Tuning DO:DM ratios modulates MHC class II immunopeptidomes

2021 ◽  
Author(s):  
Niclas E Olsson ◽  
Wei Jiang ◽  
Lital N Adler ◽  
Elizabeth Mellins ◽  
Joshua E Elias
Keyword(s):  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Computational Prediction ◽  
Class Ii ◽  
The Body ◽  
Research Strategies ◽  
Mhc Ii ◽  
Wide Range ◽  
Health And Disease ◽  
Antigen Presenting

Major histocompatibility complex class II (MHC-II) antigen presentation underlies a wide range of immune responses in health and disease. However, how MHC-II antigen presentation is regulated by the peptide-loading catalyst HLA-DM (DM), its associated modulator, HLA-DO (DO), is incompletely understood. This is due largely to technical limitations: model antigen presenting cell (APC) systems that express these MHC-II peptidome regulators at physiologically variable levels have not been described. Likewise, computational prediction tools that account for DO and DM activities are not presently available. To address these gaps, we created a panel of single MHC-II allele, HLA-DR4-expressing APC lines that cover a wide range of DO:DM ratio states. Using a combined immunopeptidomic and proteomic discovery strategy, we measured the effects DO:DM ratios have on peptide presentation by surveying over 10,000 unique DR4-presented peptides. The resulting data provide insight into peptide characteristics that influence their presentation with increasing DO:DM ratios. These include DM-sensitivity, peptide abundance, binding affinity and motif, peptide length and register positioning on the source protein. These findings have implications for designing improved HLA-II prediction algorithms and research strategies for dissecting the variety of functions that different APCs serve in the body.

scholarly journals Ubiquitination by March-I prevents MHC class II recycling and promotes MHC class II turnover in antigen-presenting cells

2015 ◽  
Vol 112 (33) ◽  
pp. 10449-10454 ◽  
Author(s):  
Kyung-Jin Cho ◽  
Even Walseng ◽  
Satoshi Ishido ◽  
Paul A. Roche
Keyword(s):  
B Cells ◽  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Antigen Presenting Cells ◽  
Class Ii ◽  
Mhc Ii ◽  
Class Ii Mhc ◽  
Subsequent Degradation ◽  
Antigen Presenting

MHC class II (MHC-II)-dependent antigen presentation by antigen-presenting cells (APCs) is carefully controlled to achieve specificity of immune responses; the regulated assembly and degradation of antigenic peptide–MHC-II complexes (pMHC-II) is one aspect of such control. In this study, we have examined the role of ubiquitination in regulating pMHC-II biosynthesis, endocytosis, recycling, and turnover in APCs. By using APCs obtained from MHC-II ubiquitination mutant mice, we find that whereas ubiquitination does not affect pMHC-II formation in dendritic cells (DCs), it does promote the subsequent degradation of newly synthesized pMHC-II. Acute activation of DCs or B cells terminates expression of the MHC-II E3 ubiquitin ligase March-I and prevents pMHC-II ubiquitination. Most importantly, this change results in very efficient pMHC-II recycling from the surface of DCs and B cells, thereby preventing targeting of internalized pMHC-II to lysosomes for degradation. Biochemical and functional assays confirmed that pMHC-II turnover is suppressed in MHC-II ubiquitin mutant DCs or by acute activation of wild-type DCs. These studies demonstrate that acute APC activation blocks the ubiquitin-dependent turnover of pMHC-II by promoting efficient pMHC-II recycling and preventing lysosomal targeting of internalized pMHC-II, thereby enhancing pMHC-II stability for efficient antigen presentation to CD4 T cells.

scholarly journals Oxidation inhibits autophagy protein deconjugation from phagosomes to sustain MHC class II restricted antigen presentation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Laure-Anne Ligeon ◽  
Maria Pena-Francesch ◽  
Liliana Danusia Vanoaica ◽  
Nicolás Gonzalo Núñez ◽  
Deepti Talwar ◽  
...  
Keyword(s):  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Antigen Processing ◽  
Redox Regulation ◽  
Molecular Mechanisms ◽  
Class Ii ◽  
Oxygen Species ◽  
Cellular Processes ◽  
Oxidative Inactivation ◽  
Wide Range

AbstractLC3-associated phagocytosis (LAP) contributes to a wide range of cellular processes and notably to immunity. The stabilization of phagosomes by the macroautophagy machinery in human macrophages can maintain antigen presentation on MHC class II molecules. However, the molecular mechanisms involved in the formation and maturation of the resulting LAPosomes are not completely understood. Here, we show that reactive oxygen species (ROS) produced by NADPH oxidase 2 (NOX2) stabilize LAPosomes by inhibiting LC3 deconjugation from the LAPosome cytosolic surface. NOX2 residing in the LAPosome membrane generates ROS to cause oxidative inactivation of the protease ATG4B, which otherwise releases LC3B from LAPosomes. An oxidation-insensitive ATG4B mutant compromises LAP and thereby impedes sustained MHC class II presentation of exogenous Candida albicans antigens. Redox regulation of ATG4B is thereby an important mechanism for maintaining LC3 decoration of LAPosomes to support antigen processing for MHC class II presentation.

scholarly journals Changes in the localization of MHC class II positive cells in hen ovarian follicles during the processes of follicular growth, postovulatory regression and atresia

Reproduction ◽  
2001 ◽  
pp. 953-957 ◽  
Author(s):  
A Barua ◽  
H Michiue ◽  
Y Yoshimura
Keyword(s):  
Mhc Class Ii ◽  
Class Ii ◽  
Ovarian Follicles ◽  
Computer Assisted ◽  
Follicular Growth ◽  
Mhc Ii ◽  
Preovulatory Follicles ◽  
Computer Assisted Image ◽  
Antigen Presenting ◽  
Cryostat Sections

The aim of this study was to determine the changes in the population of major histocompatibility complex class II positive (MHC-II(+)) cells in ovarian follicles during the processes of follicular growth, postovulatory regression and follicular atresia in hens. Cryostat sections of ovarian stroma containing cortical follicles, small white follicles, the largest (F(1)) and third largest (F(3)) preovulatory follicles, postovulatory and atretic follicles of laying hens were prepared. The sections were immunostained for MHC-II molecules using mouse anti-chicken MHC-II monoclonal antibody and positive cells were counted using a computer-assisted image analyser under a light microscope. MHC-II(+) cells were localized in the theca layer of normally growing follicles including cortical follicles, small white follicles and F(3) and F(1) preovulatory follicles, whereas they were found in both the theca and granulosa layers in postovulatory and atretic follicles. The frequency of MHC-II(+) cells in the theca layer was significantly increased during follicular growth from cortical follicles to F(3) preovulatory follicles. Although the population of MHC-II(+) cells did not differ between F(3) and F(1) preovulatory follicles, it increased significantly in postovulatory follicles (P < 0.01). The population of MHC-II(+) cells was significantly greater in the theca layer of atretic follicles than in non-atretic follicles (P < 0.01). These results indicate that the antigen-presenting function via MHC-II increases in association with follicular growth. A marked increase in MHC-II(+) cells indicates that these cells may be involved in regression of postovulatory and atretic follicular tissues.

scholarly journals Trogocytosis of peptide–MHC class II complexes from dendritic cells confers antigen-presenting ability on basophils

2017 ◽  
Vol 114 (5) ◽  
pp. 1111-1116 ◽  
Author(s):  
Kensuke Miyake ◽  
Nozomu Shiozawa ◽  
Toshihisa Nagao ◽  
Soichiro Yoshikawa ◽  
Yoshinori Yamanishi ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Cell Differentiation ◽  
Cell Surface ◽  
Mhc Class Ii ◽  
Antigen Presenting Cells ◽  
Class Ii ◽  
Gm Csf ◽  
Mhc Ii ◽  
Th2 Cell ◽  
Antigen Presenting

Th2 immunity plays important roles in both protective and allergic responses. Nevertheless, the nature of antigen-presenting cells responsible for Th2 cell differentiation remains ill-defined compared with the nature of the cells responsible for Th1 and Th17 cell differentiation. Basophils have attracted attention as a producer of Th2-inducing cytokine IL-4, whereas their MHC class II (MHC-II) expression and function as antigen-presenting cells are matters of considerable controversy. Here we revisited the MHC-II expression on basophils and explored its functional relevance in Th2 cell differentiation. Basophils generated in vitro from bone marrow cells in culture with IL-3 plus GM-CSF displayed MHC-II on the cell surface, whereas those generated in culture with IL-3 alone did not. Of note, these MHC-II–expressing basophils showed little or no transcription of the corresponding MHC-II gene. The GM-CSF addition to culture expanded dendritic cells (DCs) other than basophils. Coculture of basophils and DCs revealed that basophils acquired peptide–MHC-II complexes from DCs via cell contact-dependent trogocytosis. The acquired complexes, together with CD86, enabled basophils to stimulate peptide-specific T cells, leading to their proliferation and IL-4 production, indicating that basophils can function as antigen-presenting cells for Th2 cell differentiation. Transfer of MHC-II from DCs to basophils was also detected in draining lymph nodes of mice with atopic dermatitis-like skin inflammation. Thus, the present study defined the mechanism by which basophils display MHC-II on the cell surface and appears to reconcile some discrepancies observed in previous studies.

scholarly journals Glatiramer acetate immune modulates B-cell antigen presentation in treatment of MS

2020 ◽  
Vol 7 (3) ◽  
pp. e698 ◽  
Author(s):  
Darius Häusler ◽  
Zivar Hajiyeva ◽  
Jan W. Traub ◽  
Scott S. Zamvil ◽  
Patrice H. Lalive ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Antigen Presentation ◽  
Glatiramer Acetate ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Cell Antigen ◽  
Antigen Presenting

ObjectiveWe examined the effect of glatiramer acetate (GA) on B-cell maturation, differentiation, and antigen presentation in MS and experimental autoimmune encephalomyelitis (EAE).MethodsA cross-sectional study of blood samples from 20 GA-treated and 18 untreated patients with MS was performed by flow cytometry; 6 GA-treated patients with MS were analyzed longitudinally. GA-mediated effects on B-cell antigen-presenting function were investigated in EAE, or, alternatively, B cells were treated with GA in vitro using vehicle as a control.ResultsIn MS, GA diminished transitional B-cell and plasmablast frequency, downregulated CD69, CD25, and CD95 expression, and decreased TNF-α production, whereas IL-10 secretion and MHC Class II expression were increased. In EAE, we observed an equivalent dampening of proinflammatory B-cell properties and an enhanced expression of MHC Class II. When used as antigen-presenting cells for activation of naive T cells, GA-treated B cells promoted development of regulatory T cells, whereas proinflammatory T-cell differentiation was diminished.ConclusionsGA immune modulates B-cell function in EAE and MS and efficiently interferes with pathogenic B cell–T cell interaction.

Epigenetic control of MHC class II expression in tumor-associated macrophages by decoy receptor 3

Blood ◽  
2008 ◽  
Vol 111 (10) ◽  
pp. 5054-5063 ◽  
Author(s):  
Yung-Chi Chang ◽  
Tse-Ching Chen ◽  
Chun-Ting Lee ◽  
Chih-Ya Yang ◽  
Hsei-Wei Wang ◽  
...  
Keyword(s):  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Malignant Tumors ◽  
Class Ii ◽  
Tumor Associated Macrophages ◽  
Class Ii Transactivator ◽  
Decoy Receptor ◽  
Mhc Ii ◽  
Hla Dr ◽  
Decoy Receptor 3

Abstract Decoy receptor 3 (DcR3) is a member of the TNF receptor superfamily and is up-regulated in tumors originating from a diversity of lineages. DcR3 is capable of promoting angiogenesis, inducing dendritic cell apoptosis, and modulating macrophage differentiation. Since tumor-associated macrophages (TAMs) are the major infiltrating leukocytes in most malignant tumors, we used microarray technology to investigate whether DcR3 contributes to the development of TAMs. Among the DcR3-modulated genes expressed by TAMs, those that encode proteins involved in MHC class II (MHC-II)–dependent antigen presentation were down-regulated substantially, together with the master regulator of MHC-II expression (the class II transactivator, CIITA). The ERK- and JNK-induced deacetylation of histones associated with the CIITA promoters was responsible for DcR3-mediated down-regulation of MHC-II expression. Furthermore, the expression level of DcR3 in cancer cells correlated inversely with HLA-DR levels on TAMs and with the overall survival time of pancreatic cancer patients. The role of DcR3 in the development of TAMs was further confirmed using transgenic mice overexpressing DcR3. This elucidates the molecular mechanism of impaired MHC-II–mediated antigen presentation by TAMs, and raises the possibility that subversion of TAM-induced immunosuppression via inhibition of DcR3 expression might represent a target for the design of new therapeutics.

II. Intestinal epithelial cell exosomes: perspectives on their structure and function

2002 ◽  
Vol 283 (2) ◽  
pp. G251-G255 ◽  
Author(s):  
Guillaume van Niel ◽  
Martine Heyman
Keyword(s):  
Immune System ◽  
Antigen Presentation ◽  
Mhc Class Ii ◽  
The Body ◽  
Intestinal Lumen ◽  
Intestinal Epithelial ◽  
Effector Cells ◽  
Cellular Contact ◽  
And Function ◽  
Antigen Presenting

Intestinal epithelial cells (IEC) are located at the strategic interface between the external environment and the most extensive lymphoid compartment in the body. Besides their central role in the absorption of nutrients, they also provide sample information to the immune system on soluble or particulate antigens present in the intestinal lumen. Like professional antigen-presenting cells, IEC have recently been shown to secrete 30- to 90-nm diameter vesicles named exosomes from their apical and basolateral surfaces. These vesicles carry molecules that are implicated in adhesion and antigen presentation, such as major histocompatibility complex (MHC) class I molecules, MHC class II molecules, CD63, CD26/dipeptidyl-peptidase IV, tetraspan proteins, and A33 antigen. IEC exosomes therefore, constitute a link by which IEC may influence antigen presentation in the mucosal or systemic immune system independent of direct cellular contact with effector cells.

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.

Inhibitory Effects of Thymus-Independent Type 2 Antigens on MHC Class II-Restricted Antigen Presentation: Comparative Analysis of Carbohydrate Structures and the Antigen Presenting Cell

1997 ◽  
Vol 176 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Mercedes González-Fernández ◽  
Eugenio Carrasco-Marı́n ◽  
Carmen Alvarez-Domı́nguez ◽  
Ingrid M. Outschoorn ◽  
Francisco Leyva-Cobián
Keyword(s):  
Comparative Analysis ◽  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Inhibitory Effects ◽  
Antigen Presenting Cell ◽  
Antigen Presenting

scholarly journals Targeting Antigen-Presenting Cells in Multiple Sclerosis Treatment

2021 ◽  
Vol 11 (18) ◽  
pp. 8557
Author(s):  
Piotr Szpakowski ◽  
Dominika Ksiazek-Winiarek ◽  
Andrzej Glabinski
Keyword(s):  
Multiple Sclerosis ◽  
T Cells ◽  
Dendritic Cells ◽  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Antigen Presenting Cells ◽  
Class Ii ◽  
The Central Nervous System ◽  
Antigen Presenting ◽  
Myelin Antigens

Multiple sclerosis (MS) is common neurological disease of the central nervous system (CNS) affecting mostly young adults. Despite decades of studies, its etiology and pathogenesis are not fully unraveled and treatment is still insufficient. The vast majority of studies suggest that the immune system plays a major role in MS development. This is also supported by the effectiveness of currently available MS treatments that target immunocompetent cells. In this review, the role of antigen-presenting cells (APC) in MS development as well as the novel therapeutic options targeting those cells in MS are presented. It is known that in MS, peripheral self-antigen-specific immune cells are activated during antigen presentation process and they enter the CNS through the disrupted blood–brain barrier (BBB). Myelin-reactive CD4+ T-cells can be activated by dendritic cells, infiltrating macrophages, microglia cells, or B-cells, which all express MHC class II molecules. There are also suggestions that brain endothelial cells may act as non-professional APCs and present myelin-specific antigens with MHC class II. Similarly, astrocytes, the major glial cells in the CNS, were shown to act as non-professional APCs presenting myelin antigens to autoreactive T-cells. Several currently available MS drugs such as natalizumab, fingolimod, alemtuzumab, and ocrelizumab may modulate antigen presentation in MS. Another way to use this mechanism in MS treatment may be the usage of specific tolerogenic dendritic cells or the induction of tolerance to myelin antigens by peptide vaccines.

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