title: Regulation of the interleukin (IL)-12R beta 2 subunit expression in developing T helper 1 (Th1) and Th2 cells.
abstract: The developmental commitment to a T helper 1 (Th1)- or Th2-type response can significantly influence host immunity to pathogens. Extinction of the IL-12 signaling pathway during early Th2 development provides a mechanism that allows stable phenotype commitment. In this report we demonstrate that extinction of IL-12 signaling in early Th2 cells results from a selective loss of IL-12 receptor (IL-12R) beta 2 subunit expression. To determine the basis for this selective loss, we examined IL-12R beta 2 subunit expression during Th cell development in response to T cell treatment with different cytokines. IL-12R beta 2 is not expressed by naive resting CD4+ T cells, but is induced upon antigen activation through the T cell receptor. Importantly, IL-4 and IFN-gamma were found to significantly modify IL-12 receptor beta 2 expression after T cell activation. IL-4 inhibited IL-12R beta 2 expression leading to the loss of IL-12 signaling, providing an important point of regulation to promote commitment to the Th2 pathway. IFN-gamma treatment of early developing Th2 cells maintained IL-12R beta 2 expression and restored the ability of these cells to functionally respond to IL-12, but did not directly inhibit IL-4 or induce IFN-gamma production. Thus, IFN-gamma may prevent early Th cells from premature commitment to the Th2 pathway. Controlling the expression of the IL-12R beta 2 subunit could be an important therapeutic target for the redirection of ongoing Th cell responses.
authors.affiliation: Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Szabo
authors.forename: A S
authors.initials: AS
authors.lastname: Dighe
authors.forename: U
authors.initials: U
authors.lastname: Gubler
authors.forename: K M
authors.initials: KM
authors.lastname: Murphy
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D018123:Receptors, Interleukin / Q000096:biosynthesis* / Q000235:genetics; D053707:Receptors, Interleukin-12; D050797:STAT4 Transcription Factor; D015398:Signal Transduction; D013154:Spleen / Q000166:cytology; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects; D018417:Th1 Cells / Q000187:drug effects / Q000378:metabolism*; D018418:Th2 Cells / Q000187:drug effects / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053707:Receptors, Interleukin-12; D050797:STAT4 Transcription Factor; C494091:Stat4 protein, mouse; D015534:Trans-Activators; D018664:Interleukin-12; D007371:Interferon-gamma; D011505:Protein-Tyrosine Kinases