The effects of recombinant human interferon-gamma on a panel of human bladder cancer cell lines

We have examined the Major Histocompatibility Complex class II antigen inducing capabilities of recombinant human interferon-gamma, on a panel of human transitional cell carcinoma lines which have been raised from original tumours of varying histological grades: RT4 (grade 1), RT112 (grade 2) and MGH-U1 (grade 3). Cells were examined for class II antigens using an indirect immunofluorescent staining method and analysed on a fluorescence activated cell sorter. Twenty percent of RT4 cells constitutively expressed class II antigen. Both RT112 and MGH-U1 were repeatedly found to be negative for this antigen prior to treatment with interferon-gamma. Following treatment with interferon-gamma all three lines showed an increase in class II antigen expression, which was consistently dependent on both the length of incubation and concentration of interferon-gamma. A differential susceptibility was found amongst the three cell lines which may relate to the histological grade of the parent tumor.