Comparative studies of the long-term growth of lymphocytes from tumor infiltrates, tumor-draining lymph nodes, and peripheral blood by repeated in vitro stimulation with autologous tumor.

Abstract

Tumor-infiltrating lymphocytes (TILs) have been grown from a variety of human tumors. TILs from some patients with melanoma demonstrate lytic activity specific for autologous tumor, and can mediate tumor regression when adoptively transferred to select cancer patients. In this study, we have compared the in vitro properties of lymphocytes from peripheral blood (PBLs), from draining lymph nodes (DLNs), and from tumors (TILs) grown simultaneously from 10 patients: 2 with melanoma, 4 with breast cancer, 1 with gastric cancer, 1 with renal cancer, 1 with sarcoma and 1 with lung cancer. PBLs, TILs, and DLNs were cultured in RPMI 1640 + 10% human AB serum, 20% LAK cell culture supernatant, and 1,000 u/ml of recombinant interleukin-2. Half of each culture was restimulated with irradiated autologous tumor every 14 days. In all groups, tumor feeding enhanced lymphocyte proliferation, although TILs and DLNs consistently proliferated longer and more rapidly than PBLs. Eight of 10 early cultures of TILs and DLNs contained greater or equal proportions of CD8+ cells compared with CD4+ cells, but in long-term cultures an inversion of that ratio was seen (CD4+ greater than CD8+). In short-term chromium release assays, specific lysis of autologous tumor was seen in tumor-fed TILs and DLNs from one patient with melanoma, DLNs from one patient with breast cancer, and TILs from one patient with lung cancer. Other cultures had nonspecific lytic activity. Specific cytotoxicity against autologous tumor sometimes became apparent only after prolonged culture and repeated restimulation with autologous tumor. DLNs have in vitro properties similar to TILs and may be a useful immune reagent for cancer therapy.