Negative regulation of the anti-human immunodeficiency virus and chemotactic activity of human stromal cell-derived factor 1alpha by CD26/dipeptidyl peptidase IV.

Stromal cell-derived factor 1alpha (SDF-1alpha) is a chemokine that has been shown to prevent infection of T-tropic HIV strains and is a possible substrate of CD26/dipeptidyl peptidase IV (DPPIV). In this study, we show that SDF-1alpha was cleaved at the N-terminal region by CD26/DPPIV and as a result the inhibitory activity of SDF-1alpha against HIV infection disappeared. Moreover, the chemotactic activity of SDF-1alpha also disappeared specifically by DPPIV activity of recombinant soluble CD26. These results suggested that dissemination of T-tropic HIV strains in vivo may be facilitated by CD26/DPPIV via inactivation of functional SDF-1alpha.