DISSIMILAR TCR V-BETA FREQUENCIES IN TIL FROM DIFFERENT SITES OF THE SAME TUMOR

Tumor infiltrating lymphocytes (TIL) cultured long term in media conta ining IL-2 were shown to mediate in vitro and in vivo anti-tumor respo nses. To understand the anti-tumor activity of TIL T cells, we used po lymerase chain reaction (PCR) to characterize the TCR Vbeta repertoire of ovarian TIL which were isolated from three tumor sites of the same patient at the same time and cultured under identical conditions, res ulting in CD3+ cells with similar CD8:CD4 ratios. TIL isolated from ov ary and ascites expressed a broad distribution of Vbeta repertoire, wh ile the Vbeta phenotype of the TIL from a secondary tumor (omentum) wa s more restricted. After 5 months, cultured TIL from the primary tumor (ovary) maintained a diverse TCR Vbeta repertoire, but the Vbeta phen otype of TIL from the secondary site was dominated by the Vbeta-1, -11 and -14 families. Importantly, the percentages of Vbeta-11 and Vbeta- 1 expression in both omentum and ovary TIL at 3 and 5 months was found to correlate with the levels of lysis of the tumor localized to oment um (p =0.003 and p=0.014, respectively). No statistical correlation wa s found between cytotoxicity and the use of any other individual Vbeta families or the sum of any other families, including TCR Vbeta-3 or - 20 found increased at certain time points. This suggests that where ce rtain TCR Vbeta families are selected in tumor reactive T cells this s election may reflect tumor Ag recognition at either primary or distant tumor sites. To our knowledge, this is the first documentation of com plete TCR Vbeta repertoire of ovarian TIL and of a correlation between Vbeta usage and tumor lysis, by effectors from different sites.