Monocyte and macrophage reactions.

Abstract

For a number of years we have been working with monocytes and macrophages, and I would like to direct my remarks to a number of questions concerning the properties of the monocyte and the macrophage. I think it is quite evident that the mononuclear phagocyte has a major role in dealing with particles. I would like to start out by raising two questions: whether the particles are free particles or whether the particles have adsorbed to them materials, either proteins or ions, which they have acquired from the fluid phase upon entry (a factor which would have obvious implications concerning subsequent handling of the particle by the phagocytic cell) and the relationship of the particle to alterations in erythrocytes and the possible effect of erythrocytes in in vivo systems. I thought it would be worthwhile to specifically mention a number of recent properties of the monocyte-macrophage which may have bearing on the questions being discussed this afternoon. First, recent studies primarily from Rabinovitch's laboratory at NYU (1) have demonstrated a spreading phenomenon: namely, that a reversible spreading of the mouse macrophage occurs. In the past few months, we have demonstrated the same phenomenon with the human blood monocyte. A number of materials induce spreading. These include antigen-antibody complexes and proteolytic enzymes such as subtilisin; in addition, manganese