Anti-chemotactic activities of peptide-T: a possible mechanism of actions for its therapeutic effects on psoriasis.

Peptide T is an octapeptide (ASTTTNYT) from the V2 region of gpl20 of HIV. D-[Ala]-Ser-Thr-Thr-Thr-Asn-Tyr-Thr-amide (DAPTA) is one of its analogue. DAPTA has been shown to resolve the psoriatic lesions. The mechanisms of action of peptide T for its therapeutic effect is not clearly understood. Lymphomononuclear cells play an important roles in inflammatory disease processes. Intraepidermal collection of lymphocytes is a unique feature of the inflammatory processes of psoriasis. It is believed that chemokine such as RANTES (C-C class) plays an important role for intraepidermal localization of the inflammatory infiltrates in psoriasis. In order to study the mechanisms, we have analyzed the effects of DAPTA on monocyte and lymphocyte chemotaxis. Chemotaxis of cells was measured by using Boyden chamber. DAPTA inhibited significantly the monocyte and lymphocyte chemotactic activity of RANTES (p < 0.005, < 0.001). Antichemotactic activities of peptide T analogue could be a possible explanation for its therapeutic efficacy in psoriasis.