Restricted T cell V beta repertoire in renal allografts during acute and chronic rejection

Allo-MHC specific antigen recognition might not only be involved in acute, but also in chronic rejection. The clonotypic specificity of the T-cell receptor to recognize all-MHC is located in the variable (V) alpha and beta chain. A restricted T-cell receptor repertoire could support an immunological basis for chronic rejection. The novel feature of this study is that V beta repertoire was assessed in ongoing chronic rejection before end-stage renal failure and in acute rejection. V beta s 1 to 20 were quantitated by PCR in PBMC and biopsies of rejecting renal allografts. The V beta pattern in PBMC demonstrated a polyclonal distribution. However, the intragraft V beta repertoire was restricted to 1 to 3 dominant V betas and highly individual in 9 of 12 patients. Number and type of the HLA mismatch and the time interval between transplantation and biopsy did not correlate to the V beta distribution. The individual response is attributed to genetic predisposition factors of the recipient. Therefore, the restriction of the V beta repertoire indicates allo-MHC dependent immune processes not only in acute, but also in ongoing chronic rejection. Tailor-made antibodies against dominant V betas might offer specific individual immunosuppression in treating both acute and ongoing chronic rejection.