The natural mediator for PMN emigration in inflammation. I. Purification and characterization of leucoegresin from Arthus skin site.

A chemotactic factor (leucoegresin) for polymorphonuclear leucocytes (PMN) of rabbit, guinea-pig, rat and mice was extracted in the pseudoglobulin fraction of Arthus skin lesions and then highly purified by chromatography using Sephadex G-50, DEAE-Sephadex A-50 and CM-Sephadex C-50 in this order. Chemotactic activity was estimated by Boyden's method during the process of purification. Leucoegresin behaved as a homogeneous substance on ultracentrifugation and on moving boundary electrophoresis. This factor was a protein free of nucleic acid and its molecular weight was approximately 140,000 when measured by gel filtration. The sedimentation coefficient of this substance was 6.58S and its isoelectric point was pH 5.0. It was relatively heat-stable. Leucoegresin induced pronounced PMN migration, but did not increase vascular permeability; PMN emigration occurred only at the site of venules. Leucoegresin satisfied such criteria for the natural mediator of Arthus leucotaxis as local availability, parallel between activity (amount) and time-course of the reaction, and histological resemblance to the Arthus reaction.