IRF family proteins and type I interferon induction in dendritic cells  

作　　者：Prafullakumar Tailor Tomohiko Tamura Keiko Ozato 

机构地区：[1]Laboratory of Molecular Growth Regulation, National Institute of Child Health and Human Development, National institutes ofHealth, Bethesda, MD 20892, USA

出　　处：《Cell Research》2006年第2期134-140,共7页细胞研究（英文版）

摘　　要：Dendritic cells （DC）, although a minor population in hematopoietic cells, produce type I interferons （IFN） and other cytokines and are essential for innate immunity. They are also potent antigen presenters and regulate adaptive immunity. Among DC subtypes plasmacytoid DC （pDC） produce the highest amounts of type I IFN. In addition, pro- and anti-inflammatory cytokines such as IL-12 and IL-10 are induced in DC in response to Toll like receptor （TLR） signaling and upon viral infection. Proteins in the IRF family control many aspects of DC activity. IRF-8 and IRF-4 are essential for DC development. They differentially control the development of four DC subsets. IRF-8^-/- mice are largely devoid of pDC and CD8α^＋ DC, while IRF-4^-/- mice lack CD4^＋ DC. IRF-8^-/-, IRF4^-/-, double knock-out mice have only few CD8α CD4^-DC that lack MHC Ⅱ. IRF proteins also control type Ⅰ IFN induction in DC. IRF-7, activated upon TLR signaling is required for IFN induction not only in pDC, but also in conventional DC （cDC） and non-DC cell types. IRF-3, although contributes to IFN induction in fibroblasts, is dispensable in IFN induction in DC. Our recent evidence reveals that type Ⅰ IFN induction in DC is critically dependent on IRF-8, which acts in the feedback phase of IFN gene induction in DC. Type Ⅰ IFN induction in pDC is mediated by MyD88 dependent signaling pathway, and differs from pathways employed in other cells, which mostly rely on TLR3 and RIG-Ⅰ family proteins. Other pro-inflammatory cytokines are produced in an IRF-5 dependent manner. However, IRF-5 is not required for IFN induction, suggesting the presence of separate mechanisms for induction of type Ⅰ IFN and other pro-inflammatory cytokines. IFN and other cytokines produced by activated DC in turn advance DC maturation and change the phenotype and function of DC. These processes are also likely to be governed by IRF family proteins.

关 键 词：dendritic cells IRF-3 4 5 7 8 type Ⅰ interferon induction activate transcription signaling pathway dependence 

分 类 号：R329.2[医药卫生—人体解剖和组织胚胎学]