Reduced stimulation of helper T cells by Ki-ras transformed cells.
A number of viral genes and cellular oncogenes inhibit major histocompatibility complex (MHC) antigen expression at the cell surface. In the case of inhibition of class I MHC antigens by viral genes this results in a reduced recognition by antigen-specific cytotoxic T cells. The activated Ki-ras cellular oncogene carried by the Ki-murine sarcoma virus (Ki-MuSV) in contrast inhibits class II MHC (or Ia) antigen expression on transformed cells. We have studied how transformation with Ki-ras affects recognition by alloreactive helper T cells. We found that the Ki-ras inhibition of class II MHC antigen expression led to greatly reduced stimulation of alloreactive T cells to proliferate and to secrete interferon-gamma (IFN-gamma). These findings support our hypothesis that the ability of an oncogene to reduce class II MHC antigen expression is crucial to its ability to produce tumour cells.
Maudsley
D J
DJ
Department of Biological Sciences, University of Warwick, Coventry, U.K.
Bateman
W J
WJ
Morris
A G
AG
D000818:Animals; D002455:Cell Division / Q000276:immunology; D002472:Cell Transformation, Viral / Q000276:immunology*; D011905:Genes, ras / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D011994:Recombinant Proteins; D012513:Sarcoma, Experimental / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D011994:Recombinant Proteins; D007371:Interferon-gamma