Interleukin-6 and vascular endothelial growth factor release by renal cell carcinoma cells impedes lymphocyte-dendritic cell cross-talk.

Anti-tumour T cell response requires antigen presentation via efficient immunological synapse between antigen presenting cells, e.g. dendritic cells (DC), and specific T cells in an adapted Th1 cytokine context. Nine renal cell carcinoma (RCC) primary culture cells were used as sources of tumour antigens which were loaded on DC (DC-Tu) for autologous T cell activation assays. Cytotoxic activity of lymphocytes stimulated with DC-Tu was evaluated against autologous tumour cells. Assays were performed with 75 grays irradiated tumour cells (Tu irr) and with hydrogen peroxide +/- heat shock (Tu H(2)O(2) +/- HS) treated cells. DC-Tu irr failed to enhance cytotoxic activity of autologous lymphocytes in seven of 13 assays. In all these defective assays, irradiated tumour cells displayed high interleukin (IL)-6 and vascular endothelial growth factor (VEGF) release. Conversely, when tumour cells released low IL-6 levels (n = 4), DC-Tu irr efficiently enhanced CTL activity. When assays were performed with the same RCC cells treated with H(2)O(2) + HS, DC-Tu stimulation resulted in improved CTL activity. H(2)O(2) + HS treatment induced post-apoptotic cell necrosis of tumour cells, totally abrogated their cytokine release [IL-6, VEGF, transforming growth factor (TGF)-beta1] and induced HSP70 expression. Taken together, data show that reduction in IL-6 and VEGF release in the environment of the tumour concomitantly to tumour cell HSP expression favours induction of a stronger anti-tumour CTL response.

Interleukin-2 expanded lymphocytes from lymph node and tumor biopsies of human renal cell carcinoma, breast and ovarian cancer.

Adoptive immunotherapy with immune effector cells has proved to be potent for treatment of tumors, however neither the attendant criteria for potential clinical efficacy of the injected cells, nor the method to prepare these cells are presently well established. Our procedure of collecting lymphocytes from biological samples, was based on the use of low IL-2 concentrations (90 to 150 IU/ml) and on the stringent separation of lymphocytes from tumor cells at the very early stages of their outgrowth in culture. When lymphocytes were derived from tumor biopsies (TIL), we observed differences depending on the histological type of tumor. In renal cell carcinoma, natural killer cells were expanded in 4/11 biopsies contrary to what was observed in breast cancer (92 +/- 5% of T lymphocytes from 9 biopsies). The outgrowth of lymphocytes from breast tumors was slower and lower than from renal carcinomas. The autologous tumor cell line was more difficult to obtain from breast carcinoma (23%) than from renal cell carcinoma (61%) biopsies. For ovarian cancer, short-term culture of tumor cells could be obtained for half of the tumor-invaded biological samples. Eight of the 23 tumor-derived cultures contained more than 40% CD8 T. TIL were consistently cytolytic each time they could be evaluated. For ascitic and pleural fluids, data were of similar range. In ascitic-derived cultures, tumor cells and antigen-presenting cells are present and can be supposed to rechallenge T cells with tumor antigens. Lymphocytes derived from lymph nodes could be expanded to a larger number than TIL. However, only 1/18 of these cultures contained more than 40% CD8 T. The presence of few tumor cells in this culture was in favor of significant specific and non-specific cytotoxicity in RCC lymph node cultures and higher percentages of CD8 T in breast cancer lymph nodes. Correlations could not be established between CD8 T percentages and specific in vitro cytotoxicity in our polyclonal populations. Our conclusion is that phenotypic and functional quality of lymphocytes is of interest when the T cells are derived 1) from tumors (RCC, breast or ovarian cancer) and isolated very early to avoid inhibitor factors secreted from tumor cells or 2) from lymph nodes and ascitic and pleural fluids when very few tumor cells are co-cultivated with lymphocytes at initial steps of culture. Final expansion to a number of lymphocytes suitable for therapy (> 109) could be attained in a second step of the procedure by the use of 1,000 IU/ml IL-2 each time it was assayed with 50.106 lymphocytes. In view of these data it appears that phenotypic and functional changes occur during culture depending on the presence of a particular ratio of tumor antigens. This could be artificially reproduced.