scholarly journals Niche-specific MHC II and PD-L1 regulate CD4+CD8αα+ intraepithelial lymphocyte differentiation

2021 ◽  
Vol 218 (4) ◽  
Author(s):  
Sookjin Moon ◽  
Yunji Park ◽  
Sumin Hyeon ◽  
Young-Min Kim ◽  
Ji-Hae Kim ◽  
...  
Keyword(s):  
T Cells ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Tyrosine Phosphatase ◽  
Intraepithelial Lymphocytes ◽  
Intestinal Epithelial ◽  
Mhc Ii ◽  
Niche Adaptation ◽  
Src Homology ◽  
Src Homology 2 Domain

Conventional CD4+ T cells are differentiated into CD4+CD8αα+ intraepithelial lymphocytes (IELs) in the intestine; however, the roles of intestinal epithelial cells (IECs) are poorly understood. Here, we showed that IECs expressed MHC class II (MHC II) and programmed death–ligand 1 (PD-L1) induced by the microbiota and IFN-γ in the distal part of the small intestine, where CD4+ T cells were transformed into CD4+CD8αα+ IELs. Therefore, IEC-specific deletion of MHC II and PD-L1 hindered the development of CD4+CD8αα+ IELs. Intracellularly, PD-1 signals supported the acquisition of CD8αα by down-regulating the CD4-lineage transcription factor, T helper–inducing POZ/Krüppel-like factor (ThPOK), via the Src homology 2 domain–containing tyrosine phosphatase (SHP) pathway. Our results demonstrate that noncanonical antigen presentation with cosignals from IECs constitutes niche adaptation signals to develop tissue-resident CD4+CD8αα+ IELs.

scholarly journals Epithelial MHC class II directs microbiota-specific intestinal immune homeostasis

2022 ◽  
Author(s):  
Emily M Eshleman ◽  
Tzu-Yu Shao ◽  
Vivienne Woo ◽  
Taylor Rice ◽  
Jordan Whitt ◽  
...  
Keyword(s):  
T Cells ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Intestinal Epithelial ◽  
Mhc Ii ◽  
Adult Mice ◽  
Histocompatibility Complex ◽  
Mucosal Tissues ◽  
T Cell Regulation ◽  
Antigen Presenting

Dysregulated immune responses to resident microbes promote pathologic inflammation, however, the mechanisms instructing commensal-specific T cells remain poorly understood. Here, we find that non-hematopoietic intestinal epithelial cells (IECs) represent the primary cells expressing major histocompatibility complex (MHC) II at the intestinal host-microbiota interface. Interestingly, epithelial MHCII and commensal-specific CD4+ T cells were concurrently induced by post-natal microbiota colonization, provoking the hypothesis that epithelial MHCII regulates local commensal-specific CD4+ T cells. While MHCII on classical antigen presenting cells directs expansion of antigen-specific CD4+ T cells, loss of IEC-intrinsic MHCII surprisingly led to elevated commensal-specific CD4+ T cells in the intestine. Further, epithelial MHCII expression actively limited accumulation of antigen-specific CD4+ T cells in adult mice. Expansion of commensal-specific Th17 cells was restricted by epithelial MHCII, and remarkably mice lacking epithelial MHCII were highly susceptible to microbiota-triggered inflammation. Collectively, these data indicate that impaired epithelial MHCII-T cell regulation within mucosal tissues alters microbiota-specific immunity and predisposes to chronic inflammation.

Interferon Gamma (IFNγ)/STAT1 Signaling in Host Antigen Present Cells Suppresses MHC Class II-Dependent Presentation of Self-Antigens and Development of Graft Versus Host Disease (GVHD)

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2147-2147
Author(s):  
Caisheng Lu ◽  
Huihui Ma ◽  
Liangsong Song ◽  
Shirong Li ◽  
Suzanne Lentzsch ◽  
...  
Keyword(s):  
T Cells ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Class Ii ◽  
Invariant Chain ◽  
Wild Type ◽  
Mhc Ii ◽  
Exogenous Antigen ◽  
Stat1 Signaling ◽  
The Impact

Abstract IFNγ signaling plays a critical role in the pathogenesis of GVHD. In this study, we observed that LPS-maturated bone marrow-derived dendritic cells (BMDCs) lacking IFNγ receptor (IFNγR, GRKO) or signal transducer and activator of transcription 1 (STAT1KO) had increased expression of major histocompatibility complex class II (MHC II), CD86, CD80, and enhanced allo-stimulatory capacity. This was further confirmed using fully MHC-mismatched bone marrow transplantation (BMT) studies. APC of GRKO or STAT1KO recipients had increased MHC II expression, which was associated with enhanced activation and expansion of donor CD4 and CD8 T cells and subsequently accelerated GVHD mortality compared to wild type (WT) controls. This increased GVHD mortality and increased MHC II expression on host APCs was further observed in the absence of recipient conditioning in the B6→CB6F1 mouse model. This was associated with increased presentation of host derived endogenous Eα52-68 peptide via I-Ab on recipient CD11c+ cells as detected by staining with the YA-e antibody. Furthermore, we could demonstrate that absence of IFNγR in BMDC promotes presentation Eα52-68 peptide and subsequently elicits pronounced activation, expansion and Th1 differentiation of TEa-TCR-tg CD4 T cells which recognize the Eα52-68 peptide presented by I-Ab. Next, we assessed the impact of this pathway on presentation of exogenous antigens. Interestingly, when lysate prepared from BALB/c splenocytes was incubated with BMDCs from B6 mice, Y-Ae expression on STAT1-/- BMDCs was significantly reduced compared to wild type BMDCs allowing us to hypothesize that IFNγ/STAT1 signaling may play an important role in promoting presentation of exogenous antigen while suppressing presentation of endogenous antigen. To further confirm this hypothesis, we used ovalbumin (OVA) as a second model antigen. To assess the impact of IFNγ/STAT1 signaling on presentation of exogenous antigen, WT, GRKO or STAT1KO BMDC were directly pulsed with OVA. To address the role in endogenous antigen presentation we studied act-mOVA-transgenic wildtype, act-mOVA.GRKO or act-mOVA.STAT1KO BMDCs. Transgenic OT-II CD4 T cells express a TCR specific for the OVA peptide 323-33 presented by I-Ab. The proliferation/activation of OT II T cells was monitored by flow cytometer as readout for effective Ag presentation. Our data demonstrated that IFNγR- or STAT1-deficient BMDCs loaded with exogenous intact OVA protein were compromised in promoting OT II proliferation. In contrast, responder OT-II CD4 T cells proliferated much more vigorously when stimulated with IFNγR/STAT1-deficient m-Act-OVA BMDCs compared to controls. We further observed significantly impaired OT-II cell proliferation in IFNγR or STAT1-deficient mice immunized with OVA indicating impaired presentation of exogenous antigens. However, OT-II CD4 T cells injected into lethally irradiated act-mOVA.STAT1KO transgenic mice proliferated more robustly and displayed increased Th1 differentiation compared to control mice when tested 3 days after OT II administration. We next started to assess several key factors (Ii [invariant chain, CD74], Cathepsin S [CTSS], H2-M, CIITA and MARCH1), known to be involved in the process of MHC class II antigen presentation and MHC II expression. We found retention of Invariant chain (CD74) expression as well as reduced CTSS and H2M expression in GRKO or STAT1KO BMDC following LPS-maturation. Furthermore, we observed significantly reduced lysosome formation/function in STAT1KO BMDCs compared to wild type BMDCs after LPS maturation. These data suggest that exogenous protein-derived peptide exchange in the MHCII compartment (MIIC) is impaired in STAT1KO BMDCs. Immature and LPS-maturated STAT1-/-BMDCs had significantly increased autophagy, which could explain enhanced endogenous Ag presentation since autophagy has been demonstrated to be critical in MHC II Ag presentation of cytoplasmic constituents. Finally, we found evidence of enhanced MHC II synthesis as supported by increased CIITA mRNA expression and conversely reduced MHC II degradation as indicated by reduced MARCH1 expression. In summary our data suggest that absence of IFNγR/STAT1 signaling in DC leads to abnormal surface MHC II turnover, promotes presentation of endogenous peptides and concomitantly impairs processing and presentation of exogenous antigens. Disclosures Lentzsch: BMS: Consultancy; Foundation One: Consultancy; Celgene: Consultancy, Honoraria.

scholarly journals Ligation of MHC Class II Induces PKC-Dependent Clathrin-Mediated Endocytosis of MHC Class II

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1810
Author(s):  
Kento Masaki ◽  
Yuhji Hiraki ◽  
Hiroka Onishi ◽  
Yuka Satoh ◽  
Paul A. Roche ◽  
...  
Keyword(s):  
T Cells ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Surface Expression ◽  
Class Ii ◽  
Cellular Functions ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Class Ii Mhc ◽  
Antigen Presenting

In addition to antigen presentation to CD4+ T cells, aggregation of cell surface major histocompatibility complex class II (MHC-II) molecules induces signal transduction in antigen presenting cells that regulate cellular functions. We previously reported that crosslinking of MHC-II induced the endocytosis of MHC-II, which was associated with decreased surface expression levels in murine dendritic cells (DCs) and resulted in impaired activation of CD4+ T cells. However, the downstream signal that induces MHC-II endocytosis remains to be elucidated. In this study, we found that the crosslinking of MHC-II induced intracellular Ca2+ mobilization, which was necessary for crosslinking-induced MHC-II endocytosis. We also found that these events were suppressed by inhibitors of Syk and phospholipase C (PLC). Treatments with a phorbol ester promoted MHC-II endocytosis, whereas inhibitors of protein kinase C (PKC) suppressed crosslinking-induced endocytosis of MHC-II. These results suggest that PKC could be involved in this process. Furthermore, crosslinking-induced MHC-II endocytosis was suppressed by inhibitors of clathrin-dependent endocytosis. Our results indicate that the crosslinking of MHC-II could stimulate Ca2+ mobilization and induce the clathrin-dependent endocytosis of MHC-II in murine DCs.

823 CD4 T cells are essential for an anti-tumor effect in a B78 murine melanoma tumor model

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A873-A873
Author(s):  
Arika Feils ◽  
Mackenzie Heck ◽  
Anna Hoefges ◽  
Peter Carlson ◽  
Luke Zangl ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Growth ◽  
Cd4 T Cells ◽  
Tumor Response ◽  
Immune Cell ◽  
Cd8 T Cell ◽  
Mhc I ◽  
Mhc Ii ◽  
Flow Cytometric

BackgroundMice bearing B78 melanoma tumors can be cured using an in situ vaccine (ISV) regimen that includes radiation (RT) together with immunocytokine (tumor-targeting mAb conjugated to IL-2). B78 melanoma cells, derived from B16 cells, express minimal to no MHC-I but express MHC-II upon IFN-g/TNF-a stimulation. Although B78 cells are primarily MHC-I-deficient, an increased CD8 T cell infiltration into the tumor microenvironment (TME) has been shown following ISV.1 To further investigate the potential role of specific immune cell lineages in the B78 anti-tumor response to ISV, immune subset depletion studies and flow cytometric analyses were performed.MethodsC57BL/6 mice bearing B78 tumors were depleted of immune cell subsets with mAbs (anti-CD4, anti-CD8, anti-NK1.1, or Rat IgG control) for 3 weeks during the course of treatment. Treatment groups included no treatment, RT (12 Gy), or ISV (RT D0 and immunocytokine D5-D9). 6 mice/group (repeated three times) were followed for survival/tumor growth, and flow cytometry studies included 4 mice/group, sacrificed on D8 and D13 following the start of ISV.ResultsMice depleted of CD4 T cells during the course of ISV showed a significant reduction of anti-tumor effect as compared to mice treated with ISV/Rat IgG (pConclusionsThese studies suggest that CD4 T cells are essential for an anti-tumor response in the B78 melanoma model. In vivo depletion data show that CD4 T cells, but not CD8 or NK cells, are required for a decrease in tumor growth via ISV. Flow cytometric analyses suggest an interplay between CD4 and CD8 T cells as indicated by a decrease in CD8/IFN-g expression following ISV in the absence of CD4 T cells. The role that MHC-I and MHC-II expression plays in this CD4/CD8 T cell anti-tumor response is under investigation. In future studies, B78 melanoma may serve as a critical syngeneic model for development of more effective immunotherapy treatment regimens.Ethics ApprovalAll animal experiments were performed in accordance with protocols approved by Animal Care and Use Committees of the University of Wisconsin-Madison.ReferenceMorris Z, Guy E, Francis D, et al. In situ tumor vaccination by combining local radiation and tumor-specific antibody or immunocytokine treatments. Cancer Res 2016;76(13):3929-3941.

scholarly journals Synaptic Clusters of MHC Class II Molecules Induced on DCs by Adhesion Molecule–mediated Initial T-Cell Scanning

2005 ◽  
Vol 16 (7) ◽  
pp. 3314-3322 ◽  
Author(s):  
Hortensia de la Fuente ◽  
María Mittelbrunn ◽  
Lorena Sánchez-Martín ◽  
Miguel Vicente-Manzanares ◽  
Amalia Lamana ◽  
...  
Keyword(s):  
T Cells ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Regulatory Pathway ◽  
Immune Synapse ◽  
Mhc Ii ◽  
Cytoskeleton Reorganization ◽  
Adhesive Contacts ◽  
Enhance Antigen Presentation ◽  
Mhc Class Ii Molecules

Initial adhesive contacts between T lymphocytes and dendritic cells (DCs) facilitate recognition of peptide-MHC complexes by the TCR. In this report, we studied the dynamic behavior of adhesion and Ag receptors on DCs during initial contacts with T-cells. Adhesion molecules LFA-1- and ICAM-1,3-GFP as well as MHC class II-GFP molecules were very rapidly concentrated at the DC contact area. Binding of ICAM-3, and ICAM-1 to a lesser extent, to LFA-1 expressed by mature but not immature DC, induced MHC-II clustering into the immune synapse. Also, ICAM-3 binding to DC induced the activation of the Vav1-Rac1 axis, a regulatory pathway involved in actin cytoskeleton reorganization, which was essential for MHC-II clustering on DCs. Our results support a model in which ICAM-mediated MHC-II clustering on DC constitutes a priming mechanism to enhance antigen presentation to T-cells.

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