IMMUNOHISTOCHEMICAL ANALYSIS OF THE T-CELL RECEPTOR BETA-CHAIN VARIABLE REGIONS EXPRESSED BY T-LYMPHOCYTES INFILTRATING PRIMARY HUMAN-MELANOMA

The T-cell receptor beta-chain variable (TCRBV) region repertoire expr essed by tumor-infiltrating lymphocytes was characterized by immunohis tochemical analysis using a panel of 18 monoclonal antibodies on cryos ectioned specimens of 14 primary vertical growth phase (VGP) melanomas with a T-cell infiltrate histopathologically defined as brisk or nonb risk. T lymphocytes present in the VGP of all patients displayed a res tricted T-cell receptor usage, with a pattern of reactivity similar in brisk versus nonbrisk infiltrates. No evidence of restriction was fou nd in the extra-VGP lymphocytic infiltrates, when available, within th e same specimen. Furthermore, the repertoire of TCRBV expressed in nod al metastases was similar to that of the corresponding primary melanom as in the two cases tested. The results obtained by this in situ analy sis indicate that the TCRBV repertoire in VGP is determined by a prefe rential migration of T lymphocytes, possibly indicative of an immune r esponse to melanoma-associated antigens.