EVIDENCE FOR IN-SITU AMPLIFICATION OF CYTOTOXIC T-LYMPHOCYTES WITH ANTITUMOR-ACTIVITY IN A HUMAN REGRESSIVE MELANOMA

We have derived from lymphocytes infiltrating a human regressive melan oma lesion a series of T-cell receptor alpha/beta-dependent, HLA-B14-r estricted cytotoxic T-lymphocyte clones reactive against the autologou s tumor. Analysis of the T-cell receptor gene expression revealed that all the clones represented a unique cell expressing a Vbeta13.1/Jbeta 1.1 gene segment. T-cell receptor transcripts expressed in the cloned cells were compared to those present in the uncultured tumor tissue. T his analysis demonstrated that the specific cytotoxic T-lymphocyte clo nes characterized in vitro was actually selected and amplified in vivo at the lesion site. These results provide strong evidence that effect or T-cells have contributed to tumor regression.