The relationship between tumor cells and tumor-infiltrating lymphocytes (TIL) in tumor tissues from 12 cases of carcinoma of various sites was studied at the electron microscope level. Only at few TIL got in touch with tumor cells by several patterns of contact. Some tumor cells contacting with lymphocytes showed destructive changes similar to that of apoptosis. These findings indicate that some TIL can kill tumor cells in vivo and the main mode of tumor cell death is apoptosis, However, there were only a few TIL in contact with tumor cells. the tumoricidal effect of TIL in tumor tissue may be very limited.

Human tumor antigen elicit a cell-mediate immune response in the host have been identified. In this study, a pancreatic cancer cell line SW1990 associated apomucin was examined for the induction of tumor draining lymph node cells(TDLN) anti-tumor immune responses.The TDLN of patients with breast cancer(4 cases), gastric cancer(3 cases), colon cancer(3 cases) were isolated, cocultured with apomucin 50 ?g/ml and low dose rhIL-2 50U/ml in vitro, the cytolytic effects were measured by MTT assay. The results showed that: the proliferated lymphocytes can lysis LS174T colon cancer cells, KATO-Ⅲ gastric cancer cells, SW1990 pancreatic cancer cells and K562 leukemia cells. The most cytolytic effects were higher than LAK. This results might provide a rational basis for future attempts to elicit and manipulate apomucin vaccine for active specific immunotherapy or adoptive immunotherapy for adenocarcinoma.

90 KD.A11 the five monoclonal antibodies against this apomucin reacted with cancer cell lines and cancer tissues,while only one also reacted with normal tissues.