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Abstract
Dendritic cells (DC) are professional antigen presenting cells comprising a variety of subsets, as either resident or migrating cells, in lymphoid and non-lymphoid organs. In the steady state DC continually process and present antigens on MHCI and MHCII, processes that are highly upregulated upon activation. By expressing differential sets of pattern recognition receptors different DC subsets are able to respond to a range of pathogenic and danger stimuli, enabling functional specialisation of the DC. The knowledge of functional specialisation of DC subsets is key to efficient priming of T cells, to the design of effective vaccine adjuvants and to understanding the role of different DC in health and disease. This review outlines mouse and human steady state DC subsets and key attributes that define their distinct functions.
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Abstract
A complex interplay between pathogen and host determines the immune response during viral infection. A set of cytosolic sensors are expressed by immune cells to detect viral infection. NOD-like receptors (NLRs) comprise a large family of intracellular pattern recognition receptors. Members of the NLR family assemble into large multiprotein complexes, termed inflammasomes, which induce downstream immune responses to specific pathogens, environmental stimuli, and host cell damage. Inflammasomes are composed of cytoplasmic sensor molecules such as NLRP3 or absent in melanoma 2 (AIM2), the adaptor protein ASC (apoptosis-associated speck-like protein containing caspase recruitment domain), and the effector protein procaspase-1. The inflammasome operates as a platform for caspase-1 activation, resulting in caspase-1-dependent proteolytic maturation and secretion of interleukin (IL)-1β and IL-18. This, in turn, activates the expression of other immune genes and facilitates lymphocyte recruitment to the site of primary infection, thereby controlling invading pathogens. Moreover, inflammasomes counter viral replication and remove infected immune cells through an inflammatory cell death, program termed as pyroptosis. As a countermeasure, viral pathogens have evolved virulence factors to antagonise inflammasome pathways. In this review, we discuss the role of inflammasomes in sensing viral infection as well as the evasion strategies that viruses have developed to evade inflammasome-dependent immune responses. This information summarises our understanding of host defence mechanisms against viruses and highlights research areas that can provide new approaches to interfere in the pathogenesis of viral diseases.
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103
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Hua CK, Ackerman ME. Increasing the Clinical Potential and Applications of Anti-HIV Antibodies. Front Immunol 2017; 8:1655. [PMID: 29234320 PMCID: PMC5712301 DOI: 10.3389/fimmu.2017.01655] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/13/2017] [Indexed: 01/03/2023] Open
Abstract
Preclinical and early human clinical studies of broadly neutralizing antibodies (bNAbs) to prevent and treat HIV infection support the clinical utility and potential of bNAbs for prevention, postexposure prophylaxis, and treatment of acute and chronic infection. Observed and potential limitations of bNAbs from these recent studies include the selection of resistant viral populations, immunogenicity resulting in the development of antidrug (Ab) responses, and the potentially toxic elimination of reservoir cells in regeneration-limited tissues. Here, we review opportunities to improve the clinical utility of HIV Abs to address these challenges and further accomplish functional targets for anti-HIV Ab therapy at various stages of exposure/infection. Before exposure, bNAbs' ability to serve as prophylaxis by neutralization may be improved by increasing serum half-life to necessitate less frequent administration, delivering genes for durable in vivo expression, and targeting bNAbs to sites of exposure. After exposure and/or in the setting of acute infection, bNAb use to prevent/reduce viral reservoir establishment and spread may be enhanced by increasing the potency with which autologous adaptive immune responses are stimulated, clearing acutely infected cells, and preventing cell-cell transmission of virus. In the setting of chronic infection, bNAbs may better mediate viral remission or "cure" in combination with antiretroviral therapy and/or latency reversing agents, by targeting additional markers of tissue reservoirs or infected cell types, or by serving as targeting moieties in engineered cell therapy. While the clinical use of HIV Abs has never been closer, remaining studies to precisely define, model, and understand the complex roles and dynamics of HIV Abs and viral evolution in the context of the human immune system and anatomical compartmentalization will be critical to both optimize their clinical use in combination with existing agents and define further strategies with which to enhance their clinical safety and efficacy.
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Affiliation(s)
- Casey K. Hua
- Department of Microbiology and Immunology, Geisel School of Medicine, Lebanon, NH, United States
| | - Margaret E. Ackerman
- Department of Microbiology and Immunology, Geisel School of Medicine, Lebanon, NH, United States
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
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104
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NLRX1 Mediates MAVS Degradation To Attenuate the Hepatitis C Virus-Induced Innate Immune Response through PCBP2. J Virol 2017; 91:JVI.01264-17. [PMID: 28956771 DOI: 10.1128/jvi.01264-17] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 09/20/2017] [Indexed: 12/20/2022] Open
Abstract
Activation of innate immunity is essential for host cells to restrict the spread of invading viruses and other pathogens. However, attenuation or termination of signaling is also necessary for preventing immune-mediated tissue damage and spontaneous autoimmunity. Here, we identify nucleotide binding oligomerization domain (NOD)-like receptor X1 (NLRX1) as a negative regulator of the mitochondrial antiviral signaling protein (MAVS)-mediated signaling pathway during hepatitis C virus (HCV) infection. The depletion of NLRX1 enhances the HCV-triggered activation of interferon (IFN) signaling and causes the suppression of HCV propagation in hepatocytes. NLRX1, a HCV-inducible protein, interacts with MAVS and mediates the K48-linked polyubiquitination and subsequent degradation of MAVS via the proteasomal pathway. Moreover, poly(rC) binding protein 2 (PCBP2) interacts with NLRX1 to participate in the NLRX1-induced degradation of MAVS and the inhibition of antiviral responses during HCV infection. Mutagenic analyses further revealed that the NOD of NLRX1 is essential for NLRX1 to interact with PCBP2 and subsequently induce MAVS degradation. Our study unlocks a key mechanism of the fine-tuning of innate immunity by which NLRX1 restrains the retinoic acid-inducible gene I-like receptor (RLR)-MAVS signaling cascade by recruiting PCBP2 to MAVS for inducing MAVS degradation through the proteasomal pathway. NLRX1, a negative regulator of innate immunity, is a pivotal host factor for HCV to establish persistent infection.IMPORTANCE Innate immunity needs to be tightly regulated to maximize the antiviral response and minimize immune-mediated pathology, but the underlying mechanisms are poorly understood. In this study, we report that NLRX1 is a proviral host factor for HCV infection and functions as a negative regulator of the HCV-triggered innate immune response. NLRX1 recruits PCBP2 to MAVS and induces the K48-linked polyubiquitination and degradation of MAVS, leading to the negative regulation of the IFN signaling pathway and promoting HCV infection. Overall, this study provides intriguing insights into how innate immunity is regulated during viral infection.
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105
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NLRX1 modulates differentially NLRP3 inflammasome activation and NF-κB signaling during Fusobacterium nucleatum infection. Microbes Infect 2017; 20:615-625. [PMID: 29024797 DOI: 10.1016/j.micinf.2017.09.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 09/28/2017] [Indexed: 01/18/2023]
Abstract
NOD-like receptors (NLRs) play a large role in regulation of host innate immunity, yet their role in periodontitis remains to be defined. NLRX1, a member of the NLR family that localizes to mitochondria, enhances mitochondrial ROS (mROS) generation. mROS can activate the NLRP3 inflammasome, yet the role of NLRX1 in NLRP3 inflammasome activation has not been examined. In this study, we revealed the mechanism by which NLRX1 positively regulates ATP-induced NLRP3 inflammasome activation through mROS in gingival epithelial cells (GECs). We found that depletion of NLRX1 by shRNA attenuated ATP-induced mROS generation and redistribution of the NLRP3 inflammasome adaptor protein, ASC. Furthermore, depletion of NLRX1 inhibited Fusobacterium nucleatum infection-activated caspase-1, suggesting that it also inhibits the NLRP3 inflammasome. Conversely, NLRX1 also acted as a negative regulator of NF-κB signaling and IL-8 expression. Thus, NLRX1 stimulates detection of the pathogen F. nucleatum via the inflammasome, while dampening cytokine production. We expect that commensals should not activate the inflammasome, and NLRX1 should decrease their ability to stimulate expression of pro-inflammatory cytokines such as IL-8. Therefore, NLRX1 may act as a potential switch with regards to anti-microbial responses in healthy or diseased states in the oral cavity.
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106
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Feng H, Lenarcic EM, Yamane D, Wauthier E, Mo J, Guo H, McGivern DR, González-López O, Misumi I, Reid LM, Whitmire JK, Ting JPY, Duncan JA, Moorman NJ, Lemon SM. NLRX1 promotes immediate IRF1-directed antiviral responses by limiting dsRNA-activated translational inhibition mediated by PKR. Nat Immunol 2017; 18:1299-1309. [PMID: 28967880 PMCID: PMC5690873 DOI: 10.1038/ni.3853] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 09/11/2017] [Indexed: 12/14/2022]
Abstract
NLRX1 is unique among nucleotide-binding domain and leucine-rich repeat (NLR) proteins in its mitochondrial localization and capacity to negatively regulate MAVS- and STING-dependent antiviral innate immunity. However, some studies suggest a positive regulatory role for NLRX1 in inducing antiviral responses. We show that NLRX1 exerts opposing regulatory effects on virus activation of the transcription factors IRF1 and IRF3, potentially explaining these contradictory results. Whereas NLRX1 suppresses MAVS-mediated IRF3 activation, NLRX1 conversely facilitates virus-induced increases in IRF1 expression, thereby enhancing control of virus infection. NLRX1 has a minimal effect on NF-κB-mediated IRF1 transcription, and regulates IRF1 abundance post-transcriptionally by preventing translational shutdown mediated by the dsRNA-activated protein kinase PKR, thereby allowing virus-induced increases in IRF1 protein abundance.
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Affiliation(s)
- Hui Feng
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Erik M Lenarcic
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Daisuke Yamane
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Eliane Wauthier
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jinyao Mo
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Haitao Guo
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - David R McGivern
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Olga González-López
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ichiro Misumi
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Lola M Reid
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jason K Whitmire
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jenny P-Y Ting
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Joseph A Duncan
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Pharmacology, The University of North Carolina, Chapel Hill, North Carolina, USA
| | - Nathaniel J Moorman
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Stanley M Lemon
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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107
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Activation of the Innate Immune Receptors: Guardians of the Micro Galaxy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1024:1-35. [DOI: 10.1007/978-981-10-5987-2_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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108
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Tocker AM, Durocher E, Jacob KD, Trieschman KE, Talento SM, Rechnitzer AA, Roberts DM, Davis BK. The Scaffolding Protein IQGAP1 Interacts with NLRC3 and Inhibits Type I IFN Production. THE JOURNAL OF IMMUNOLOGY 2017; 199:2896-2909. [PMID: 28864474 DOI: 10.4049/jimmunol.1601370] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 08/07/2017] [Indexed: 12/24/2022]
Abstract
Sensing of cytosolic nucleotides is a critical initial step in the elaboration of type I IFN. One of several upstream receptors, cyclic GMP-AMP synthase, binds to cytosolic DNA and generates dicyclic nucleotides that act as secondary messengers. These secondary messengers bind directly to stimulator of IFN genes (STING). STING recruits TNFR-associated NF-κB kinase-binding kinase 1 which acts as a critical node that allows for efficient activation of IFN regulatory factors to drive the antiviral transcriptome. NLRC3 is a recently characterized nucleotide-binding domain, leucine-rich repeat containing protein (NLR) that negatively regulates the type I IFN pathway by inhibiting subcellular redistribution and effective signaling of STING, thus blunting the transcription of type I IFNs. NLRC3 is predominantly expressed in lymphoid and myeloid cells. IQGAP1 was identified as a putative interacting partner of NLRC3 through yeast two-hybrid screening. In this article, we show that IQGAP1 associates with NLRC3 and can disrupt the NLRC3-STING interaction in the cytosol of human epithelial cells. Furthermore, knockdown of IQGAP1 in THP1 and HeLa cells causes significantly more IFN-β production in response to cytosolic nucleic acids. This result phenocopies NLRC3-deficient macrophages and fibroblasts and short hairpin RNA knockdown of NLRC3 in THP1 cells. Our findings suggest that IQGAP1 is a novel regulator of type I IFN production, possibly via interacting with NLRC3 in human monocytic and epithelial cells.
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Affiliation(s)
- Aaron M Tocker
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
| | - Emily Durocher
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
| | - Kimberly D Jacob
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
| | - Kate E Trieschman
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
| | - Suzanna M Talento
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
| | - Alma A Rechnitzer
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
| | - David M Roberts
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
| | - Beckley K Davis
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604
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109
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Darrah EJ, Stoltz KP, Ledwith M, Tarakanova VL. ATM supports gammaherpesvirus replication by attenuating type I interferon pathway. Virology 2017; 510:137-146. [PMID: 28732227 DOI: 10.1016/j.virol.2017.07.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/21/2017] [Accepted: 07/10/2017] [Indexed: 12/17/2022]
Abstract
Ataxia-Telangiectasia mutated (ATM) kinase participates in multiple networks, including DNA damage response, oxidative stress, and mitophagy. ATM also supports replication of diverse DNA and RNA viruses. Gammaherpesviruses are prevalent cancer-associated viruses that benefit from ATM expression during replication. This proviral role of ATM had been ascribed to its signaling within the DNA damage response network; other functions of ATM have not been considered. In this study increased type I interferon (IFN) responses were observed in ATM deficient gammaherpesvirus-infected macrophages. Using a mouse model that combines ATM and type I IFN receptor deficiencies we show that increased type I IFN response in the absence of ATM fully accounts for the proviral role of ATM during gammaherpesvirus replication. Further, increased type I IFN response rendered ATM deficient macrophages more susceptible to antiviral effects of type II IFN. This study identifies attenuation of type I IFN responses as the primary mechanism underlying proviral function of ATM during gammaherpesvirus infection.
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Affiliation(s)
- Eric J Darrah
- Department of Microbiology and Immunology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, United States
| | - Kyle P Stoltz
- Department of Microbiology and Immunology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, United States
| | - Mitchell Ledwith
- Department of Microbiology and Immunology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, United States
| | - Vera L Tarakanova
- Department of Microbiology and Immunology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, United States; Cancer Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, United States.
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110
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Li Y, Wilson HL, Kiss-Toth E. Regulating STING in health and disease. J Inflamm (Lond) 2017; 14:11. [PMID: 28596706 PMCID: PMC5463399 DOI: 10.1186/s12950-017-0159-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/26/2017] [Indexed: 12/15/2022] Open
Abstract
The presence of cytosolic double-stranded DNA molecules can trigger multiple innate immune signalling pathways which converge on the activation of an ER-resident innate immune adaptor named "STimulator of INterferon Genes (STING)". STING has been found to mediate type I interferon response downstream of cyclic dinucleotides and a number of DNA and RNA inducing signalling pathway. In addition to its physiological function, a rapidly increasing body of literature highlights the role for STING in human disease where variants of the STING proteins, as well as dysregulated STING signalling, have been implicated in a number of inflammatory diseases. This review will summarise the recent structural and functional findings of STING, and discuss how STING research has promoted the development of novel therapeutic approaches and experimental tools to improve treatment of tumour and autoimmune diseases.
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Affiliation(s)
- Yang Li
- Department of Infection; Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX UK
| | - Heather L. Wilson
- Department of Infection; Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX UK
| | - Endre Kiss-Toth
- Department of Infection; Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX UK
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111
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Abe T, Lee A, Sitharam R, Kesner J, Rabadan R, Shapira SD. Germ-Cell-Specific Inflammasome Component NLRP14 Negatively Regulates Cytosolic Nucleic Acid Sensing to Promote Fertilization. Immunity 2017; 46:621-634. [PMID: 28423339 DOI: 10.1016/j.immuni.2017.03.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 01/31/2017] [Accepted: 02/15/2017] [Indexed: 12/19/2022]
Abstract
Cytosolic sensing of nucleic acids initiates tightly regulated programs to limit infection. Oocyte fertilization represents a scenario wherein inappropriate responses to exogenous yet non-pathogen-derived nucleic acids would have negative consequences. We hypothesized that germ cells express negative regulators of nucleic acid sensing (NAS) in steady state and applied an integrated data-mining and functional genomics approach to identify a rheostat of DNA and RNA sensing-the inflammasome component NLRP14. We demonstrated that NLRP14 interacted physically with the nucleic acid sensing pathway and targeted TBK1 (TANK binding kinase 1) for ubiquitination and degradation. We further mapped domains in NLRP14 and TBK1 that mediated the inhibitory function. Finally, we identified a human nonsense germline variant associated with male sterility that results in loss of NLRP14 function and hyper-responsiveness to nucleic acids. The discovery points to a mechanism of nucleic acid sensing regulation that may be of particular importance in fertilization.
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Affiliation(s)
- Takayuki Abe
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University, New York, NY 10032, USA
| | - Albert Lee
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biomedical Informatics, Columbia University, New York, NY 10032, USA
| | - Ramaswami Sitharam
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University, New York, NY 10032, USA
| | - Jordan Kesner
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University, New York, NY 10032, USA
| | - Raul Rabadan
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biomedical Informatics, Columbia University, New York, NY 10032, USA
| | - Sagi D Shapira
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University, New York, NY 10032, USA.
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112
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Kim JH, Park ME, Nikapitiya C, Kim TH, Uddin MB, Lee HC, Kim E, Ma JY, Jung JU, Kim CJ, Lee JS. FAS-associated factor-1 positively regulates type I interferon response to RNA virus infection by targeting NLRX1. PLoS Pathog 2017; 13:e1006398. [PMID: 28542569 PMCID: PMC5456407 DOI: 10.1371/journal.ppat.1006398] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 06/02/2017] [Accepted: 05/04/2017] [Indexed: 12/25/2022] Open
Abstract
FAS-associated factor-1 (FAF1) is a component of the death-inducing signaling complex involved in Fas-mediated apoptosis. It regulates NF-κB activity, ubiquitination, and proteasomal degradation. Here, we found that FAF1 positively regulates the type I interferon pathway. FAF1gt/gt mice, which deficient in FAF1, and FAF1 knockdown immune cells were highly susceptible to RNA virus infection and showed low levels of inflammatory cytokines and type I interferon (IFN) production. FAF1 was bound competitively to NLRX1 and positively regulated type I IFN signaling by interfering with the interaction between NLRX1 and MAVS, thereby freeing MAVS to bind RIG-I, which switched on the MAVS-RIG-I-mediated antiviral signaling cascade. These results highlight a critical role of FAF1 in antiviral responses against RNA virus infection.
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Affiliation(s)
- Jae-Hoon Kim
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Min-Eun Park
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Chamilani Nikapitiya
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Tae-Hwan Kim
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Md Bashir Uddin
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
- Faculty of Veterinary & Animal Science, Sylhet Agricultural University, Sylhet, Bangladesh
| | - Hyun-Cheol Lee
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Eunhee Kim
- College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, Korea
| | - Jin Yeul Ma
- Korean Medicine (KM)-Application Center, Korea Institute of Oriental Medicine (KIOM), Daegu, Republic of Korea
| | - Jae U. Jung
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, California, United States of America
| | - Chul-Joong Kim
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Jong-Soo Lee
- College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea
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113
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Ma Z, Hopcraft SE, Yang F, Petrucelli A, Guo H, Ting JPY, Dittmer DP, Damania B. NLRX1 negatively modulates type I IFN to facilitate KSHV reactivation from latency. PLoS Pathog 2017; 13:e1006350. [PMID: 28459883 PMCID: PMC5426799 DOI: 10.1371/journal.ppat.1006350] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 05/11/2017] [Accepted: 04/12/2017] [Indexed: 12/22/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is a herpesvirus that is linked to Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and multicentric Castleman's disease (MCD). KSHV establishes persistent latent infection in the human host. KSHV undergoes periods of spontaneous reactivation where it can enter the lytic replication phase of its lifecycle. During KSHV reactivation, host innate immune responses are activated to restrict viral replication. Here, we report that NLRX1, a negative regulator of the type I interferon response, is important for optimal KSHV reactivation from latency. Depletion of NLRX1 in either iSLK.219 or BCBL-1 cells significantly suppressed global viral transcription levels compared to the control group. Concomitantly, fewer viral particles were present in either cells or supernatant from NLRX1 depleted cells. Further analysis revealed that upon NLRX1 depletion, higher IFNβ transcription levels were observed, which was also associated with a transcriptional upregulation of JAK/STAT pathway related genes in both cell lines. To investigate whether IFNβ contributes to NLRX1's role in KSHV reactivation, we treated control and NLRX1 depleted cells with a TBK1 inhibitor (BX795) or TBK1 siRNA to block IFNβ production. Upon BX795 or TBK1 siRNA treatment, NLRX1 depletion exhibited less inhibitory effects on reactivation and infectious virion production, suggesting that NLRX1 facilitates KSHV lytic replication by negatively regulating IFNβ responses. Our data suggests that NLRX1 plays a positive role in KSHV lytic replication by suppressing the IFNβ response during the process of KSHV reactivation, which might serve as a potential target for restricting KSHV replication and transmission.
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Affiliation(s)
- Zhe Ma
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Sharon E. Hopcraft
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Fan Yang
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Alex Petrucelli
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Haitao Guo
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Jenny P-Y Ting
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Dirk P. Dittmer
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Sandstrom TS, Ranganath N, Angel JB. Impairment of the type I interferon response by HIV-1: Potential targets for HIV eradication. Cytokine Growth Factor Rev 2017; 37:1-16. [PMID: 28455216 DOI: 10.1016/j.cytogfr.2017.04.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 12/11/2022]
Abstract
By interfering with the type I interferon (IFN1) response, human immunodeficiency virus 1 (HIV-1) can circumvent host antiviral signalling and establish persistent viral reservoirs. HIV-1-mediated defects in the IFN pathway are numerous, and include the impairment of protein receptors involved in pathogen detection, downstream signalling cascades required for IFN1 upregulation, and expression or function of key IFN1-inducible, antiviral proteins. Despite this, the activation of IFN1-inducible, antiviral proteins has been shown to facilitate the killing of latently HIV-infected cells in vitro. Understanding how IFN1 signalling is blocked in physiologically-relevant models of HIV-1 infection, and whether these defects can be reversed, is therefore of great importance for the development of novel therapeutic strategies aimed at eradicating the HIV-1 reservoir.
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Affiliation(s)
- Teslin S Sandstrom
- Ottawa Hospital Research Institute, ORCC Room C4445, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.
| | - Nischal Ranganath
- Ottawa Hospital Research Institute, ORCC Room C4445, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.
| | - Jonathan B Angel
- Ottawa Hospital Research Institute, ORCC Room C4445, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada; Division of Infectious Diseases, Ottawa Hospital-General Campus, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada.
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115
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Shen Z, Rodriguez-Garcia M, Ochsenbauer C, Wira CR. Characterization of immune cells and infection by HIV in human ovarian tissues. Am J Reprod Immunol 2017; 78. [PMID: 28397318 DOI: 10.1111/aji.12687] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 03/20/2017] [Indexed: 01/02/2023] Open
Abstract
PROBLEM New HIV infections in women are predominantly spread through sexual intercourse. Recent non-human primate studies demonstrated that simian immunodeficiency virus (SIV) deposited in the vagina infected immune cells in the ovary. Whether immune cells in the human ovary are susceptible to HIV infection is unknown. METHOD OF STUDY Immune cells were isolated from ovaries and characterized by flow cytometry. Cells were exposed to HIV for 2 hours. HIV infection was measured by flow cytometry and p24 secretion following 6 days in culture. RESULTS CD4+ T cells and CD14+ cells are present in the ovary and susceptible to infection by HIV-BaL. Among the CD45+ cells present, 30% were CD3+ T cells (with similar proportions of CD4+ or CD8+ T cells), and 7%-10% were CD14+ cells. Both CD4+ T cells and CD14+ cells were productively infected and supported replication. CONCLUSION Immune cells in the ovary are potential targets for HIV infection.
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Affiliation(s)
- Zheng Shen
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Marta Rodriguez-Garcia
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Christina Ochsenbauer
- Department of Medicine and UAB Center for AIDS Research, University of Alabama, Birmingham, AL, USA
| | - Charles R Wira
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
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116
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Chen Y, Wang L, Jin J, Luan Y, Chen C, Li Y, Chu H, Wang X, Liao G, Yu Y, Teng H, Wang Y, Pan W, Fang L, Liao L, Jiang Z, Ge X, Li B, Wang P. p38 inhibition provides anti-DNA virus immunity by regulation of USP21 phosphorylation and STING activation. J Exp Med 2017; 214:991-1010. [PMID: 28254948 PMCID: PMC5379979 DOI: 10.1084/jem.20161387] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/05/2016] [Accepted: 12/29/2016] [Indexed: 01/09/2023] Open
Abstract
Chen et al. show that USP21 is a deubiquitinating enzyme for the adaptor protein STING and that it negatively regulates the DNA virus–induced production of type I interferons. HSV-1 infection recruited USP21 to STING at a late stage by p38-mediated phosphorylation of USP21 at Ser538. Stimulator of IFN genes (STING) is a central adaptor protein that mediates the innate immune responses to DNA virus infection. Although ubiquitination is essential for STING function, how the ubiquitination/deubiquitination system is regulated by virus infection to control STING activity remains unknown. In this study, we found that USP21 is an important deubiquitinating enzyme for STING and that it negatively regulates the DNA virus–induced production of type I interferons by hydrolyzing K27/63-linked polyubiquitin chain on STING. HSV-1 infection recruited USP21 to STING at late stage by p38-mediated phosphorylation of USP21 at Ser538. Inhibition of p38 MAPK enhanced the production of IFNs in response to virus infection and protected mice from lethal HSV-1 infection. Thus, our study reveals a critical role of p38-mediated USP21 phosphorylation in regulating STING-mediated antiviral functions and identifies p38-USP21 axis as an important pathway that DNA virus adopts to avoid innate immunity responses.
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Affiliation(s)
- Yunfei Chen
- Department of Central Laboratory, School of Life Science and Technology, Shanghai Tenth People's Hospital of Tongji University, Tongji University, Shanghai 200072, China
| | - Lufan Wang
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Jiali Jin
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Yi Luan
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Cong Chen
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Yu Li
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Hongshang Chu
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Xinbo Wang
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Guanghong Liao
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Yue Yu
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Hongqi Teng
- Department of Central Laboratory, School of Life Science and Technology, Shanghai Tenth People's Hospital of Tongji University, Tongji University, Shanghai 200072, China
| | - Yanming Wang
- Department of Central Laboratory, School of Life Science and Technology, Shanghai Tenth People's Hospital of Tongji University, Tongji University, Shanghai 200072, China
| | - Weijuan Pan
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Lan Fang
- Department of Central Laboratory, School of Life Science and Technology, Shanghai Tenth People's Hospital of Tongji University, Tongji University, Shanghai 200072, China
| | - Lujian Liao
- Shanghai Key Laboratory of Regulatory Biology, East China Normal University, Shanghai 200241, China
| | - Zhengfan Jiang
- State Key Laboratory of Protein and Plant Gene Research, Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100000, China.,Peking University-Tsinghua University Joint Center for Life Sciences, Beijing 100084, China
| | - Xin Ge
- Department of Clinical Laboratory Medicine, Shanghai Tenth People's Hospital of Tongji University, Tongji University, Shanghai 200072, China
| | - Bin Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai 200025, China
| | - Ping Wang
- Department of Central Laboratory, School of Life Science and Technology, Shanghai Tenth People's Hospital of Tongji University, Tongji University, Shanghai 200072, China
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117
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Song S, Peng P, Tang Z, Zhao J, Wu W, Li H, Shao M, Li L, Yang C, Duan F, Zhang M, Zhang J, Wu H, Li C, Wang X, Wang H, Ruan Y, Gu J. Decreased expression of STING predicts poor prognosis in patients with gastric cancer. Sci Rep 2017; 7:39858. [PMID: 28176788 PMCID: PMC5296877 DOI: 10.1038/srep39858] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/28/2016] [Indexed: 12/18/2022] Open
Abstract
STING (stimulator of interferon genes) has recently been found to play an important role in host defenses against virus and intracellular bacteria via the regulation of type-I IFN signaling and innate immunity. Chronic infection with Helicobacter pylori is identified as the strongest risk factor for gastric cancer. Thus, we aim to explore the function of STING signaling in the development of gastric cancer. Immunohistochemistry was used to detect STING expression in 217 gastric cancer patients who underwent surgical resection. STING protein expression was remarkably decreased in tumor tissues compared to non-tumor tissues, and low STING staining intensity was positively correlated with tumor size, tumor invasion depth, lymph mode metastasis, TNM stage, and reduced patients’ survival. Multivariate analysis identified STING as an independent prognostic factor, which could improve the predictive accuracy for overall survival when incorporated into TNM staging system. In vitro studies revealed that knock-down of STING promoted colony formation, viability, migration and invasion of gastric cancer cells, and also led to a defect in cytosolic DNA sensing. Besides, chronic H. pylori infection up-regulated STING expression and activated STING signaling in mice. In conclusion, STING was proposed as a novel independent prognostic factor and potential immunotherapeutic target for gastric cancer.
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Affiliation(s)
- Shushu Song
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Peike Peng
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Zhaoqing Tang
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Junjie Zhao
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Weicheng Wu
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Haojie Li
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Miaomiao Shao
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Lili Li
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Caiting Yang
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Fangfang Duan
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, P.R. China
| | - Mingming Zhang
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Jie Zhang
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, P.R. China
| | - Hao Wu
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Can Li
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Xuefei Wang
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Hongshan Wang
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Yuanyuan Ruan
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China
| | - Jianxin Gu
- Key Laboratory of Glycoconjugate Research Ministry of Public Health, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, P.R. China.,Institutes of Biomedical Sciences, Fudan University, Shanghai, P.R. China
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118
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Leber A, Hontecillas R, Tubau-Juni N, Zoccoli-Rodriguez V, Hulver M, McMillan R, Eden K, Allen IC, Bassaganya-Riera J. NLRX1 Regulates Effector and Metabolic Functions of CD4 + T Cells. THE JOURNAL OF IMMUNOLOGY 2017; 198:2260-2268. [PMID: 28159898 DOI: 10.4049/jimmunol.1601547] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 01/12/2017] [Indexed: 12/15/2022]
Abstract
Nucleotide oligomerization domain-like receptor X1 (NLRX1) has been implicated in viral response, cancer progression, and inflammatory disorders; however, its role as a dual modulator of CD4+ T cell function and metabolism has not been defined. The loss of NLRX1 results in increased disease severity, populations of Th1 and Th17 cells, and inflammatory markers (IFN-γ, TNF-α, and IL-17) in mice with dextran sodium sulfate-induced colitis. To further characterize this phenotype, we used in vitro CD4+ T cell-differentiation assays and show that NLRX1-deficient T cells have a greater ability to differentiate into an inflammatory phenotype and possess greater proliferation rates. Further, NLRX1-/- cells have a decreased responsiveness to immune checkpoint pathways and greater rates of lactate dehydrogenase activity. When metabolic effects of the knockout are impaired, NLRX1-deficient cells do not display significant differences in differentiation or proliferation. To confirm the role of NLRX1 specifically in T cells, we used an adoptive-transfer model of colitis. Rag2-/- mice receiving NLRX1-/- naive or effector T cells experienced increased disease activity and effector T cell populations, whereas no differences were observed between groups receiving wild-type or NLRX1-/- regulatory T cells. Metabolic effects of NLRX1 deficiency are observed in a CD4-specific knockout of NLRX1 within a Citrobacter rodentium model of colitis. The aerobic glycolytic preference in NLRX1-/- effector T cells is combined with a decreased sensitivity to immunosuppressive checkpoint pathways to provide greater proliferative capabilities and an inflammatory phenotype bias leading to increased disease severity.
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Affiliation(s)
- Andrew Leber
- Nutritional Immunology and Molecular Medicine Laboratory, Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061
| | - Raquel Hontecillas
- Nutritional Immunology and Molecular Medicine Laboratory, Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061
| | - Nuria Tubau-Juni
- Nutritional Immunology and Molecular Medicine Laboratory, Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061
| | - Victoria Zoccoli-Rodriguez
- Nutritional Immunology and Molecular Medicine Laboratory, Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061
| | - Matthew Hulver
- Metabolic Phenotyping Core, Virginia Tech, Blacksburg, VA 24061.,Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061; and
| | - Ryan McMillan
- Metabolic Phenotyping Core, Virginia Tech, Blacksburg, VA 24061.,Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061; and
| | - Kristin Eden
- Nutritional Immunology and Molecular Medicine Laboratory, Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061.,Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061
| | - Irving C Allen
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061
| | - Josep Bassaganya-Riera
- Nutritional Immunology and Molecular Medicine Laboratory, Biocomplexity Institute of Virginia Tech, Blacksburg, VA 24061;
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120
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Schott K, Riess M, König R. Role of Innate Genes in HIV Replication. Curr Top Microbiol Immunol 2017; 419:69-111. [PMID: 28685292 DOI: 10.1007/82_2017_29] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cells use an elaborate innate immune surveillance and defense system against virus infections. Here, we discuss recent studies that reveal how HIV-1 is sensed by the innate immune system. Furthermore, we present mechanisms on the counteraction of HIV-1. We will provide an overview how HIV-1 actively utilizes host cellular factors to avoid sensing. Additionally, we will summarize effectors of the innate response that provide an antiviral cellular state. HIV-1 has evolved passive mechanism to avoid restriction and to regulate the innate response. We review in detail two prominent examples of these cellular factors: (i) NLRX1, a negative regulator of the innate response that HIV-1 actively usurps to block cytosolic innate sensing; (ii) SAMHD1, a restriction factor blocking the virus at the reverse transcription step that HIV-1 passively avoids to escape sensing.
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Affiliation(s)
- Kerstin Schott
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany
| | - Maximilian Riess
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany. .,Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA. .,German Center for Infection Research (DZIF), 63225, Langen, Germany.
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121
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Kong X, Yuan Z, Cheng J. The function of NOD-like receptors in central nervous system diseases. J Neurosci Res 2016; 95:1565-1573. [PMID: 28029680 DOI: 10.1002/jnr.24004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 11/11/2016] [Accepted: 11/28/2016] [Indexed: 12/17/2022]
Abstract
NOD-like receptors (NLRs) are critical cytoplasmic pattern-recognition receptors (PRRs) that play an important role in the host innate immune response and immunity homeostasis. There is a growing body of evidence that NLRs are involved in a wide range of inflammatory diseases, including cancer, metabolic diseases, and autoimmune disorders. Recent studies have indicated that the proteins of the NLR family are linked with the pathophysiology of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), and psychological diseases. In this review, we mainly focus on the role of NLRs and the underlying signaling pathways in central nervous system (CNS) diseases. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiangxi Kong
- The State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,School of Basic Medical Science, Lanzhou University, Lanzhou, 730000, Gansu Province, China
| | - Zengqiang Yuan
- The State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, 100069, China
| | - Jinbo Cheng
- The State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, 100069, China
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122
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The first 24 h: targeting the window of opportunity for antibody-mediated protection against HIV-1 transmission. Curr Opin HIV AIDS 2016; 11:561-568. [PMID: 27559708 DOI: 10.1097/coh.0000000000000319] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE OF REVIEW I will review evidence that antibodies protect against HIV-1 transmission in a short window of opportunity, involving neutralization, Fc-mediated effector function, or both. RECENT FINDINGS The last decade witnessed a dramatic progress in the understanding of antibody-mediated protection against HIV-1, including active and passive immunization studies in nonhuman primates; association between reduced infection risk and the specificities and function of antibodies in the RV144 clinical trial; identification of potent, broadly neutralizing antibodies; high-resolution structural studies of the HIV-1 envelope trimer; and an increasing appreciation that Fc-mediated effector function is critical to protection against transmission for neutralizing and nonneutralizing antibodies. Less information is known about how antibodies protect in situ, except that they must do in the first 24 h after exposure. New evidence suggests that antibodies protect in an acute innate immune environment involving the NXLRX1 inflammasome and transforming growth factor beta (TGF-β) that favors infection and rapid dissemination of CCR6RORγ Th17 cells. SUMMARY These recent findings set the stage for understanding how antibodies can prevent the transmission of HIV-1. In this context, antibodies must prevent infection in an innate immune environment that strongly favors transmission. This information is key for the development of a vaccine against HIV-1.
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123
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Mitochondria as Molecular Platforms Integrating Multiple Innate Immune Signalings. J Mol Biol 2016; 429:1-13. [PMID: 27923767 DOI: 10.1016/j.jmb.2016.10.028] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/20/2016] [Accepted: 10/23/2016] [Indexed: 12/14/2022]
Abstract
The immune system of vertebrates confers protective mechanisms to the host through the sensing of stress-induced agents expressed during infection or cell stress. Among them, the first line of host defense composed of the innate immune sensing of these agents by pattern recognition receptors enables downstream adaptive immunity to be primed, mediating the body's appropriate response to clear infection and tissue damage. Mitochondria are «bacteria within» that allowed the emergence of functional eukaryotic cells by positioning themselves as the cell powerhouse and an initiator of cell death programs. It is striking to consider that such ancestral bacteria, which had to evade host defense at some point to develop evolutionary endosymbiosis, have become instrumental for the modern eukaryotic cell in alerting the immune system against various insults including infection by other pathogens. Mitochondria have indeed become critical regulators of innate immune responses to both pathogens and cell stress. They host numerous modulators, which play a direct role into the assembly of innate sensing machineries that trigger host immune response in both sterile and non-sterile conditions. Several lines of evidence indicate the existence of a complex molecular interplay between mechanisms involved in inflammation and metabolism. Mitochondrial function seems to participate in innate immunity at various stages as diverse as the transcriptional regulation of inflammatory cytokines and chemokines and their maturation by inflammasomes. Here, we review the mechanisms by which mitochondria orchestrate innate immune responses at different levels by promoting a cellular metabolic reprogramming and the cytosolic immune signaling cascades.
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124
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Tao J, Zhou X, Jiang Z. cGAS-cGAMP-STING: The three musketeers of cytosolic DNA sensing and signaling. IUBMB Life 2016; 68:858-870. [PMID: 27706894 DOI: 10.1002/iub.1566] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 09/11/2016] [Indexed: 12/19/2022]
Abstract
Innate immunity is the first line of host defense against invading pathogens. The detection of aberrant nucleic acids which represent some conserved PAMPs triggers robust type I IFN-mediated innate immune responses. Host- or pathogen-derived cytosolic DNA binds and activates the DNA sensor cGAS, which synthesizes the second messenger 2'3'-cGAMP and triggers STING-dependent downstream signaling. Here, we highlight recent progress in cGAS-cGAMP-STING, the Three Musketeers of cytosolic DNA sensing and signaling, and their essential roles in infection, autoimmune diseases, and cancer. We also focus on the regulation of these critical signal components by variant host/pathogen proteins and update our understanding of this indispensable pathway to provide new insights for drug discovery. © 2016 IUBMB Life, 68(11):858-870, 2016.
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Affiliation(s)
- Jianli Tao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Xiang Zhou
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Zhengfan Jiang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China. .,Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing, China. .,Peking-Tsinghua Center for Life Sciences, Beijing, China.
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125
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Abstract
Immune evasion by HIV-1 during acute infection is critical for the establishment of latency. Barouch et al. (2016) and Guo et al. (2016) demonstrate in independent studies that Nod-like receptor X1 (NLRX1) may facilitate early systemic dissemination of HIV-1 by inhibiting the virus-triggered innate immune response.
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Affiliation(s)
- Katrina B Mar
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - John W Schoggins
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA.
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126
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Tomalka J, Ghneim K, Bhattacharyya S, Aid M, Barouch DH, Sekaly RP, Ribeiro SP. The sooner the better: innate immunity as a path toward the HIV cure. Curr Opin Virol 2016; 19:85-91. [PMID: 27497036 DOI: 10.1016/j.coviro.2016.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 07/04/2016] [Indexed: 02/07/2023]
Abstract
To combat the diverse pathogens that infect humans, the immune system has evolved complex and diverse transcriptional signatures, which drive differential cellular and humoral responses. These signatures are induced by immune receptor sensing of pathogens and by cytokines produced at the earliest onset of infection. The specific nature of immune activation is as critical to pathogen clearance as the induction of an adaptive immune response. This is particularly true for HIV, which has developed numerous immune evasion mechanisms. In this review, we will highlight recent findings that show the differential role for early innate immune responses in promoting infection versus clearance and demonstrate the need for continued research on these pathways for development of effective HIV treatments.
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Affiliation(s)
- Jeffrey Tomalka
- Case Western Reserve University, Department of Pathology, Cleveland, OH, USA
| | - Khader Ghneim
- Case Western Reserve University, Department of Pathology, Cleveland, OH, USA
| | | | - Malika Aid
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Dan H Barouch
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Ragon Institute of MGH, MIT and Harvard, Boston, MA, USA
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127
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The expanding regulatory network of STING-mediated signaling. Curr Opin Microbiol 2016; 32:144-150. [PMID: 27414485 PMCID: PMC4983512 DOI: 10.1016/j.mib.2016.05.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 05/20/2016] [Indexed: 01/07/2023]
Abstract
The identification and characterization of DNA-sensing pathways has been a subject of intensive investigation for the last decade. This interest, in part, is supported by the fact that the main outcome of DNA-responses is production of type I interferon (IFN-I), which, if produced in excessive amounts, leads to various pathologies. STING (stimulator of interferon genes) is positioned in the center of these responses and is activated either via direct sensing of second messengers or via interaction with upstream sensors of dsDNA. STING mediates responses to pathogens as well as host-derived DNA and is, therefore, linked to various autoimmune diseases, cancer predisposition and ageing. Recent mouse models of DNA damage showed the adaptor STING to be crucial for heightened resting levels of IFN-I. In this review, we will focus on recent advances in understanding the regulation of STING-signaling and identification of its novel components.
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Dempsey LA. NLRX1 negatively regulates STING. Nat Immunol 2016. [DOI: 10.1038/ni.3472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Barouch DH, Ghneim K, Bosche WJ, Li Y, Berkemeier B, Hull M, Bhattacharyya S, Cameron M, Liu J, Smith K, Borducchi E, Cabral C, Peter L, Brinkman A, Shetty M, Li H, Gittens C, Baker C, Wagner W, Lewis MG, Colantonio A, Kang HJ, Li W, Lifson JD, Piatak M, Sekaly RP. Rapid Inflammasome Activation following Mucosal SIV Infection of Rhesus Monkeys. Cell 2016; 165:656-67. [PMID: 27085913 PMCID: PMC4842119 DOI: 10.1016/j.cell.2016.03.021] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/31/2016] [Accepted: 03/14/2016] [Indexed: 01/10/2023]
Abstract
The earliest events following mucosal HIV-1 infection, prior to measurable viremia, remain poorly understood. Here, by detailed necropsy studies, we show that the virus can rapidly disseminate following mucosal SIV infection of rhesus monkeys and trigger components of the inflammasome, both at the site of inoculation and at early sites of distal virus spread. By 24 hr following inoculation, a proinflammatory signature that lacked antiviral restriction factors was observed in viral RNA-positive tissues. The early innate response included expression of NLRX1, which inhibits antiviral responses, and activation of the TGF-β pathway, which negatively regulates adaptive immune responses. These data suggest a model in which the virus triggers specific host mechanisms that suppress the generation of antiviral innate and adaptive immune responses in the first few days of infection, thus facilitating its own replication. These findings have important implications for the development of vaccines and other strategies to prevent infection.
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Affiliation(s)
- Dan H Barouch
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA.
| | - Khader Ghneim
- Case Western Reserve University, Cleveland, OH 44106, USA
| | - William J Bosche
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Yuan Li
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Brian Berkemeier
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Michael Hull
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | | | - Mark Cameron
- Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jinyan Liu
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Kaitlin Smith
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Erica Borducchi
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Crystal Cabral
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Lauren Peter
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Amanda Brinkman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Mayuri Shetty
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Hualin Li
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | | | | | | | | | | | - Hyung-Joo Kang
- University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Wenjun Li
- University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Michael Piatak
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
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