Interferon-induced changes in the expression and topography of H-2 antigens and receptors for SRBC in tumour cells.
The expression of H-2 antigens has been investigated in methylcholanthrene-transformed C3H embryonic fibroblasts of clones 36 and 57. Private specificities H-2.23 and H-2.32, typical of the H-2k haplotype, were present on cells of the two clones but differed considerably in their expression. After interferon treatment, the expression of H-2 antigens increased in both clones, though more markedly in clone 57. Interferon treatment also affected the topography of H-2 antigenic determinants on the cell membrane. The blocking index for antigenic determinants coded by a single region of the H-2 complex increased in both clones. Between antigenic determinants controlled by two regions of H-2 the blocking index remained unaltered in clone 36 but decreased significantly in clone 57. Rosette formation with SRBC was consistent with the results of the blocking test between H-2K and H-2D antigenic determinants; rosette formation decreased slightly in clone 36 but increased in clone 57 after interferon treatment. All the results suggest that alterations in expression of H-2 antigens following interferon treatment are due to the rearrangement of the cell membrane rather than to the virtual increase in the number of H-2 antigenic determinants. Cells of clone 57 exhibiting more pronounced changes in the topography of H-2 antigens were more resistant to the inhibitory effect of interferon on cell growth.
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D003602:Cytotoxicity, Immunologic; D004912:Erythrocytes / Q000276:immunology; D006183:H-2 Antigens; D007372:Interferons / Q000494:pharmacology*; D008748:Methylcholanthrene; D051379:Mice; D008809:Mice, Inbred C3H; D011971:Receptors, Immunologic / Q000187:drug effects*; D012397:Rosette Formation; D012756:Sheep
D006183:H-2 Antigens; D011971:Receptors, Immunologic; D008748:Methylcholanthrene; D007372:Interferons