title: Partial characterization of the soluble mediator of leukocyte adherence inhibition.
abstract: The leukocyte adherence inhibition (LAI) test in arthritis is a model of cooperation between monocytes, T cells and polymorphonuclear cells (PMN). Mononuclear cells (MNC) from patients with rheumatoid arthritis in contact with aggregated IgG release within 60 min in the test tube a supernatant capable of inhibiting the adherence of PMN to glass (LAI activity). By protein labeling, fractionation and electroblotting, we showed that the supernatant LAI activity was located in the 14-20 kDa region of the gel and was actively secreted upon MNC stimulation. Under negative conditions, the factors with LAI activity were able to constitute larger complexes and their charge was heterogeneous. Their relationship to interleukin-1 (IL-1) is discussed, since the supernatant gave a positive response in the thymocyte proliferation assay; small amounts of IL-1 had the capacity to inhibit PMN adhesiveness and anti-IL-1 blocked this activity.
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood*; D002448:Cell Adhesion; D002850:Chromatography, Gel; D006801:Humans; D007074:Immunoglobulin G; D007375:Interleukin-1 / Q000494:pharmacology; D007957:Leukocyte Adherence Inhibition Test; D007962:Leukocytes / Q000032:analysis*; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000032:analysis*
chemical_list: D007074:Immunoglobulin G; D007375:Interleukin-1; D009363:Neoplasm Proteins; C042035:humoral leukocyte adherence inhibition factor, human