Immunological characterization of cell lines established from malignant and normal human urothelium

Abstract

Cell lines from normal or malignant human urothelium, described elsewhere by morphological, cell kinetic and genotypical criteria, have been characterized further by their response to antibody or lymphocyte mediated cytotoxicity in vitro. Four groups of cell lines were included: (1) two fast proliferating cell lines from normal urothelium, (2) three fast proliferating cell lines from transitional cell carcinoma (TCC) together with two transformed sublines of normal derived cell lines, (3) six slowly proliferating TCC lines, and (4) a line from squamous cell carcinoma. HLA antigen expression was demonstrated in the cell lines of groups 1 and 3, but not in lines from group 2 or 4. The sensitivity to spontaneous lymphocyte mediated cytotoxicity (SLMC) of cells in group 1 and 2 exceeded that of cells from group 3 by a factor of 8. The TCC line, HU 456, was more susceptible to SLMC than T 24. Specifically increased cytotoxicity of lymphocytes from patients suffering from interstitial cystitis (IC) against HU 609 from normal urothelium indicated that this line expresses tissue specific antigens, and at the same time that an immune reaction may be part of the pathogenesis of IC. By a sensitive test for antibody-dependent, cell-mediated cytotoxicity (ADCC) antibody activity against HU 456 was found in only one of nine TCC patients and none of five clinical controls. A pronounced non-disease-related blocking serum activity, frequently found, may account for some of the negative findings. The SLMC against HU 456 could be inhibited but not abolished by Fab fragments of rabbit anti-human immunoglobulin, indicating an ADCC mechanism as part of the SLMC.