title: Enhancement and inhibition of cellular responsiveness mediated by the anti-leucocyte monoclonal antibody NDS 71.
abstract: In this paper we describe the effects of a novel monoclonal antibody (mAb), which either inhibited or enhanced IL-2-stimulated proliferation of human peripheral blood leukocytes (PBL) at the same antibody concentration, under different culture conditions. An effect of this nature on IL-2-stimulated proliferation has not, to our knowledge, previously been described. The mAb NDS 71 bound to more than 98% of both freshly isolated and PHA-stimulated human PBL, with the level of binding markedly up-regulated on activation. An antigen of molecular weight 38-46 kDa was immunoprecipitated. When added to PBL at the beginning of in vitro culture, NDS 71 inhibited IL-2-stimulated proliferation. PHA-stimulated proliferation was enhanced by NDS 71 in identical conditions, demonstrating that the effects of NDS 71 on IL-2-stimulated proliferation were not merely due to non-specific inhibition of cellular proliferation. When NDS 71 was added to IL-2-stimulated PBL 4 h after the start of in vitro culture, proliferation was markedly enhanced, in contrast to the inhibition seen when the same concentration of antibody was added at the start of culture. In summary, NDS 71 markedly affected IL-2-stimulated proliferation, the same concentration of antibody causing either marked inhibition or enhancement, depending on the culture conditions.
authors.affiliation: Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Higgins
authors.forename: M J
authors.initials: MJ
authors.lastname: Dallman
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000494:pharmacology*; D001666:Binding Sites, Antibody / Q000187:drug effects; D001667:Binding, Competitive; D002448:Cell Adhesion / Q000276:immunology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007962:Leukocytes / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D010835:Phytohemagglutinins / Q000494:pharmacology
chemical_list: D000276:Adjuvants, Immunologic; D000911:Antibodies, Monoclonal; D007166:Immunosuppressive Agents; D010835:Phytohemagglutinins