PARTIAL CHARACTERIZATION OF INVIVO CHEMOTACTIC ACTIVITY - COMPARISON TO HUMAN C5A

[摘要] Spontaneous eosinophil chemotactic activity (SECA) can mediate the directed movement of human eosinophils and neutrophils. A preliminary characterization of SECA was done. SECA is nondialyzable and heat-stable (56.degree. C, 30 min). Chromatography on Sephadex G-75 demonstrated that SECA had elutional and functional properties similar to C5a (prepared from endotoxin-activated normal sera). Polyacrylamide gel electrophoresis (PAGE), with the use of 15% bisacrylamide gels of lyophilized, chemotactically active column fractions, demonstrated a single protein band of identical electrophoretic mobility from SECA or C5a preparations. Enzymatic hydrolysis with carboxypeptidase B, a known inhibitor of C5a activity, significantly decreased chemotactic C5a and SECA. The addition of purified anti-C5 to SECA or C5a significantly inhibited chemotactic activity, SECA is a naturally occurring chemotactic activity identical to human C5a. C5a may be an important source of in vivo chemotactic activity in various inflammatory disorders.