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Sun X, Huang X, Park KS, Zhou X, Kennedy AA, Pretto CD, Wu Q, Wan Z, Xu Y, Gong W, Sexton JZ, Tai AW, Lei YL, Moon JJ. Self-Assembled STING-Activating Coordination Nanoparticles for Cancer Immunotherapy and Vaccine Applications. ACS Nano 2024; 18:10439-10453. [PMID: 38567994 PMCID: PMC11031738 DOI: 10.1021/acsnano.3c11374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
The cGAS-STING pathway plays a crucial role in innate immune activation against cancer and infections, and STING agonists based on cyclic dinucleotides (CDN) have garnered attention for their potential use in cancer immunotherapy and vaccines. However, the limited drug-like properties of CDN necessitate an efficient delivery system to the immune system. To address these challenges, we developed an immunostimulatory delivery system for STING agonists. Here, we have examined aqueous coordination interactions between CDN and metal ions and report that CDN mixed with Zn2+ and Mn2+ formed distinctive crystal structures. Further pharmaceutical engineering led to the development of a functional coordination nanoparticle, termed the Zinc-Mn-CDN Particle (ZMCP), produced by a simple aqueous one-pot synthesis. Local or systemic administration of ZMCP exerted robust antitumor efficacy in mice. Importantly, recombinant protein antigens from SARS-CoV-2 can be simply loaded during the aqueous one-pot synthesis. The resulting ZMCP antigens elicited strong cellular and humoral immune responses that neutralized SARS-CoV-2, highlighting ZMCP as a self-adjuvant vaccine platform against COVID-19 and other infectious pathogens. Overall, this work establishes a paradigm for developing translational coordination nanomedicine based on drug-metal ion coordination and broadens the applicability of coordination medicine for the delivery of proteins and other biologics.
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Affiliation(s)
- Xiaoqi Sun
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xuehui Huang
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kyung Soo Park
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xingwu Zhou
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Andrew A Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Carla D Pretto
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Qi Wu
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ziye Wan
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yao Xu
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Wang Gong
- Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Cancer Biology at the University of Texas M.D. Anderson Cancer Center, Houston, Texas, 77030, United States
| | - Jonathan Z Sexton
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Andrew W Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Yu Leo Lei
- Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Otolaryngology─Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan 48109, United States
- Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Head and Neck Surgery, Department of Cancer Biology, Department of Translational Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, United States
| | - James J Moon
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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2
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Zhang J, Kennedy A, de Melo Jorge DM, Xing L, Reid W, Bui S, Joppich J, Rose M, Ercan S, Tang Q, Tai AW, Wang Y. SARS-CoV-2 remodels the Golgi apparatus to facilitate viral assembly and secretion. bioRxiv 2024:2022.03.04.483074. [PMID: 35291301 PMCID: PMC8923104 DOI: 10.1101/2022.03.04.483074] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The COVID-19 pandemic is caused by SARS-CoV-2, an enveloped RNA virus. Despite extensive investigation, the molecular mechanisms for its assembly and secretion remain largely elusive. Here, we show that SARS-CoV-2 infection induces global alterations of the host endomembrane system, including dramatic Golgi fragmentation. SARS-CoV-2 virions are enriched in the fragmented Golgi. Disrupting Golgi function with small molecules strongly inhibits viral infection. Significantly, SARS-CoV-2 infection down-regulates GRASP55 but up-regulates TGN46 protein levels. Surprisingly, GRASP55 expression reduces both viral secretion and spike number on each virion, while GRASP55 depletion displays opposite effects. In contrast, TGN46 depletion only inhibits viral secretion without affecting spike incorporation into virions. TGN46 depletion and GRASP55 expression additively inhibit viral secretion, indicating that they act at different stages. Taken together, we show that SARS-CoV-2 alters Golgi structure and function to control viral assembly and secretion, highlighting the Golgi as a potential therapeutic target for blocking SARS-CoV-2 infection.
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3
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Bragazzi Cunha J, Leix K, Sherman EJ, Mirabelli C, Frum T, Zhang CJ, Kennedy AA, Lauring AS, Tai AW, Sexton JZ, Spence JR, Wobus CE, Emmer BT. Type I interferon signaling induces a delayed antiproliferative response in respiratory epithelial cells during SARS-CoV-2 infection. J Virol 2023; 97:e0127623. [PMID: 37975674 PMCID: PMC10734423 DOI: 10.1128/jvi.01276-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/22/2023] [Indexed: 11/19/2023] Open
Abstract
ABSTRACT Disease progression during SARS-CoV-2 infection is tightly linked to the fate of lung epithelial cells, with severe cases of COVID-19 characterized by direct injury of the alveolar epithelium and an impairment in its regeneration from progenitor cells. The molecular pathways that govern respiratory epithelial cell death and proliferation during SARS-CoV-2 infection, however, remain unclear. We now report a high-throughput CRISPR screen for host genetic modifiers of the survival and proliferation of SARS-CoV-2-infected Calu-3 respiratory epithelial cells. The top four genes identified in our screen encode components of the same type I interferon (IFN-I) signaling complex—IFNAR1, IFNAR2, JAK1, and TYK2. The fifth gene, ACE2, was an expected control encoding the SARS-CoV-2 viral receptor. Surprisingly, despite the antiviral properties of IFN-I signaling, its disruption in our screen was associated with an increase in Calu-3 cell fitness. We validated this effect and found that IFN-I signaling did not sensitize SARS-CoV-2-infected cultures to cell death but rather inhibited the proliferation of surviving cells after the early peak of viral replication and cytopathic effect. We also found that IFN-I signaling alone, in the absence of viral infection, was sufficient to induce this delayed antiproliferative response in both Calu-3 cells and iPSC-derived type 2 alveolar epithelial cells. Together, these findings highlight a cell autonomous antiproliferative response by respiratory epithelial cells to persistent IFN-I signaling during SARS-CoV-2 infection. This response may contribute to the deficient alveolar regeneration that has been associated with COVID-19 lung injury and represents a promising area for host-targeted therapeutic development.
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Affiliation(s)
- Juliana Bragazzi Cunha
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Kyle Leix
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Emily J. Sherman
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Carmen Mirabelli
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Tristan Frum
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Charles J. Zhang
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, USA
| | - Andrew A. Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Adam S. Lauring
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Andrew W. Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan, USA
| | - Jonathan Z. Sexton
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, USA
| | - Jason R. Spence
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan, USA
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Brian T. Emmer
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Tai AW, Sewell JL. How to Effectively Engage With Preclinical Medical Learners. Gastroenterology 2023; 165:529-533. [PMID: 37209950 DOI: 10.1053/j.gastro.2023.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023]
Affiliation(s)
- Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan; Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan; Medicine Service, Ann Arbor Veterans Administration Health System, Ann Arbor, Michigan.
| | - Justin L Sewell
- Division of Gastroenterology, Department of Internal Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California; University of California San Francisco School of Medicine, San Francisco, California.
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5
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Williams JM, Chen YJ, Cho WJ, Tai AW, Tsai B. Reticulons promote formation of ER-derived double-membrane vesicles that facilitate SARS-CoV-2 replication. J Cell Biol 2023; 222:e202203060. [PMID: 37093123 PMCID: PMC10130743 DOI: 10.1083/jcb.202203060] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 08/24/2022] [Accepted: 04/06/2023] [Indexed: 04/25/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiologic agent for the global COVID-19 pandemic, triggers the formation of endoplasmic reticulum (ER)-derived replication organelles, including double-membrane vesicles (DMVs), in the host cell to support viral replication. Here, we clarify how SARS-CoV-2 hijacks host factors to construct the DMVs. We show that the ER morphogenic proteins reticulon-3 (RTN3) and RTN4 help drive DMV formation, enabling viral replication, which leads to productive infection. Different SARS-CoV-2 variants, including the delta variant, use the RTN-dependent pathway to promote infection. Mechanistically, our results reveal that the membrane-embedded reticulon homology domain (RHD) of the RTNs is sufficient to functionally support viral replication and physically engage NSP3 and NSP4, two viral non-structural membrane proteins known to induce DMV formation. Our findings thus identify the ER morphogenic RTN3 and RTN4 membrane proteins as host factors that help promote the biogenesis of SARS-CoV-2-induced DMVs, which can act as viral replication platforms.
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Affiliation(s)
- Jeffrey M. Williams
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Yu-Jie Chen
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Woo Jung Cho
- Biomedical Research Core Facilities, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Andrew W. Tai
- Department of Internal Medicine and Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
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6
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Xu C, Dobson HE, Yu M, Gong W, Sun X, Park KS, Kennedy A, Zhou X, Xu J, Xu Y, Tai AW, Lei YL, Moon JJ. STING agonist-loaded mesoporous manganese-silica nanoparticles for vaccine applications. J Control Release 2023; 357:84-93. [PMID: 36948420 PMCID: PMC10164691 DOI: 10.1016/j.jconrel.2023.03.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/25/2023] [Accepted: 03/19/2023] [Indexed: 03/24/2023]
Abstract
Cyclic dinucleotides (CDNs), as one type of Stimulator of Interferon Genes (STING) pathway agonist, have shown promising results for eliciting immune responses against cancer and viral infection. However, the suboptimal drug-like properties of conventional CDNs, including their short in vivo half-life and poor cellular permeability, compromise their therapeutic efficacy. In this study, we have developed a manganese-silica nanoplatform (MnOx@HMSN) that enhances the adjuvant effects of CDN by achieving synergy with Mn2+ for vaccination against cancer and SARS-CoV-2. MnOx@HMSN with large mesopores were efficiently co-loaded with CDN and peptide/protein antigens. MnOx@HMSN(CDA) amplified the activation of the STING pathway and enhanced the production of type-I interferons and other proinflammatory cytokines from dendritic cells. MnOx@HMSN(CDA) carrying cancer neoantigens elicited robust antitumor T-cell immunity with therapeutic efficacy in two different murine tumor models. Furthermore, MnOx@HMSN(CDA) loaded with SARS-CoV-2 antigen achieved strong and durable (up to one year) humoral immune responses with neutralizing capability. These results demonstrate that MnOx@HMSN(CDA) is a versatile nanoplatform for vaccine applications.
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Affiliation(s)
- Cheng Xu
- Department of Pharmaceutical Science, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hannah E Dobson
- Department of Pharmaceutical Science, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mengjie Yu
- Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Wang Gong
- Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Xiaoqi Sun
- Department of Pharmaceutical Science, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kyung Soo Park
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Andrew Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Xingwu Zhou
- Department of Pharmaceutical Science, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jin Xu
- Department of Pharmaceutical Science, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yao Xu
- Department of Pharmaceutical Science, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Andrew W Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Yu Leo Lei
- Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, MI, USA; Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI, USA
| | - James J Moon
- Department of Pharmaceutical Science, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI, USA; Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA.
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7
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Cunha JB, Leix K, Sherman EJ, Mirabelli C, Kennedy AA, Lauring AS, Tai AW, Wobus CE, Emmer BT. Type I interferon signaling induces a delayed antiproliferative response in Calu-3 cells during SARS-CoV-2 infection. bioRxiv 2023:2023.02.28.530557. [PMID: 36909579 PMCID: PMC10002732 DOI: 10.1101/2023.02.28.530557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Disease progression during SARS-CoV-2 infection is tightly linked to the fate of lung epithelial cells, with severe cases of COVID-19 characterized by direct injury of the alveolar epithelium and an impairment in its regeneration from progenitor cells. The molecular pathways that govern respiratory epithelial cell death and proliferation during SARS-CoV-2 infection, however, remain poorly understood. We now report a high-throughput CRISPR screen for host genetic modifiers of the survival and proliferation of SARS-CoV-2-infected Calu-3 respiratory epithelial cells. The top 4 genes identified in our screen encode components of the same type I interferon signaling complex - IFNAR1, IFNAR2, JAK1, and TYK2. The 5th gene, ACE2, was an expected control encoding the SARS-CoV-2 viral receptor. Surprisingly, despite the antiviral properties of IFN-I signaling, its disruption in our screen was associated with an increase in Calu-3 cell fitness. We validated this effect and found that IFN-I signaling did not sensitize SARS-CoV-2-infected cultures to cell death but rather inhibited the proliferation of surviving cells after the early peak of viral replication and cytopathic effect. We also found that IFN-I signaling alone, in the absence of viral infection, was sufficient to induce this delayed antiproliferative response. Together, these findings highlight a cell autonomous antiproliferative response by respiratory epithelial cells to persistent IFN-I signaling during SARS-CoV-2 infection. This response may contribute to the deficient alveolar regeneration that has been associated with COVID-19 lung injury and represents a promising area for host-targeted therapeutic development.
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Affiliation(s)
| | - Kyle Leix
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
| | - Emily J. Sherman
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
| | - Carmen Mirabelli
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
| | - Andrew A. Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
| | - Adam S. Lauring
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
| | - Andrew W. Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
- VA Ann Arbor Healthcare System, Ann Arbor MI
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
| | - Brian T. Emmer
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
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8
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Bagchi P, Speckhart K, Kennedy A, Tai AW, Tsai B. A specific EMC subunit supports Dengue virus infection by promoting virus membrane fusion essential for cytosolic genome delivery. PLoS Pathog 2022; 18:e1010717. [PMID: 35834589 PMCID: PMC9321775 DOI: 10.1371/journal.ppat.1010717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 07/26/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Dengue virus (DENV) represents the most common human arboviral infection, yet its cellular entry mechanism remains unclear. The multi-subunit endoplasmic reticulum membrane complex (EMC) supports DENV infection, in part, by assisting the biosynthesis of viral proteins critical for downstream replication steps. Intriguingly, the EMC has also been shown to act at an earlier step prior to viral protein biogenesis, although this event is not well-defined. Here we demonstrate that the EMC subunit EMC4 promotes fusion of the DENV and endosomal membranes during entry, enabling delivery of the viral genome into the cytosol which is then targeted to the ER for viral protein biosynthesis. We also found that EMC4 mediates ER-to-endosome transfer of phosphatidylserine, a phospholipid whose presence in the endosome facilitates DENV-endosomal membrane fusion. These findings clarify the EMC-dependent DENV early entry step, suggesting a mechanism by which an ER-localized host factor can regulate viral fusion at the endosome.
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Affiliation(s)
- Parikshit Bagchi
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Kaitlyn Speckhart
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Andrew Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Andrew W. Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
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9
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Sherman EJ, Mirabelli C, Tang VT, Khan TG, Leix K, Kennedy AA, Graham SE, Willer CJ, Tai AW, Sexton JZ, Wobus CE, Emmer BT. Identification of cell type specific ACE2 modifiers by CRISPR screening. PLoS Pathog 2022; 18:e1010377. [PMID: 35231079 PMCID: PMC8929698 DOI: 10.1371/journal.ppat.1010377] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 03/17/2022] [Accepted: 02/15/2022] [Indexed: 12/26/2022] Open
Abstract
SARS-CoV-2 infection is initiated by binding of the viral spike protein to its receptor, ACE2, on the surface of host cells. ACE2 expression is heterogeneous both in vivo and in immortalized cell lines, but the molecular pathways that govern ACE2 expression remain unclear. We now report high-throughput CRISPR screens for functional modifiers of ACE2 surface abundance. In liver-derived HuH7 cells, we identified 35 genes whose disruption was associated with a change in the surface abundance of ACE2. Enriched among these ACE2 regulators were established transcription factors, epigenetic regulators, and functional networks. We further characterized individual HuH7 cell lines with disruption of SMAD4, EP300, PIAS1, or BAMBI and found these genes to regulate ACE2 at the mRNA level and to influence cellular susceptibility to SARS-CoV-2 infection. Orthogonal screening of lung-derived Calu-3 cells revealed a distinct set of ACE2 modifiers comprised of ACE2, KDM6A, MOGS, GPAA1, and UGP2. Collectively, our findings clarify the host factors involved in SARS-CoV-2 entry, highlight the cell type specificity of ACE2 regulatory networks, and suggest potential targets for therapeutic development. The amount of ACE2 on the surface of human cells is an important determinant of SARS-CoV-2 infection, but the molecular pathways that regulate ACE2 remain poorly understood. Identification of these pathways may clarify host factors involved in COVID-19 outcomes and offer targets for therapeutic development. ACE2-targeted therapies may furthermore be less susceptible than viral spike-targeted therapies to evasion by SARS-CoV-2 variants. To systematically identify regulators of human ACE2, we therefore performed high-throughput CRISPR screening for modifiers of ACE2 surface abundance in HuH7 liver-derived and Calu-3 lung-derived cell lines. Unexpectedly, aside from ACE2 itself, we identified distinct sets of ACE2 modifiers in either cell line. For a subset of ACE2 regulators, we validated their functional effect on ACE2, confirmed their relevance to SARS-CoV-2 infection, and clarified their level of regulation. Our findings demonstrate the important influence of cell type on investigations of SARS-CoV-2 infection and nominate candidate pathways for ACE2-targeted therapeutic development.
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Affiliation(s)
- Emily J. Sherman
- Department of Internal Medicine, Division of Hospital Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Carmen Mirabelli
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Vi T. Tang
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Taslima G. Khan
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Chemical Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Kyle Leix
- Department of Internal Medicine, Division of Hospital Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew A. Kennedy
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sarah E. Graham
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Cristen J. Willer
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew W. Tai
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan, United States of America
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan, United States of America
| | - Jonathan Z. Sexton
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Brian T. Emmer
- Department of Internal Medicine, Division of Hospital Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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10
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Zafferani M, Haddad C, Luo L, Davila-Calderon J, Chiu LY, Mugisha CS, Monaghan AG, Kennedy AA, Yesselman JD, Gifford RJ, Tai AW, Kutluay SB, Li ML, Brewer G, Tolbert BS, Hargrove AE. Amilorides inhibit SARS-CoV-2 replication in vitro by targeting RNA structures. Sci Adv 2021; 7:eabl6096. [PMID: 34826236 PMCID: PMC8626076 DOI: 10.1126/sciadv.abl6096] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/06/2021] [Indexed: 05/15/2023]
Abstract
The SARS-CoV-2 pandemic, and the likelihood of future coronavirus pandemics, emphasized the urgent need for development of novel antivirals. Small-molecule chemical probes offer both to reveal aspects of virus replication and to serve as leads for antiviral therapeutic development. Here, we report on the identification of amiloride-based small molecules that potently inhibit OC43 and SARS-CoV-2 replication through targeting of conserved structured elements within the viral 5′-end. Nuclear magnetic resonance–based structural studies revealed specific amiloride interactions with stem loops containing bulge like structures and were predicted to be strongly bound by the lead amilorides in retrospective docking studies. Amilorides represent the first antiviral small molecules that target RNA structures within the 5′ untranslated regions and proximal region of the CoV genomes. These molecules will serve as chemical probes to further understand CoV RNA biology and can pave the way for the development of specific CoV RNA–targeted antivirals.
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Affiliation(s)
- Martina Zafferani
- Chemistry Department, Duke University, 124 Science Drive, Durham, NC 27705, USA
| | - Christina Haddad
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 441106, USA
| | - Le Luo
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 441106, USA
| | | | - Liang-Yuan Chiu
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 441106, USA
| | - Christian Shema Mugisha
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Adeline G. Monaghan
- Chemistry Department, Duke University, 124 Science Drive, Durham, NC 27705, USA
| | - Andrew A. Kennedy
- Department of Internal Medicine and Department of Microbiology and Immunology, University of Michigan, 1150 W Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Joseph D. Yesselman
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Robert J. Gifford
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd., Bearsden, Glasgow G61 1QH, UK
| | - Andrew W. Tai
- Department of Internal Medicine and Department of Microbiology and Immunology, University of Michigan, 1150 W Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Sebla B. Kutluay
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Mei-Ling Li
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, 675 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Gary Brewer
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, 675 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Blanton S. Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 441106, USA
| | - Amanda E. Hargrove
- Chemistry Department, Duke University, 124 Science Drive, Durham, NC 27705, USA
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11
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Jangra S, Landers JJ, Rathnasinghe R, O’Konek JJ, Janczak KW, Cascalho M, Kennedy AA, Tai AW, Baker JR, Schotsaert M, Wong PT. A Combination Adjuvant for the Induction of Potent Antiviral Immune Responses for a Recombinant SARS-CoV-2 Protein Vaccine. Front Immunol 2021; 12:729189. [PMID: 34603303 PMCID: PMC8481386 DOI: 10.3389/fimmu.2021.729189] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/30/2021] [Indexed: 01/03/2023] Open
Abstract
Several SARS-CoV-2 vaccines have received EUAs, but many issues remain unresolved, including duration of conferred immunity and breadth of cross-protection. Adjuvants that enhance and shape adaptive immune responses that confer broad protection against SARS-CoV-2 variants will be pivotal for long-term protection as drift variants continue to emerge. We developed an intranasal, rationally designed adjuvant integrating a nanoemulsion (NE) that activates TLRs and NLRP3 with an RNA agonist of RIG-I (IVT DI). The combination adjuvant with spike protein antigen elicited robust responses to SARS-CoV-2 in mice, with markedly enhanced TH1-biased cellular responses and high virus-neutralizing antibody titers towards both homologous SARS-CoV-2 and a variant harboring the N501Y mutation shared by B1.1.7, B.1.351 and P.1 variants. Furthermore, passive transfer of vaccination-induced antibodies protected naive mice against heterologous viral challenge. NE/IVT DI enables mucosal vaccination, and has the potential to improve the immune profile of a variety of SARS-CoV-2 vaccine candidates to provide effective cross-protection against future drift variants.
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MESH Headings
- Adaptive Immunity/immunology
- Adjuvants, Immunologic/pharmacology
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- COVID-19/prevention & control
- COVID-19 Vaccines/immunology
- Chlorocebus aethiops
- Cross Protection/immunology
- DEAD Box Protein 58
- HEK293 Cells
- Humans
- Immunity, Humoral/immunology
- Immunization, Passive
- Mice
- Mice, Inbred C57BL
- Receptors, Immunologic/agonists
- Recombinant Proteins/immunology
- SARS-CoV-2/immunology
- Spike Glycoprotein, Coronavirus/immunology
- Vaccination
- Vaccines, Synthetic/immunology
- Vero Cells
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Affiliation(s)
- Sonia Jangra
- Department of Microbiology, Icahn School of Medicine at Mount Sinai New York, NY, United States
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Jeffrey J. Landers
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School, Ann Arbor, MI, United States
- Mary H. Weiser Food Allergy Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Raveen Rathnasinghe
- Department of Microbiology, Icahn School of Medicine at Mount Sinai New York, NY, United States
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Jessica J. O’Konek
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School, Ann Arbor, MI, United States
- Mary H. Weiser Food Allergy Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Katarzyna W. Janczak
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School, Ann Arbor, MI, United States
- Mary H. Weiser Food Allergy Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Marilia Cascalho
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
- Department of Surgery, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Andrew A. Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Andrew W. Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
- Medicine Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, United States
| | - James R. Baker
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School, Ann Arbor, MI, United States
- Mary H. Weiser Food Allergy Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Michael Schotsaert
- Department of Microbiology, Icahn School of Medicine at Mount Sinai New York, NY, United States
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Pamela T. Wong
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School, Ann Arbor, MI, United States
- Mary H. Weiser Food Allergy Center, University of Michigan Medical School, Ann Arbor, MI, United States
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12
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Zupancic JM, Desai AA, Schardt JS, Pornnoppadol G, Makowski EK, Smith MD, Kennedy AA, Garcia de Mattos Barbosa M, Cascalho M, Lanigan TM, Tai AW, Tessier PM. Directed evolution of potent neutralizing nanobodies against SARS-CoV-2 using CDR-swapping mutagenesis. Cell Chem Biol 2021; 28:1379-1388.e7. [PMID: 34171229 PMCID: PMC8223476 DOI: 10.1016/j.chembiol.2021.05.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 04/06/2021] [Accepted: 05/27/2021] [Indexed: 02/01/2023]
Abstract
There is widespread interest in facile methods for generating potent neutralizing antibodies, nanobodies, and other affinity proteins against SARS-CoV-2 and related viruses to address current and future pandemics. While isolating antibodies from animals and humans are proven approaches, these methods are limited to the affinities, specificities, and functional activities of antibodies generated by the immune system. Here we report a surprisingly simple directed evolution method for generating nanobodies with high affinities and neutralization activities against SARS-CoV-2. We demonstrate that complementarity-determining region swapping between low-affinity lead nanobodies, which we discovered unintentionally but find is simple to implement systematically, results in matured nanobodies with unusually large increases in affinity. Importantly, the matured nanobodies potently neutralize both SARS-CoV-2 pseudovirus and live virus, and possess drug-like biophysical properties. We expect that our methods will improve in vitro nanobody discovery and accelerate the generation of potent neutralizing nanobodies against diverse coronaviruses.
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Affiliation(s)
- Jennifer M Zupancic
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alec A Desai
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - John S Schardt
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Ann Arbor, MI 48109, USA; Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ghasidit Pornnoppadol
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Emily K Makowski
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Matthew D Smith
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Andrew A Kennedy
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Marilia Cascalho
- Department of Surgery, University of Michigan, Ann Arbor, MI 48109, USA; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas M Lanigan
- Division of Rheumatology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA; Medicine Service, Ann Arbor Veterans Administration Health System, Ann Arbor, MI, USA
| | - Peter M Tessier
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Ann Arbor, MI 48109, USA; Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA.
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13
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Sherman EJ, Mirabelli C, Tang VT, Khan TG, Kennedy AA, Graham SE, Willer CJ, Tai AW, Sexton JZ, Wobus CE, Emmer BT. Identification of ACE2 modifiers by CRISPR screening. bioRxiv 2021:2021.06.10.447768. [PMID: 34127970 PMCID: PMC8202422 DOI: 10.1101/2021.06.10.447768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
SARS-CoV-2 infection is initiated by binding of the viral spike protein to its receptor, ACE2, on the surface of host cells. ACE2 expression is heterogeneous both in vivo and in immortalized cell lines, but the molecular pathways that govern ACE2 expression remain unclear. We now report high-throughput CRISPR screens for functional modifiers of ACE2 surface abundance. We identified 35 genes whose disruption was associated with a change in the surface abundance of ACE2 in HuH7 cells. Enriched among these ACE2 regulators were established transcription factors, epigenetic regulators, and functional networks. We further characterized individual cell lines with disruption of SMAD4, EP300, PIAS1 , or BAMBI and found these genes to regulate ACE2 at the mRNA level and to influence cellular susceptibility to SARS-CoV-2 infection. Collectively, our findings clarify the host factors involved in SARS-CoV-2 entry and suggest potential targets for therapeutic development.
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14
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de Mattos Barbosa MG, Liu H, Huynh D, Shelley G, Keller ET, Emmer BT, Sherman E, Ginsburg D, Kennedy AA, Tai AW, Wobus C, Mirabeli C, Lanigan TM, Samaniego M, Meng W, Rosenfeld AM, Prak ETL, Platt JL, Cascalho M. IgV somatic mutation of human anti-SARS-CoV-2 monoclonal antibodies governs neutralization and breadth of reactivity. JCI Insight 2021; 6:147386. [PMID: 33769311 PMCID: PMC8262290 DOI: 10.1172/jci.insight.147386] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/24/2021] [Indexed: 12/24/2022] Open
Abstract
Abs that neutralize SARS-CoV-2 are thought to provide the most immediate and effective treatment for those severely afflicted by this virus. Because coronavirus potentially diversifies by mutation, broadly neutralizing Abs are especially sought. Here, we report a possibly novel approach to rapid generation of potent broadly neutralizing human anti-SARS-CoV-2 Abs. We isolated SARS-CoV-2 spike protein-specific memory B cells by panning from the blood of convalescent subjects after infection with SARS-CoV-2 and sequenced and expressed Ig genes from individual B cells as human mAbs. All of 43 human mAbs generated in this way neutralized SARS-CoV-2. Eighteen of the forty-three human mAbs exhibited half-maximal inhibitory concentrations (IC50) of 6.7 × 10-12 M to 6.7 × 10-15 M for spike-pseudotyped virus. Seven of the human mAbs also neutralized (with IC50 < 6.7 × 10-12 M) viruses pseudotyped with mutant spike proteins (including receptor-binding domain mutants and the S1 C-terminal D614G mutant). Neutralization of the Wuhan Hu-1 founder strain and of some variants decreased when coding sequences were reverted to germline, suggesting that potency of neutralization was acquired by somatic hypermutation and selection of B cells. These results indicate that infection with SARS-CoV-2 evokes high-affinity B cell responses, some products of which are broadly neutralizing and others highly strain specific. We also identify variants that would potentially resist immunity evoked by infection with the Wuhan Hu-1 founder strain or by vaccines developed with products of that strain, suggesting evolutionary courses that SARS-CoV-2 could take.
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Affiliation(s)
| | | | | | | | | | | | - Emily Sherman
- Department of Internal Medicine
- Life Sciences Institute
| | - David Ginsburg
- Department of Internal Medicine
- Life Sciences Institute
- Departments of Human Genetics and Pediatrics and Howard Hughes Medical Institute
| | | | | | | | | | - Thomas M. Lanigan
- Department of Internal Medicine
- Vector Core, Biomedical Research Core Facilities, University of Michigan, Ann Arbor, Michigan, USA
| | - Milagros Samaniego
- Department of Medicine, Henry Ford Health Systems, Detroit, Michigan, USA
| | - Wenzhao Meng
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Aaron M. Rosenfeld
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eline T. Luning Prak
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jeffrey L. Platt
- Department of Surgery
- Department of Microbiology and Immunology, and
| | - Marilia Cascalho
- Department of Surgery
- Department of Microbiology and Immunology, and
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15
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Jangra S, Landers JJ, Rathnasinghe R, O'Konek JJ, Janczak KW, Cascalho M, Kennedy AA, Tai AW, Baker JR, Schotsaert M, Wong PT. A Combination Adjuvant for the Induction of Potent Antiviral Immune Responses for a Recombinant SARS-CoV-2 Protein Vaccine. bioRxiv 2021:2021.02.18.431484. [PMID: 33619480 PMCID: PMC7899444 DOI: 10.1101/2021.02.18.431484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Several SARS-CoV-2 vaccines have received EUAs, but many issues remain unresolved, including duration of conferred immunity and breadth of cross-protection. Adjuvants that enhance and shape adaptive immune responses that confer broad protection against SARS-CoV-2 variants will be pivotal for long-term protection. We developed an intranasal, rationally designed adjuvant integrating a nanoemulsion (NE) that activates TLRs and NLRP3 with an RNA agonist of RIG-I (IVT DI). The combination adjuvant with spike protein antigen elicited robust responses to SARS-CoV-2 in mice, with markedly enhanced T H 1-biased cellular responses and high virus-neutralizing antibody titers towards both homologous SARS-CoV-2 and a variant harboring the N501Y mutation shared by B1.1.7, B.1.351 and P.1 variants. Furthermore, passive transfer of vaccination-induced antibodies protected naive mice against heterologous viral challenge. NE/IVT DI enables mucosal vaccination, and has the potential to improve the immune profile of a variety of SARS-CoV-2 vaccine candidates to provide effective cross-protection against future drift variants.
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16
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Monrad SU, Bibler Zaidi NL, Grob KL, Kurtz JB, Tai AW, Hortsch M, Gruppen LD, Santen SA. What faculty write versus what students see? Perspectives on multiple-choice questions using Bloom's taxonomy. Med Teach 2021; 43:575-582. [PMID: 33590781 DOI: 10.1080/0142159x.2021.1879376] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
BACKGROUND Using revised Bloom's taxonomy, some medical educators assume they can write multiple choice questions (MCQs) that specifically assess higher (analyze, apply) versus lower-order (recall) learning. The purpose of this study was to determine whether three key stakeholder groups (students, faculty, and education assessment experts) assign MCQs the same higher- or lower-order level. METHODS In Phase 1, stakeholders' groups assigned 90 MCQs to Bloom's levels. In Phase 2, faculty wrote 25 MCQs specifically intended as higher- or lower-order. Then, 10 students assigned these questions to Bloom's levels. RESULTS In Phase 1, there was low interrater reliability within the student group (Krippendorf's alpha = 0.37), the faculty group (alpha = 0.37), and among three groups (alpha = 0.34) when assigning questions as higher- or lower-order. The assessment team alone had high interrater reliability (alpha = 0.90). In Phase 2, 63% of students agreed with the faculty as to whether the MCQs were higher- or lower-order. There was low agreement between paired faculty and student ratings (Cohen's Kappa range .098-.448, mean .256). DISCUSSION For many questions, faculty and students did not agree whether the questions were lower- or higher-order. While faculty may try to target specific levels of knowledge or clinical reasoning, students may approach the questions differently than intended.
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Affiliation(s)
- Seetha U Monrad
- Division of Rheumatology, Department of Internal Medicine, University of Michigan Medical School (UMMS), Ann Arbor, MA, USA
| | | | - Karri L Grob
- Office of Medical School Education, University of Michigan Medical School, Ann Arbor, MA, USA
| | - Joshua B Kurtz
- University of Michigan Medical School, Ann Arbor, MA, USA
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MA, USA
| | - Michael Hortsch
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MA, USA
| | - Larry D Gruppen
- Department of Learning Health Sciences, University of Michigan Medical School, Ann Arbor, MA, USA
| | - Sally A Santen
- Department of Emergency Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
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17
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Martina Z, Christina H, Le L, Jesse DC, Liang YC, Christian SM, Monaghan AG, Kennedy AA, Yesselman JD, Gifford RR, Tai AW, Kutluay SB, Li ML, Brewer G, Tolbert BS, Hargrove AE. Amilorides inhibit SARS-CoV-2 replication in vitro by targeting RNA structures. bioRxiv 2020:2020.12.05.409821. [PMID: 33299997 PMCID: PMC7724665 DOI: 10.1101/2020.12.05.409821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The SARS-CoV-2 pandemic, and the likelihood of future coronavirus pandemics, has rendered our understanding of coronavirus biology more essential than ever. Small molecule chemical probes offer to both reveal novel aspects of virus replication and to serve as leads for antiviral therapeutic development. The RNA-biased amiloride scaffold was recently tuned to target a viral RNA structure critical for translation in enterovirus 71, ultimately uncovering a novel mechanism to modulate positive-sense RNA viral translation and replication. Analysis of CoV RNA genomes reveal many conserved RNA structures in the 5'-UTR and proximal region critical for viral translation and replication, including several containing bulge-like secondary structures suitable for small molecule targeting. Following phylogenetic conservation analysis of this region, we screened an amiloride-based small molecule library against a less virulent human coronavirus, OC43, to identify lead ligands. Amilorides inhibited OC43 replication as seen in viral plaque assays. Select amilorides also potently inhibited replication competent SARS-CoV-2 as evident in the decreased levels of cell free virions in cell culture supernatants of treated cells. Reporter screens confirmed the importance of RNA structures in the 5'-end of the viral genome for small molecule activity. Finally, NMR chemical shift perturbation studies of the first six stem loops of the 5'-end revealed specific amiloride interactions with stem loops 4, 5a, and 6, all of which contain bulge like structures and were predicted to be strongly bound by the lead amilorides in retrospective docking studies. Taken together, the use of multiple orthogonal approaches allowed us to identify the first small molecules aimed at targeting RNA structures within the 5'-UTR and proximal region of the CoV genome. These molecules will serve as chemical probes to further understand CoV RNA biology and can pave the way for the development of specific CoV RNA-targeted antivirals.
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Affiliation(s)
- Zafferani Martina
- Chemistry Department, Duke University, 124 Science Drive; Durham, NC USA 27705
| | - Haddad Christina
- Department of Chemistry, Case Western Reserve University, Cleveland OH 441106
| | - Luo Le
- Department of Chemistry, Case Western Reserve University, Cleveland OH 441106
| | | | - Yuan-Chiu Liang
- Department of Chemistry, Case Western Reserve University, Cleveland OH 441106
| | - Shema Mugisha Christian
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Adeline G. Monaghan
- Chemistry Department, Duke University, 124 Science Drive; Durham, NC USA 27705
| | - Andrew A. Kennedy
- Department of Internal Medicine and Department of Microbiology & Immunology, University of Michigan, 1150 W Medical Center Dr, Ann Arbor MI 48109
| | - Joseph D. Yesselman
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588 USA
| | - Robert R. Gifford
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow, UK, G61 1QH
| | - Andrew W. Tai
- Department of Internal Medicine and Department of Microbiology & Immunology, University of Michigan, 1150 W Medical Center Dr, Ann Arbor MI 48109
| | - Sebla B. Kutluay
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Mei-Ling Li
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, 675 Hoes Lane West, Piscataway, NJ USA 08854
| | - Gary Brewer
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, 675 Hoes Lane West, Piscataway, NJ USA 08854
| | - Blanton S. Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland OH 441106
| | - Amanda E. Hargrove
- Chemistry Department, Duke University, 124 Science Drive; Durham, NC USA 27705
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18
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Reddy CA, Schneider BJ, Brackett LM, Tai AW. Nivolumab-induced large-duct cholangiopathy treated with ursodeoxycholic acid and tocilizumab. Immunotherapy 2019; 11:1527-1531. [PMID: 31789069 DOI: 10.2217/imt-2019-0121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Immune checkpoint inhibitor therapy has become a cornerstone in the management of many oncologic diseases. Although it is well tolerated in most patients, a wide spectrum of adverse events has been described as a result of immune system alteration. We present a case of a woman with metastatic bronchogenic adenocarcinoma who was initially thought to have immune-mediated hepatitis, but eventually discovered to have a rarely described immune-mediated cholangiopathy. Her cholangiopathy appeared to stabilize following ursodeoxycholic acid and tocilizumab after several lines of guideline-directed therapy. Awareness of this unique toxicity following immune checkpoint inhibitor, and potential treatment options may help clinicians manage this rare but serious complication.
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Affiliation(s)
- Chanakyaram A Reddy
- Division of Gastroenterology & Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bryan J Schneider
- Division of Hematology & Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lindsay M Brackett
- Division of Hematology & Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Andrew W Tai
- Division of Gastroenterology & Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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19
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Flint M, Chatterjee P, Lin DL, McMullan LK, Shrivastava-Ranjan P, Bergeron É, Lo MK, Welch SR, Nichol ST, Tai AW, Spiropoulou CF. A genome-wide CRISPR screen identifies N-acetylglucosamine-1-phosphate transferase as a potential antiviral target for Ebola virus. Nat Commun 2019; 10:285. [PMID: 30655525 PMCID: PMC6336797 DOI: 10.1038/s41467-018-08135-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/19/2018] [Indexed: 12/28/2022] Open
Abstract
There are no approved therapies for Ebola virus infection. Here, to find potential therapeutic targets, we perform a screen for genes essential for Ebola virus (EBOV) infection. We identify GNPTAB, which encodes the α and β subunits of N-acetylglucosamine-1-phosphate transferase. We show that EBOV infection of a GNPTAB knockout cell line is impaired, and that this is reversed by reconstituting GNPTAB expression. Fibroblasts from patients with mucolipidosis II, a disorder associated with mutations in GNPTAB, are refractory to EBOV, whereas cells from their healthy parents support infection. Impaired infection correlates with loss of the expression of cathepsin B, known to be essential for EBOV entry. GNPTAB activity is dependent upon proteolytic cleavage by the SKI-1/S1P protease. Inhibiting this protease with the small-molecule PF-429242 blocks EBOV entry and infection. Disruption of GNPTAB function may represent a strategy for a host-targeted therapy for EBOV. Genetic screens are important tools to identify host factors associated with viral infections. Here, Flint et al. perform a genome-wide CRISPR screen using infectious Ebola virus (EBOV) and show that the host transferase GNPTAB is required for EBOV infection and a potential target for antiviral therapies
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Affiliation(s)
- Mike Flint
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA.
| | - Payel Chatterjee
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA
| | - David L Lin
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Laura K McMullan
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA
| | - Punya Shrivastava-Ranjan
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA
| | - Éric Bergeron
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA
| | - Michael K Lo
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA
| | - Stephen R Welch
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA
| | - Stuart T Nichol
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA
| | - Andrew W Tai
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.,Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Christina F Spiropoulou
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G-14, Atlanta, GA, 30329, USA.
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Perry JW, Tai AW. Random Insertional Mutagenesis of a Serotype 2 Dengue Virus Clone. Bio Protoc 2018; 8:e2975. [PMID: 30214914 DOI: 10.21769/bioprotoc.2975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Protein tagging is a powerful method of investigating protein function. However, modifying positive-strand RNA virus proteins in the context of viral infection can be particularly difficult as their compact genomes and multifunctional proteins mean even small changes can inactivate or attenuate the virus. Although targeted approaches to functionally tag viral proteins have been successful, these approaches are time consuming and inefficient. A strategy that has been successfully applied to several RNA viruses is whole-genome transposon insertional mutagenesis. A library of viral genomes, each containing a single randomly placed small insertion, is selected by passaging in cell culture and the insertion sites can be identified using Next Generation Sequencing (NGS). Here we describe a protocol for transposon mutagenesis of the 16681 strain of dengue virus, serotype 2. Mutant dengue virus libraries containing short randomly placed insertions are passaged through mammalian cells and insertions are mapped by NGS of the viable progeny. The protocol is divided into four stages: transposon mutagenesis of a dengue cDNA clone, viral genome transfection into permissive cells, isolation of viral progeny genomes, and sequencing library preparation.
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Affiliation(s)
- Jeffrey W Perry
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Microbiology & Immunology, University of Michigan, Ann Arbor, MI, USA.,Medicine Service, Ann Arbor Veterans Administration Health System, Ann Arbor, MI, USA
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Perry JW, Chen Y, Speliotes E, Tai AW. Functional Analysis of the Dengue Virus Genome Using an Insertional Mutagenesis Screen. J Virol 2018; 92:e02085-17. [PMID: 29321321 PMCID: PMC5972875 DOI: 10.1128/jvi.02085-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/03/2018] [Indexed: 12/29/2022] Open
Abstract
In the last few decades, dengue virus, an arbovirus, has spread to over 120 countries. Although a vaccine has been approved in some countries, limitations on its effectiveness and a lack of effective antiviral treatments reinforce the need for additional research. The functions of several viral nonstructural proteins are essentially unknown. To better understand the functions of these proteins and thus dengue virus pathogenesis, we embarked on a genomewide transposon mutagenesis screen with next-generation sequencing to determine sites in the viral genome that tolerate 15-nucleotide insertions. Using this approach, we generated support for several published predicted transmembrane and enzymatic domains. Next, we created 7 mutants containing the 15-nucleotide insertion from the original selection and found 6 of them were capable of replication in both mammalian and mosquito tissue culture cells. Interestingly, one mutation had a significant impairment of viral assembly, and this mutation may lead to a better understanding of viral assembly and release. In addition, we created a fully infectious virus expressing a functionally tagged NS4B protein, which will provide a much-needed tool to elucidate the role of NS4B in viral pathogenesis.IMPORTANCE Dengue virus is a mosquito-borne virus distributed in tropical and subtropical regions globally that can result in hospitalization and even death in some cases. Although a vaccine exists, its limitations and a lack of approved antiviral treatments highlight our limited understanding of dengue virus pathogenesis and host immunity. The functions of many viral proteins are poorly understood. We used a previously published approach using transposon mutagenesis to develop tools to study these proteins' functions by adding insertions randomly throughout the viral genomes. These genomes were transferred into cells, and infectious progeny were recovered to determine sites that tolerated insertions, as only the genomes that tolerated insertions would be able to propagate. Using these results, we created viruses with epitope tags, one in the viral structural protein Capsid and one in the viral nonstructural protein NS4B. Further investigation of these mutants may elucidate the roles of Capsid and NS4B during dengue virus infections.
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Affiliation(s)
- Jeffrey W Perry
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Yanhua Chen
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Elizabeth Speliotes
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
- Medicine Service, Ann Arbor Veterans Administration Health System, Ann Arbor, Michigan, USA
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22
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Wang H, Tai AW. Continuous de novo generation of spatially segregated hepatitis C virus replication organelles revealed by pulse-chase imaging. J Hepatol 2017; 66:55-66. [PMID: 27599826 PMCID: PMC5167665 DOI: 10.1016/j.jhep.2016.08.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 08/22/2016] [Accepted: 08/26/2016] [Indexed: 01/22/2023]
Abstract
BACKGROUND & AIMS Like all positive-sense RNA viruses, hepatitis C virus (HCV) induces host membrane alterations for its replication. In chronically infected cells, it is not known whether these viral replication organelles are being continually resupplied by newly synthesized viral proteins in situ, or whether they are generated de novo. Here we aimed to study temporal events in replication organelles formation and maturation. METHODS Here we use pulse-chase labeling in combination with confocal microscopy, correlative light electron microscopy and biochemical methods to identify temporally distinct populations of replication organelles in living cells and study the formation, morphogenesis as well as compositional and functional changes of replication organelles over time. RESULTS We found that HCV replication organelles are continuously generated de novo at spatially distinct sites from preformed ones. This process is accompanied by accumulated intracellular membrane alteration, increased cholesterol delivery, NS5A phosphorylation, and positive-strand RNA content, and by eventual association with HCV core protein around lipid droplets. Generation of spatially segregated foci requires viral NS5A and the host factors phosphatidylinositol 4-kinase and oxysterol-binding protein, while association of foci with lipid droplets requires cholesterol. CONCLUSIONS Our results reveal that HCV replication organelles are not static structures, but instead are continuously generated and dynamically change in composition and possibly also in function. LAY SUMMARY Hepatitis C virus replication membrane structures are continuously generated at spatially distinct sites. New replication organelles are different in composition, and possibly also in function, compared to old replication organelles.
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Affiliation(s)
- Hongliang Wang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Andrew W. Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
,Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan
,Medicine Service, Ann Arbor Veterans Administration Health System, Ann Arbor, Michigan
,Correspondence: Andrew W. Tai, University of Michigan, 6520 MSRB I SPC 5682, 1150 W Medical Center Dr, Ann Arbor, MI 48109-5682, Tel: (734) 764-2804, FAX: (734) 763-2535,
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23
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Abstract
Phosphatidylinositol (PI) and its phosphorylated derivatives, collectively called phosphoinositides, are important second messengers involved in a variety of cellular processes, including cell proliferation, apoptosis, metabolism, and migration. These derivatives are generated by a family of kinases called phosphoinositide lipid kinases (PIKs). Due to the central role of these kinases in signaling pathways, assays for measuring their activity are often used for drug development. Lipid kinase substrates are present in unique membrane environments in vivo and are insoluble in aqueous solutions. Therefore the most important consideration in developing successful lipid kinase assays is the physical state of lipid kinase substrates. Here we describe the preparation of lipid substrates for two major classes of lipid kinases, phosphatidylinositol 3-kinases (PI3Ks) and phosphatidylinositol 4-kinases (PI4Ks). Using PI4Ks as an example, we also provide a detailed protocol for small-scale kinase expression and affinity purification from transiently transfected mammalian cells. For measuring lipid kinase activity we apply a universal bioluminescent ADP detection approach. The approach is compatible with diverse lipid substrates and can be used as a single integrated platform for measuring all classes of lipid and protein kinases.
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Affiliation(s)
- Andrew W Tai
- University of Michigan, 6520 MSRB I SPC 5682, 1150 W Medical Center Dr, Ann Arbor, MI, 48109-5682, USA.
| | - Jolanta Vidugiriene
- Promega Corporation, Research and Development Department, 2800 Woods Hollow Road, Madison, WI, 53711, USA.
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Wang H, Tai AW. Mechanisms of Cellular Membrane Reorganization to Support Hepatitis C Virus Replication. Viruses 2016; 8:v8050142. [PMID: 27213428 PMCID: PMC4885097 DOI: 10.3390/v8050142] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/20/2016] [Accepted: 05/15/2016] [Indexed: 12/13/2022] Open
Abstract
Like all positive-sense RNA viruses, hepatitis C virus (HCV) induces host membrane alterations for its replication termed the membranous web (MW). Assembling replication factors at a membranous structure might facilitate the processes necessary for genome replication and packaging and shield viral components from host innate immune defenses. The biogenesis of the HCV MW is a complex process involving a concerted effort of HCV nonstructural proteins with a growing list of host factors. Although a comprehensive understanding of MW formation is still missing, a number of important viral and host determinants have been identified. This review will summarize the recent studies that have led to our current knowledge of the role of viral and host factors in the biogenesis of the MWs and discuss how HCV uses this specialized membrane structure for its replication.
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Affiliation(s)
- Hongliang Wang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
- Medicine Service, Ann Arbor Veterans Administration Health System, Ann Arbor, MI 48105, USA.
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Cui J, Chen W, Sun J, Guo H, Madley R, Xiong Y, Pan X, Wang H, Tai AW, Weiss MA, Arvan P, Liu M. Competitive Inhibition of the Endoplasmic Reticulum Signal Peptidase by Non-cleavable Mutant Preprotein Cargos. J Biol Chem 2015; 290:28131-28140. [PMID: 26446786 DOI: 10.1074/jbc.m115.692350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 12/30/2022] Open
Abstract
Upon translocation across the endoplasmic reticulum (ER) membrane, secretory proteins are proteolytically processed to remove their signal peptide by signal peptidase (SPase). This process is critical for subsequent folding, intracellular trafficking, and maturation of secretory proteins. Prokaryotic SPase has been shown to be a promising antibiotic target. In contrast, to date, no eukaryotic SPase inhibitors have been reported. Here we report that introducing a proline immediately following the natural signal peptide cleavage site not only blocks preprotein cleavage but also, in trans, impairs the processing and maturation of co-expressed preproteins in the ER. Specifically, we find that a variant preproinsulin, pPI-F25P, is translocated across the ER membrane, where it binds to the catalytic SPase subunit SEC11A, inhibiting SPase activity in a dose-dependent manner. Similar findings were obtained with an analogous variant of preproparathyroid hormone, demonstrating that inhibition of the SPase does not depend strictly on the sequence or structure of the downstream mature protein. We further show that inhibiting SPase in the ER impairs intracellular processing of viral polypeptides and their subsequent maturation. These observations suggest that eukaryotic SPases (including the human ortholog) are, in principle, suitable therapeutic targets for antiviral drug design.
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Affiliation(s)
- Jingqiu Cui
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China,; Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Wei Chen
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105,; Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Jinhong Sun
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Huan Guo
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Rachel Madley
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Yi Xiong
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Xingyi Pan
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Hongliang Wang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Michael A Weiss
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106.
| | - Peter Arvan
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China,; Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
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Tai AW. An interferon-free, all-oral regimen is effective in treatment of genotype 1 chronic HCV infection. ACTA ACUST UNITED AC 2013; 19:67. [PMID: 24282171 DOI: 10.1136/eb-2013-101566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Andrew W Tai
- Department of Internal Medicine, University of Michigan, , Ann Arbor, Michigan, USA
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27
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Salloum S, Wang H, Ferguson C, Parton RG, Tai AW. Rab18 binds to hepatitis C virus NS5A and promotes interaction between sites of viral replication and lipid droplets. PLoS Pathog 2013; 9:e1003513. [PMID: 23935497 PMCID: PMC3731246 DOI: 10.1371/journal.ppat.1003513] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 06/07/2013] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV) is a single-stranded RNA virus that replicates on endoplasmic reticulum-derived membranes. HCV particle assembly is dependent on the association of core protein with cellular lipid droplets (LDs). However, it remains uncertain whether HCV assembly occurs at the LD membrane itself or at closely associated ER membranes. Furthermore, it is not known how the HCV replication complex and progeny genomes physically associate with the presumed sites of virion assembly at or near LDs. Using an unbiased proteomic strategy, we have found that Rab18 interacts with the HCV nonstructural protein NS5A. Rab18 associates with LDs and is believed to promote physical interaction between LDs and ER membranes. Active (GTP-bound) forms of Rab18 bind more strongly to NS5A than a constitutively GDP-bound mutant. NS5A colocalizes with Rab18-positive LDs in HCV-infected cells, and Rab18 appears to promote the physical association of NS5A and other replicase components with LDs. Modulation of Rab18 affects genome replication and possibly also the production of infectious virions. Our results support a model in which specific interactions between viral and cellular proteins may promote the physical interaction between membranous HCV replication foci and lipid droplets. Hepatitis C virus (HCV) chronically infects about 170 million people worldwide and can ultimately lead to liver failure and liver cancer. HCV, like other RNA viruses, exploits cellular proteins and membranes to promote their own replication and virion production. In particular, HCV replication occurs at membranes derived from the endoplasmic reticulum, while HCV virion assembly is believed to occur at or near cellular lipid droplets. In this work, we report that Rab18, a lipid droplet-associated cellular protein, binds to the viral protein NS5A, and that the silencing of Rab18 reduces the association of other HCV replication complex components with lipid droplets. These data are consistent with a model in which Rab18 promotes the physical interaction between sites of viral replication to lipid droplets. We also speculate that Rab18 may help to link sites of viral replication to sites of virion assembly. Understanding how viruses exploit cellular proteins may result in new methods of disrupting viral infection.
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Affiliation(s)
- Shadi Salloum
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Hongliang Wang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Charles Ferguson
- The University of Queensland, Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, Brisbane, Queensland, Australia
| | - Robert G. Parton
- The University of Queensland, Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, Brisbane, Queensland, Australia
| | - Andrew W. Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Division of Gastroenterology, Department of Internal Medicine, Ann Arbor Veterans Administration Health System, Ann Arbor, Michigan, United States of America
- * E-mail:
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28
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Zhao H, Lin W, Kumthip K, Cheng D, Fusco DN, Hofmann O, Jilg N, Tai AW, Goto K, Zhang L, Hide W, Jang JY, Peng LF, Chung RT. A functional genomic screen reveals novel host genes that mediate interferon-alpha's effects against hepatitis C virus. J Hepatol 2012; 56:326-33. [PMID: 21888876 PMCID: PMC3261326 DOI: 10.1016/j.jhep.2011.07.026] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 06/28/2011] [Accepted: 07/12/2011] [Indexed: 01/08/2023]
Abstract
BACKGROUND & AIMS The precise mechanisms by which IFN exerts its antiviral effect against HCV have not yet been elucidated. We sought to identify host genes that mediate the antiviral effect of IFN-α by conducting a whole-genome siRNA library screen. METHODS High throughput screening was performed using an HCV genotype 1b replicon, pRep-Feo. Those pools with replicate robust Z scores ≥2.0 entered secondary validation in full-length OR6 replicon cells. Huh7.5.1 cells infected with JFH1 were then used to validate the rescue efficacy of selected genes for HCV replication under IFN-α treatment. RESULTS We identified and confirmed 93 human genes involved in the IFN-α anti-HCV effect using a whole-genome siRNA library. Gene ontology analysis revealed that mRNA processing (23 genes, p=2.756e-22), translation initiation (nine genes, p=2.42e-6), and IFN signaling (five genes, p=1.00e-3) were the most enriched functional groups. Nine genes were components of U4/U6.U5 tri-snRNP. We confirmed that silencing squamous cell carcinoma antigen recognized by T cells (SART1), a specific factor of tri-snRNP, abrogates IFN-α's suppressive effects against HCV in both replicon cells and JFH1 infectious cells. We further found that SART1 was not IFN-α inducible, and its anti-HCV effector in the JFH1 infectious model was through regulation of interferon stimulated genes (ISGs) with or without IFN-α. CONCLUSIONS We identified 93 genes that mediate the anti-HCV effect of IFN-α through genome-wide siRNA screening; 23 and nine genes were involved in mRNA processing and translation initiation, respectively. These findings reveal an unexpected role for mRNA processing in generation of the antiviral state, and suggest a new avenue for therapeutic development in HCV.
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Affiliation(s)
- Hong Zhao
- Department of Infectious Diseases, Peking University First Hospital, Beijing, 100034, China, Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Wenyu Lin
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Kattareeya Kumthip
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Du Cheng
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Dahlene N Fusco
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Oliver Hofmann
- Bioinformatics Core, Harvard School of Public Health, Boston, MA 02115
| | - Nikolaus Jilg
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Andrew W. Tai
- Department of Medicine, Gastroenterology, University of Michigan Health System Ann Arbor, MI 48105
| | - Kaku Goto
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Leiliang Zhang
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Winston Hide
- Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115
| | - Jae Young Jang
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Lee F Peng
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Raymond T Chung
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114,Corresponding author: Raymond T. Chung, M.D. GI Unit, Warren 1007 Massachusetts General Hospital Boston, MA 02114 Phone: (617) 724-7562 Fax: (617) 643-0446
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Huang Y, Tong S, Tai AW, Hussain M, Lok ASF. Hepatitis B virus core promoter mutations contribute to hepatocarcinogenesis by deregulating SKP2 and its target, p21. Gastroenterology 2011; 141:1412-21, 1421.e1-5. [PMID: 21704589 PMCID: PMC3186859 DOI: 10.1053/j.gastro.2011.06.048] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 06/09/2011] [Accepted: 06/13/2011] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS Clinical studies have associated hepatitis B virus core promoter (CP) mutations with an increased risk of hepatocellular carcinoma. The CP region overlaps with the HBV X (HBx) gene, which has been implicated in hepatocarcinogenesis. The cyclin kinase inhibitor p21WAF1/CIP1 is an important regulator of cell cycle progression and proliferation. We determined whether HBx mutants that result from mutations in the CP deregulate p21 and these processes. METHODS We constructed a series of HBx mutants with changes in the CP region that correspond to A1762T/G1764A (TA), T1753A, T1768A, or a combination of these (combo) and expressed them, along with wild-type HBx under control of its endogenous promoter, in primary human hepatocytes (PHHs) and HepG2 cells. We then analyzed the effects of CP mutations on expression and degradation of p21 and the effects on cell cycle progression and proliferation. RESULTS The combo mutant decreased levels of p21 and increased cyclin E expression in PHHs and HepG2 cells. The combo mutant, but not HBx with single or double CP mutations, accelerated p21 degradation in HepG2 cells. The combo mutant increased expression of S-phase kinase-associated protein 2 (SKP2) in PHHs and Huh7 cells. Silencing of SKP2 abrogated the effects of CP mutations on p21 expression. The kinetics of p21 expression correlated with changes in cell cycle distribution. The combo mutant accelerated cell cycle progression; p21 overexpression restored G1 arrest. CONCLUSIONS HBx mutants with changes that correspond to a combination of CP mutations up-regulate SKP2, which then down-regulates p21 via ubiquitin-mediated proteasomal degradation. CP mutations might increase the risk of hepatocellular carcinoma via this pathway.
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Affiliation(s)
- Yuehua Huang
- Division of Gastroenterology and Hepatology, University of Michigan Health Systems, Ann Arbor, MI, USA
| | - Shuping Tong
- Liver Research Center, Rhode Island Hospital and Brown Medical School, Providence, RI, USA
| | - Andrew W. Tai
- Division of Gastroenterology and Hepatology, University of Michigan Health Systems, Ann Arbor, MI, USA,Division of Gastroenterology, Ann Arbor Veterans Administration Health Systems, Ann Arbor, MI, USA
| | - Munira Hussain
- Division of Gastroenterology and Hepatology, University of Michigan Health Systems, Ann Arbor, MI, USA
| | - Anna SF Lok
- Division of Gastroenterology and Hepatology, University of Michigan Health Systems, Ann Arbor, MI, USA
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Tai AW, Bojjireddy N, Balla T. A homogeneous and nonisotopic assay for phosphatidylinositol 4-kinases. Anal Biochem 2011; 417:97-102. [PMID: 21704602 DOI: 10.1016/j.ab.2011.05.046] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/25/2011] [Accepted: 05/31/2011] [Indexed: 11/25/2022]
Abstract
Phosphatidylinositol 4-kinases (PI 4-kinases) catalyze the conversion of phosphatidylinositol to phosphatidylinositol 4-phosphate (PtdIns4P). The four known mammalian PI 4-kinases, PI4KA, PI4KB, PI4K2A, and PI4K2B have roles in intracellular lipid and protein trafficking. PI4KA and PI4KB also assist in the replication of several positive-sense RNA viruses. The identification of selective inhibitors of these kinases would be facilitated by assays suitable for high-throughput screening. We describe a homogeneous and nonisotopic assay for PI 4-kinase activity based on the bioluminescent detection of the ADP produced by kinase reactions. We have evaluated this assay with known nonselective inhibitors of PI 4-kinases and show that it performs similar to radiometric assay formats previously described in the literature. In addition, this assay generates Z-factor values of >0.7 for PI4KA in a 384-well format, demonstrating its suitability for high-throughput screening applications.
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Affiliation(s)
- Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48105, USA.
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Tai AW, Chung RT. Racial differences in response to interferon-based antiviral therapy for hepatitis C virus infection: a hardwiring issue? J Infect Dis 2009; 199:1101-3. [PMID: 19284288 DOI: 10.1086/597385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Tai AW, Benita Y, Peng LF, Kim SS, Sakamoto N, Xavier RJ, Chung RT. A functional genomic screen identifies cellular cofactors of hepatitis C virus replication. Cell Host Microbe 2009; 5:298-307. [PMID: 19286138 DOI: 10.1016/j.chom.2009.02.001] [Citation(s) in RCA: 350] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2008] [Revised: 12/22/2008] [Accepted: 02/10/2009] [Indexed: 02/06/2023]
Abstract
Hepatitis C virus (HCV) chronically infects 3% of the world's population, and complications from HCV are the leading indication for liver transplantation. Given the need for better anti-HCV therapies, one strategy is to identify and target cellular cofactors of the virus lifecycle. Using a genome-wide siRNA library, we identified 96 human genes that support HCV replication, with a significant number of them being involved in vesicle organization and biogenesis. Phosphatidylinositol 4-kinase PI4KA and multiple subunits of the COPI vesicle coat complex were among the genes identified. Consistent with this, pharmacologic inhibitors of COPI and PI4KA blocked HCV replication. Targeting hepcidin, a peptide critical for iron homeostasis, also affected HCV replication, which may explain the known dysregulation of iron homeostasis in HCV infection. The host cofactors for HCV replication identified in this study should serve as a useful resource in delineating new targets for anti-HCV therapies.
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Affiliation(s)
- Andrew W Tai
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Kim KA, Lin W, Tai AW, Shao RX, Weinberg E, De Sa Borges CB, Bhan AK, Zheng H, Kamegaya Y, Chung RT. Hepatic SOCS3 expression is strongly associated with non-response to therapy and race in HCV and HCV/HIV infection. J Hepatol 2009; 50:705-11. [PMID: 19231005 PMCID: PMC3146466 DOI: 10.1016/j.jhep.2008.12.021] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 11/11/2008] [Accepted: 12/09/2008] [Indexed: 12/20/2022]
Abstract
BACKGROUND/AIMS The response rates of HCV infection to interferon therapy vary depending on viral and host factors. We hypothesized that key regulators of the IFN signaling pathway are predictive of treatment outcome. METHODS We measured the expression of signal transducer and activator of transcription 1 (STAT1) and suppressor of cytokine signaling 3 (SOCS3) in pretreatment liver biopsies. Staining quantitation was compared to treatment outcomes. RESULTS Forty-nine patients with HCV and 25 patients with HCV/HIV infection treated with peginterferon/ribavirin were analyzed. Pretreatment hepatic SOCS3 expression was higher in non-responders than responders. Genotype 1 responders had similar levels of SOCS3 as genotype 2/3 responders. African Americans (AA) had higher hepatic SOCS3 than non-AA. Pretreatment hepatic SOCS3 was the most powerful independent predictor of sustained virologic response (SVR), even more so than genotype by logistic regression analysis. Failure to achieve SVR and AA race were independently associated with high hepatic SOCS3 levels. The hepatic expression of STAT-1 did not differ between responders and non-responders. CONCLUSIONS Our data indicate that hepatic SOCS3 is a stronger baseline predictor of antiviral response than viral genotype. Poor response to antiviral therapy in AA may be associated with higher hepatic SOCS3 expression.
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Affiliation(s)
- Kyung-Ah Kim
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA,Department of Medicine, Ilsan Paik Hospital, Inje University, Goyang, Republic of Korea
| | - Wenyu Lin
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - Andrew W. Tai
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - Run-Xuan Shao
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - Ethan Weinberg
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - Carolina B. De Sa Borges
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - Atul K. Bhan
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Hui Zheng
- Biostatistics Center, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Yoshitaka Kamegaya
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - Raymond T. Chung
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA,Corresponding author. Tel.: +1 617 724 7562; fax: +1 617 643 0446. (R.T. Chung)
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Abstract
Hepatitis C virus (HCV) has evolved remarkable mechanisms that favor viral persistence by interfering with host innate and adaptive immune responses. These same mechanisms are likely to contribute to resistance to exogenously administered interferon used for HCV treatment. We review the host innate and adaptive immune responses in the context of HCV infection as well as the strategies by which these responses are subverted by the virus. In addition, the contribution of host factors, such as race and insulin resistance, to interferon non-responsiveness is discussed. Our progress in understanding the molecular underpinnings of interferon treatment failure in HCV infection has resulted in several promising and novel treatment strategies for HCV treatment non-responders.
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Lin W, Weinberg EM, Tai AW, Peng LF, Brockman MA, Kim KA, Kim SS, Borges CB, Shao RX, Chung RT. HIV increases HCV replication in a TGF-beta1-dependent manner. Gastroenterology 2008; 134:803-11. [PMID: 18325393 DOI: 10.1053/j.gastro.2008.01.005] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Accepted: 12/17/2007] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Human immunodeficiency virus (HIV) coinfection increases hepatitis C virus (HCV)-related progression of hepatic fibrosis, increases HCV persistence, and decreases response rates to interferon-based anti-HCV therapy. It has remained unclear how HIV, a nonhepatotropic virus, accelerates the progression of liver disease by HCV. METHODS We explored the possibility that circulating HIV and/or its proteins contribute to the pathogenesis of HCV through engagement of extracellular coreceptors on hepatocytes. RESULTS In this study, we found that inactivated HIV or gp120 increases HCV replication and enhances HCV-regulated transforming growth factor (TGF)-beta1 expression in both a replicon and an infectious model of HCV. This proviral effect of HIV and gp120 on HCV replication is neutralized by antibodies to CCR5 or CXCR4. However, HIV and gp120 did not alter type I interferon-mediated signaling in these HCV models, indicating that HIV regulates HCV replication through an alternative mechanism. Interestingly, we found that human TGF-beta1 also enhanced HCV replication. The effect of HIV on HCV replication was blocked by a neutralizing antibody to TGF-beta1, indicating that its effects on HCV replication are TGF-beta1 dependent. CONCLUSIONS These results suggest a novel mechanism by which HIV not only enhances HCV replication but also contributes to progression of hepatic fibrosis.
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Affiliation(s)
- Wenyu Lin
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Abstract
Despite the existence of multiple subunit isoforms for the microtubule motor cytoplasmic dynein, it has not yet been directly shown that dynein complexes with different compositions exhibit different properties. The 14-kD dynein light chain Tctex-1, but not its homologue RP3, binds directly to rhodopsin's cytoplasmic COOH-terminal tail, which encodes an apical targeting determinant in polarized epithelial Madin-Darby canine kidney (MDCK) cells. We demonstrate that Tctex-1 and RP3 compete for binding to dynein intermediate chain and that overexpressed RP3 displaces endogenous Tctex-1 from dynein complexes in MDCK cells. Furthermore, replacement of Tctex-1 by RP3 selectively disrupts the translocation of rhodopsin to the MDCK apical surface. These results directly show that cytoplasmic dynein function can be regulated by its subunit composition and that cytoplasmic dynein is essential for at least one mode of apical transport in polarized epithelia.
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Affiliation(s)
- Andrew W. Tai
- Department of Cell Biology and Anatomy, The Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021
| | - Jen-Zen Chuang
- Department of Ophthalmology, The Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021
| | - Ching-Hwa Sung
- Department of Cell Biology and Anatomy, The Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021
- Department of Ophthalmology, The Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021
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Tai AW, Newkirk MM. An autoantibody targeting glycated IgG is associated with elevated serum immune complexes in rheumatoid arthritis (RA). Clin Exp Immunol 2000; 120:188-93. [PMID: 10759782 PMCID: PMC1905622 DOI: 10.1046/j.1365-2249.2000.01188.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/1999] [Indexed: 11/20/2022] Open
Abstract
Advanced glycation end-products (AGE) play a role in diabetes complications and in RA. An autoantibody to IgG-AGE has been shown to correlate with RA disease activity. Thus we sought to analyse serum immune complexes (IC) and AGE-modified proteins in Caucasians and North American Indians to see if the presence of anti-IgG-AGE influenced their composition. Polyethylene glycol precipitation of IC from the serum of anti-IgG-AGE-positive or -negative RA patients, and healthy and diabetic controls were examined. Concentrations of circulating IC were highest in anti-IgG-AGE+ RA patients, followed by anti-IgG-AGE- RA patients, which were greater than healthy controls. IC amounts in the Ojibwe were consistently higher than in Caucasians. Affinity purification of AGE-modified proteins from IC and immunoblotting with antibodies against Ig gamma and mu heavy chains, kappa and lambda light chains, and AGE Nepsilon(carboxymethyl)lysine and imidazolone yielded similar results: anti-AGE+ RA patients had elevated levels relative to those without the autoantibody. Levels in both RA groups were higher than in controls. Glycated albumin amounts followed a similar distribution, but were not influenced by the presence of anti-AGE antibodies. A heavily glycated kappa-chain was present primarily in IC from anti-IgG-AGE+ patients. These studies indicate that anti-AGE antibodies have a direct impact on the accumulation of IgG-AGE but not glycated albumin, and may block the normal clearance of IgG-AGE through AGE receptors.
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Affiliation(s)
- A W Tai
- Division of Rheumatology, Montreal General Hospital, Montreal General Hospital Research Institute, McGill University, Montreal, QC, Canada
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Abstract
We review the sorting/targeting steps involved in the delivery of rhodopsin to the outer segment compartment of highly polarized photoreceptor cells. The transport of rhodopsin includes (1) the sorting/budding of rhodopsin-containing vesicles at the trans-Golgi network, (2) the directional translocation of rhodopsin-bearing vesicles through the inner segment, and (3) the delivery of rhodopsin across the connecting cilium to the outer segment. Several independent lines of evidence suggest that the carboxyl-terminal, cytoplasmic tail of rhodopsin is involved in the post-Golgi trafficking of rhodopsin. Inappropriate subcellular targeting of naturally occurring rhodopsin mutants in vivo leads to photoreceptor cell death. Thus, the genes encoding mutations in the cellular components involved in photoreceptor protein transport are likely candidate genes for retinal dystrophies.
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Affiliation(s)
- C H Sung
- Department of Cell Biology and Anatomy, Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021, USA.
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Tai AW, Chuang JZ, Bode C, Wolfrum U, Sung CH. Rhodopsin's carboxy-terminal cytoplasmic tail acts as a membrane receptor for cytoplasmic dynein by binding to the dynein light chain Tctex-1. Cell 1999; 97:877-87. [PMID: 10399916 DOI: 10.1016/s0092-8674(00)80800-4] [Citation(s) in RCA: 370] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The interaction of cytoplasmic dynein with its cargoes is thought to be indirectly mediated by dynactin, a complex that binds to the dynein intermediate chain. However, the roles of other dynein subunits in cargo binding have been unknown. Here we demonstrate that dynein translocates rhodopsin-bearing vesicles along microtubules. This interaction occurs directly between the C-terminal cytoplasmic tail of rhodopsin and Tctex-1, a dynein light chain. C-terminal rhodopsin mutations responsible for retinitis pigmentosa inhibit this interaction. Our results point to an alternative docking mechanism for cytoplasmic dynein, provide novel insights into the role of motor proteins in the polarized transport of post-Golgi vesicles, and shed light on the molecular basis of retinitis pigmentosa.
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Affiliation(s)
- A W Tai
- Department of Cell Biology and Anatomy, Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021, USA
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Tai AW, Chuang JZ, Sung CH. Localization of Tctex-1, a cytoplasmic dynein light chain, to the Golgi apparatus and evidence for dynein complex heterogeneity. J Biol Chem 1998; 273:19639-49. [PMID: 9677391 DOI: 10.1074/jbc.273.31.19639] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To date, much attention has been focused on the heavy and intermediate chains of the multisubunit cytoplasmic dynein complex; however, little is known about the localization or function of dynein light chains. In this study, we find that Tctex-1, a light chain of cytoplasmic dynein, localizes predominantly to the Golgi apparatus in interphase fibroblasts. Immunofluorescent staining reveals striking juxtanuclear staining characteristic of the Golgi apparatus as well as nuclear envelope and punctate cytoplasmic staining that often decorates microtubules. Tctex-1 colocalization with Golgi compartment markers, its distribution upon treatment with various pharmacological agents, and the cofractionation of Tctex-1-associated membranes with Golgi membranes are all consistent with a Golgi localization. The distribution of Tctex-1 in interphase cells only partially overlaps with the dynein intermediate chain and p150(Glued) upon immunofluorescence, but most of Tctex-1 is redistributed onto mitotic spindles along with other dynein/dynactin subunits. Using sequential immunoprecipitations, we demonstrate that there is a subset of Tctex-1 not associated with the intermediate chain at steady state; the converse also appears to be true. Distinct populations of dynein complexes are likely to exist, and such diversity may occur in part at the level of their light chain compositions.
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Affiliation(s)
- A W Tai
- Department of Cell Biology and Anatomy, Margaret M. Dyson Vision Research Institute, Cornell University Medical College, New York, New York 10021, USA
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Abstract
Hydroxyguanidine contains both features of guanidine and hydroxyurea and has antiviral and anticancer activities both in vitro and in vivo. In order to enhance the antiviral and anticancer activity of this compound, a new series of hydroxyguanidine derivatives with the following structures were synthesized: R = NNHC(= NH)NHOH, where R = aromatic or heterocyclic aldehyde. This series of compounds was prepared in order to alter the lipophilic/hydrophilic balance, as well as the electronic and steric properties of hydroxyguanidine. The anticancer activities of the compounds were tested against cultured L1210 cells. The ID50 values of the above compounds are in the range of 7.80-126 microM. They are about 10-fold more active than hydroxyurea and hydroxyguanidine. The antiviral activities were also tested by assaying the inhibition of transformation of chicken embryo fibroblasts infected with Rous sarcoma virus. The ID50 values of these new compounds are in the range of 2.76-195.2 microM. The most active ones are about 100-fold more active than hydroxyguanidine. At the ID50, no apparent toxicity to the cells was noticed.
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Tai AW, Lien EJ, Moore EC, Chun Y, Roberts JD. Studies of N-hydroxy-N'-aminoguanidine derivatives by nitrogen-15 nuclear magnetic resonance spectroscopy and as ribonucleotide reductase inhibitors. J Med Chem 1983; 26:1326-9. [PMID: 6350588 DOI: 10.1021/jm00363a021] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hydroxyguanidine, with the imino group of guanidine and the hydroxyamino group of hydroxyurea, has functional groups believed to be important for both anticancer and antiviral activities (Adamson, R.H. Nature (London) 1972, 236, 400-401). Three new N-hydroxy-N'-aminoguanidine derivatives have been synthesized and found to be 20-30 times more active than the hydroxyguanidine itself as inhibitors of ribonucleotide reductase from rat Novikoff tumors (Tai, W.A.; Lai, M.M.; Lien, E.J. "Novel N-Hydroxyguanidine Derivatives as Antiviral Agents", North American Medicinal Chemistry Symposium, University of Toronto, Toronto, Canada, June 20-24, 1982; Abstr, p 144). The character of the tautomeric equilibria, the pKa values, and the protonation sites of these hydroxyguanidine derivatives have been determined by 15N NMR spectroscopy.
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