Analysis of T-cell receptor beta chain variable gene segment usage in healthy adult responders and nonresponders to recombinant hepatitis B vaccine.

One to 10 per cent of healthy adult individuals do not produce protective levels of anti-hepatitis B surface (HBs) antibodies, following a standard vaccination protocol. Lack of an HBs antigen (Ag)-specific T-cell repertoire is amongst the possible defects, which may lead to humoral unresponsiveness and is the main objective of this study. We analysed TcR BV (T-cell receptor beta chain variable) gene usage in T lymphocytes from nine healthy adult responders and six nonresponders to recombinant HB vaccine, before and after booster vaccination. CD4+ and CD8+ T-cell populations were isolated from peripheral blood mononuclear cells by magnetic beads, and the expression of TcR BV genes in each population was investigated by reverse transcription polymerase chain reaction and hybridization with specific probe. When the usage of each TcR BV gene within CD4+ and CD8+ T cells of the responders was compared with that of nonresponders, statistically significant difference (P < 0.01) was noted for BV5S2-3 gene family in CD4+ T cells of nonresponders. Furthermore, individual vaccinees were shown to overexpress several TcR BV genes. To characterize the T-cell repertoire and determine their clonal nature, analysis of CDR3 length polymorphism was performed. Our results show that T-cell response to HBsAg is generally oligoclonal and involves multiple BV families. Furthermore, overexpressed individual TcR BV genes and CDR3 length distributions in response to HBsAg are subject-dependent. In conclusion, our results are not in line with the notion that defective TcR repertoire may be an explanation for unresponsiveness to recombinant HBsAg vaccine.