Specificity of Cytotoxic Heterologous Antiserum to Cultured Human Cancer Cells

Summary Rabbit antisera prepared against representative cultures of human cancer cells (SV40 virus-transformed, HeLa, and EB2 cells) showed high cytotoxic specificity for homologous cells when tested against these and cells of other lines and strains. Similar results were observed with antisera against a new cell culture originating from human lung cancer. Antisera against cultures of normal human cells also showed specificity, but relatively low titers. Cross-reactions were observed between HeLa cell antiserum and J-111 cells and also between EB2 antiserum and EB3 cells and a new cell culture originating from human lymphosarcoma. The cytotoxic activity of the antisera was absorbed by cells of human lines or strains other than those used to produce the antisera, but more effectively by homologous than heterologous cells. The apparent ambiguity arising from the simultaneous occurrence of high specificity of antisera with respect to cytotoxicity and low specificity with respect to absorption is discussed.