scholarly journals Interleukin-6/STAT3 signaling regulates the ability of naive T cells to acquire B-cell help capacities

Blood ◽  
2009 ◽  
Vol 113 (11) ◽  
pp. 2426-2433 ◽  
Author(s):  
Fouad Eddahri ◽  
Sébastien Denanglaire ◽  
Fabrice Bureau ◽  
Rosanne Spolski ◽  
Warren J. Leonard ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Interleukin 6 ◽  
Cell Activation ◽  
B Cell Activation ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Helper Cells

Abstract The conditions leading to the activation/differentiation of T-helper (Th) cells dedicated for B-cell antibody production are still poorly characterized. We now demonstrate that interleukin-6 (IL-6) promotes the differentiation of naive T lymphocytes into helper cells able to promote B-cell activation and antibody secretion. IL-6–driven acquisition of B-cell help capacity requires expression of the signal transducer and activator of transcription 3 (STAT3), but not STAT4 or STAT6 transcription factors, suggesting that the ability to provide help to B cells is not restricted to a well-defined Th1 or Th2 effector population. T cell–specific STAT3-deficient mice displayed reduced humoral responses in vivo that could not be related to an altered expansion of CXCR5-expressing helper T cells. IL-6 was shown to promote IL-21 secretion, a cytokine that was similarly found to promote the differentiation of naive T cells into potent B-cell helper cells. Collectively, these data indicate that the ability to provide B-cell help is regulated by IL-6/IL-21 through STAT3 activation, independently of Th1, Th2, Th17, or follicular helper T cell (TFH) differentiation.

scholarly journals Antigen-independent activation of naive and memory resting T cells by a cytokine combination.

1994 ◽  
Vol 180 (3) ◽  
pp. 1159-1164 ◽  
Author(s):  
D Unutmaz ◽  
P Pileri ◽  
S Abrignani
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Effector Function ◽  
Necrosis Factor Alpha ◽  
Naive T Cells ◽  
Naïve T Cells

We investigated whether human resting T cells could be activated to proliferate and display effector function in the absence of T cell receptor occupancy. We report that combination of interleukin 2 (IL-2), tumor necrosis factor alpha, and IL-6 activated highly purified naive (CD45RA+) and memory (CD45RO+) resting CD4+ T cells to proliferate. Under this condition, memory resting T cells could also display effector function as measured by lymphokine synthesis and help for immunoglobulin production by B cells. This novel Ag-independent pathway of T cell activation may play an important role in vivo in recruiting effector T cells at the site of immune response and in maintaining the clonal size of memory T cells in the absence of antigenic stimulation. Moreover, cytokines can induce proliferation of naive T cells without switch to memory phenotype and this may help the maintenance of the peripheral pool of naive T cells.

scholarly journals B cell-intrinsic requirement for WNK1 kinase in T cell-dependent antibody responses

2021 ◽  
Author(s):  
Darryl Hayward ◽  
Lesley Vanes ◽  
Stefanie Wissmann ◽  
Sujana Sivapatham ◽  
Harald Hartweger ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Migration ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Plasma Cells ◽  
Antibody Responses ◽  
B Cell Activation

AbstractMigration and adhesion play critical roles in B cells, regulating recirculation between lymphoid organs, migration within lymphoid tissue and interaction with CD4+ T cells. However, there is limited knowledge of how B cells integrate chemokine receptor and integrin signaling with B cell activation to generate efficient humoral responses. Here we show that the WNK1 kinase, a regulator of migration and adhesion, is essential in B cells for T-dependent antibody responses. We demonstrate that WNK1 transduces signals from the BCR, CXCR5 and CD40, and using intravital imaging we show that WNK1 regulates migration of naive and activated B cells, and their interactions with T cells. Unexpectedly, we show that WNK1 is required for BCR- and CD40-induced proliferation, acting through the OXSR1 and STK39 kinases, and for efficient B cell-T cell collaboration in vivo. Thus, WNK1 is critical for humoral immune responses, by regulating B cell migration, adhesion and T cell-dependent activation.SummaryThe WNK1 kinase is essential in B cells for T-dependent antibody responses because it is activated by signaling from BCR, CXCR5 and CD40 and regulates B cell migration, adhesion, T-dependent activation, and differentiation into germinal center B cells and plasma cells.

scholarly journals Activated CLL B Cells Variably Modulate microRNA-155 Levels in Naïve CD4+ T Cells, and the Direction and Magnitude of microRNA-155 Change Correlates with Th17 Levels and Clinical Course

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4402-4402
Author(s):  
Byeongho Jung ◽  
Gerardo Ferrer ◽  
Pui Yan Chiu ◽  
Rukhsana Aslam ◽  
Florencia Palacios ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Th17 Cells ◽  
Cell Activation ◽  
B Cell Activation ◽  
Mutation Status ◽  
Naive T Cells ◽  
Naïve T Cells

Abstract T-helper 17 (Th17) cells constitute a subset of T cells that characteristically secrete IL-17. In addition to their normal adaptive immune functions, Th17 cells also play roles in supporting dysfunctional immune responses found in autoimmunity and cancer. Several studies suggest that Th17 cells play a protective role in chronic lymphocytic leukemia (CLL). For example, CLL patients exhibit varied levels of circulating Th17 cells, and elevated levels positively correlate with better clinical outcome regardless of IGHV-mutation status. To understand this relationship and elucidate the cellular and molecular mechanisms of Th17 generation in CLL, in particular the role of microRNAs known to affect Th17 development, we investigated cross-talk between naïve CD4+ T cells and CLL B cells. Moreover, since intraclonal leukemic B-cell subpopulations differing in time since cell birth/division can exhibit different functional effects on antigen presentation, we explored the effect of B-cell activation on this T - leukemic B-cell dialogue and how it affects the generation of Th17 cells. To determine potential candidates differentially expressed in CLL, we conducted genome-wide single-cell expression analysis comparing fluorescence activated cell sorting (FACS)-purified mature Th17 cells (CD3+/CD4+/CD45+/CD161+/CCR6+/ CCR4+/CXCR3-) from CLL patients and healthy donors. Selected candidate genes met the criteria of >7-fold increase in expression in CLL, adjusted p-value <1.5 x 10-6, and link to lymphocyte biology. Among selected candidates, microRNA-155 (miR-155), a critical regulator of Th17 differentiation, was found. Follow-up real time, quantitative PCR (RT-qPCR) analyses indicated a significant increase (P < 0.01) in miR-155 expression in CLL Th17 cells as compared to Th17 cells from healthy controls. Since there was no difference in expression between naïve T cells (CD3+/CD4+/CD62L+/CD45RO-) cells, this suggested a CLL-unique mechanism of miR-155 modulation. To determine whether CLL cells directly influence miR-155 levels in naïve CD4+ T cells, co-culture experiments using autologous leukemic or healthy B cells were carried out. FACS-purified peripheral blood naïve CD4+ T cells and B cells from CLL patients and from age-matched healthy controls were co-cultured for 3 days, and expression of T-cell miR-155 was determined by RT-qPCR. In the presence of unstimulated CLL or healthy B cells, miR-155 expression in naïve T cells remained unchanged across all co-cultures. However, upon activation, healthy and leukemic B cells exerted differential effects on miR-155 expression in autologous naïve T cells. In the presence of autologous healthy B cells pre-activated with CpG-ODN2006 and IL-15, miR-155 expression in healthy naïve T cells was significantly increased (P = 0.0313) across all samples. Conversely, CLL naïve T cells co-cultured with autologous, pre-activated leukemic B cells showed heterogeneous modulation of miR-155. Of interest, the magnitude and direction of miR-155 changes in the autologous CLL co-cultures positively correlated not only with circulating Th17 levels (P = 0.019), as determined by flow cytometry, but also with patient time to first treatment (P = 0.0003). Moreover, when samples were divided into 2 groups based on an increase or decrease in miR-155 levels after exposure to activated compared to resting CLL B cells, a significant difference was seen with median survival of 237 months and 67 months, respectively (P = 0.005). Consistent with previous observations from our lab, this correlation was independent of various prognostic markers, including IGHV-mutation status. Our results suggest the existence of a miR-155 modulatory mechanism mediated by CLL B cells that differs based on leukemic B-cell activation state and the degree of change occurring when naïve T cells are exposed to resting vs. activated B cells. Moreover, this variable effect in CLL patients differs from that in normal individuals, and the effect influences number of Th17 cells and patient outcome. Studies are underway to determine the effects that leukemic B cells, unstimulated or CpG-ODN2006 + IL-15 stimulated, have on autologous naïve T-cell maturation into Th17 cells, and the extent that this process depends on the variable miR-155 modulatory capacity of leukemic B cells. Disclosures Chiorazzi: Janssen, Inc: Consultancy; AR Pharma: Equity Ownership.

scholarly journals Role of T-cell activation in salt-sensitive hypertension

2019 ◽  
Vol 316 (6) ◽  
pp. H1345-H1353 ◽  
Author(s):  
Jiafa Ren ◽  
Steven D. Crowley
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
T Subsets ◽  
Underlying Mechanisms ◽  
Salt Sensitive Hypertension

The contributions of T lymphocytes to the pathogenesis of salt-sensitive hypertension has been well established. Under hypertensive stimuli, naive T cells develop into different subsets, including Th1, Th2, Th17, Treg, and cytotoxic CD8+ T cells, depending on the surrounding microenviroment in organs. Distinct subsets of T cells may play totally different roles in tissue damage and hypertension. The underlying mechanisms by which hypertensive stimuli activate naive T cells involve many events and different organs, such as neoantigen presentation by dendritic cells, high salt concentration, and the milieu of oxidative stress in the kidney and vasculature. Infiltrating and activated T subsets in injured organs, in turn, exert considerable impacts on tissue dysfunction, including sodium retention in the kidney, vascular stiffness, and remodeling in the vasculature. Therefore, a thorough knowledge of T-cell actions in hypertension may provide novel insights into the development of new therapeutic strategies for patients with hypertension.

scholarly journals T Cell Accumulation in B Cell Follicles Is Regulated by Dendritic Cells and Is Independent of B Cell Activation

2003 ◽  
Vol 197 (2) ◽  
pp. 195-206 ◽  
Author(s):  
Simon Fillatreau ◽  
David Gray
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
B Cell Activation ◽  
Cell Accumulation ◽  
Antigen Presenting ◽  
Deficient Mice

We investigated the mechanism of CD4 T cell accumulation in B cell follicles after immunization. Follicular T cell numbers were correlated with the number of B cells, indicating B cell control of the niche that T cells occupy. Despite this, we found no role for B cells in the follicular migration of T cells. Instead, T cells are induced to migrate into B cell follicles entirely as a result of interaction with dendritic cells (DCs). Migration relies on CD40-dependent maturation of DCs, as it did not occur in CD40-deficient mice but was reconstituted with CD40+ DCs. Restoration was not achieved by the activation of DCs with bacterial activators (e.g., lipopolysaccharide, CpG), but was by the injection of OX40L–huIgG1 fusion protein. Crucially, the up-regulation of OX40L (on antigen-presenting cells) and CXCR-5 (on T cells) are CD40-dependent events and we show that T cells do not migrate to follicles in immunized OX40-deficient mice.

Steady-state dendritic cells expressing cognate antigen terminate memory CD8+ T-cell responses

Blood ◽  
2008 ◽  
Vol 111 (4) ◽  
pp. 2091-2100 ◽  
Author(s):  
Tony J. Kenna ◽  
Ranjeny Thomas ◽  
Raymond J. Steptoe
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Steady State ◽  
T Cell ◽  
Developmental Plasticity ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Cognate Antigen ◽  
Costimulatory Signals

Antigen stimulation of naive T cells in conjunction with strong costimulatory signals elicits the generation of effector and memory populations. Such terminal differentiation transforms naive T cells capable of differentiating along several terminal pathways in response to pertinent environmental cues into cells that have lost developmental plasticity and exhibit heightened responsiveness. Because these cells exhibit little or no need for the strong costimulatory signals required for full activation of naive T cells, it is generally considered memory and effector T cells are released from the capacity to be inactivated. Here, we show that steady-state dendritic cells constitutively presenting an endogenously expressed antigen inactivate fully differentiated memory and effector CD8+ T cells in vivo through deletion and inactivation. These findings indicate that fully differentiated effector and memory T cells exhibit a previously unappreciated level of plasticity and provide insight into how memory and effector T-cell populations may be regulated.

Distinct Patterns of Systemic Immune Dysregulation in Indolent B Cell Lymphoma

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3780-3780
Author(s):  
Petros Christopoulos ◽  
Dietmar Pfeifer ◽  
Kilian Bartholomé ◽  
Marie Follo ◽  
Paul Fisch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Dysregulation ◽  
Cell Phenotype ◽  
Cd4 Cells ◽  
Th Cells

Abstract Mutual interactions of the neoplastic clone with the non-neoplastic immune system may influence immune function and the clinical behaviour of lymphoma. Individuals with immunodeficiency or autoimmune diseases have an increased risk for lymphoma development. The immune microenvironment appears to have a major influence on the prognosis of indolent lymphomas. Conversely, leukemic lymphomas may also cause immunodeficiency: In CLL, direct lymphoma-T cell interactions, which may occur ubiquitously, induce defects in T cell functions (Görgün et al., 2005). We demonstrate here a systemic perturbance of cellular immunity in a prospective study in patients with untreated de novo, limited-stage, non-leukemic indolent B cell lymphomas. Calibrated, quantitative flow cytometry showed a significant reduction of circulating T helper (TH) cells in follicular (FL; n=11; p<0.005) and extranodal marginal zone (eMZL; n=7; p<0.05) lymphomas compared to age-matched healthy persons. Naive TH cells were strongest reduced to 51% (p=0.002) in FL and 24% (p=0.002) in eMZL. Regulatory T cells (CD4loCD25hi; CD4+FoxP3+) were affected less (p=0.04). T cell receptor excision circles within CD4+ cells as assessed by quantitative PCR were not altered in lymphoma patients, indicating neither increased increased thymic output nor homeostatic T cell proliferation to compensate the contracted pool of naive T cells. The TH memory compartments, the global numbers and subsets of CD8+ T (TC) cells, NK, and NKT cells were normal. The peripheral lymphocyte composition was altered differently in early CLL (stage Binet A; leukocyte counts < 28/nl; n=9) with increased TH (p=0.04) and TC (p=0.0002) cells. No significant changes in lymphocyte subsets were noted in monoclonal gammopathy of unknown significance (MGUS; n=6). The functional T cell phenotype in vivo was altered in eMZL as indicated by four- and twofold increased HLA-DR+ TH (p<0.02) and TC (p=0.05) cells. This T cell activation may also explain an increased fraction of terminally differentiated (CD45RA+CD27−) TC cells (p<0.05). Qualitatively similar abnormalities were seen in FL, where activated TH cells were more frequent (p<0.005), and in CLL, where activated TC cells were increased (p=0.04), but not in MGUS. Finally, an increased T cell activation may effect senescence, which was evident by elevated fractions of CD57+ and CD28− cells within the TC compartment of FL/eMZL (p<0.05) and CLL (p<0.005) patients. The activated T cell phenotype was paralleled by increased upregulation of activation markers (CD25, OX40, CD95, p<0.005 for each) and proliferation (p<0.005) by purified CD4 cells from FL/eMZL patients in a standardized anti-CD3/anti-CD28 stimulation culture. None of these parameters was significantly aberrant in CLL. Expression of the activation marker CD69, which is downregulated rapidly after T cell activation, was markedly reduced both in vivo and after in vitro stimulation in FL/eMZL. Collectively, these data demonstrate a global, “preactivated” and presenescent state of peripheral T cells in non-leukemic, indolent T cell lymphomas. Finally, a shift towards TH2 cells was evident in FL/eMZL TH stimulation cultures by increased secretion of IL-4 and IL-5 (p=0.01), but not of IL-2, IFNg, IL-10, and TNFa. This cytokine pattern was absent in CLL and MGUS. The TH2 shift, and the qualitative difference in the immune status in FL/eMZL versus CLL was validated by gene expression profiling of stimulated TH cells with Affymetrix U133 arrays. KEGG annotation revealed decreased expression of proximal TCR signalling molecules and TCR/CD28 transduction pathways with the exception of NFAT in FL/eMZL and CLL. Extensive correlative analyses between gene expression profiles and functional data indicated at least two distinct immune dysregulation patterns: A hyperreactivity/TH2 pattern which is operational even in early disease; and a B cell burden-dependent impairment of TCR signalling. The latter pattern predominates in CLL, which has a comparatively high B cell burden in early disease. These data are clinically relevant since we demonstrate in a prospective trial that untreated FL/eMZL patients fail to respond to protective hepatitis B vaccination (p<0.005). Precise definition of functional T cell defects will permit to study the causes, the prognostic influence, and potential reversibility of immune dysregulation patterns in indolent B cell lymphomas.

A spectrum of biophysical interaction modes between T cells and different antigen-presenting cells during priming in 3-D collagen and in vivo

Blood ◽  
2004 ◽  
Vol 104 (9) ◽  
pp. 2801-2809 ◽  
Author(s):  
Matthias Gunzer ◽  
Carsten Weishaupt ◽  
Anja Hillmer ◽  
Yasmin Basoglu ◽  
Peter Friedl ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Antigen Presenting Cells ◽  
Model Systems ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Antigen Presenting ◽  
Activated B Cells

Abstract For activation T cells engage antigen-presenting cells (APCs) in lymphatic tissues. The contact duration and kinetics (static versus dynamic) vary considerably in different model systems; however, it is unclear whether T cells, APCs, or the environment are responsible for the observed discrepancies. Using 3-D collagen matrices as structural scaffold, we directly compared the kinetics of T-cell engagement and activation by functionally major APC types, ie, dendritic cells (DCs) and resting or activated B cells. Resting B cells engaged T cells in long-lived (several hours), adhesive, and leukocyte function-associated antigen-1 (LFA-1)-dependent conjugates in 3-D collagen as well as in intact lymph nodes in vivo. DCs and preactivated B cells, however, supported predominantly dynamic, short-lived (minutes), and sequential contacts to T cells that were dependent on high cytoskeletal activity of the APCs but could not be inhibited by anti-LFA-1 treatment. Naive T cells were most strongly activated by DCs and activated B cells, whereas resting B cells were 100-fold less efficient to induce T-cell proliferation. Thus, in the same 3-D environment, naive T cells respond with a spectrum of different interaction modes dependent on the type and activation state of the APCs. Thereby, more dynamic interaction kinetics is positively correlated with higher T-cell priming efficiency. (Blood. 2004;104: 2801-2809)

scholarly journals Antigen presentation by resting B cells. Radiosensitivity of the antigen-presentation function and two distinct pathways of T cell activation.

1984 ◽  
Vol 159 (3) ◽  
pp. 881-905 ◽  
Author(s):  
J D Ashwell ◽  
A L DeFranco ◽  
W E Paul ◽  
R H Schwartz
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Antigen Presentation ◽  
Cell Activation ◽  
T Cell Proliferation ◽  
B Cell Activation ◽  
Antigen Presenting

In this report we have examined the ability of small resting B cells to act as antigen-presenting cells (APC) to antigen-specific MHC-restricted T cells as assessed by either T cell proliferation or T cell-dependent B cell stimulation. We found that 10 of 14 in vitro antigen-specific MHC-restricted T cell clones and lines and three of four T cell hybridomas could be induced to either proliferate or secrete IL-2 in the presence of lightly irradiated (1,000 rads) purified B cells and the appropriate foreign antigen. All T cell lines and hybridomas were stimulated to proliferate or make IL-2 by macrophage- and dendritic cell-enriched populations and all T cells tested except one hybridoma caused B cell activation when stimulated with B cells as APC. Furthermore, lightly irradiated, highly purified syngeneic B cells were as potent a source of APC for inducing B cell activation as were low density dendritic and macrophage-enriched cells. Lymph node T cells freshly taken from antigen-primed animals were also found to proliferate when cultured with purified B cells and the appropriate antigen. Thus, small resting B cells can function as APC to a variety of T cells. This APC function was easily measured when the cells were irradiated with 1,000 rads, but was greatly diminished or absent when they were irradiated with 3,300 rads. Thus, the failure of some other laboratories to observe this phenomenon may be the result of the relative radiosensitivity of the antigen-presenting function of the B cells. In addition, this radiosensitivity allowed us to easily distinguish B cell antigen presentation from presentation by the dendritic cell and macrophage, as the latter was resistant to 3,300 rads. Finally, one T cell clone that failed to proliferate when B cells were used as APC was able to recruit allogeneic B cells to proliferate in the presence of syngeneic B cells and the appropriate antigen. This result suggests that there are at least two distinct pathways of activation in T cells, one that leads to T cell proliferation and one that leads to the secretion of B cell recruitment factor(s).

scholarly journals B lymphocytes in vivo fail to prime naive T cells but can stimulate antigen-experienced T lymphocytes.

1993 ◽  
Vol 177 (3) ◽  
pp. 679-690 ◽  
Author(s):  
F Ronchese ◽  
B Hausmann
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Class Ii ◽  
T Cell Response ◽  
Scid Mice ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Cell Responses

The ability of B cells or macrophages and dendritic cells (DC) to elicit class II-restricted T cell responses in vivo was compared using a mouse chimera model. Severe combined immunodeficient (SCID) mice (H-2d), reconstituted either with T or T+B lymphocytes from (H-2d x H-2b) donors, were immunized subcutaneously with protein antigen (Ag) to induce a class II-restricted T cell response. The frequency and major histocompatibility complex restriction of the resulting Ag-specific T cells were analyzed to establish whether B cells were necessary for the induction of class II-restricted T cell responses, and to determine the cell type on which priming had occurred. The results indicated that: (a) B cells are not necessary for the induction of a class II-restricted T cell response in vivo, as the frequencies of interleukin 2 (IL-2)- or IL-3-secreting T cells induced in the presence or absence of B cells were comparable. (b) Activation of naive T cells requires presentation of Ag on DC; Ag presented only on B cells is not sufficient to elicit a response. No H-2b-restricted, IL-3-secreting cells could in fact be detected in SCID mice reconstituted with naive (H-2d x H-2b) T cells and nonimmune or antigen-primed (H-2d x H-2b) B cells. (c) Previously primed T cells are able to be stimulated by Ag presented by both B cells and DC. H-2b-restricted, IL-3-secreting cells could in fact be readily demonstrated in SCID mice reconstituted with antigen-primed (H-2d x H-2b) T and B cells. Irrespective of whether the T cells were naive or previously activated, B cells were able to respond with an Ag-specific immunoglobulin G response, indicating that B cells were functional and able to present Ag in order to receive specific T cell help. Therefore, it appears that B cells are not necessary and do not participate in the initial priming of T cells; however, Ag presented by B cells can reactivate previously primed T cells. Taken together, these data indicate that during the course of an immune response Ag is first presented to naive T cells via DC, and only subsequently primed T cells can be stimulated by Ag presented by B cells.

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