title: Impaired H-2 expression in B16 melanoma variants.
abstract: We studied the expression of H-2b alloantigens in three different B16 melanoma lines cultures in vitro. Cell lines were B16-F1 and two cell cultures (named B16-A and B16-B) newly derived from two different in vivo sublines of B16 melanoma. The assays used were in vivo tumour growth in allogeneic (BALB/c and B10.BR) as compared to syngeneic mice, in vitro cell-mediated cytotoxicity by anti-H-2b immune lymphocytes and absorption of anti-H-2b antisera activity. The B16-F1 line was able to efficiently kill allogeneic hosts, could not be lysed by anti-H-2b cytotoxic effectors and did not express any serologically detectable amount of H-2b alloantigens. The B16-A line was H-2 positive during the early in vitro passages, then, at the 8th-10th passages, it acquired the capacity to kill allogeneic hosts, lost the sensitivity to anti-H-2b cytotoxic effectors and the H-2Kb antigens became undetectable The expression of H-2Db was reduced, although at a lower degree. Similar data were obtained with B16-B cells, which after 10 in vitro passages grew and killed allogeneic hosts, showed a decreased sensitivity to cytotoxic anti-H-2b effectors and a very low expression of the K region antigens. The results indicate that H-2 expression is altered in B16 melanoma lines and this may influence the different metastatic capacity of such cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D005260:Female; D006183:H-2 Antigens; D008545:Melanoma / Q000276:immunology* / Q000556:secondary; D051379:Mice; D008815:Mice, Inbred Strains; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D013997:Time Factors
chemical_list: D006183:H-2 Antigens