Production and characterization of xenogeneic antisera to a human renal cell carcinoma-associated antigen

Antisera to human renal cell carcinomas were produced by the immunization of goats and rabbits with dissociated tumor cells and/or tumor homogenates from single donors. After absorptions with human red blood cells and homogenates of human liver, lung, spleen, and heart, all the immune sera reacted on immunofluorescence with the brush border of the proximal convoluted tubules of adult and fetal human kidneys and with the proximal convoluted tubular epithelia of rabbits, guinea pigs, rats, and mice. After further absorption with pooled normal human kidney homogenates, the immune sera on immunofluorescence showed cytoplasmic staining of smears and sections of 21 of the 22 human renal cell carcinomas tested. These sera did not show any staining of normal adult human tissues including normal kidney adjacent to the carcinomas, perirenal fibroblasts and peripheral blood leukocytes from the patients, human fetal kidneys, transplanted renal adenocarcinoma of BALB/c mice, and several human tumors tested, i.e., transitional cell carcinoma of the bladder, adenocarcinomas of the breast and colon, squamous cell carcinoma of the lungs, malignant lymphoma, and melanoma. Autoradiography of tissue sections with 131I-labeled antitumor globulins revealed greater localization of radioactivity in tumors than in adjacent normal kidney. Membrane immunofluorescence with the immune sera rendered tumor-specific after appropriate absorptions revealed tumor-associated antigens on the surfaces of all 5 human renal carcinoma cell lines tested.