title: Role of antigen-presenting cells in the polarized development of helper T cell subsets: evidence for differential cytokine production by Th0 cells in response to antigen presentation by B cells and macrophages.
abstract: Immune challenges can elicit polarized responses skewed towards the development of T helper type 1 (Th1) or Th2 T cell subsets. To determine if distinct antigen-presenting cells (APC) populations might selectively influence Th subset development, we studied the role of two key APC populations, B cells and macrophages, in the differentiation of effector Th populations from naive precursor Th in vitro. Antigen (Ag)-specific, naive CD4+ T cells were enriched from a mouse strain, AND, bearing a transgenic alpha/beta T cell receptor (TCR) encoding reactivity with pigeon cytochrome c peptide 88-104. Peptide Ag was used throughout these studies so that differences in the uptake and processing by the two APC populations would not influence the results. Both APC populations, activated B cells and bone marrow-derived macrophages, supported the development of effector Th having the capacity to secrete high levels of cytokines when restimulated. Regardless of APC population present during effector development, exogenous interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) had dominant effects on Th subset development. Thus, with both APC populations, effector Th generated in the presence of IFN-gamma acquired a Th1-type cytokine profile, Th generated with IL-4 acquired a Th2-type cytokine profile, and Th generated without IFN-gamma or IL-4 acquired a Th0-type cytokine profile. B cells and macrophages also had equivalent APC function in the restimulation of Th1 and Th2-like effectors, since only minor differences in cytokine production were noted for these effector populations when restimulated with the two APC populations. However, in 8 of 19 experiments, the Th0-like effector population generated in the presence of IL-2 differentially responded to restimulation with B cells and macrophages, secreting significantly more IFN-gamma when restimulated with B cells, and significantly more IL-4 when restimulated with macrophages. We also found that Th effector populations recultured in IFN-gamma or IL-4 assumed a more Th1 or Th2-like phenotype, respectively, regardless of their initial cytokine profile. We conclude that through a subtle capacity to skew cytokine production by a Th0 subset, different APC may selectively influence Th subset development under conditions of prolonged or chronic stimulation in an autocrine fashion.
authors.affiliation: Department of Biology, University of California, San Diego, La Jolla.
authors.forename: D D
authors.initials: DD
authors.lastname: Duncan
authors.forename: S L
authors.initials: SL
authors.lastname: Swain
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D003574:Cytochrome c Group / Q000276:immunology; D016207:Cytokines / Q000502:physiology; D005260:Female; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D003574:Cytochrome c Group; D016207:Cytokines