Characterization of novel anti-tumor effector cells in long-term cultures of human tumor-infiltrating lymphocytes

TIL were isolated from human solid tumors and cultured in rIL 2. Long-term TIL lines from primary tumors showed a shorter lag period, better expansion, and higher anti-tumor activity in vitro than those from metastatic tumors. The anti-tumor effector cells in TIL and A-PBL cultures had CD3+ Leu 19+ and CD3- Leu19+ phenotypes and morphology consistent with LGL/LAK cells. These cells mediated lysis of both autologous and allogeneic fresh tumor cell targets, while CD3+ Leu19- cells had little or no antitumor cytotoxicity.