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Author

Shizuo Akira

Bio: Shizuo Akira is an academic researcher from Osaka University. The author has contributed to research in topics: Innate immune system & Immune system. The author has an hindex of 261, co-authored 1308 publications receiving 320561 citations. Previous affiliations of Shizuo Akira include University of California, Berkeley & Wakayama Medical University.


Papers
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Journal ArticleDOI
TL;DR: A novel mechanism whereby the genomic DNA of a virus can engage TLR9 and result in the secretion of IFN-α by pDCs is demonstrated.
Abstract: Plasmacytoid dendritic cells (pDCs) have been identified as a potent secretor of the type I interferons (IFNs) in response to CpG as well as several viruses. In this study, we examined the molecular mechanism of virus recognition by pDCs. First, we demonstrated that the CD11c+Gr-1intB220+ pDCs from mouse bone marrow secreted high levels of IFN-α in response to either live or UV-inactivated Herpes simplex virus-2 (HSV-2). Next, we identified that IFN-α secretion by pDCs required the expression of the adaptor molecule MyD88, suggesting the involvement of a Toll-like receptor (TLR) in HSV-2 recognition. To test whether a TLR mediates HSV-2–induced IFN-α secretion from pDCs, various knockout mice were examined. These experiments revealed a clear requirement for TLR9 in this process. Further, we demonstrated that purified HSV-2 DNA can trigger IFN-α secretion from pDCs and that inhibitory CpG oligonucleotide treatment diminished HSV-induced IFN-α secretion by pDCs in a dose-dependent manner. The recognition of HSV-2 by TLR9 was mediated through an endocytic pathway that was inhibited by chloroquine or bafilomycin A1. The strict requirement for TLR9 in IFN-α secretion was further confirmed by the inoculation of HSV-2 in vivo. Therefore, these results demonstrate a novel mechanism whereby the genomic DNA of a virus can engage TLR9 and result in the secretion of IFN-α by pDCs.

1,207 citations

Journal ArticleDOI
TL;DR: It is proposed that TLR4 first induces TIRAP-MyD88 signaling at the plasma membrane and is then endocytosed and activates TRAM-TRIF signaling from early endosomes, emphasizing a unifying theme in innate immune recognition whereby all type I interferon–inducing receptors signal from an intracellular location.
Abstract: Toll-like receptor 4 (TLR4) induces two distinct signaling pathways controlled by the TIRAP-MyD88 and TRAM-TRIF pairs of adaptor proteins, which elicit the production of proinflammatory cytokines and type I interferons, respectively. How TLR4 coordinates the activation of these two pathways is unknown. Here we show that TLR4 activated these two signaling pathways sequentially in a process organized around endocytosis of the TLR4 complex. We propose that TLR4 first induces TIRAP-MyD88 signaling at the plasma membrane and is then endocytosed and activates TRAM-TRIF signaling from early endosomes. Our data emphasize a unifying theme in innate immune recognition whereby all type I interferon–inducing receptors signal from an intracellular location.

1,199 citations

Journal ArticleDOI
TL;DR: Results indicate that TLR3, TLR7 and TLR9 may play an important role in detecting and combating viral infections.

1,138 citations

Journal ArticleDOI
TL;DR: The recent advances in pathogen recognition by TLRs and TLR signaling are described and their roles in shaping pathogen-specific humoral and cellular adaptive immune responses are described.

1,112 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
24 Feb 2006-Cell
TL;DR: New insights into innate immunity are changing the way the way the authors think about pathogenesis and the treatment of infectious diseases, allergy, and autoimmunity.

10,685 citations

Journal ArticleDOI
TL;DR: A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older and safety over a median of 2 months was similar to that of other viral vaccines.
Abstract: Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a world...

10,274 citations

Journal ArticleDOI
24 Jul 2008-Nature
TL;DR: The molecular pathways of this cancer-related inflammation are now being unravelled, resulting in the identification of new target molecules that could lead to improved diagnosis and treatment.
Abstract: The mediators and cellular effectors of inflammation are important constituents of the local environment of tumours. In some types of cancer, inflammatory conditions are present before a malignant change occurs. Conversely, in other types of cancer, an oncogenic change induces an inflammatory microenvironment that promotes the development of tumours. Regardless of its origin, 'smouldering' inflammation in the tumour microenvironment has many tumour-promoting effects. It aids in the proliferation and survival of malignant cells, promotes angiogenesis and metastasis, subverts adaptive immune responses, and alters responses to hormones and chemotherapeutic agents. The molecular pathways of this cancer-related inflammation are now being unravelled, resulting in the identification of new target molecules that could lead to improved diagnosis and treatment.

9,282 citations

Journal ArticleDOI
19 Mar 2010-Cell
TL;DR: The principal mechanisms that govern the effects of inflammation and immunity on tumor development are outlined and attractive new targets for cancer therapy and prevention are discussed.

8,664 citations