Analysis of T Cell Receptor Vβ Diversity in Peripheral CD4+ and CD8+ T Lymphocytes Obtained From Patients With Chronic Severe Hepatitis B.

backgroundThe hepatitis B virus (HBV) antigen-induced cellular immune response plays an important role in HBV clearance. Changes in the diversity of complementarity determining region 3 (CDR3) and T-cell receptor (TCR) sequences are used to monitor the response of T cells to antigens.

objectivesThe aim of the present study was to determine whether the TCR Vβ repertoire of patients with chronic severe hepatitis B (CSHB) undergoes increased stimulation, and to identify conserved motifs in specific TCR Vβ families. PATIENTS AND

methodsPeripheral blood mononuclear cells (PBMCs) from 18 patients with CSHB were sorted into CD4+ and CD8+ T subsets, using monoclonal antibody-coated magnetic beads. The TCR Vβ CDR3 was subsequently characterized using immune spectratyping. The TCR Vβ families exhibiting a CDR3 spectratype that underwent monoclonal expansion were sequenced.

resultsThe number of oligoclonal or monoclonal expansion TCR Vβ families detected in the analyzed CD8+ T cells was significantly higher than the number detected in CD4+ T cells. The CDR3 spectratype analysis showed predominant usage of TCR Vβ5, Vβ7, Vβ9, Vβ12, and Vβ18 families in CD8+ T cell subsets of CSHB patients. Furthermore, conserved amino acid motifs were found to be associated with the monoclonal expansion of CD8+ TCR Vβ families. In addition, JB1S1 and JB2S7 region genes were present at a high frequency.

conclusionsThe CD4+ and CD8+ TCR Vβ gene families undergo clonal expansion in CSHB patients, and CD8+ T cells play a major role in the pathogenesis of CSHB. Moreover, the conserved motifs and limited use of joining region genes observed in the CSHB patients of this cohort indicated that similar antigenic epitopes are recognized.