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Expression of RORC2 Controls the Development of Human Th17 Cells
Clinical Immunology (2008) 127, S17–S28
a v a i l a b l e a t w w w. s c i e n c e d i r e c t . c o m
w w w. e l s e v i e r. c o m / l o c a t e / y c l i m
Oral Presentations: Saturday, June 7 #2201: Translating Regulatory T Cells into the Clinic Saturday, June 7 10:45 am–11:00 am Expansion of Allogeneic CD4+ CD25high FoxP3+ Regulatory T Cells by Human Colonic Myofibroblasts Irina Pinchuk, Ellen Beswick, Jamal Saada, Victor Reyes, Don Powell. University of Texas Medical Branch, Galveston, TX
#2202: Key Cytokines in Autoimmunity Saturday, June 7 10:45 am–11:00 am Expression of RORC2 Controls the Development of Human Th17 Cells Sarah Crome, Adele Wang, Megan Levings. University of British Columbia, Vancouver, BC, Canada
Background & Aims: The exact mechanism underlying intestinal mucosal tolerance remains unknown. Antigen presenting cells (APCs) are likely involved since they are key regulators of T cell responses. We recently reported that human colonic myofibroblasts (CMFs) are novel non professional MHC class II+ APCs in the human colonic mucosa that suppress proliferation of activated CD4+ effector T cells via mechanisms involving B7-negative costimulators. In the present work we extended our study of the suppressive capacity of CMFs and evaluated whether these cells stimulate expansion of suppressive T regulatory cells (Treg) with a CD4+CD25highFoxP3+ phenotype. Methods: T cell phenotype was determined by immunostaining followed by FACS analysis. Lymphoproliferation assays and cytokine ELISAs were used to evaluate proliferation/activation of Treg cells co-cultured with CMFs. Results: CMFs induced the allogeneic proliferation of naturally occurring CD4+CD25highFoxP3+ Treg cells. Moreover, CMFS induced generation of the CD4+CD25highFoxP3+ Treg cells from CD4+CD25-FoxP3- T helper cells. These processes were MHC class II- and PGE2-dependent. The frequency of the Treg cells was markedly decreased (65-90%) in the presence of antiMHC class II blocking antibodies and/or the PGE2 synthesis inhibitor indomethacin. The newly generated Treg cells were functionally active, since they inhibited the proliferation of activated autologous CD4+ effector T cells. Conclusions: These data support our hypothesis that CMFs are among the essential contributors in the induction /maintenance of mucosal tolerance in the colon via at least two mechanisms: (1) expression of B7 negative co-stimulators and (2) induction of the regulatory T cells. Supported by NIDDK and CCFA.
A novel CD4+ T helper (Th) cell, characterized by secretion of IL-17, is a key mediator of inflammation and involved in the pathogenesis of a variety of inflammatory diseases. The complete cytokine profile and molecular phenotype of these Th17 cells is not yet established, but it is clear that in addition to IL-17, they produce IL-6, TNF-α, and IL-22, express CCR6 and the Retinoic-AcidRelated Orphan Receptor (ROR)-γt. Work in mice demonstrated that stimulating T cells with IL-6, TGF−β and IL-23 induces Th17 cells. The factors driving human Th17 cell development are less well defined, and appear to involve IL-1β, IL-6 and IL-23. In mice, ROR-γt may be a lineage differentiation factor for Th17 cells, but the role of this transcription factor in human Th17 development is unknown. Using a lentiviral gene-transfer system we investigated the role of RORC2, the human orthologue of ROR-γt, in the development, phenotype and function of human CD4+ T cells. Ectopic expression of RORC2 in CD4+ T cells resulted in induction of cytokines associated with Th17 cells, including IL-17, IL-6, TNF-α and IL-22, and expression of Th17-associated chemokine receptors. We also determined the effects of RORC2 on proliferation and susceptibility to suppression by T regulatory cells. Ectopic expression of RORC2 resulted in reduced proliferation in the absence of co-stimulation. Furthermore, like in vitro differentiated Th17 cells, following RORC2 gene transfer, CD4+ T cells became resistant to T regulatory cell-mediated suppression. These data provide the first direct evidence for the role of RORC2 in the development of human Th17 cells and provide insight into the phenotype and function of this newly identified CD4+ T cell subset.
doi:10.1016/j.clim.2008.03.042
doi:10.1016/j.clim.2008.03.043
a v a i l a b l e a t w w w. s c i e n c e d i r e c t . c o m
w w w. e l s e v i e r. c o m / l o c a t e / y c l i m
Oral Presentations: Saturday, June 7 #2201: Translating Regulatory T Cells into the Clinic Saturday, June 7 10:45 am–11:00 am Expansion of Allogeneic CD4+ CD25high FoxP3+ Regulatory T Cells by Human Colonic Myofibroblasts Irina Pinchuk, Ellen Beswick, Jamal Saada, Victor Reyes, Don Powell. University of Texas Medical Branch, Galveston, TX
#2202: Key Cytokines in Autoimmunity Saturday, June 7 10:45 am–11:00 am Expression of RORC2 Controls the Development of Human Th17 Cells Sarah Crome, Adele Wang, Megan Levings. University of British Columbia, Vancouver, BC, Canada
Background & Aims: The exact mechanism underlying intestinal mucosal tolerance remains unknown. Antigen presenting cells (APCs) are likely involved since they are key regulators of T cell responses. We recently reported that human colonic myofibroblasts (CMFs) are novel non professional MHC class II+ APCs in the human colonic mucosa that suppress proliferation of activated CD4+ effector T cells via mechanisms involving B7-negative costimulators. In the present work we extended our study of the suppressive capacity of CMFs and evaluated whether these cells stimulate expansion of suppressive T regulatory cells (Treg) with a CD4+CD25highFoxP3+ phenotype. Methods: T cell phenotype was determined by immunostaining followed by FACS analysis. Lymphoproliferation assays and cytokine ELISAs were used to evaluate proliferation/activation of Treg cells co-cultured with CMFs. Results: CMFs induced the allogeneic proliferation of naturally occurring CD4+CD25highFoxP3+ Treg cells. Moreover, CMFS induced generation of the CD4+CD25highFoxP3+ Treg cells from CD4+CD25-FoxP3- T helper cells. These processes were MHC class II- and PGE2-dependent. The frequency of the Treg cells was markedly decreased (65-90%) in the presence of antiMHC class II blocking antibodies and/or the PGE2 synthesis inhibitor indomethacin. The newly generated Treg cells were functionally active, since they inhibited the proliferation of activated autologous CD4+ effector T cells. Conclusions: These data support our hypothesis that CMFs are among the essential contributors in the induction /maintenance of mucosal tolerance in the colon via at least two mechanisms: (1) expression of B7 negative co-stimulators and (2) induction of the regulatory T cells. Supported by NIDDK and CCFA.
A novel CD4+ T helper (Th) cell, characterized by secretion of IL-17, is a key mediator of inflammation and involved in the pathogenesis of a variety of inflammatory diseases. The complete cytokine profile and molecular phenotype of these Th17 cells is not yet established, but it is clear that in addition to IL-17, they produce IL-6, TNF-α, and IL-22, express CCR6 and the Retinoic-AcidRelated Orphan Receptor (ROR)-γt. Work in mice demonstrated that stimulating T cells with IL-6, TGF−β and IL-23 induces Th17 cells. The factors driving human Th17 cell development are less well defined, and appear to involve IL-1β, IL-6 and IL-23. In mice, ROR-γt may be a lineage differentiation factor for Th17 cells, but the role of this transcription factor in human Th17 development is unknown. Using a lentiviral gene-transfer system we investigated the role of RORC2, the human orthologue of ROR-γt, in the development, phenotype and function of human CD4+ T cells. Ectopic expression of RORC2 in CD4+ T cells resulted in induction of cytokines associated with Th17 cells, including IL-17, IL-6, TNF-α and IL-22, and expression of Th17-associated chemokine receptors. We also determined the effects of RORC2 on proliferation and susceptibility to suppression by T regulatory cells. Ectopic expression of RORC2 resulted in reduced proliferation in the absence of co-stimulation. Furthermore, like in vitro differentiated Th17 cells, following RORC2 gene transfer, CD4+ T cells became resistant to T regulatory cell-mediated suppression. These data provide the first direct evidence for the role of RORC2 in the development of human Th17 cells and provide insight into the phenotype and function of this newly identified CD4+ T cell subset.
doi:10.1016/j.clim.2008.03.042
doi:10.1016/j.clim.2008.03.043