Effects of cytokines combined with high-dose gamma irradiation on the expression of major histocompatibility complex molecules and intercellular adhesion molecule-1 in human ovarian cancers.

Tumor cells from 7 freshly isolated human ovarian tumors and 2 continuous human ovarian cancer cell lines were analyzed for their surface expression of MHC class-1, class 11 and ICAM-1 surface antigens before and after exposure to gamma-irradiation and/or the cytokines TNF-alpha plus IFN-gamma. All 7 fresh tumors expressed high levels of MHC class 1 and 1CAM-1 antigens, and levels were markedly up-regulated after exposure to TNF-alpha plus IFN-gamma Similarly, class-11 antigens were either induced (3 out of 7 tumors) or significantly up-regulated by TNF-alpha plus IFN-gamma. Exposure to high doses of gamma-irradiation also increased the expression of MHC class-1 and ICAM-1 antigens, albeit to a modest degree. MHC class 1 and ICAM-1 antigens expression was much lower on continuous human ovarian cell lines than on the fresh tumors. Exposure of these cells to TNF-alpha plus IFN-gamma markedly up-regulated antigen expression to levels comparable to those expressed on the freshly isolated tumors. With the established ovarian cell lines, removal of cytokines caused a rapid down-regulation of antigen expression to basal levels within 6 days, while in the fresh tumors a low level of up-regulation was still present at this time. In contrast, exposure to cytokines followed by high-dose gamma-irradiation resulted in a highly significant and long-lasting expression of each surface antigen which was either up-regulated or induced by the cytokines. These data indicated that the combination of these modalities may be beneficial in generating optimal antigen expression for use of tumor cells in vaccine studies.

Development and characterization of an IL-4-secreting human ovarian carcinoma cell line.

Human ovarian carcinoma cell lines were genetically engineered to secrete the cytokine interleukin-4 (IL-4) by retroviral-mediated gene transduction. These cells were transduced with the LXSN retroviral vector containing the human IL-4 gene and the neomycin resistance selection marker. Numerous IL-4-secreting clones were isolated from different papillary serous carcinoma cell lines, including SKOV-3, UCI-101, and UCI-107, and one clone derived from UCI-107 extensively characterized. This clone, termed UCI 107E IL-4 GS, was shown to constitutively express high levels of IL-4 (i.e., 900 to 1300 pg/ml/10(5) cells/48 hr) for over 35 passages and 6 months of study. Like the parental cell line (UCI-107), UCI 107E IL-4 GS cells expressed MHC class I and Her-2/neu surface antigens but did not express detectable MHC class II, ICAM 1, CA 125, or IL-4 receptors. No increase in expression of surface proteins was noted between parental and UCI 107E IL-4 GS. The morphology of this clone did not differ from that of the parental or LXSN vector control cells; however, parental cells had a faster growth rates than transductants. UCI 107E IL-4 GS was sensitive to gamma irradiation since as little as 2500 rad killed most of the cells within 10 days of irradiation. However, after irradiation, IL-4 secretion continued until about Day 8. The potential use of these IL-4-secreting ovarian carcinoma cells as vaccines for woman with advanced ovarian cancer will be discussed.