THE ROLE OF CARBOXY-TERMINAL PORTION OF BETA-SUBUNIT OF HUMAN CHORIONIC-GONADOTROPIN IN HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

Human chorionic gonadotropin (hCG) and the beta subunit of this dimer glycoprotein hormone (beta hCG) have been reported by us to inhibit HI V replication. In order to identify the active site responsible for th e antiviral activity, twelve overlapping peptides spanning across beta hCG were examined for their effect against HIV-caused cell death. Alt hough the NH2-terminus of beta hCG appeared to contribute to activity, the core region was biologically inert. The most potent activity was observed with the fragment representing the carboxy-terminus of beta h CG. The dose response curve to serial dilutions of the peptide, contai ning amino acid residues 106-145, had a bell-shaped appearance charact eristic of hCG and beta hCG. The peak of activity corresponded to 100 ng/ml - the dose at which two thirds of virus-exposed MT-4 T lymphocyt es survived. None of the tested peptides were toxic to MT-4. While the mechanism of action remains unclear, the results suggest that the COO H-terminal portion, unique to beta hCG, confers anti-HIV activity. (C) 1997 Elsevier Science Inc.