Development of highly immunogenic variants of a rat fibrosarcoma line during in vitro cultivation.
Rat fibrosarcoma KMT-17 cells decreased in tumorigenicity when cultured in vitro. Eight clones derived from cultured KMT-17 cell lines (c-KMT-17) were examined for their tumorigenicity, immunosensitivity, and immunogenicity. All the clones were less or nontumorigenic in normal syngeneic rats than KMT-17 cells maintained in vivo. All eight clones produced tumors in rats immunosuppressed with 600 rad 60Co; differences in degree of tumorigenicity were seen among clones in rats irradiated with 250 rad 60Co. Although immunosensitivity of the eight clones to complement-dependent and cell-mediated cytotoxicity was the same or less than that of KMT-17 cells, al leight clones induced greater transplantation resistance to KMT-17 than KMT-17 itself. Cold target inhibition tests demonstrated new antigens in a highly immunogenic variant in addition to the original tumor associated antigen (TAA). New glycolipids, not observed in KMT-17 cells, were demonstrated in the clones by thin layer chromatography. These results suggest that new antigens appearing during culture of KMT-17 may act as helper antigens for TAA, increasing the immunogenicity and decreasing the tumorigenicity of the cultured cells.
D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis / Q000276:immunology; D002460:Cell Line; D002462:Cell Membrane / Q000032:analysis; D005260:Female; D005354:Fibrosarcoma / Q000276:immunology*; D006017:Glycolipids / Q000032:analysis; D007106:Immune Sera / Q000276:immunology; D007114:Immunization; D007694:Killer Cells, Natural / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains
D000951:Antigens, Neoplasm; D006017:Glycolipids; D007106:Immune Sera