ISOLATION OF TUMOR-SPECIFIC CYTOTOXIC CD4(-CELL CLONES INFILTRATING ACUTANEOUS T-CELL LYMPHOMA() AND CD4(+)CCD8DIM(+) T)

We have isolated several T-cell clones from lymphocytes infiltrating a human major histocompatibility class (MHC) II negative cutaneous T-ce ll lymphoma (CTCL). We describe here two of these clones, TC5 and TC7, with, respectively, a CD4(+)CD8dim(+) and CD4(+)CD8(-) phenotype. Bot h clones mediated a specific MHC class I-restricted cytotoxic activity toward the fresh autologous tumor cells, and autologous tumor cell li nes previously established with interleukin-2 (IL-2) and IL-7 from the skin and from the blood. Analysis of the T-cell receptor (TCR) V beta gene expression showed that the tumor cells, which were shown to have a trisomy 7 by fluorescent in situ hybridization, expressed V beta 7/ J beta 2.3, V beta 13/J beta 2.5, and V beta 22/J beta 2.5 rearrangeme nts. Phenotypic analysis using specific anti-V beta monoclonal antibod ies indicated that only V beta 13 could be detected on the cell membra ne of the tumor cells. Analysis of the TCR V beta gene expression of t he clones showed that TC5 and TC7 expressed a unique TCR-V beta transc ript, corresponding, respectively, to V beta 5/J beta 2.3 and V beta 1 7/J beta 2.7 gene segments. To determine whether these reactive T lymp hocytes were present in vivo, we used specific primers corresponding t o TC5- and TC7-V beta TCR transcripts. The results showed that both cy totoxic T-cell clones were present at the lesional skin site and ampli fied in vitro, TC7 was found in the patient peripheral blood invaded b y tumoral cells, whereas TC5 was not, indicating that the repertoire o f the reactional lymphocytes differs in the blood and at the tumor sit e, These results show for the first time the presence of reactive T ly mphocytes with CD4 or double-positive phenotype infiltrating a CTCL. T hese findings raise the question of the role of these antitumoral effe ctor T cells in the tumor growth. (C) 1998 by The American Society of Hematology.