Production and characterization of xenogeneic antisera to tumor-associated antigen(s)

Tumor-associated antigen(s) from a specimen of human malignant melanoma and from spent culture medium of a melanoma cell line were extracted and purified. The incidence of antibody activity to these antigens, in sera from cancer patients with neoplasms of various histologic types, was higher (65--83%) than normal donors' (19--25%) by the complement fixation assay. These purified antigens were then used to raise antisera in rabbits and sheep. After absorption with various human normal tissues, these antisera reacted against melanoma, sarcoma, and carcinoma extracts, but not against human normal liver, skin, or muscle extracts. However, the antisera showed reactivity against a human fetal homogenate. Results indicate that the xenogeneic antisera contained antibodies to fetal antigens and to tumor-associated antigen(s). Xenogeneic antisera could be used to purify tumor-associated antigens and oncofetal antigen(s) from crude extracts by affinity chromatography.