Clonal expanded TRA and TRB subfamily T cells in peripheral blood from patients with diffuse large B-cell lymphoma

Abstract

T cell immunodeficiency is a common feature in cancer patients and may be a contributing factor to the initiation and development of the tumor. In order to characterize the immune status in a group of patients with diffuse large B-cell lymphoma (DLBL), the repertoires of T cell receptor alpha and beta variable regions (TRAV and TRBV) were analyzed. The CDR3 of 29 TRAV and 24 TRBV subfamily genes were analyzed in peripheral blood mononuclear cells from six cases with DLBL using RT-PCR and GeneScan technique. Six normal individuals served as controls. Marked restriction of TRBV repertoire was observed in peripheral blood mononuclear cells (PBMCs) from DLBL. Clonal expanded T cells were found frequently in PBMCs from all DLBL patients; the oligoclonality was most frequent in TRAV6, TRAV8, TRAV12, TRAV21, TRAV22 and TRAV25 subfamilies. Similarly, clonally expanded TRBV subfamily T cells were found in all DLBL patients. The oligoclonality was most frequent in TRBV3, TRBV13 and TRBV15 subfamilies, which could be detected in four out of six cases. In conclusion, the frequent and restricted clonal expansion αβ+ T cells were thought to be the specific immune response to lymphoma-associated antigen.