title: Characterization of primary T helper cell activation and T helper cell lines stimulated by hapten-modified, cultured Langerhans cells.
abstract: It has recently been shown that hapten-modified cultured Langerhans cells are able to activate small resting syngeneic L3T4+ T helper cells from nonsensitized animals. Repeated stimulation of these T cells with hapten-modified cultured Langerhans cells leads to the establishment of L3T4+ hapten-specific interleukin-4-producing T-cell lines. Here we report on further characteristics of primary hapten-dependent activation of L3T4+ T cells and of T-cell lines derived from them. Dendritic cell-enriched spleen cells were as able as Langerhans cells to activate nonsensitized T helper cells after hapten modification. However, M12c, a major histocompatibility complex class II-positive B-cell line that was able to activate small, resting, allogeneic L3T4+ T cells was not able to stimulate syngeneic T helper cells after hapten modification. Thy1+ dendritic epidermal cells did not significantly affect the magnitude of primary T helper cell proliferation induced by cultured Langerhans cells. Restimulation of in vitro primed T helper cells with hapten-modified cultured Langerhans cells revealed the presence, within the primed T helper cell population, of activated cells with specificity to an unrelated hapten, suggesting that, in hapten-dependent T helper cell activation, hapten-nonspecific cells are activated along with those that are hapten specific. Restimulation of a hapten-specific long-term T helper cell subline using different antigen-presenting cell types demonstrates that factors other than major histocompatibility complex class II density or tissue derivation of the antigen-presenting cell play a role in the activation of T cells in vitro. Finally, we demonstrate that in vitro generated hapten-specific T helper cell lines may not show strict major histocompatibility complex restriction.
authors.affiliation: Dermatology Branch, National Cancer Institute, Bethesda, Maryland.
authors.forename: C
authors.initials: C
authors.lastname: Hauser
authors.forename: W M
authors.initials: WM
authors.lastname: Yokoyama
authors.forename: S I
authors.initials: SI
authors.lastname: Katz
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000954:Antigens, Surface; D002460:Cell Line; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology; D000078404:Epidermal Cells; D006241:Haptens; D007801:Langerhans Cells / Q000276:immunology*; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex; D051379:Mice; D013154:Spleen / Q000166:cytology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D018800:Thy-1 Antigens
chemical_list: D000954:Antigens, Surface; D006241:Haptens; D018800:Thy-1 Antigens