scholarly journals Mechanistic diversity in MHC class I antigen recognition

2021 ◽  
Vol 478 (24) ◽  
pp. 4187-4202
Author(s):  
Camila R. R. Barbosa ◽  
Justin Barton ◽  
Adrian J. Shepherd ◽  
Michele Mishto
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
T Cell Response ◽  
Class I ◽  
Antigenic Peptides ◽  
Human Immune System ◽  
Mhc Class I Antigen ◽  
Human Immune

Throughout its evolution, the human immune system has developed a plethora of strategies to diversify the antigenic peptide sequences that can be targeted by the CD8+ T cell response against pathogens and aberrations of self. Here we provide a general overview of the mechanisms that lead to the diversity of antigens presented by MHC class I complexes and their recognition by CD8+ T cells, together with a more detailed analysis of recent progress in two important areas that are highly controversial: the prevalence and immunological relevance of unconventional antigen peptides; and cross-recognition of antigenic peptides by the T cell receptors of CD8+ T cells.

scholarly journals The natural immune response to inhaled soluble protein antigens involves major histocompatibility complex (MHC) class I-restricted CD8+ T cell-mediated but MHC class II-restricted CD4+ T cell-dependent immune deviation resulting in selective suppression of immunoglobulin E production.

1993 ◽  
Vol 178 (3) ◽  
pp. 889-899 ◽  
Author(s):  
C McMenamin ◽  
P G Holt
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Cd8 T Cells ◽  
Immunoglobulin E ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Class I

The immunological basis for atopy is currently ascribed to an inherent bias in the CD4+ T cell response to nonreplicating antigens presented at mucosal surfaces, resulting in dominance of the T helper 2 (Th2) interleukin 4 (IL-4)-producing phenotype, which favors IgE production. In contrast, the "normal" response to such antigens involves a predominance of interferon gamma (IFN-gamma)-producing Th1 clones. This difference has been suggested to be the result of active selection in atopics for Th2 (and hence against Th1) clones at the time of initial antigen presentation. In the study below, we demonstrate that the natural immune response to inhaled protein antigens, particularly in animals expressing the low immunoglobulin E (IgE) responder phenotype, includes a major histocompatibility complex (MHC) class I-restricted CD8+ T cell component, the appearance of which is associated with active suppression of IgE antibody production. Thus, continued exposure of rats to aerosolized ovalbumin (OVA) antigen elicits a transient IgE response, that is terminated by the onset of a state of apparent "tolerance" to further challenge, and this tolerant state is transferable to naive animals with CD8+ T cells. Kinetic studies on in vitro T cell reactivity in these aerosol-exposed rats demonstrated biphasic CD4+ Th2 responses which terminated, together with IgE antibody production, and coincident with the appearance of MHC class I-restricted OVA-specific IFN-gamma-producing CD8+ T cells. However, the latter were not autonomous in vitro and required a source of exogenous IL-2 for initial activation, which in CD(8+)-enriched splenocyte cultures could be provided by small numbers of contaminating OVA-specific CD4+ T cells. This represents the first formal evidence for the induction of an MHC class I-restricted T cell response to natural mucosal exposure to an inert protein antigen, and is consistent with a growing literature demonstrating sensitization of MHC class I-restricted CD8+ T cells by deliberate immunization with soluble proteins. We suggest that crossregulation of MHC class II-restricted CD4+ T cells via cytokine signals generated in parallel CD8+ T cell responses represents a covert and potentially important selection pressure that can shape the nature of host responses to nonreplicating antigens presented at mucosal surfaces.

T-cell epitopes within the complementarity-determining and framework regions of the tumor-derived immunoglobulin heavy chain in multiple myeloma

Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 4930-4936 ◽  
Author(s):  
Lotta Hansson ◽  
Hodjattallah Rabbani ◽  
Jan Fagerberg ◽  
Anders Österborg ◽  
Håkan Mellstedt
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Heavy Chain ◽  
T Cell Response ◽  
Class I ◽  
Type I ◽  
T Cell Epitopes ◽  
Hla Binding

Abstract The idiotypic structure of the monoclonal immunoglobulin (Ig) in multiple myeloma (MM) might be regarded as a tumor-specific antigen. The present study was designed to identify T-cell epitopes of the variable region of the Ig heavy chain (VH) in MM (n = 5) using bioinformatics and analyze the presence of naturally occurring T cells against idiotype-derived peptides. A large number of human-leukocyte-antigen (HLA)–binding (class I and II) peptides were identified. The frequency of predicted epitopes depended on the database used: 245 in bioinformatics and molecular analysis section (BIMAS) and 601 in SYFPEITHI. Most of the peptides displayed a binding half-life or score in the low or intermediate affinity range. The majority of the predicted peptides were complementarity-determining region (CDR)–rather than framework region (FR)–derived (52%-60% vs 40%-48%, respectively). Most of the predicted peptides were confined to the CDR2-FR3-CDR3 “geographic” region of the Ig-VH region (70%), and significantly fewer peptides were found within the flanking (FR1-CDR1-FR2 and FR4) regions (P < .01). There were 8– to 10–amino acid (aa) long peptides corresponding to the CDRs and fitting to the actual HLA-A/B haplotypes that spontaneously recognized, albeit with a low magnitude, type I T cells (interferon γ), indicating an ongoing major histocompatibility complex (MHC) class I–restricted T-cell response. Most of those peptides had a low binding half-life (BIMAS) and a low/intermediate score (SYFPEITHI). Furthermore, 15- to 20-aa long CDR1-3–derived peptides also spontaneously recognized type I T cells, indicating the presence of MHC class II–restricted T cells as well. This study demonstrates that a large number of HLA-binding idiotypic peptides can be identified in patients with MM. Such peptides may spontaneously induce a type I MHC class I– as well as class II–restricted memory T-cell response.

scholarly journals Peptide vaccination directed against IDO1-expressing immune cells elicits CD8+ and CD4+ T-cell-mediated antitumor immunity and enhanced anti-PD1 responses

2020 ◽  
Vol 8 (2) ◽  
pp. e000605
Author(s):  
Souvik Dey ◽  
Erika Sutanto-Ward ◽  
Katharina L Kopp ◽  
James DuHadaway ◽  
Arpita Mondal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Mhc Class I ◽  
Adoptive Transfer ◽  
Immune Cells ◽  
Class Ii ◽  
T Cell Response ◽  
Class I ◽  
Antitumor Effects

BackgroundThe tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1), which subverts T-cell immunity at multiple levels, is itself subject to inherent T-cell reactivity. This intriguing deviation from central tolerance has been interpreted as counterbalancing IDO1-mediated immunosuppression. Based on this hypothesis, clinical studies employing an IDO1 peptide-based vaccine approach for cancer treatment have been initiated, but there remains a pressing need to further investigate the immunological ramifications of stimulating the anti-IDO1 T-cell response in this manner.MethodsCT26 colon carcinoma tumors were evaluated for expression of IDO1 protein by western blot analysis, immunofluorescence microscopy and flow cytometry. Mouse IDO1-derived peptides, predicted to bind either major histocompatibility complex (MHC) class I or II of the H2d BALB/c strain, were emulsified in 50% Montanide for prophylactic or therapeutic vaccine treatment of CT26 tumor-bearing mice initiated either 7 days prior to or following tumor cell injection, respectively. In some therapeutic treatment experiments, administration of programmed cell death protein 1-binding antibody (anti-PD1 antibody) or epacadostat was concurrently initiated. Tumor size was determined by caliper measurements and comparative tumor growth suppression was assessed by longitudinal analyses of tumor growth data. For adoptive transfer, T cells from complete responder animals were isolated using paramagnetic beads and fluorescence-activated cell sorting.ResultsThis study identifies mouse MHC class I-directed and II-directed, IDO1-derived peptides capable of eliciting antitumor responses, despite finding IDO1 expressed exclusively in tumor-infiltrating immune cells. Treatment of established tumors with anti-PD1 antibody and class I-directed but not class II-directed IDO1 peptide vaccines produced an enhanced antitumor response. Likewise, class I-directed and II-directed IDO1 peptides elicited an enhanced combinatorial response, suggesting distinct mechanisms of action. Consistent with this interpretation, adoptive transfer of isolated CD8+ T cells from class I and CD4+ T cells from class II peptide-vaccinated responder mice delayed tumor growth. The class II-directed response was completely IDO1-dependent while the class I-directed response included an IDO1-independent component consistent with antigen spread.ConclusionsThe in vivo antitumor effects demonstrated with IDO1-based vaccines via targeting of the tumor microenvironment highlight the utility of mouse models for further exploration and refinement of this novel vaccine-based approach to IDO1-directed cancer therapy and its potential to improve patient response rates to anti-PD1 therapy.

scholarly journals Efficient Targeting of Protein Antigen to the Dendritic Cell Receptor DEC-205 in the Steady State Leads to Antigen Presentation on Major Histocompatibility Complex Class I Products and Peripheral CD8+ T Cell Tolerance

2002 ◽  
Vol 196 (12) ◽  
pp. 1627-1638 ◽  
Author(s):  
Laura Bonifaz ◽  
David Bonnyay ◽  
Karsten Mahnke ◽  
Miguel Rivera ◽  
Michel C. Nussenzweig ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
Steady State ◽  
T Cell ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Class I ◽  
Histocompatibility Complex ◽  
Dc Maturation

To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal αDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c− cells, to OVA-specific, CD4+ and CD8+ T cells. Receptor-mediated presentation was at least 400 times more efficient than unconjugated OVA and, for MHC class I, the DCs had to express transporter of antigenic peptides (TAP) transporters. When αDEC-205:OVA was injected subcutaneously, OVA protein was identified over a 4–48 h period in DCs, primarily in the lymph nodes draining the injection site. In vivo, the OVA protein was selectively presented by DCs to TCR transgenic CD8+ cells, again at least 400 times more effectively than soluble OVA and in a TAP-dependent fashion. Targeting of αDEC-205:OVA to DCs in the steady state initially induced 4–7 cycles of T cell division, but the T cells were then deleted and the mice became specifically unresponsive to rechallenge with OVA in complete Freund's adjuvant. In contrast, simultaneous delivery of a DC maturation stimulus via CD40, together with αDEC-205:OVA, induced strong immunity. The CD8+ T cells responding in the presence of agonistic αCD40 antibody produced large amounts of interleukin 2 and interferon γ, acquired cytolytic function in vivo, emigrated in large numbers to the lung, and responded vigorously to OVA rechallenge. Therefore, DEC-205 provides an efficient receptor-based mechanism for DCs to process proteins for MHC class I presentation in vivo, leading to tolerance in the steady state and immunity after DC maturation.

Sialoadhesin-Positive Host Macrophages Play an Essential Role in Graft-Versus-Leukemia Reactivity in Mice

Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4375-4386 ◽  
Author(s):  
Susanne Müerköster ◽  
Marian Rocha ◽  
Paul R. Crocker ◽  
Volker Schirrmacher ◽  
Victor Umansky
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Cd8 T Cells ◽  
Class I ◽  
Peptide Epitope ◽  
Peptide Epitopes ◽  
Graft Versus Leukemia

We recently established an effective immune T-cell–mediated graft-versus-leukemia (GVL) murine model system in which complete tumor remissions were achievable even in advanced metastasized cancer. We now describe that this T-cell–mediated therapy is dependent on host macrophages expressing the lymphocyte adhesion molecule sialoadhesin (Sn). Depletion of Kupffer cells in tumor-bearing mice during adoptive immunotherapy (ADI) or the treatment of these animals with anti-Sn monoclonal antibodies led to complete or partial inhibition of the immune T-cell–mediated therapeutic effect. Furthermore, Sn+ host macrophages in livers formed clusters during ADI with donor CD8 T cells. To test for a possible antigen presentation function of these macrophages, we used as an in vitro model the antigen β-galactosidase for which a dominant major histocompatibility complex (MHC) class I Ld-restricted peptide epitope is known to be recognized by specific CD8 cytotoxic T lymphocytes (CTL). We demonstrate that purified Sn+ macrophages can process exogenous β-galactosidase and stimulate MHC class I peptide-restricted CTL responses. Thus, Sn+ macrophages, which are significantly increased in the liver after ADI, may process tumor-derived proteins via the MHC class I pathway as well as via the MHC class II pathway, as shown previously, and present respective peptide epitopes to CD8 as well as to CD4 immune T cells, respectively. The synergistic interactions observed before between immune CD4 and CD8 T cells during ADI could thus occur in the observed clusters with Sn+ host macrophages.

Tumor-specific recognition of human myeloma cells by idiotype-induced CD8+ T cells

Blood ◽  
2000 ◽  
Vol 96 (8) ◽  
pp. 2828-2833 ◽  
Author(s):  
Yiwen Li ◽  
Maurizio Bendandi ◽  
Yuping Deng ◽  
Cynthia Dunbar ◽  
Nikhil Munshi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Class I ◽  
Specific Lysis ◽  
Myeloma Cells ◽  
Id Protein ◽  
Human Myeloma Cells

Immunoglobulin secreted by myeloma cells contains a unique antigenic determinant (idiotype [Id]) that may serve as a tumor-specific antigen. Although Id-protein–specific T-cell responses have been reported in patients with myeloma, it is not known whether primary myeloma tumor cells can present naturally processed Id peptides on their surface as a target. We immunized 2 healthy human stem-cell donors with Id proteins from their recipients. T cells from the immunized donors released high levels of T-helper 1–type cytokines in response to stimulation with myeloma cells from their recipients. The T-cell–mediated cytokine response to tumor cells was blocked by a major histocompatibility complex (MHC) class I monoclonal antibody, whereas the response to soluble Id protein was dependent on MHC class II. To investigate whether Id-specific CD8+ T cells can recognize and kill autologous myeloma cells, we generated T cells from peripheral blood mononuclear cells from a third patient with myeloma by means of in vitro stimulation with autologous dendritic cells pulsed with Id protein. Tumor-specific lysis of myeloma cells was demonstrated by the lack of killing of autologous nonmalignant B cells or natural killer–sensitive K562 cells. Lysis of autologous myeloma targets was restricted by MHC class I molecules. These data represent the first report of class I–restricted T-cell recognition of fresh autologous myeloma targets and formally demonstrate that human myeloma cells can serve as targets of an Id-specific T-cell response.

scholarly journals An antigen-specific pathway for CD8 T cells across the blood-brain barrier

2007 ◽  
Vol 204 (9) ◽  
pp. 2023-2030 ◽  
Author(s):  
Ian Galea ◽  
Martine Bernardes-Silva ◽  
Penny A. Forse ◽  
Nico van Rooijen ◽  
Roland S. Liblau ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Blood Brain Barrier ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Class I ◽  
Cerebral Endothelium ◽  
Cognate Antigen ◽  
The Brain

CD8 T cells are nature's foremost defense in encephalitis and brain tumors. Antigen-specific CD8 T cells need to enter the brain to exert their beneficial effects. On the other hand, traffic of CD8 T cells specific for neural antigen may trigger autoimmune diseases like multiple sclerosis. T cell traffic into the central nervous system is thought to occur when activated T cells cross the blood-brain barrier (BBB) regardless of their antigen specificity, but studies have focused on CD4 T cells. Here, we show that selective traffic of antigen-specific CD8 T cells into the brain occurs in vivo and is dependent on luminal expression of major histocompatibility complex (MHC) class I by cerebral endothelium. After intracerebral antigen injection, using a minimally invasive technique, transgenic CD8 T cells only infiltrated the brain when and where their cognate antigen was present. This was independent of antigen presentation by perivascular macrophages. Marked reduction of antigen-specific CD8 T cell infiltration was observed after intravenous injection of blocking anti–MHC class I antibody. These results expose a hitherto unappreciated route by which CD8 T cells home onto their cognate antigen behind the BBB: luminal MHC class I antigen presentation by cerebral endothelium to circulating CD8 T cells. This has implications for a variety of diseases in which antigen-specific CD8 T cell traffic into the brain is a beneficial or deleterious feature.

Sialoadhesin-Positive Host Macrophages Play an Essential Role in Graft-Versus-Leukemia Reactivity in Mice

Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4375-4386 ◽  
Author(s):  
Susanne Müerköster ◽  
Marian Rocha ◽  
Paul R. Crocker ◽  
Volker Schirrmacher ◽  
Victor Umansky
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Cd8 T Cells ◽  
Class I ◽  
Peptide Epitope ◽  
Peptide Epitopes ◽  
Graft Versus Leukemia

Abstract We recently established an effective immune T-cell–mediated graft-versus-leukemia (GVL) murine model system in which complete tumor remissions were achievable even in advanced metastasized cancer. We now describe that this T-cell–mediated therapy is dependent on host macrophages expressing the lymphocyte adhesion molecule sialoadhesin (Sn). Depletion of Kupffer cells in tumor-bearing mice during adoptive immunotherapy (ADI) or the treatment of these animals with anti-Sn monoclonal antibodies led to complete or partial inhibition of the immune T-cell–mediated therapeutic effect. Furthermore, Sn+ host macrophages in livers formed clusters during ADI with donor CD8 T cells. To test for a possible antigen presentation function of these macrophages, we used as an in vitro model the antigen β-galactosidase for which a dominant major histocompatibility complex (MHC) class I Ld-restricted peptide epitope is known to be recognized by specific CD8 cytotoxic T lymphocytes (CTL). We demonstrate that purified Sn+ macrophages can process exogenous β-galactosidase and stimulate MHC class I peptide-restricted CTL responses. Thus, Sn+ macrophages, which are significantly increased in the liver after ADI, may process tumor-derived proteins via the MHC class I pathway as well as via the MHC class II pathway, as shown previously, and present respective peptide epitopes to CD8 as well as to CD4 immune T cells, respectively. The synergistic interactions observed before between immune CD4 and CD8 T cells during ADI could thus occur in the observed clusters with Sn+ host macrophages.

Double Loading of Dendritic Cell MHC Class I and MHC Class II with an AML Antigen Repertoire Enhances Primary and Secondary T-Cell Responses In Vitro.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2529-2529
Author(s):  
William K. Decker ◽  
Dongxia Xing ◽  
Sufang Li ◽  
Simon N. Robinson ◽  
Hong Yang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class Ii ◽  
Cd8 T Cells ◽  
Class Ii ◽  
T Cell Response ◽  
Class I ◽  
Cross Presentation ◽  
Ifn Γ

Abstract Despite improvements in therapy for acute myelogenous leukemia (AML), a significant percentage of patients still relapse and succumb to their disease. Dendritic cell immunotherapy offers the promise of potentially effective supportive therapy for a variety of neoplastic conditions; and the use of DCs loaded with tumor antigens is now recognized as an important investigational therapy. Though a variety of methods have been used to load DC vaccines, the loading of the MHC class II compartment with tumor lysate has predominated. The priming of a class II-mediated (CD4) T-cell response may be crucial to the success of DC immunotherapy as such a response is likely required for the development of memory CD8+ T-cells. DC cross-presentation is credited with the ability of lysate-loaded DCs to prime both CD4 and CD8 T-cell responses, enabling the generation of CD8+ CTLs without the loading of the MHC class I compartment (i.e. the cytoplasm). Recently, however, several reports have raised doubts as to the efficiency of cross-presentation as a mechanism for CTL priming in vivo. To examine this issue, we have loaded human DCs with both AML tumor lysate and mRNA. This technique allows the full repertoire of class I antigens to be presented without dependence upon cross-presentation; and, moreover, provides a full complement of class II antigens necessary for CD4 T-cell priming and the generation of memory responses. Methods: CD14+ precursors were isolated from normal donor PBPCs by magnetic separation. Immature DCs were then generated by culturing precursors for six days in GM-CSF and IL-4. Lysate was produced by three successive freeze/thaw cycles of blasts. mRNA was extracted from blasts using Trizol and oligo-dT separation. Immature DCs were pulsed for three hours with AML lysate and subsequently electroporated with AML mRNA. Loaded DCs were matured for 48 hours with IL-1β, TNF-α, IL-6, and PGE2 and then used to prime autologous T-cells. Short-term responses were assayed on day 5 of the 1st stimulation. Memory responses were assayed on day 10 of a tertiary stimulation. Results: Doubly-loaded DCs can prime a superior T-cell response in vitro in comparison to that of singly-loaded DCs, demonstrating a 30–70% increase in IFN-γ ELISpots over lysate-loaded DCs (p<0.001) and a 3–4 fold increase in ELISpots in comparison to mRNA loaded DCs (p<0.001). These results were verified by flow cytometry which showed 35% of CD8+ T-cells primed by doubly-loaded DCs were CD69+/IFN-γ+ vs. 14% of CD8+ T-cells primed by lysate-loaded DCs (p<0.001). This enhancement may be based upon both an upregulation of CD83 surface expression (p<0.0019) of doubly-loaded DCs and/or the upregulation of B7.1/B7.2 that accompanies elevated CD40L signaling. Memory responses were also greatly improved, with a 126% increase in total ELISpots (double loaded DCs versus lysate loaded DCs; p<0.03) and a 187% increase in total IFN-γ secretion (p<0.03). Unloaded (p<0.01) and mRNA (p<0.007) loaded DCs exhibited a virtual inability to generate memory T-cells in vitro, suggesting that the perpetuation of the memory response is reliant upon T-cell help. Conclusion: DCs doubly-loaded with lysate and mRNA are more efficient in the generation of primary and secondary immune responses than are singly-loaded DCs. The clinical administration of such doubly-loaded DCs may offer an important therapeutic option to patients with AML.

Sign in / Sign up

Export Citation Format

Share Document