scholarly journals Small B cells as antigen-presenting cells in the induction of tolerance to soluble protein antigens.

1992 ◽  
Vol 175 (1) ◽  
pp. 131-138 ◽  
Author(s):  
E E Eynon ◽  
D C Parker
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Soluble Protein ◽  
Antigen Presenting Cells ◽  
Scid Mice ◽  
Protein Antigens ◽  
Helper T Cell ◽  
Cell Compartment ◽  
Antigen Presenting

We have investigated the ability of resting B cells, acting as antigen-presenting cells, to induce tolerance to soluble protein antigens in mice, using an antigen targeted specifically to B cells. We inject mice intravenously with ultracentrifuged Fab fragments of rabbit anti-mouse immunoglobulin D (IgD) (Fab anti-delta). Treatment with Fab anti-delta results in profound tolerance to challenge with 100 micrograms Fab nonimmune rabbit Ig (Fab NRG), precipitated in alum, as measured by antibody production. Tolerance to rabbit Fab is antigen specific, since the treated mice make normal antibody responses to a control antigen, chicken Ig. Tolerance is dependent on antigen presentation by B cells, since intravenous injection of soluble Fab NRG, which is not targeted to B cells, results in a much lower frequency and degree of tolerance, especially at lower doses. T cell help in this system is affected, since T cells from Fab anti-delta-treated mice fail to provide help for an adoptive primary antibody response to Fab NRG when transferred together with normal B cells into severe combined immunodeficient (SCID) mice. The antigen-specific B cell compartment is also affected during tolerance induction, since B cells from treated animals make less antibody than normal B cells when transferred into SCID mice with normal T cells. Although the mechanism of nonresponsiveness in the helper T cell compartment remains to be determined, we think it is likely that the precursors of helper T cells are inactivated or deleted by encountering antigen presented by small, resting B cells, which lack accessory signals necessary to induce helper T cell proliferation and differentiation to effector function.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Abortive Proliferation of Rare T Cells Induced by Direct or Indirect Antigen Presentation by Rare B Cells In Vivo

1998 ◽  
Vol 187 (10) ◽  
pp. 1611-1621 ◽  
Author(s):  
Sarah E. Townsend ◽  
Christopher C. Goodnow
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Antigen Presentation ◽  
Cell Fate ◽  
T Cell Activation ◽  
Cell Activation ◽  
Antigen Presenting Cells ◽  
Antigen Presenting

Antigen-specific B cells are implicated as antigen-presenting cells in memory and tolerance responses because they capture antigens efficiently and localize to T cell zones after antigen capture. It has not been possible, however, to visualize the effect of specific B cells on specific CD4+ helper T cells under physiological conditions. We demonstrate here that rare T cells are activated in vivo by minute quantities of antigen captured by antigen-specific B cells. Antigen-activated B cells are helped under these conditions, whereas antigen-tolerant B cells are killed. The T cells proliferate and then disappear regardless of whether the B cells are activated or tolerant. We show genetically that T cell activation, proliferation, and disappearance can be mediated either by transfer of antigen from antigen-specific B cells to endogenous antigen-presenting cells or by direct B–T cell interactions. These results identify a novel antigen presentation route, and demonstrate that B cell presentation of antigen has profound effects on T cell fate that could not be predicted from in vitro studies.

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 Efficient T cell–B cell collaboration guides autoantibody epitope bias and onset of celiac disease

2019 ◽  
Vol 116 (30) ◽  
pp. 15134-15139 ◽  
Author(s):  
Rasmus Iversen ◽  
Bishnudeo Roy ◽  
Jorunn Stamnaes ◽  
Lene S. Høydahl ◽  
Kathrin Hnida ◽  
...  
Keyword(s):  
T Cells ◽  
Celiac Disease ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Antigen Presentation ◽  
Disease Onset ◽  
Antigen Presenting Cells ◽  
Autoantibody Production ◽  
Antigen Presenting

B cells play important roles in autoimmune diseases through autoantibody production, cytokine secretion, or antigen presentation to T cells. In most cases, the contribution of B cells as antigen-presenting cells is not well understood. We have studied the autoantibody response against the enzyme transglutaminase 2 (TG2) in celiac disease patients by generating recombinant antibodies from single gut plasma cells reactive with discrete antigen domains and by undertaking proteomic analysis of anti-TG2 serum antibodies. The majority of the cells recognized epitopes in the N-terminal domain of TG2. Antibodies recognizing C-terminal epitopes interfered with TG2 cross-linking activity, and B cells specific for C-terminal epitopes were inefficient at taking up TG2-gluten complexes for presentation to gluten-specific T cells. The bias toward N-terminal epitopes hence reflects efficient T-B collaboration. Production of antibodies against N-terminal epitopes coincided with clinical onset of disease, suggesting that TG2-reactive B cells with certain epitope specificities could be the main antigen-presenting cells for pathogenic, gluten-specific T cells. The link between B cell epitopes, antigen presentation, and disease onset provides insight into the pathogenic mechanisms of a T cell-mediated autoimmune condition.

scholarly journals T cell-independent antibody-mediated clearance of polyoma virus in T cell-deficient mice.

1996 ◽  
Vol 183 (2) ◽  
pp. 403-411 ◽  
Author(s):  
E Szomolanyi-Tsuda ◽  
R M Welsh
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Nude Mice ◽  
Knockout Mice ◽  
Cell Receptor ◽  
Genetically Engineered ◽  
Scid Mice ◽  
Myeloproliferative Disease ◽  
Alpha Beta

Polyomavirus (PyV) infection of SCID mice, which lack functional T and B cells, leads to a lethal acute myeloproliferative disease (AMD) and to high levels of virus replication in several organs by two wk after infection. This is in contrast to infection of T cell-deficient athymic nude mice, which are resistant to acute PyV-induced disease and poorly replicate the virus in their organs. This major difference in the virus load and in the outcome of PyV infection between SCID and nude mice suggested that an efficient, T cell-independent antiviral mechanism operates in T cell-deficient, PyV infected mice. To investigate this possibility, mice with different genetically engineered T and/or B cell deficiencies and SCID mice adoptively reconstituted with B and/or T cells were infected with PyV. The results indicated that the presence of B cells in the absence of T cells protected mice from the AMD, and this was accompanied by a major reduction of PyV in all organs tested. Sera from PyV-infected T cell receptor (TCR) alpha beta knockout or TCR alpha beta gamma delta knockout mice contained IgG2a antibodies to PyV. Sera or purified immunoglobulin fractions from PyV-infected TCR alpha beta knockout mice protected SCID mice from the PyV-induced AMD. To our knowledge, this is the first report of an effective T cell-independent antibody response clearing a virus and changing the outcome of infection from 100% mortality to 100% survival.

scholarly journals Development of Stable Chimeric IL-15 for Trans-Presentation by the Antigen Presenting Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Manoj Patidar ◽  
Naveen Yadav ◽  
Sarat K. Dalai
Keyword(s):  
T Cells ◽  
T Cell ◽  
Half Life ◽  
Therapeutic Potential ◽  
Chimeric Protein ◽  
Antigen Presenting Cells ◽  
T Cell Response ◽  
Antigen Presenting

IL-15 is one of the important biologics considered for vaccine adjuvant and treatment of cancer. However, a short half-life and poor bioavailability limit its therapeutic potential. Herein, we have structured IL-15 into a chimeric protein to improve its half-life enabling greater bioavailability for longer periods. We have covalently linked IL-15 with IgG2 base to make the IL-15 a stable chimeric protein, which also increased its serum half-life by 40 fold. The dimeric structure of this kind of IgG based biologics has greater stability, resistance to proteolytic cleavage, and less frequent dosing schedule with minimum dosage for achieving the desired response compared to that of their monomeric forms. The structured chimeric IL-15 naturally forms a dimer, and retains its affinity for binding to its receptor, IL-15Rβ. Moreover, with the focused action of the structured chimeric IL-15, antigen-presenting cells (APC) would transpresent chimeric IL-15 along with antigen to the T cell, that will help the generation of quantitatively and qualitatively better antigen-specific memory T cells. In vitro and in vivo studies demonstrate the biological activity of chimeric IL-15 with respect to its ability to induce IL-15 signaling and modulating CD8+ T cell response in favor of memory generation. Thus, a longer half-life, dimeric nature, and anticipated focused transpresentation by APCs to the T cells will make chimeric IL-15 a super-agonist for memory CD8+ T cell responses.

Abstract 252: Interleukin-27 Signaling Regulates Myeloid Cells Activation in Atherosclerosis

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Iuliia Peshkova ◽  
Aliia Fatkhullina ◽  
Ekaterina Koltsova
Keyword(s):  
T Cells ◽  
T Cell ◽  
Inflammatory Cytokines ◽  
Antigen Presenting Cells ◽  
Atherosclerotic Lesions ◽  
Mediators Of Inflammation ◽  
Antigen Presenting ◽  
Deficient Mice ◽  
Pro Inflammatory Cytokines

Atherosclerosis is a lipid-driven inflammatory disease characterized by the progressive plaque growth in the vessels. Cytokines are important mediators of inflammation and atherosclerosis. While pro-inflammatory cytokines were extensively investigated, little is known about the role of anti-inflammatory cytokines as to their ability to control vascular inflammation. We tested whether immunoregulatory IL-27R signaling is important to control inflammation in mouse models of atherosclerosis. We found that atherosclerosis-prone mice with hematopoietic deficiency of IL-27R ( Ldlr -/- mice reconstituted with bone marrow from Il27ra -/- ) or global deficiency ( Il27ra -/- x Apoe -/- ) developed significantly larger atherosclerotic lesions compared to controls. Atherosclerotic lesions in IL-27R deficient mice contained more CD45 + leukocytes and CD4 + T cells, which produced pro-atherogenic cytokines IL-17A and TNF-α. These cytokines normally suppressed by IL-27, regulated the expression of CCL2 and other chemokines, which in turn led to accumulation of myeloid CD11b + and CD11c + cells in atherosclerotic aortas. Using two-photon microscopy, we found enhanced interactions between antigen presenting cells and T cells in the aortas of IL-27R deficient mice accompanied by enhanced CD4 T cell proliferation. Moreover, macrophages in Il27ra -/- aortas also demonstrated enhanced ability to produce pro-inflammatory cytokines, including IL-1. The blockade of IL-1R signaling, however, strongly suppressed atherosclerosis progression in IL-27R deficient but not control mice, suggesting an important role of IL-27 in the regulation of IL-1 production in atherosclerosis. Overall, our data demonstrate that IL-27R signaling in atherosclerosis is required to control function of antigen presenting cells modulating subsequent T cell activation in the aortas. Moreover, it controls macrophage activation and pro-inflammatory myeloid cell-derived cytokine production. These mechanisms altogether curb pathogenic T cell lineage differentiation and, thus, atherosclerosis, suggesting potent anti-atherogenic role of IL-27.

scholarly journals Distinct Roles of α7 nAChRs in Antigen-Presenting Cells and CD4+ T Cells in the Regulation of T Cell Differentiation

2019 ◽  
Vol 10 ◽  
Author(s):  
Masato Mashimo ◽  
Masayo Komori ◽  
Yuriko Y. Matsui ◽  
Mami X. Murase ◽  
Takeshi Fujii ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Cd4 T Cells ◽  
Antigen Presenting Cells ◽  
T Cell Differentiation ◽  
Antigen Presenting ◽  
Α7 Nachrs
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