T Cell Receptor ( TCR ) Gene Rearrangement During the Course of Chronic Hepatitis

T cells recogttize speciftc antigens through the T celL receptor (TCR) and self M HC nolecules. Structural variation in the TCR to recognise the enonnous diversity, of antigens is effected b), naturation rearrange,nent of TCR genes in a tilaruter analogous to inrnunoglobulin genes. Although it is believed that T cells play a uajor role in the seroconversiotr of e Ag positive hepatitis B caliers, the tnechanisnts are still unclear. To etanine the role of TCR rearrangetne,lts in chronic hepatitis B we have carried ouI Southertl transfers of DNA aliqu.otsfrom peripheral blood tttononuclear celk (PBMC) usitrg TCR chain specific probes. Rearranget,rcn$ affecting as few as 5 % of PBMC could. be detected. Rearrangentents were iltote cornnnn in e Ag positive than negative. Of several rearrangenrcnt patterns a 5 kb EcoRl and 5.5 kb Hind III were ùtost coilmrcn. Longitudinal studies of 6 patients suggested the appearence of the rearrat'tgement band preceded seroconversion and could be detected in PBMCfor 6 nonths after seroconversion. It is postulated that duritrg seroconversion the appearance of a clone of T cells with a particular rearrangernent is associated with seroconversion and characterisation ofthese clones is currently being undertaken.