Non random usage of T cell receptor α gene expression in atopy using anchored PCR

Abstract

The T cell receptor (TCR) αβ heterodimer recognises antigenic peptide fragments presented by Class II MHC. This interaction initiates T cell activation and cytokine release with subsequent recruitment of inflammatory cells. Previous work from our group suggests a qualitative difference in variable α gene expression in atopy as compared to non atopic controls. In this study we examine TCR α repertoire using anchored PCR to provide a quantitative assessment of the Vα and Jα repertoire. One atopic (DRB1*0701,DRB1*15: DRB4*0101, DRB5*01: DQB1* 0303, DQB1*601/2) and one non-atopic (DRB1*0701,DRB1*03011/2: DRB4*01, DRB3*0x: DQB1* 0303, DQB1*0201/2) control were studied. Variable gene usage was markedly limited in the atopic individual. Vα 1, 3, 8 accounted for 60% and Jα 12, 31 30% of the gene usage. There was evidence of preferential Vα-Jα gene pairing and clonal expansion. We conclude that there is a marked non random TCR α gene distribution in atopy using both Vα family and anchored PCR. This may be due in part to antigen driven clonal expansion.