title: Quantitation of T-macrophage binding avidity with and without antigen using a novel centrifugation assay.
abstract: The T cell-macrophage interaction, necessary for T cell activation, has nonspecific and specific components. Nonspecific T-macrophage interactions are mediated by surface glycoproteins such as LFA 1, 2 and 3, while specific interactions are mediated by the T3-Ti complex on the T cell and antigen plus Ia molecules on the macrophage. To determine the relative contributions of specific antigen to the total avidity of T-macrophage binding we adapted a novel assay capable of providing quantitative estimations of the avidity of cell-cell interactions. Using this assay we determined the avidity of a cloned CD4+ antigen specific T cell line for autologous macrophages with and without antigen. The presence of specific antigen increased binding avidity by approximately 25%. This assay should prove useful in further characterizing the avidity of T-macrophage interactions.
mesh_terms: D000941:Antigens; D002448:Cell Adhesion; D002460:Cell Line; D002498:Centrifugation; D006801:Humans; D066298:In Vitro Techniques; D008264:Macrophages / Q000166:cytology*; D013601:T-Lymphocytes / Q000166:cytology*; D013696:Temperature; D013745:Tetanus Toxoid / Q000276:immunology; D013997:Time Factors
chemical_list: D000941:Antigens; D013745:Tetanus Toxoid