NYMC Faculty Publications

Title

Concurrent Production of Macrophage Agglutination Factor and Factor VII by Antigen-Stimulated Human Peripheral Blood Mononuclear Cells

Document Type

Article

Publication Date

January 1986

Department

Pathology

Abstract

We have studied concurrent production of macrophage agglutination factor (MAggF) and procoagulant activity by antigen-stimulated human blood mononuclear cells to gain insight into biochemical mechanisms underlying delayed hypersensitivity inflammatory reactions. After stimulation of cells from tuberculin-sensitive donors with tuberculin, MAggF was present in culture supernatants while the overwhelming majority of procoagulant activity remained cell-associated. Neither MAggF nor procoagulant activity was found in reconstituted control cultures, nor in tuberculin-stimulated cultures of non-sensitive cells. Concanavalin A and lipopolysaccharide elicited both activities from cultured mononuclear cells, regardless of donor sensitivity. Human MAggF bound to insolubilized gelatin, heparin and a monoclonal anti-fibronectin (FN) antibody, and its activity was inhibited by another monoclonal antibody directed against the gelatin-binding domain of FN. Treatment of indicator peritoneal exudate cells with monoclonal anti-FN receptor antibody inhibited their response to human MAggF. These results suggest that human MAggF, like the analogous guinea-pig activity, is FN-associated. Antigen-elicited procoagulant activity shortened the recalcification time of normal, factor VII- and factor IX-deficient plasma, partially corrected prothrombin times of factor VII-deficient plasma, had no effect on recalcification and prothrombin items of factor X- and factor V-deficient plasma, and was inhibited by specific anti-factor VII antibody. Thus, human mononuclear cell procoagulant consists of both tissue factor and factor VII, whether it is induced by antigen or mitogen. Antigen-stimulated blood mononuclear cells are able to provide a signal for local fibrin deposition and a protein mediating fibrin binding to mononuclear phagocytes and collagen at sites of delayed hypersensitivity reactions.

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