Identification of C5ades arg and an anionic neutrophil-activating peptide (ANAP) in psoriatic scales.

Scales from patients with nonpustular psoriasis were investigated for the presence of peptides capable of activating functional activities in human polymorphonuclear leukocytes (PMNL). Two compounds with similar molecular weight (12,500 and 15,000) were isolated which markedly stimulated PMNL functional activities including chemotaxis, generation of superoxide radical anion (O-2), and liberation of beta-glucuronidase as a marker enzyme. As revealed by ion-exchange and subsequent radioimmunoassay followed by chromatofocusing, one peptide proved to be the desarginated form of the complement split product C5ades arg. No C5a was detectable. As a second psoriatic scale chemotaxin we isolated an anionic neutrophil-activating peptide (ANAP) which shows a single isoelectric point at pH 6.8. This peptide shares some of the characteristics of epidermal cell-derived thymocyte-activating factor and interleukin 1 and, as shown by deactivation experiments, it cross-reacts with a monocyte-derived cytokine. The 2 newly described neutrophil-activating peptides (C5ades arg and ANAP) may play an important role in the psoriatic tissue reaction.