CDR3 SPECTRATYPING OF ANTIGEN RECEPTORS FROM GLOMERULAR T CELLS IN ACTIVE HEYMANN NEPHRITIS

Walters GD, Wu H, Knight JF.

Centre for Kidney Research, Royal Alexandra Hospital for Children, PO Box 3515, Parramatta, NSW 2124, Australia.

Active Heymann nephritis (HN) is a rat model of human membranous nephropathy associated with immune deposits in glomeruli and infiltration of the glomeruli and interstitium by mononuclear cells. We have previously described the T cell receptor (TCR) repertoire in the renal interstitium. We have now performed CDR3 size spectratyping of TCR in HN glomeruli.

HN was induced in Lewis rats by immunisation with renal tubular antigen (Fx1A) in CFA. Control rats were injected with CFA alone. Kidneys were collected 4, 6 and 8 weeks after immunisation. Glomeruli were separated by a standard sieving method. T cells in glomeruli were identified on immunoperoxidase staining. RT-PCR with primers specific for rat TCR BV families and CDR3 size spectratyping were used to measure TCR BV repertoire diversity in the diseased glomeruli. BV13 had an oligoclonal peak profile with identical size CDR3 in four different animals at 4 weeks and at 6 weeks, suggesting that BV13 bearing T cells in glomeruli use a restricted subset of BV13. Identical size BV8 CDR3 spectratypes were seen in glomeruli at 6 and 8 weeks in four different animals. In contrast, CDR3 spectratyping of each BV gene from HN rat spleen showed a diverse array of clonotypes of varying CDR3 lengths in a Gaussian distribution.

Restricted TCR BV13 and BV8 gene usage suggests clonal expansion of individual T cells in the glomeruli with HN at 4, 6 and 8 weeks. T-cells infiltrating the glomeruli in this model may recognise a specific antigen or set of antigens

Presented at the Annual Scientific Meeting of the Australian and New Zealand Society of Nephrology, Melbourne, March 2000