title: Suppression of human T-cell mitogenesis and E-rosette formation by the monoclonal antibody OKT11A.
abstract: OKT11A, a monoclonal anti-human T-cell antibody was studied for its in vitro effects on lymphocyte functions. At a concentration as low as 10 ng/ml, OKT11A significantly suppressed T-cell proliferation induced by OKT3, purified protein derivative (PPD), tetanus toxoid and allogeneic non-T cells. Total inhibition of proliferation was noticed at concentrations of 1-10 microgram OKT11A/ml. The antibody was only fully effective when added to stimulated cell cultures within the first 2 hr of the culturing period. OKT11A also blocked total and active sheep erythrocyte (E)-rosette formation by T lymphocytes: this activity closely paralleled the suppression of proliferative response. Quantitative studies on the binding of 125I-labelled IKT11A indicated that an average of 2 x 10(4) antibody molecules were bound per T cell. Taken together, these findings show that OKT11A recognizes a sparsely represented T-cell surface determinant that is associated with the inhibition of mitogenic responsiveness and E-rosette formation. Furthermore, our data imply that the E-rosette receptor of T cells is involved in the regulation of immune functions.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002455:Cell Division; D002478:Cells, Cultured; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal