Project description:Type I interferons (IFN) are crucial mediators of human innate and adaptive immunity and are massively produced from plasmacytoid dendritic cells (pDC). IRF7 is a critical regulator of type I IFN production when pathogens are detected by TLR7/9 in pDC. However, hyperactivation of pDC can cause life-threatening autoimmune diseases. To avoid the deleterious effects of aberrant pDC activation, tight regulation of IRF7 is required. Nonetheless, the detailed mechanisms of how IRF7 transcription is regulated in pDC are still elusive. To this end, we identified the global gene expression changes after stimulation of human primary pDC with the TLR9 agonist CpGB. We identified that the transcription factor MYC is prominently upregulated upon CpGB engagement in pDC. Moreover, when we knocked down MYC in the pDC-like cell line GEN2.2, production of interferon-stimulated genes (ISGs) was dramatically increased and was further enhanced by CpGB. Interestingly, MYC is shown to be recruited to the IRF7 promoter region through interaction with NCOR2/HDAC3 for its repression, and HDAC3 inhibition enhanced IRF7 expression and IFNβ production. Interestingly, activation of TLR9-mediated NF-kB and MAPK and nuclear translocation of IRF7 were greatly enhanced by MYC depletion. Pharmaceutical inhibition of MYC recovered IRF7 expression, further confirming the negative role of MYC in the antiviral response by pDC. Furthermore, the inverse correlation of MYC and IRF7 was validated in psoriasis skin sample datasets. Therefore, our results identify the novel immunomodulatory role of MYC in human pDC and may add to our understanding of aberrant pDC function in autoimmune diseases.
Project description:Type I interferons (IFN) are crucial mediators of human innate and adaptive immunity and are massively produced from plasmacytoid dendritic cells (pDC). IRF7 is a critical regulator of type I IFN production when pathogens are detected by TLR7/9 in pDC. However, hyperactivation of pDC can cause life-threatening autoimmune diseases. To avoid the deleterious effects of aberrant pDC activation, tight regulation of IRF7 is required. Nonetheless, the detailed mechanisms of how IRF7 transcription is regulated in pDC are still elusive. To this end, we identified the global gene expression changes after stimulation of human primary pDC with the TLR9 agonist CpGB. We identified that the transcription factor MYC is prominently upregulated upon CpGB engagement in pDC. Moreover, when we knocked down MYC in the pDC-like cell line GEN2.2, production of interferon-stimulated genes (ISGs) was dramatically increased and was further enhanced by CpGB. Interestingly, MYC is shown to be recruited to the IRF7 promoter region through interaction with NCOR2/HDAC3 for its repression, and HDAC3 inhibition enhanced IRF7 expression and IFNβ production. Interestingly, activation of TLR9-mediated NF-kB and MAPK and nuclear translocation of IRF7 were greatly enhanced by MYC depletion. Pharmaceutical inhibition of MYC recovered IRF7 expression, further confirming the negative role of MYC in the antiviral response by pDC. Furthermore, the inverse correlation of MYC and IRF7 was validated in psoriasis skin sample datasets. Therefore, our results identify the novel immunomodulatory role of MYC in human pDC and may add to our understanding of aberrant pDC function in autoimmune diseases.
Project description:Type I interferons (IFN) are crucial mediators of human innate and adaptive immunity and are massively produced from plasmacytoid dendritic cells (pDC). IRF7 is a critical regulator of type I IFN production when pathogens are detected by TLR7/9 in pDC. However, hyperactivation of pDC can cause life-threatening autoimmune diseases. To avoid the deleterious effects of aberrant pDC activation, tight regulation of IRF7 is required. Nonetheless, the detailed mechanisms of how IRF7 transcription is regulated in pDC are still elusive. To this end, we identified the global gene expression changes after stimulation of human primary pDC with the TLR9 agonist CpGB. We identified that the transcription factor MYC is prominently upregulated upon CpGB engagement in pDC. Moreover, when we knocked down MYC in the pDC-like cell line GEN2.2, production of interferon-stimulated genes (ISGs) was dramatically increased and was further enhanced by CpGB. Interestingly, MYC is shown to be recruited to the IRF7 promoter region through interaction with NCOR2/HDAC3 for its repression, and HDAC3 inhibition enhanced IRF7 expression and IFNβ production. Interestingly, activation of TLR9-mediated NF-kB and MAPK and nuclear translocation of IRF7 were greatly enhanced by MYC depletion. Pharmaceutical inhibition of MYC recovered IRF7 expression, further confirming the negative role of MYC in the antiviral response by pDC. Furthermore, the inverse correlation of MYC and IRF7 was validated in psoriasis skin sample datasets. Therefore, our results identify the novel immunomodulatory role of MYC in human pDC and may add to our understanding of aberrant pDC function in autoimmune diseases.
Project description:This SuperSeries is composed of the following subset Series: GSE36241: Identification of a FOXO3/IRF7 circuit that limits inflammatory sequelae of antiviral responses (ChIP-Seq) GSE37051: Identification of a FOXO3/IRF7 circuit that limits inflammatory sequelae of antiviral responses (expression) Refer to individual Series
Project description:We predict that a member of the forkhead family of transcription factors, FOXO3, is a negative regulator of a subset of antiviral genes. This prediction was validated using macrophages isolated from Foxo3-null mice. Genome-wide location analysis combined with gene deletion studies identified the Irf7 gene as a critical target of FOXO3. FOXO3 was identified as a negative regulator of Irf7 transcription. Our data suggest that the FOXO3-IRF7 regulatory circuit represents a novel mechanism for establishing the requisite set points in the interferon pathway.
Project description:We predict that a member of the forkhead family of transcription factors, FOXO3, is a negative regulator of a subset of antiviral genes. This prediction was validated using macrophages isolated from Foxo3-null mice. Genome-wide location analysis combined with gene deletion studies identified the Irf7 gene as a critical target of FOXO3. FOXO3 was identified as a negative regulator of Irf7 transcription. Our data suggest that the FOXO3-IRF7 regulatory circuit represents a novel mechanism for establishing the requisite set points in the interferon pathway. C57BL/6 mice were obtained from Jackson Laboratories. Foxo3-/- mice in the FVB background were obtained from MMRRC and were backcrossed to C57BL/6 mice at least 5 times to generate congenic mice. C57BL/6 Foxo3+/- heterozygotes were intercrossed to generate Foxo3-/- mice. Mice were maintained at the animal facility of the Institute for Systems Biology and used at 8–12 weeks of age. All animals were housed and handled according to the approved protocols of University of Washington and Institute for Systems Biology's Institutional Animal Care and Use Committees.
Project description:IRF7 plays a critical role in the production and amplification of the antiviral type I and III interferon response. Autosomal recessive IRF7-deficiency resulted in life-threatening influenza disease in a 3-year-old child. We studied the impact of IRF7-deficiency in non-hematopoietic tissues (fibroblasts and lung epithelial cells) as well in hematopoietic cells (peripheral blood mononuclear cells (PBMCs)). Genome-wide gene expression analysis demonstrated a profound loss of type I and III IFNs in PBMCs infected with influenza virus. PBMCs were isolated from 4 healthy donors and patients with deficiencies for IRF7 and UNC93B. The cells were infected with influenza virus A/CA/4/2009 at a multiplicity of infection (MOI) of 2 for 8 and 16 hours. Uninfected cells were cultured for 16 hours.