CHARACTERISTICS AND IN-VIVO HOMING OF LONG-TERM T-CELL LINES AND CLONES DERIVED FROM TUMOR-DRAINING LYMPH-NODES

Lymph nodes draining a progressively growing tumor contain T-cells whi ch can be activated sequentially by anti-CD3 and IL-2 to differentiate into tumor-specific effector cells. In this study, long-term cultured T-cell lines were established from activated MCA 106 tumor-draining l ymph node cells by periodic stimulation with irradiated tumor cells in the presence of low concentrations of IL-2 (less than or equal to 60 International units/ml). Such long-term cultured cell lines maintained therapeutic effects when transferred to tumor-bearing mice. Although the initial anti-CD3/IL-2-activated T-cells displayed a broad distribu tion of T-cell antigen receptor beta chain variable region (V beta) us ages, long-term cultured cells were dominated by T-cells expressing a few V beta elements. Of six fell lines, only three V beta phenotypes ( V beta 5, 11, 13) were identified, and individual cell lines frequentl y expressed a single V beta gene product. Despite restricted V beta ex pression, each cell line mediated tumor-specific reactivity in adoptiv e immunotherapy. Many T-cell clones were isolated from long-term cell lines. Three V beta 13 T-cell clones demonstrated specific in vivo ant itumor effects, whereas two V beta 11 and two V beta 5 clones revealed a significant degree of cross-reactivity against the antigenically di stinct MCA 205 tumor. Although the initial anti-CD3/IL-2-activated cel ls lacked demonstrable cytotoxic reactivity, T-cell clones derived fro m them exhibited cytotoxic effects to the MCA 106 tumor cells. The spe cificity of the cytotoxicity mediated by each clone reflected its in v ivo antitumor effects. Furthermore, studies of in vivo localization of cloned T-cells demonstrated tumor-specific infiltration of the 5A2 (V beta 13) clone to the MCA 106 tumor metastases, whereas clone 9H6 (V beta 5) revealed some accumulation in the MCA 205 tumor. Again, the in vivo antitumor effects of the 9H6 clone correlated with its in vivo i nfiltration into the specific MCA 106 and the nonspecific MCA 205 meta stases. Taken together, the long-term culture of anti-CD3/IL-2-activat ed tumor-draining lymph node cells resulted in selective expansion of a few T-cells as evidenced by the limited T-cell receptor V beta expre ssion. Our results also demonstrated that systemically administered an titumor T-cell clones gained access and accumulated at metastatic tumo r sites, and the degree of infiltration correlated with the specificit y of the in vivo antitumor effect as well as the in vitro cytotoxic ac tivity.