scholarly journals TRIM-mediated precision autophagy targets cytoplasmic regulators of innate immunity

2015 ◽  
Vol 210 (6) ◽  
pp. 973-989 ◽  
Author(s):  
Tomonori Kimura ◽  
Ashish Jain ◽  
Seong Won Choi ◽  
Michael A. Mandell ◽  
Kate Schroder ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Mammalian Cells ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Key Factors ◽  
Autophagic Degradation ◽  
Response Systems ◽  
Mediterranean Fever ◽  
Trim Proteins

The present paradigms of selective autophagy in mammalian cells cannot fully explain the specificity and selectivity of autophagic degradation. In this paper, we report that a subset of tripartite motif (TRIM) proteins act as specialized receptors for highly specific autophagy (precision autophagy) of key components of the inflammasome and type I interferon response systems. TRIM20 targets the inflammasome components, including NLRP3, NLRP1, and pro–caspase 1, for autophagic degradation, whereas TRIM21 targets IRF3. TRIM20 and TRIM21 directly bind their respective cargo and recruit autophagic machinery to execute degradation. The autophagic function of TRIM20 is affected by mutations associated with familial Mediterranean fever. These findings broaden the concept of TRIMs acting as autophagic receptor regulators executing precision autophagy of specific cytoplasmic targets. In the case of TRIM20 and TRIM21, precision autophagy controls the hub signaling machineries and key factors, inflammasome and type I interferon, directing cardinal innate immunity response systems in humans.

scholarly journals The Regulatory Network of Cyclic GMP-AMP Synthase-Stimulator of Interferon Genes Pathway in Viral Evasion

2021 ◽  
Vol 12 ◽  
Author(s):  
Tongyu Hu ◽  
Mingyu Pan ◽  
Yue Yin ◽  
Chen Wang ◽  
Ye Cui ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Cyclic Gmp ◽  
Mammalian Cells ◽  
Type I Interferon ◽  
Viral Proteins ◽  
Current Status ◽  
Type I ◽  
Non Coding Rnas ◽  
Sting Pathway ◽  
Viral Evasion

Virus infection has been consistently threatening public health. The cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) pathway is a critical defender to sense various pathogens and trigger innate immunity of mammalian cells. cGAS recognizes the pathogenic DNA in the cytosol and then synthesizes 2′3′-cyclic GMP-AMP (2′3′cGAMP). As the second messenger, cGAMP activates STING and induces the following cascade to produce type I interferon (IFN-I) to protect against infections. However, viruses have evolved numerous strategies to hinder the cGAS-STING signal transduction, promoting their immune evasion. Here we outline the current status of the viral evasion mechanism underlying the regulation of the cGAS-STING pathway, focusing on how post-transcriptional modifications, viral proteins, and non-coding RNAs involve innate immunity during viral infection, attempting to inspire new targets discovery and uncover potential clinical antiviral treatments.

scholarly journals Mycobacterium tuberculosis MmsA (Rv0753c) Interacts with STING and Blunts the Type I Interferon Response

mBio ◽  
2020 ◽  
Vol 11 (6) ◽  
Author(s):  
Yifan Sun ◽  
Wei Zhang ◽  
Chunsheng Dong ◽  
Sidong Xiong
Keyword(s):  
Mass Spectrometry ◽  
Mycobacterium Tuberculosis ◽  
Proteomic Analysis ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Type I Ifn ◽  
Content Type ◽  
C Terminus ◽  
Autophagic Degradation

ABSTRACT Type I interferon (IFN) plays an important role in Mycobacterium tuberculosis persistence and disease pathogenesis. M. tuberculosis has evolved a number of mechanisms to evade host immune surveillance. However, it is unclear how the type I IFN response is tightly regulated by the M. tuberculosis determinants. Stimulator of interferon genes (STING) is an essential adaptor for type I IFN production triggered by M. tuberculosis genomic DNA or cyclic dinucleotides upon infection. To investigate how the type I IFN response is regulated by M. tuberculosis determinants, immunoprecipitation-mass spectrometry-based (IP-MS) proteomic analysis was performed to screen proteins interacting with STING in the context of M. tuberculosis infection. Among the many predicted candidates interacting with STING, the M. tuberculosis coding protein Rv0753c (MmsA) was identified. We confirmed that MmsA binds and colocalizes with STING, and the N-terminal regions of MmsA (amino acids [aa] 1 to 251) and STING (aa 1 TO 190) are responsible for MmsA-STING interaction. Type I IFN production was impaired with exogenous expression of MmsA in RAW264.7 cells. MmsA inhibited the STING-TBK1-IRF3 pathway, as evidenced by reduced STING levelS and subsequent IRF3 activation. Furthermore, MmsA facilitated p62-mediated STING autophagic degradation by binding p62 with its C terminus (aa 252 to 455), which may account for the negative regulation of M. tuberculosis MmsA in STING-mediated type I IFN production. Additionally, the M. tuberculosis mmsA R138W mutation, detected in a hypervirulent clinical isolate, enhanced the degradation of STING, implying the important relevance of MmsA in disease outcome. Together, we report a novel mechanism where M. tuberculosis MmsA serves as an antagonist of type I IFN response by targeting STING with p62-mediated autophagic degradation. IMPORTANCE It is unclear how the type I IFN response is regulated by mycobacterial determinants. Here, we characterized the previously unreported role of M. tuberculosis MmsA in immunological regulation of type I IFN response by targeting the central adaptor STING in the DNA sensing pathway. We identified STING-interacting MmsA by coimmunoprecipitation-mass spectrometry-based (IP-MS) proteomic analysis and showed MmsA interacting with STING and autophagy receptor p62 via its N terminus and C terminus, respectively. We also showed that MmsA downregulated type I IFN by promoting p62-mediated STING degradation. Moreover, the MmsA mutant R138W is potentially associated with the virulence of M. tuberculosis clinical strains owing to the modulation of STING protein. Our results provide novel insights into the regulatory mechanism of type I IFN response manipulated by mycobacterial MmsA and the additional cross talk between autophagy and STING in M. tuberculosis infection, wherein a protein from microbial pathogens induces autophagic degradation of host innate immune molecules.

scholarly journals Hepatitis-D Virus Infection Is Not Impaired by Innate Immunity but Increases Cytotoxic T-Cell Activity

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3253
Author(s):  
Sebastian Maximilian Altstetter ◽  
Oliver Quitt ◽  
Francesca Pinci ◽  
Veit Hornung ◽  
Aaron Michael Lucko ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Chronic Hepatitis ◽  
T Cell ◽  
Chronic Inflammation ◽  
Type I Interferon ◽  
Interferon Response ◽  
Cytotoxic T Cell ◽  
Type I ◽  
Hepatitis D ◽  
Hepatitis D Virus

Approximately 70 million humans worldwide are affected by chronic hepatitis D, which rapidly leads to liver cirrhosis and hepatocellular carcinoma due to chronic inflammation. The triggers and consequences of this chronic inflammation, induced by co-infection with the hepatitis D virus (HDV) and the hepatitis B virus (HBV), are poorly understood. Using CRISPR technology, we characterized the recognition of HDV mono- and co-infection by intracellular innate immunity and determined its influence on the viral life cycle and effector T-cell responses using different HBV and HDV permissive hepatoma cell lines. We showed that HDV infection is detected by MDA5 and -after a lag phase -induces a profound type I interferon response in the infected cells. The type I interferon response, however, was not able to suppress HDV replication or spread, thus providing a persistent trigger. Using engineered T-cells directed against the envelope proteins commonly used by HBV and HDV, we found that HDV immune recognition enhanced T-cell cytotoxicity. Interestingly, the T-cell effector function was enhanced independently of antigen presentation. These findings help to explain immune mediated tissue damage in chronic hepatitis D patients and indicate that combining innate triggers with T-cell activating therapies might allow for a curative approach.

scholarly journals Crosstalk Between Mammalian Antiviral Pathways

2019 ◽  
Vol 5 (1) ◽  
pp. 29 ◽  
Author(s):  
Samir Watson ◽  
Lisanne Knol ◽  
Jeroen Witteveldt ◽  
Sara Macias
Keyword(s):  
Small Rna ◽  
Mammalian Cells ◽  
Viral Infections ◽  
Type I Interferon ◽  
Innate Immune ◽  
Type I Interferons ◽  
Interferon Response ◽  
Classical Type ◽  
Type I ◽  
Rna Biogenesis

As part of their innate immune response against viral infections, mammals activate the expression of type I interferons to prevent viral replication and dissemination. An antiviral RNAi-based response can be also activated in mammals, suggesting that several mechanisms can co-occur in the same cell and that these pathways must interact to enable the best antiviral response. Here, we will review how the classical type I interferon response and the recently described antiviral RNAi pathways interact in mammalian cells. Specifically, we will uncover how the small RNA biogenesis pathway, composed by the nucleases Drosha and Dicer can act as direct antiviral factors, and how the type-I interferon response regulates the function of these. We will also describe how the factors involved in small RNA biogenesis and specific small RNAs impact the activation of the type I interferon response and antiviral activity. With this, we aim to expose the complex and intricate network of interactions between the different antiviral pathways in mammals.

Viral Invasion and Type I Interferon Response Characterize the Immunophenotypes during COVID-19 Infection

2020 ◽  
Author(s):  
Lai Wei ◽  
Siqi Ming ◽  
Bin Zou ◽  
Yongjian Wu ◽  
Zhongsi Hong ◽  
...  
Keyword(s):  
Type I Interferon ◽  
Interferon Response ◽  
Type I

scholarly journals Positive natural selection in primate genes of the type I interferon response

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elena N. Judd ◽  
Alison R. Gilchrist ◽  
Nicholas R. Meyerson ◽  
Sara L. Sawyer
Keyword(s):  
Natural Selection ◽  
Positive Selection ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Multiple Sequence Alignments ◽  
Interferon Stimulated Genes ◽  
Interferon Induction

Abstract Background The Type I interferon response is an important first-line defense against viruses. In turn, viruses antagonize (i.e., degrade, mis-localize, etc.) many proteins in interferon pathways. Thus, hosts and viruses are locked in an evolutionary arms race for dominance of the Type I interferon pathway. As a result, many genes in interferon pathways have experienced positive natural selection in favor of new allelic forms that can better recognize viruses or escape viral antagonists. Here, we performed a holistic analysis of selective pressures acting on genes in the Type I interferon family. We initially hypothesized that the genes responsible for inducing the production of interferon would be antagonized more heavily by viruses than genes that are turned on as a result of interferon. Our logic was that viruses would have greater effect if they worked upstream of the production of interferon molecules because, once interferon is produced, hundreds of interferon-stimulated proteins would activate and the virus would need to counteract them one-by-one. Results We curated multiple sequence alignments of primate orthologs for 131 genes active in interferon production and signaling (herein, “induction” genes), 100 interferon-stimulated genes, and 100 randomly chosen genes. We analyzed each multiple sequence alignment for the signatures of recurrent positive selection. Counter to our hypothesis, we found the interferon-stimulated genes, and not interferon induction genes, are evolving significantly more rapidly than a random set of genes. Interferon induction genes evolve in a way that is indistinguishable from a matched set of random genes (22% and 18% of genes bear signatures of positive selection, respectively). In contrast, interferon-stimulated genes evolve differently, with 33% of genes evolving under positive selection and containing a significantly higher fraction of codons that have experienced selection for recurrent replacement of the encoded amino acid. Conclusion Viruses may antagonize individual products of the interferon response more often than trying to neutralize the system altogether.

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