Identification of Specific TRAV6 and TRAV23 Genes in Peripheral Blood T Cells from Patients with Diffuse Large B-Cell Lymphoma.

Antigen specific T cells were identified in peripheral blood from some malignancy, for example melanoma, as well as in B-ALL. The T cells proliferation in response to tumor antigen could be identified by analysis of T cell receptor repertoire, which can display the distribution of TRAV or TRBV subfamilies and the clonaltiy of different subfamily T cells, the clonal expanded T cells are thought to be relate to antigen specific T cells in non-T-cell malignancy. In order to identify the specific T cell clone which was expected to have a specific anti-DLBL (diffuse large B-cell lymphomas) effect and to use as immunotherapeutic cells to prevent minimal residual disease in patients with DLBL, TRAV subfamily genes from clonal expanded T cells were analyzed by using RT-PCR, genescan and DNA sequencing techniques. Peripheral blood mononuclear cells from 6 cases with DLBL were used in the study. By using RT-PCR with 29 specific TRAV subfamily primers, some of TRAV subfamilies could be detected in different samples, 4 monoclonal expanded TRAV subfamily T cells were identified by genescan analysis, in which PCR products direct sequencing was performed to identify the CDR3 sequence. Specific TRAV6 and TRAV23 sequences were obtained in 3 cases respectively, however the CDR3 sequence of TRAV6 or TRAV23 form different patients were not complete identical, suggesting that they recognized and bound specifically to different DLBL-associated antigens. And the CDR3 sequences of these 4 identified genes (two TRAV6 and two TRAV23) were not be reported in Genebank. The whole sequence of both TRAV6 and TRAV23 genes were obtained by RT-PCR amplification the global rearrangement TRAV6 or TRAV23 segments. There are being registered in NCBI Genebank. The sequences will be farther used in TCR gene transfer to T cells to establish the specific anti-DLBL T cell clone and to confirm its specific cytotoxicity.