title: Conventional, naive CD4+ T cells provide an initial source of IL-4 during Th2 differentiation.
abstract: IL-4 is known to promote the differentiation of CD4+ T cells into IL-4-secreting Th2 cells. However, the cellular source of the early burst of IL-4 that drives Th2 responses in vivo has not been conclusively identified. Mice deficient for the IL-4 receptor alpha-chain (IL-4Ralpha-/-) retain the capacity to secrete IL-4 and can be used to identify those cell types that produce IL-4 without a requirement for prior IL-4-mediated stimulation. To address whether naive, conventional CD4+ T cells may act as initial producers of IL-4 in Ag-specific responses, we crossed the BALB/c IL-4Ralpha-/-mice to DO11.10/scid TCR transgenic mice. Lymph node cells from wild-type and IL-4Ralpha-/- DO11.10/scid mice secreted approximately 50 pg of IL-4 per10(6) cells within 48 h after peptide stimulation. This small amount of IL-4 was sufficient to cause the differentiation of wild-type CD4+ T cells into Th2 cells, particularly if IFN-gamma and IL-12 were neutralized during the priming cultures. CD4+ cells from the IL-4Ralpha-/- mice gave rise to a minor proportion (approximately 2%) of IL-4-producing cells upon stimulation in the presence of anti-IFN-gamma and anti-IL-12. These data show that conventional, naive CD4+ T cells may be considered as initial sources of IL-4 and, in the absence of IFN-gamma and IL-12, this IL-4 can induce Th2 polarization.
authors.affiliation: Laboratory of Immunology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA. nnoben@niaid.nih.gov
authors.forename: N
authors.initials: N
authors.lastname: Noben-Trauth
authors.forename: J
authors.initials: J
authors.lastname: Hu-Li
authors.forename: W E
authors.initials: WE
authors.lastname: Paul
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000008:administration & dosage; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D016764:Cell Polarity / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D007072:Immunoglobulin D / Q000276:immunology; D007279:Injections, Subcutaneous; D015847:Interleukin-4 / Q000096:biosynthesis*; D007399:Interphase / Q000235:genetics / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D008819:Mice, Nude; D016513:Mice, SCID; D008822:Mice, Transgenic; D019948:Receptors, Interleukin-4 / Q000172:deficiency / Q000235:genetics; D013045:Species Specificity; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D018418:Th2 Cells / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007072:Immunoglobulin D; D019948:Receptors, Interleukin-4; C039951:anti-IgD; D015847:Interleukin-4