A Mechanism of Migration Inhibition Involving Components of the Coagulation System

Abstract

Lymph from pigs given BCG and stimulated in the drainage area of a cannulated lymph node with tuberculin (PPD [purified protein derivative]) had potent in vitro macrophage migration inhibitory activity. A similar observation has previously been made in sheep. In the sheep, part of, and in the pig, almost all of, this inhibitory activity was produced, not by a factor resembling the migration inhibitory factor, but by a mechanism involving a protease and fibrinogen. Exudate cells, having potent coagulation-promoting activity, can apparently promote the deposition of fibrin about themselves, and being trapped, are unable to migrate.