title: Evaluation of accessory cell heterogeneity. II. Failure of dendritic cells to activate antigen-specific T helper cells to soluble antigens.
abstract: The activation of antigen-specific T cells requires Ia+, antigen-presenting accessory cells (AC). Dendritic cells (DC) and macrophages (M phi) isolated from spleen an peritoneal exudate were tested as AC for the activation of the activation of T helper cells and the induction of T cell proliferation. The cell separations to obtain DC and splenic M phi were performed by discontinuous bovine serum albumin gradients, adherence on petri dishes and rosetting with opsonized sheep erythrocytes. DC as well as the M phi were able to induce antigen-specific T cell proliferation, but only the M phi and not the DC activated antigen-specific T helper cells which help B cells for antibody production to soluble antigens. Keyhole limpet hemocyanin-specific T cells repeatedly stimulated with DC and antigen also did not express helper activity. The failure of DC to induce T helper cells was not due to the activation of a suppressor pathway. Thus, dendritic cells, although very efficient as AC in the induction of various T cell functions, are not able to activate T helper cells required for carrier-specific T-B cooperation and therefore cannot be the sole accessory cells. Based on these results and on previous data using Ia+ tumor cell lines as AC, we confirm the existence of functional AC heterogeneity.
authors.forename: G
authors.initials: G
authors.lastname: Ramila
authors.forename: I
authors.initials: I
authors.lastname: Sklenar
authors.forename: M
authors.initials: M
authors.lastname: Kennedy
authors.forename: G H
authors.initials: GH
authors.lastname: Sunshine
authors.forename: P
authors.initials: P
authors.lastname: Erb
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000941:Antigens; D006433:Hemocyanins / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D051379:Mice; D011961:Receptors, Fc / Q000032:analysis; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000941:Antigens; D000949:Histocompatibility Antigens Class II; D011961:Receptors, Fc; D006433:Hemocyanins