In vitro generation of tumour-specific lymphocyte reactivity to colonic carcinoma cells

Summary Purified tumour cells and normal mucosa cells from fresh human colorectal cancer resection specimens, and T-cell-enriched autologous peripheral blood lymphocytes, were mixed in short-term (6 day) mixed lymphocytetumour cell (MLTC) microcultures. Lymphocyte stimulation was measured by ³H-thymidine uptake, and a stimulation index (SI=[lymphocytes vs tumour cells (cpm)–tumour cells (cpm)]/[lymphocytes (cpm)])>3 was regarded as significant. Significant lymphocyte reactivity was found in 10/15 patients with colon carcinoma. However, 1 patient with autologous tumour reactivity, also showed significant stimulation against autologous normal mucosa cells, suggesting tumour-associated reactivity. Maximum stimulation occurred most frequently at a lymphocyte:tumour cell ratio of 2:1 and with nylon wool-passaged lymphocytes.Project was supported by a grant from the Cancer Research CampaignSupported by New South Wales Cancer Council Fellowship