Corticotropin-releasing hormone (CRH) is a 41-amino acid neuropeptide
which increases the transcription of the proopiomelanocortin (POMC) ge
ne, as well as the biosynthesis and secretion of POMC-derived peptides
. Using a specific human CRH radioimmunoassay we have shown that human
T-lymphocytes contain immunoreactive CRH. We studied the effects of p
hytohemagglutinin (PHA) and 12-O-tetradecanoylphorbol-13-acetate (TPA)
on the biosynthesis of CRH in human T-lymphocyte cell cultures. A sig
nificant increase in CRH mRNA levels was observed in human lymphocytes
after 12 h of PHA/TPA treatment, while the levels decreased after 22
h. These findings could imply an immunomodulatory role for CRH that co
uld be due to autocrine and/or paracrine interactions.