RMA/S cells present endogenously synthesized cytosolic proteins to class I-restricted cytotoxic T lymphocytes.
RMA/S is a mutant cell line with decreased cell surface expression of major histocompatibility complex class I molecules that has been reported to be deficient in presenting endogenously synthesized influenza virus nucleoprotein (NP) to cytotoxic T lymphocytes (CTL). In the present study we show that RMA/S cells can present vesicular stomatitis virus nucleocapsid protein, and, under some conditions, NP, to Kb-and Db-restricted CTL, respectively. Antigen presentation results from processing of cytosolic pools of endogenously synthesized proteins, and not the binding to cell surface class I molecules of antigenic peptides present in the virus inoculum or released from infected cells. Antigen processing of RMA/S differs, however, from processing by wild-type cells in requiring greater amounts of antigen, longer times to assemble or transport class I-peptide complexes, and in being more sensitive to blocking by anti-CD8 antibody. Thus, the antigen processing deficit in RMA/S cells is of a partial rather than absolute nature.
Esquivel
F
F
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Yewdell
J
J
Bennink
J
J
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D020126:Brefeldin A; D002213:Capsid / Q000276:immunology; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D003517:Cyclopentanes / Q000494:pharmacology; D003600:Cytosol / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D009980:Influenza A virus / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008815:Mice, Inbred Strains; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins / Q000276:immunology*; D016601:RNA-Binding Proteins; D013045:Species Specificity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014721:Vesicular stomatitis Indiana virus / Q000276:immunology; D014758:Viral Core Proteins / Q000276:immunology*
D000998:Antiviral Agents; D003517:Cyclopentanes; D015395:Histocompatibility Antigens Class I; C048842:NP protein, Influenza A virus; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D016601:RNA-Binding Proteins; D014758:Viral Core Proteins; D020126:Brefeldin A; D003513:Cycloheximide