title: CD8 is needed for development of cytotoxic T cells but not helper T cells.
abstract: A mutant mouse strain without CD8 (Lyt-2 and Lyt-3) expression on the cell surface has been generated by disrupting the Lyt-2 gene using embryonic stem cell technology. In these mice, CD8+ T lymphocytes are not present in peripheral lymphoid organs, but the CD4+ T lymphocyte population seems to be unaltered. Cytotoxic response of T lymphocytes from these mice against alloantigens and viral antigens is dramatically decreased. Proliferative response against alloantigens and in vivo help to B lymphocytes, however, are not affected. These data suggest that CD8 is necessary for the maturation and positive selection of class I MHC restricted cytotoxic T lymphocytes but is not required on any of the intermediate thymocyte populations (CD8+CD4-TcR- or CD4+CD8+TcRlow) during the development of functional class II MHC restricted helper T cells.
authors.affiliation: Ontario Cancer Institute, University of Toronto, Canada.
authors.forename: W P
authors.initials: WP
authors.lastname: Fung-Leung
authors.forename: M W
authors.initials: MW
authors.lastname: Schilham
authors.forename: A
authors.initials: A
authors.lastname: Rahemtulla
authors.forename: T M
authors.initials: TM
authors.lastname: Kündig
authors.forename: M
authors.initials: M
authors.lastname: Vollenweider
authors.forename: J
authors.initials: J
authors.lastname: Potter
authors.forename: W
authors.initials: W
authors.lastname: van Ewijk
authors.forename: T W
authors.initials: TW
authors.lastname: Mak
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D000950:Antigens, Ly / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens; D005805:Genes, MHC Class I; D005802:Genes, MHC Class II; D007519:Isoantigens / Q000276:immunology; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D009154:Mutation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology; D014721:Vesicular stomatitis Indiana virus / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000956:Antigens, Viral; D016827:CD8 Antigens; D007519:Isoantigens