INCREASED NUMBERS OF T CELLS IN ADRIAMYCIN-INDUCED NEPHROPATHY EXPRESSING V 6/V 1 AND SHOWING A CANONICAL RESTRICTION OF THE CDR3 REGION

Wu H¹, Wang YP², Knight JF¹, Alexander SI¹ and Harris DCH^2
1Centre for Kidney Research, The Children's Hospital at Westmead, ² Dept of Renal Medicine, University of Sydney at Westmead Hospital, Sydney, 2145

We have reported that the presence of T cells is associated with kidney damage in human IgA nephropathy and in rat models of adriamycin (ADR) induced nephropathy (AN) and Heymann nephritis. We have also shown that these T cells use a restricted set of T cell receptor (TCR) genes. This study examines whether T cells infiltrating the kidney also use a restricted set of T cell receptor genes in AN, a mouse model of chronic proteinuric renal disease.

AN was induced in BALB/c mice by a single injection of ADR (10mg/kg BW, iv). Kidneys and spleen were collected at 3 and 5 weeks after administration of ADR. T cells were isolated from the kidney using a gradient separation method. Flow cytometry analysis (FACS) was used to determine the percentage of T cells as a proportion of the total number of CD3+ T cells. TCR V repertoire was measured by RT-PCR and sequencing was used to characterise the diversity of the CDR3 region of these receptors.

Flow cytometry showed that T cells as a proportion of CD3+ T cells were significantly increased in AN kidneys (16.8 3.9%) but not in lymph nodes (1.3 0.8%), (n = 16, p ‹ 0.001). Analysis of the kidney TCR V repertoire showed that these cells predominantly expressed V 6/V 1 genes. Sequencing analysis of the V 6/V 1 junctional region showed that they used canonical sequences identical to those expressed on fetal thymocytes.

These results demonstrate that the majority of T cells in the AN kidney use an invariant, canonical V 6/V 1 TCR - exactly the same TCR as we have previously described in the rat ADR kidney and HN kidney. These canonical V 6/V 1 T cells may recognise an unknown common ligand expressed in the kidney in response to a wide variety of causes of chronic inflammation and reflect another pathway in the innate immune system.

Presented at Australian and New Zealand Society of Nephrology (ANZSN). 38th Annual Scientific Meeting. Sydney, NSW, 2-4 Sept 2002