NEGATIVE REGULATION OF THE ANTI-HUMAN-IMMUNODEFICIENCY-VIRUS AND CHEMOTACTIC ACTIVITY OF HUMAN STROMAL CELL-DERIVED FACTOR 1-ALPHA BY CD26 DIPEPTIDYL PEPTIDASE-IV/

Stromal cell-derived factor 1 alpha (SDF-1 alpha) is a chemokine that has been shown to prevent infection of T-tropic HIV strains and is a p ossible substrate of CD26/dipeptidyl peptidase IV (DPPIV). In this stu dg, we show that SDF-1 alpha was cleaved at the N-terminal region by C D26/DPPIV and as a result the inhibitory activity of SDF-1 alpha again st HIV infection disappeared, Moreover, the chemotactic activity of SD F-1 alpha also disappeared specifically by DPPIV activity of recombina nt soluble CD26, These results suggested that dissemination of T-tropi c HIV strains in vivo may be facilitated by CD26/DPPIV via inactivatio n of functional SDF-1 alpha. (C) 1998 Federation of European Biochemic al Societies.