CD4 and Epstein-Barr virus infection: In conclusion, here we show for the first time that all immunomodulating agents after renal transplantation namely immunosuppressive drugs, alloantigenic stimulation and chronic EBV infection results in modifications of the EBV-specific T cell repertoire with skewed responses towards the N-terminal portion of the EBNA-3A protein and with defective EBV-specific Th1 effector CD4+ T cell responses.