ABSTRACT
The nature and local functions of tumor-infiltrating lymphocytes (TIL) in solid human tumors remain unclear, as does the precise relationship between these cells and tumor growth. Lymphocytes are often the most prominent cellular component of inflammatory infiltrates into human solid tumors. Fresh TIL, if recovered in sufficiently large numbers, were stained with labeled monoclonal antibodies to the lymphocyte surface antigens before culture and analyzed in a flow cytometer. Recent functional studies with freshly isolated and in vitro-cultured TIL from human solid tumors have failed generally to confirm that these tumors contain cytotoxic T lymphocytes specific for autologous tumor cells. Cultures of TIL were serially monitored for cytotoxicity against natural killer (NK) cell-sensitive and NK-resistant tumor targets during culture. Murine TIL cultured in vitro in the presence of recombinant interleukin-2 were claimed to be distinct from lymphokine-activated killer cells because of their specificity for autologous tumor targets, better expansion in vitro, and greater antitumor cytolytic potential.
