This study was undertaken to investigate the possibility that Listeria monocytogenes, Brucella abortus, and Salmonella typhimurium share antigenic components with guinea pig line 10 hepatocarcinoma cells. Rabbits were immunized with sonicates of these bacteria or line 10 tumor cells. Other rabbits were immunized with line 1 cells, a tumor with antigenic characteristics different from those of line 10. The binding of antibodies to radiolabeled antigens prepared from extracts of bacteria and line 10 cells was studied by precipitation of radiolabeled antigen-antibody complexes with anti-rabbit immunoglobulin.
Antibodies in sera from rabbits immunized with these bacteria and line 10 cells bound both the labeled bacteria and line 10 antigens. Antibodies in sera from rabbits immunized with line 1 cells did not bind the bacterial antigens. Inhibition studies involving reactions between radiolabeled Listeria and line 10 antigens and antibodies to Listeria and line 10 cells confirmed that the binding reactions were specific and that line 10 cells shared antigens with Listeria cells. The possibility that B. abortus and S. typhimurium also shared antigens with line 10 cells was suggested. Whether antigens shared by these bacteria and line 10 cells are identical with tumor-specific antigens was not determined.
This investigation was supported by Grant CA15446 awarded by the National Cancer Institute, Department of Health, Education and Welfare, and Grant AI10398 awarded by the Allergy Disease Center, Department of Health, Education and Welfare.