RELEASE OF PAF BY HUMAN POLYMORPHONUCLEAR LEUKOCYTES STIMULATED BY IMMUNE-COMPLEXES BOUND TO SEPHAROSE PARTICLES AND HUMAN-ERYTHROCYTES

  • 1 January 1983
    • journal article
    • research article
    • Vol. 50  (1) , 43-51
Abstract
Human polymorphonuclear leukocytes (PMN) incubated with surface-bound immune complexes (IC) release a substance that induces platelet aggregation and serotonin release. This substance was identified as platelet-activating factor (PAF) on the basis of its sensitivity to phospholipase A2 and of its purification by TLC in identical conditions to those used to purify zymosan-induced PAF. Two types of substrates were used to absorb IC:Sepharose particles to which human serum albumin was coupled, and which were later incubated with specific rabbit antiserum to form surface-bound IC and human erythrocytes, to which soluble IC can be passively adsorbed. Both types of surface-bound IC stimulated the release of PAF by human PMN in the absence of complement. PMN may play a central role in the early stages of IC-induced inflammation: they recognize IC adsorbed to red cells or to any other cell able to adsorb IC, and they induce the activation of platelets and release of vasoactive amines, which leads to the increase of vascular permeability believed to be essential for extravascular IC deposition.