Comparing TCR beta chain variable gene profile skewness between children with tuberculosis and BCG-vaccinated children.

ABSTRACT

BACKGROUND: We compared the T cell antigen receptor (TCR-BV) gene families of peripheral blood mononuclear cells (PMBC) between children with tuberculosis (TB) and those inoculated with the Bacille Calmette Guerin (BCG) vaccine. METHODS: The total RNA was extracted from PMBC of 15 TB children, 15 BCG-vaccinated children and 15 healthy controls. The RNAs were reverse-transcribed and amplified by polymerase chain reaction (PCR). PCR products were separated on 1.5% agarose gel and analyzed with the Genescan technique. RESULTS: Some TCR-BV gene families in TB children and BCG-vaccinated children exhibited a blur band in the predicted position on 1.5% agarose gel, some showed a distinct or fainted band. In general, many shared predominant clonal TCR-BV gene families (Vß2, Vß16, Vß21, Vß22) and the restricted-expression families (Vß14 and Vß17). All the gene families of the control children only exhibited blur bands and polyclonal. CONCLUSIONS: The skewed profile of TCR-BV gene families in TB children and BCG-vaccinated children are similar, which may probably explain the protective effects of BCG-vaccine against TB in children.