Tissue factor-like activity of the human monocytic tumor cell line U937.
Undisrupted cells of the human monocytic tumor cell line U937 have procoagulant activity that is Ca2+ dependent and is not demonstrable in Factor VII or Factor X deficient plasma. Furthermore, U937 cells when incubated with purified human Factor VII in the presence of Ca2+ and then repeatedly washed promoted coagulation of Factor VII deficient plasma in the absence of added tissue factor. Culture with endotoxin increased the procoagulant activity of U937 cells approximately 5-fold. In separate experiments, exposure to lymphokines obtained from phytohemagglutinin-stimulated lymphocytes enhanced the procoagulant activity of U937 cells 4 to 110-fold. Other cell lines (of myeloid and lymphoid origin) tested lacked the procoagulant activity found in U937 cells. These results indicate that the constitutive tissue factor-like activity of U937 cells resembles that of normal activated human monocytes.
D001665:Binding Sites; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000032:analysis; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D004731:Endotoxins / Q000494:pharmacology; D005167:Factor VII / Q000378:metabolism; D005168:Factor VII Deficiency / Q000097:blood; D005171:Factor X Deficiency / Q000097:blood; D005173:Factor XI Deficiency / Q000097:blood; D006801:Humans; D008222:Lymphokines / Q000494:pharmacology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000032:analysis*; D009000:Monocytes / Q000032:analysis*; D013925:Thromboplastin / Q000032:analysis*
D001779:Blood Coagulation Factors; D004731:Endotoxins; D008222:Lymphokines; D005167:Factor VII; D013925:Thromboplastin