCT. Figure Figure. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5289-5289 ◽  
Author(s):  
Georgiana Grigore ◽  
Martin Perez-Andres ◽  
Susana Barrena ◽  
Rosa Ana Rivas ◽  
Marcos González ◽  
...  

Abstract Introduction Management of B-cell chronic lymphocytic leukemia (CLL) is currently undergoing profound changes. Accordingly, new treatment options with an expected less toxicity than standard regimens are been explored. Recent results show that chemoimmunotherapy may improve the life expectancy of CLLpatients and has proven to be more efficient than chemotherapy alone in depleting malignant cells. Despite its efficacy, little is known about its precise immunomodulatory effects. Aim To evaluate the effects of chemoimmunotherapy with bendamustine plusrituximab (BR) on the distribution of normal residual leucocyte populations in peripheral blood (PB) from advanced-stage CLL patients, with special emphasis on maturation-associated B-cell subsets (immature, naïve, memory IgM/IgG/IgA and plasma cells). Material and Methods Distribution of PB neoplastic cells and residual normal immune cell subpopulations were analyzed in 72 CLL patients with advanced disease (Binet B/C), before therapy (M0) and after 1 course of BR (M1). The same analysis was repeated 3 months after completing treatment (M3) in 31/72 patients. PB leucocyte cell subsets were identified at each time-point by 8-color flow cytometry with monoclonal antibody reagents against CD3, CD4, CD5, CD8, TCRgd, CD19, CD20, CD27, CD38, CD45, CD56, sIgM, sIgA, sIgG, sIgLambda and sIgKappa. Results After the first BR course, absolute counts of all PB myeloid subsets were significantly decreased as compared to time M0, including neutrophils (2,744±1,830 vs 4,764±2,906 cells/uL, p<0.001), eosinophils (132±185 vs 215±245 cells/uL; p<0.001), basophils (37±28 vs 59±47 cells/uL, p<0.001), monocytes (334±280 vs 504±424 cells/uL, p=0.001) and dendritic cells (DCs, 41±40 vs 89±168 cells/uL, p=0.02), as well as NK cells (120±147 vs 550±599 cells/uL, p<0.001). At M3, all these populations remained decreased when compared to M0, but at similar levels to M1 (except for the absolute number of DCs, found to be increased vs. M1 -74±46 vs 41±40 cells/uL, p=0.008- and closer to M0). In turn, total T cells were reduced in M1 as compared to M0 values (818±655 vs 3,905±2,375 cells/uL, p<0.001), due to decreased numbers of CD4+ (424±376 vs 1,573±1,204 cells/uL, p<0.001), CD8+ (342±330 vs 1,334±1,218 cells/uL, p<0.001) and TCRgd (21±28 vs 141±289 cells/uL, p=0.001) T cells, leading to an increased CD4/CD8 ratio (1.8±1.3 vs 1.4±0.8, p=0.004). Also, decreased levels of CD4 (222±156 cells/uL), CD8 (501±544 cells/uL) and TCRgd (21±40 cells/uL) T cells were observed at time M3 vs. baseline values. No changes (p>0.05) were observed for CD8 and TCRgd for M3 vs. M1, while CD4+ T-cell numbers were significantly reduced (p=0.006), resulting in an inverted CD4/CD8 ratio (0.9±1.0 vs. 1.8±1.3, p=0.005) at the M3 time-point. As regards B cells, the absolute count of both neoplastic and normal B lymphocytes were significantly decreased at time M1 vs. M0 (3,363±9,353 vs 53,521±56,602 CLL cells/uL and 2±6 vs 58±107 normal B-cells/uL, p=0.006 and p<0.001, respectively). Within the normal residual B-cell compartment, we found significantly decreased numbers of immature (0.07±0.22 vs 6.55±21.64 cells/uL, p=0.01) and memory (1.3±14.7 vs 35.1±43.6 cells/uL, p<0.001) B cells -including sIgM (0.5±2.3 vs 14.5±24.8 cells/uL, p<0.001), sIgG (0.2±1.0 vs 11.5±17.2 cells/uL; p<0.001) and sIgA (0.6±3.1 vs 9.5±12.5 cells/uL, p<0.001) memory B cells-. At time M3, decreased (p<0.01) naïve (0.46±2.58 cells/uL) and memory B-cells (1.34±6.75 cells/uL), including IgM (0.46±2.58 cells/uL), IgG (0.34±1.69 cells/uL) and IgA (0.09±0.31 cells/uL), but not immature cells (2.28±8.84 cells/uL, p=0.9), were observed as compared to time M0. Differences did not reach statistical significance when comparing M3 vs. M1. The number of circulating plasma cells did not significantly vary during treatment. Conclusions All PB leucocyte subsets are affected by BR treatment in advanced-stage CLL. Interestingly, at time M3 the CD4+ T-cell subset continues to be decreased, while the other T-cell compartments seem to remain stable. Also, normal B cells are affected by BR treatment, and the depletion induced after one course therapy is maintained even three months after finishing BR therapy, except for immature B cells, that seem to be the first to recover in PB. Further studies will offer a more accurate insight into the biology of cell recovery during and after BR therapy in CLL patients. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Christine Harrer ◽  
Ferdinand Otto ◽  
Georg Pilz ◽  
Elisabeth Haschke-Becher ◽  
Eugen Trinka ◽  
...  

Abstract Background C-X-C chemokine ligand 13 (CXCL13) is frequently elevated in cerebrospinal fluid (CSF) in a variety of inflammatory central nervous system (CNS) diseases, has been detected in meningeal B cell aggregates in brain tissues of multiple sclerosis patients, and proposedly recruits B cells into the inflamed CNS. Besides B cells also follicular helper T (Tfh) cells express the cognate receptor C-X-C chemokine receptor type 5 (CXCR5) and follow CXCL13 gradients in lymphoid tissues. These highly specialized B cell helper T cells are indispensable for B cell responses to infection and vaccination and involved in autoimmune diseases. Phenotypically and functionally related circulating CXCR5+CD4 T cells occur in blood. Their co-recruitment to the inflamed CSF is feasible but unresolved. Methods We approached this question with a retrospective study including data of all patients between 2017 and 2019 of whom immune phenotyping data of CXCR5 expression and CSF CXCL13 concentrations were available. Discharge diagnoses and CSF laboratory parameters were retrieved from records. Patients were categorized as pyogenic/aseptic meningoencephalitis (ME, n = 29), neuroimmunological diseases (NIMM, n = 22), and non-inflammatory neurological diseases (NIND, n = 6). ANOVA models and Spearman’s Rank-Order correlation were used for group comparisons and associations of CXCL13 levels with immune phenotyping data. Results In fact, intrathecal CXCL13 elevations strongly correlated with CXCR5+CD4 T cell frequencies in the total cohort (p < 0.0001, r = 0.59), and ME (p = 0.003, r = 0.54) and NIMM (p = 0.043, r = 0.44) patients. Moreover, the ratio of CSF-to-peripheral blood (CSF/PB) frequencies of CXCR5+CD4 T cells strongly correlated with CXCL13 levels both in the total cohort (p = 0.001, r = 0.45) and ME subgroup (p = 0.005, r = 0.50), indicating selective accumulation. ME, NIMM and NIND groups differed with regard to CSF cell counts, albumin quotient, intrathecal IgG, CXCL13 elevations and CXCR5+CD4 T cells, which were higher in inflammatory subgroups. Conclusion The observed link between intrathecal CXCL13 elevations and CXCR5+CD4 T cell frequencies does not prove but suggests recruitment of possible professional B cell helpers to the inflamed CSF. This highlights CSF CXCR5+CD4 T cells a key target and potential missing link to the poorly understood phenomenon of intrathecal B cell and antibody responses with relevance for infection control, chronic inflammation and CNS autoimmunity.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 778-778
Author(s):  
Takahiro Maeda ◽  
Taha Merghoub ◽  
Lin Dong ◽  
Manami Maeda ◽  
Robin Hobbs ◽  
...  

Abstract LRF (Leukaemia/Lymphoma Related Factor, formerly described as Pokemon, FBI-1 and OCZF, encoded by the Zbtb7a gene) is a transcriptional repressor that belongs to the POK (POZ/BTB and Krüppel) protein family. We recently reported that LRF is a proto-oncogene, which is highly expressed in Non-Hodgkin’s Lymphoma tissues (Nature. 433, 278–85). To elucidate its function in fetal and adult lymphopoiesis, we analyzed LRF knockout mice (Zbtb7a−/−) and the conditional knockout mutants (Zbtb7a flox/−Mx-1cre+), respectively. Zbtb7a −/− mice are embryonic lethal due to severe anemia around 16.5 d.p.c. Absolute number of mature B cells was markedly decreased in 15.5 d.p.c Zbtb7a−/− fetal livers (FL), while total number of the earliest immature B cells (Lin-AA4.1+CD19−B220+) was comparable to wild type (WT) littermates. Flow-Sorted Zbtb7a−/− FL Hematopoietic Stem Cells (FL-HSCs) did not give rise to ProB cells in vitro in an OP9 cell culture system. Furthermore, competitive repopulation assay suggested that the defect in B cell development in Zbtb7a−/− FL was cell-autonomous. Conditional inactivation of LRF in adult mice resulted in a significant decrease of B220+ B cells in the peripheral blood (PB). Absolute numbers of both ProB and PreB cells in the BM were drastically reduced in Zbtb7a flox/−Mx-1cre+ mice after pIpC injections, while PreProB cells were rather accumulated. Zbtb7a flox/−Mx-1cre+ PreProB cells did not give rise to ProB cells in vitro in OP9 cell culture. Unexpectedly, Zbtb7a flox/−Mx-1cre+ PreProB cells ectopically expressed T cell genes (e.g. pTCRα, Notch1, Notch3, Hes1, Gata3, TCF1), while they lacked B-cell specific gene expression (e.g. E2A, Ebf1, Pax5, Rag, VpreB1). In agreement with this finding, Zbtb7a flox/−Mx-1cre+ PreProB cells efficiently differentiated into DP-T cells upon 6 days of culture on OP9-DL1 cells, which overexpress Notch1 ligand Delta-like1. We did not observe a gross defect in the T cell compartment in PB and Thymus of Zbtb7a flox/−Mx-1cre+ mice. However, we observed an accumulation of CD4/8 double positive (DP) T cells in their BM. DP-T cells consisted of nearly 30% of the BM mononuclear cells (MNCs) in Zbtb7a flox/−Mx-1cre+ mice. Since the phenotype of LRF conditional knockout mice is reminiscent of that of ICN1 (Intracellular domain of Notch1) overexpression in the mouse BM, we hypothesized that LRF could oppose Notch1 signaling pathway at the early lymphoid progenitor stage. We found that pTCRα, a Notch1 target gene, is highly up-regulated in Zbtb7a flox/−Mx-1cre+ CLPs and that LRF transcriptionally represses mouse pTCRα promoter activity. Our finding strongly indicates that LRF loss at the early lymphoid progenitor stage causes aberrant de-repression of T-cell specific genes, which results in the block of B cell development and generation of T cells in the BM. We therefore propose that LRF is essential in instructing the early lymphoid progenitors into B cell lineage by repressing T cell-instructive signal produced by Notch.


2017 ◽  
Vol 86 (2) ◽  
Author(s):  
Raymond M. Johnson ◽  
Hong Yu ◽  
Norma Olivares Strank ◽  
Karuna Karunakaran ◽  
Ying Zhu ◽  
...  

ABSTRACTSurveillance and defense of the enormous mucosal interface with the nonsterile world are critical to protecting the host from a wide range of pathogens.Chlamydia trachomatisis an intracellular bacterial pathogen that replicates almost exclusively in the epithelium of the reproductive tract. The fallopian tubes and vagina are poorly suited to surveillance and defense, with limited immune infrastructure positioned near the epithelium. However, a dynamic process during clearing primary infections leaves behind new lymphoid clusters immediately beneath the epithelium. These memory lymphocyte clusters (MLCs) harboring tissue-resident memory (Trm) T cells are presumed to play an important role in protection from subsequent infections. Histologically, humanChlamydiaMLCs have prominent B cell populations. We investigated the status of genital tract B cells duringC. muridaruminfections and the nature of T cells recovered from immune mice using immune B cells as antigen-presenting cells (APCs). These studies revealed a genital tract plasma B cell population and a novel genital tract CD4 T cell subset producing both gamma interferon (IFN-γ) and interleukin-13 (IL-13). A panel of CD4 T cell clones and microarray analysis showed that the molecular fingerprint of CD4γ13 T cells includes a Trm-like transcriptome. Adoptive transfer of aChlamydia-specific CD4γ13 T cell clone completely prevented oviduct immunopathology without accelerating bacterial clearance. Existence of a CD4γ13 T cell subset provides a plausible explanation for the observation that human peripheral blood mononuclear cell (PBMC)Chlamydia-specific IFN-γ and IL-13 responses predict resistance to reinfection.


2004 ◽  
Vol 78 (13) ◽  
pp. 6827-6835 ◽  
Author(s):  
Rebecca L. Sparks-Thissen ◽  
Douglas C. Braaten ◽  
Scott Kreher ◽  
Samuel H. Speck ◽  
Herbert W. Virgin

ABSTRACT CD4 T cells are important for control of infection with murine gammaherpesvirus 68 (γHV68), but it is not known whether CD4 T cells function via provision of help to other lymphocyte subsets, such as B cells and CD8 T cells, or have an independent antiviral function. Moreover, under conditions of natural infection, the CD4 T-cell response is not sufficient to eliminate infection. To determine the functional capacities of CD4 T cells under optimal or near-optimal conditions and to determine whether CD4 T cells can control γHV68 infection in the absence of CD8 T cells or B cells, we studied the effect of ovalbumin (OVA)-specific CD4 T cells on infection with a recombinant γHV68 that expresses OVA. OVA-specific CD4 T cells limited acute γHV68 replication and prolonged the life of infected T-cell receptor-transgenic RAG (DO.11.10/RAG) mice, demonstrating CD4 T-cell antiviral activity, independent of CD8 T cells and B cells. Despite CD4 T-cell-mediated control of acute infection, latent infection was established in DO.11.10/RAG mice. However, OVA-specific CD4 T cells reduced the frequency of latently infected cells both early (16 days postinfection) and late (42 days postinfection) after infection of mice containing CD8 T cells and B cells (DO.11.10 mice). These results show that OVA-specific CD4 T cells have B-cell and CD8 T-cell-independent antiviral functions in the control of acute infection and can, in the absence of preexisting CD8 T-cell or B-cell immunity, inhibit the establishment of gammaherpesvirus latency.


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