Transcriptional regulation of RANTES expression in T lymphocytes

We first identified the RANTES chemokine as part of a search for genes expr essed by T lymphocytes "late", 3-5 days, after T-cell activation. The kinet ics of expression of RANTES and a small number of other genes are unusual a nd the mechanism of such delayed expression is unknown. In order to uncover a mechanism for such "late" expression, we identified and characterized th e RANTES promoter and a novel transcription factor regulating RANTES expres sion in T lymphocytes. RANTES factor of late activated T lymphocytes (RFLAT )-1 is a member of the Kruppel-like family of transcription factors. Like R ANTES, RFLAT-1 expression is "late" after T-cell activation. But, unlike RA NTES, regulation of RFLAT-1 expression appears to be translational rather t han transcriptional.