Characterizations of distribution and clonality of T cell receptor Vα and T cell receptor Vβ subfamily T lymphocytes in diffuse large B cell lymphoma patients

Abstract

Objective To investigate the situation of T cell receptor (TCR) Vα and TCR Vβ gene subfamily repertoire and clonal proliferation of T lymphocytes from peripheral blood of patients with diffuse large B-cell lymphoma (DLBCL). Methods April, May and July 2006, a total of three patients with DLBCL who were admitted in the First Affiliated Hospital of Guangzhou Medical University were collected in this study. Another of three healthy individuals who received medical examination in the same period were included into control group. The study protocol was approved by the Ethical Review Board of Investigation in Human Beings of the First Affiliated Hospital of Guangzhou Medical University. Informed consent was obtained from all participants. There were no significant differences of subjects' general clinical features between two groups (P>0.05). The blood specimens (10 mL) from the subjects were collected at the clinical laboratory. The complementarity determining region 3 (CDR3) of 29 TCR Vα and 24 TCR Vβ subfamily genes in peripheral blood T lymphocytes were amplified by real-time polymerase chain reaction (RT-PCR). CDR3 sequence and length of RT-PCR products were analyzed by gene scan. The clinical data of two groups were retrospectively analyzed: The expression of TCR Vα and Vβ subfamily genes in T lymphocytes of two groups were compared, and clonal proliferation of T lymphocytes in study group was analyzed. Results ① Different from the control group, 20-22 TCR Vα and 9-20 TCR Vβ subfamilies were identified in 3 DLBCL patients of study groups, respectively. ② Oligoclonality, biclonality and oligoclonal tendency of one or more TCR Vα and TCR Vβ subfamilies T lymphocytes were observed in all 3 DLBCL patients. TCR Vα subfamily genes expressed in clonal proliferative T lymphocytes were TCR Vα6, Vα8, Vα14, Vα15, Vα21, Vα22, Vα23 and Vα25. TCR Vβ subfamily genes expressed in clonal proliferative T lymphocytes were TCR Vβ1, Vβ3, Vβ13, Vβ15 and Vβ16. T lymphocytes predominately expressed TCR Vα6, Vα8, Vα14, Vα15, Vα23 and TCR Vβ13, Vβ15 subfamily genes were all in clonal proliferation. TCR Vα6, Vα23 and TCR Vβ3, Vβ13 subfamily T lymphocytes were obviously monoclonal proliferation, and their gene scan results were all closely monoclonaliity shape. Conclusions TCR Vα and TCR Vβ subfamilies T lymphocytes from peripheral blood of patients with DLBCL showed characteristics of advantage utilization and clonal proliferation. Key words: Lymphoma, large B-cell, diffuse; Genes, T-cell receptor alpha; Genes, T-cell receptor beta; T-lymphocytes