title: In vitro primary sensitization and restimulation of hapten-specific T cells by fresh and cultured human epidermal Langerhans' cells.
abstract: We examined the capacity of human Langerhans's cells (LC) to sensitize autologous T cells to the trinitrophenyl hapten (TNP) in vitro. Two-day cultured Langerhans' cells, but not freshly prepared Langerhans' cells, can induce in vitro primary proliferative reactions to the TNP hapten. Using a CD45RA+ naive T-cell subset, similar results were found, therefore making the possibility of a previous in vivo T-cell contact with the hapten unlikely. The primary in vitro response was strongly inhibited by monoclonal antibodies to major histocompatibility complex (MHC) class I and II, CD4 antigens and ICAM-1 and LFA-3 adhesion molecules. Furthermore, we found that fresh LC can prime T cells to TNP, as revealed by a significant secondary T-cell proliferation after restimulation of the recovered T lymphocytes by fresh hapten-modified autologous LC. Nevertheless, the ability of these fresh LC to stimulate in vitro secondary hapten-specific T-cell proliferation was very limited in comparison with that of 2-day incubated Langerhans' cells. After secondary stimulation with TNP-cultured LC, sensitized T cells could be non-specifically expanded without losing hapten specificity. The TNP-specific T-cell lines were mostly of the CD4+ phenotype. The present findings extend previous studies in the mouse, showing that culture LC are potent antigen-presenting cells (APC) in primary hapten-dependent proliferation assays. Furthermore, this in vitro priming assay, using cultured human Langerhans' cells as APC, might be useful to analyse the early steps of T-cell sensitization and subsequently to develop in vitro predictive tests allowing detection of sensitizing compounds.
authors.affiliation: Laboratoire Peau Humaine et Immunité, INSERM U346, Hôpital E. Herriot, Lyons, France.
authors.forename: C
authors.initials: C
authors.lastname: Moulon
authors.forename: J
authors.initials: J
authors.lastname: Péguet-Navarro
authors.forename: P
authors.initials: P
authors.lastname: Courtellemont
authors.forename: G
authors.initials: G
authors.lastname: Redziniak
authors.forename: D
authors.initials: D
authors.lastname: Schmitt
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D003877:Dermatitis, Contact / Q000276:immunology; D004817:Epidermis / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D006241:Haptens / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology; D007700:Kinetics; D007801:Langerhans Cells / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D006241:Haptens; D014301:Trinitrobenzenes