IN-VITRO EXPANSION AND ANALYSIS OF T-LYMPHOCYTE MICROCULTURES OBTAINED FROM THE VACCINATION SITES OF CANCER-PATIENTS UNDERGOING ACTIVE SPECIFIC IMMUNIZATION WITH AUTOLOGOUS NEWCASTLE-DISEASE-VIRUS-MODIFIED TUMOR-CELLS

In order to understand further the effects of Newcastle-disease-virus( NDV)-modified tumour vaccines we investigated the feasibility of isola ting lymphocytes from the site of injection of patients undergoing pos toperative active specific immunization (ASI) with autologous NDV-modi fied tumour cells. Delayed-type-hypersensitivity(DTH)-like reactions f rom five cancer patients were surgically removed, minced and the tissu e particles were digested with collagenase and DNase. Lymphoid cells r ecovered were expanded in a highly efficient limiting-dilution analysi s system optimized for T cell growth [Moretta et al. (1983) J Exp Med 157: 743] and lymphocyte microcultures (clonal probability >0.8) could be grown for up to 1 year. Analysis of the microcultures for phenotyp e and function showed that the majority were positive for CD4 (92%) an d TCRalphabeta (96%). Concanavalin-A-induced production of interleukin -2 (IL-2), IL-6, interferon gamma and tumour necrosis factor a was det ected in more than 70% of the microcultures. Lectin-dependent cytotoxi city was only very rarely observed. The general characteristics of the microcultures obtained support the notion of a DTH-like reaction taki ng place at the site of tumour cell challenge. The possibility of in v itro expansion and cultivation of T lymphocytes from ASI vaccination s ites should help to elucidate further the role of these cells in activ e specific immunization against autologous tumour cells.