title: A central role for HSC70 in regulating antigen trafficking and MHC class II presentation.
abstract: Cells rely on multiple intracellular trafficking pathways to capture antigens for proteolysis. The resulting peptides bind to MHC class II molecules to promote CD4(+) T cell recognition. Endocytosis enhances the capture of extracellular and cell surface bound antigens for processing and presentation, while autophagy pathways shunt cytoplasmic and nuclear antigens for presentation in the context of MHC class II molecules. Understanding how physiological changes and cellular stress alter antigen trafficking and the repertoire of peptides presented by class II molecules remains challenging, yet important in devising novel approaches to boost immune responses to pathogens and tumors. An abundant, constitutively expressed cytoplasmic chaperone, HSC70 plays a central role in modulating antigen transport within cells to control MHC class II presentation during nutrient stress. HSC70 may serve as a molecular switch to modulate endocytic and autophagy pathways, impacting the source of antigens delivered for MHC class II presentation during cellular stress.
authors.affiliation: Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Deffit
authors.affiliation: Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, United States. Electronic address: jblum@iupui.edu.
authors.forename: Janice S
authors.initials: JS
authors.lastname: Blum
mesh_terms: D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology*; D000941:Antigens / Q000276:immunology / Q000378:metabolism*; D001343:Autophagy / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D004705:Endocytosis / Q000276:immunology; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D010455:Peptides / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D013312:Stress, Physiological / Q000276:immunology
chemical_list: D000941:Antigens; D050883:HSC70 Heat-Shock Proteins; C494371:HSPA8 protein, human; D000949:Histocompatibility Antigens Class II; D010455:Peptides
keywords: Antigen presentation; Autophagy; Cell stress; HSC70; MHC class II molecules