1
|
Pierce BG, Felbinger N, Metcalf M, Toth EA, Ofek G, Fuerst TR. Hepatitis C Virus E1E2 Structure, Diversity, and Implications for Vaccine Development. Viruses 2024; 16:803. [PMID: 38793684 PMCID: PMC11125608 DOI: 10.3390/v16050803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/02/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Hepatitis C virus (HCV) is a major medical health burden and the leading cause of chronic liver disease and cancer worldwide. More than 58 million people are chronically infected with HCV, with 1.5 million new infections occurring each year. An effective HCV vaccine is a major public health and medical need as recognized by the World Health Organization. However, due to the high variability of the virus and its ability to escape the immune response, HCV rapidly accumulates mutations, making vaccine development a formidable challenge. An effective vaccine must elicit broadly neutralizing antibodies (bnAbs) in a consistent fashion. After decades of studies from basic research through clinical development, the antigen of choice is considered the E1E2 envelope glycoprotein due to conserved, broadly neutralizing antigenic domains located in the constituent subunits of E1, E2, and the E1E2 heterodimeric complex itself. The challenge has been elicitation of robust humoral and cellular responses leading to broad virus neutralization due to the relatively low immunogenicity of this antigen. In view of this challenge, structure-based vaccine design approaches to stabilize key antigenic domains have been hampered due to the lack of E1E2 atomic-level resolution structures to guide them. Another challenge has been the development of a delivery platform in which a multivalent form of the antigen can be presented in order to elicit a more robust anti-HCV immune response. Recent nanoparticle vaccines are gaining prominence in the field due to their ability to facilitate a controlled multivalent presentation and trafficking to lymph nodes, where they can interact with both the cellular and humoral components of the immune system. This review focuses on recent advances in understanding the E1E2 heterodimeric structure to facilitate a rational design approach and the potential for development of a multivalent nanoparticle-based HCV E1E2 vaccine. Both aspects are considered important in the development of an effective HCV vaccine that can effectively address viral diversity and escape.
Collapse
Affiliation(s)
- Brian G. Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Nathaniel Felbinger
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Matthew Metcalf
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Eric A. Toth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
| | - Gilad Ofek
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Thomas R. Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| |
Collapse
|
2
|
Xiang J, Chang Q, McLinden JH, Bhattarai N, Welch JL, Kaufman TM, Stapleton JT. Characterization of "Off-Target" Immune Modulation Induced by Live Attenuated Yellow Fever Vaccine. J Infect Dis 2024; 229:786-794. [PMID: 36994927 PMCID: PMC10938199 DOI: 10.1093/infdis/jiad086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/09/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023] Open
Abstract
BACKGROUND Live attenuated vaccines alter immune functions and are associated with beneficial outcomes. We previously demonstrated that live attenuated yellow fever virus (YFV) vaccine (LA-YF-Vax) dampens T-cell receptor (TCR) signaling in vitro via an RNA-based mechanism. We examined study participants before and after LA-YF-Vax to assess TCR-mediated functions in vivo. METHODS Serum samples and peripheral blood mononuclear cells (PBMCs) were obtained before and after LA-YF-Vax (with or without additional vaccines) or quadrivalent influenza vaccine. TCR-mediated activation was determined by interleukin 2 release or phosphorylation of the lymphocyte-specific Src kinase. TCR-regulating phosphatase (protein tyrosine phosphatase receptor type E [PTPRE]) expression was also measured. RESULTS Compared with prevaccination findings, LA-YF-Vax recipient PBMCs demonstrated transient reduction in interleukin 2 release after TCR stimulation and PTPRE levels, unlike in control participants who received quadrivalent influenza vaccine. YFV was detected in 8 of 14 participants after LA-YF-Vax. After incubation of healthy donor PBMCs in serum-derived extracellular vesicles prepared from LA-YF-Vax recipients, TCR signaling and PTPRE levels were reduced after vaccination, even in participants without detectable YFV RNA. CONCLUSIONS LA-YF-Vax reduces TCR functions and PTPRE levels after vaccination. Extracellular vesicles from serum recapitulated this effect in healthy cells. This likely contributes to the reduced immunogenicity for heterologous vaccines after LA-YF-Vax administration. Identification of specific immune mechanisms related to vaccines should contribute to understanding of the "off-target," beneficial effects of live vaccines.
Collapse
Affiliation(s)
- J Xiang
- Iowa City Department of Veterans Affairs Healthcare System, University of Iowa, Iowa City, Iowa, USA
| | - Q Chang
- Iowa City Department of Veterans Affairs Healthcare System, University of Iowa, Iowa City, Iowa, USA
| | - J H McLinden
- Iowa City Department of Veterans Affairs Healthcare System, University of Iowa, Iowa City, Iowa, USA
| | - N Bhattarai
- Division of Cellular and Gene Therapies, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - J L Welch
- Iowa City Department of Veterans Affairs Healthcare System, University of Iowa, Iowa City, Iowa, USA
| | - T M Kaufman
- Iowa City Department of Veterans Affairs Healthcare System, University of Iowa, Iowa City, Iowa, USA
| | - Jack T Stapleton
- Iowa City Department of Veterans Affairs Healthcare System, University of Iowa, Iowa City, Iowa, USA
| |
Collapse
|
3
|
Hepatitis Viruses Control Host Immune Responses by Modifying the Exosomal Biogenesis Pathway and Cargo. Int J Mol Sci 2022; 23:ijms231810862. [PMID: 36142773 PMCID: PMC9505460 DOI: 10.3390/ijms231810862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022] Open
Abstract
The development of smart immune evasion mechanisms is crucial for the establishment of acute and chronic viral hepatitis. Hepatitis is a major health problem worldwide arising from different causes, such as pathogens, metabolic disorders, and xenotoxins, with the five hepatitis viruses A, B, C, D, and E (HAV, HBV, HCV, HDV, and HEV) representing the majority of the cases. Most of the hepatitis viruses are considered enveloped. Recently, it was reported that the non-enveloped HAV and HEV are, in reality, quasi-enveloped viruses exploiting exosomal-like biogenesis mechanisms for budding. Regardless, all hepatitis viruses use exosomes to egress, regulate, and eventually escape from the host immune system, revealing another key function of exosomes apart from their recognised role in intercellular communication. This review will discuss how the hepatitis viruses exploit exosome biogenesis and transport capacity to establish successful infection and spread. Then, we will outline the contribution of exosomes in viral persistence and liver disease progression.
Collapse
|
4
|
McKay LGA, Thomas J, Albalawi W, Fattaccioli A, Dieu M, Ruggiero A, McKeating JA, Ball JK, Tarr AW, Renard P, Pollakis G, Paxton WA. The HCV Envelope Glycoprotein Down-Modulates NF-κB Signalling and Associates With Stimulation of the Host Endoplasmic Reticulum Stress Pathway. Front Immunol 2022; 13:831695. [PMID: 35371105 PMCID: PMC8964954 DOI: 10.3389/fimmu.2022.831695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Following acute HCV infection, the virus establishes a chronic disease in the majority of patients whilst few individuals clear the infection spontaneously. The precise mechanisms that determine chronic HCV infection or spontaneous clearance are not completely understood but are proposed to be driven by host and viral genetic factors as well as HCV encoded immunomodulatory proteins. Using the HIV-1 LTR as a tool to measure NF-κB activity, we identified that the HCV E1E2 glycoproteins and more so the E2 protein down-modulates HIV-1 LTR activation in 293T, TZM-bl and the more physiologically relevant Huh7 liver derived cell line. We demonstrate this effect is specifically mediated through inhibiting NF-κB binding to the LTR and show that this effect was conserved for all HCV genotypes tested. Transcriptomic analysis of 293T cells expressing the HCV glycoproteins identified E1E2 mediated stimulation of the endoplasmic reticulum (ER) stress response pathway and upregulation of stress response genes such as ATF3. Through shRNA mediated inhibition of ATF3, one of the components, we observed that E1E2 mediated inhibitory effects on HIV-1 LTR activity was alleviated. Our in vitro studies demonstrate that HCV Env glycoprotein activates host ER Stress Pathways known to inhibit NF-κB activity. This has potential implications for understanding HCV induced immune activation as well as oncogenesis.
Collapse
Affiliation(s)
- Lindsay G. A. McKay
- Department of Clinical Infection, Microbiology and Immunology, Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Jordan Thomas
- Department of Clinical Infection, Microbiology and Immunology, Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Wejdan Albalawi
- Department of Clinical Infection, Microbiology and Immunology, Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Antoine Fattaccioli
- Laboratory of Biochemistry and Cell Biology (URBC), Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), Namur, Belgium
| | - Marc Dieu
- MaSUN, Mass Spectrometry Facility, University of Namur (UNamur), Namur, Belgium
| | - Alessandra Ruggiero
- Department of Clinical Infection, Microbiology and Immunology, Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Jane A. McKeating
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Jonathan K. Ball
- Wolfson Centre for Global Virus Research and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Alexander W. Tarr
- Wolfson Centre for Global Virus Research and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Patricia Renard
- Laboratory of Biochemistry and Cell Biology (URBC), Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), Namur, Belgium,MaSUN, Mass Spectrometry Facility, University of Namur (UNamur), Namur, Belgium
| | - Georgios Pollakis
- Department of Clinical Infection, Microbiology and Immunology, Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - William A. Paxton
- Department of Clinical Infection, Microbiology and Immunology, Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom,*Correspondence: William A. Paxton,
| |
Collapse
|
5
|
A short hepatitis C virus NS5A peptide expression by AAV vector modulates human T cell activation and reduces vector immunogenicity. Gene Ther 2022; 29:616-623. [PMID: 34759330 PMCID: PMC9091046 DOI: 10.1038/s41434-021-00302-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 01/09/2023]
Abstract
Viral vector-mediated gene therapies have the potential to treat many human diseases; however, host immune responses against the vector and/or the transgene pose a safety risk to the patients and can negatively impact product efficacy. Thus, novel strategies to reduce vector immunogenicity are critical for the advancement of these therapies. T cell activation (TCA) is required for the development of immune responses during gene therapy. We hypothesized that modulation of TCA by incorporating a novel viral immunomodulatory factor into a viral vector may reduce unwanted TCA and immune responses during gene therapy. To test this hypothesis, we identified an immunomodulatory domain of the hepatitis C virus (HCV) NS protein 5A (NS5A) protein and studied the effect of viral vectors expressing NS5A peptide on TCA. Lentiviral vector-mediated expression of a short 20-mer peptide derived from the NS5A protein in human T cells was sufficient to inhibit TCA. Synthetic 20-mer NS5A peptide also inhibited TCA in primary human T cells. Mechanistically, the NS5A protein interacted with Lck and inhibited proximal TCR signaling. Importantly, NS5A peptide expression did not cause global T cell signaling dysfunction as distal T cell signaling was not inhibited. Finally, recombinant adeno-associated virus (AAV) vector expressing the 20-mer NS5A peptide reduced both the recall antigen and the TCR-mediated activation of human T cells and did not cause global T cell signaling dysfunction. Together, these data suggest that expression of a 20-mer NS5A peptide by an AAV vector may reduce unwanted TCA and may contribute to lower vector immunogenicity during gene therapy.
Collapse
|
6
|
Keshavarz Alikhani H, Shokoohian B, Rezasoltani S, Hossein-Khannazer N, Yadegar A, Hassan M, Vosough M. Application of Stem Cell-Derived Extracellular Vesicles as an Innovative Theranostics in Microbial Diseases. Front Microbiol 2021; 12:785856. [PMID: 34917064 PMCID: PMC8669997 DOI: 10.3389/fmicb.2021.785856] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022] Open
Abstract
Extracellular vesicles (EVs), as nano-/micro-scale vehicles, are membranous particles containing various cargoes including peptides, proteins, different types of RNAs and other nucleic acids, and lipids. These vesicles are produced by all cell types, in which stem cells are a potent source for them. Stem cell-derived EVs could be promising platforms for treatment of infectious diseases and early diagnosis. Infectious diseases are responsible for more than 11 million deaths annually. Highly transmissible nature of some microbes, such as newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), drives researcher's interest to set up different strategies to develop novel therapeutic strategies. Recently, EVs-based diagnostic and therapeutic approaches have been launched and gaining momentum very fast. The efficiency of stem cell-derived EVs on treatment of clinical complications of different viruses and bacteria, such as SARS-CoV-2, hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), Staphylococcus aureus, Escherichia coli has been demonstrated. On the other hand, microbial pathogens are able to incorporate their components into their EVs. The microbe-derived EVs have different physiological and pathological impacts on the other organisms. In this review, we briefly discussed biogenesis and the fate of EVs. Then, EV-based therapy was described and recent developments in understanding the potential application of stem cell-derived EVs on pathogenic microorganisms were recapitulated. Furthermore, the mechanisms by which EVs were exploited to fight against infectious diseases were highlighted. Finally, the deriver challenges in translation of stem cell-derived EVs into the clinical arena were explored.
Collapse
Affiliation(s)
- Hani Keshavarz Alikhani
- Department of Regenerative Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research, Tehran, Iran
| | - Bahare Shokoohian
- Department of Regenerative Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research, Tehran, Iran
| | - Sama Rezasoltani
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nikoo Hossein-Khannazer
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Yadegar
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Moustapha Hassan
- Experimental Cancer Medicine, Institution for Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
| | - Massoud Vosough
- Department of Regenerative Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research, Tehran, Iran.,Experimental Cancer Medicine, Institution for Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
| |
Collapse
|
7
|
Occult Infection with Hepatitis C Virus: Looking for Clear-Cut Boundaries and Methodological Consensus. J Clin Med 2021; 10:jcm10245874. [PMID: 34945170 PMCID: PMC8707082 DOI: 10.3390/jcm10245874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 02/07/2023] Open
Abstract
The sustained virologic response and elimination of HCV is widely viewed as a true cure of chronic hepatitis C as it associates with amelioration of histological liver damage and improved clinical outcomes. Therefore, the existence and clinical burden of occult HCV infection (OCI) has been a controversial issue for many years. In this review, we summarize recently published data that adds new information on the molecular and clinical background of OCI and its epidemiological significance. We also identify and discuss the most important methodological pitfalls, which can be a source of inconsistency between studies. Data that have accumulated so far, strongly support the existence of extrahepatic HCV replication in individuals negative for serum HCV-RNA by conventional clinical tests. OCI emerges as a condition where the immune system is unable to fully resolve infection but it is continuously stimulated by low levels of HCV antigens, leading to progression of liver pathology and extrahepatic HCV-related complications. Moreover, the development of monitoring strategies or management guidelines for OCI is still hampered by the lack of clear definition and the confusion regarding its clinical significance. Careful study design and the introduction of uniform protocols for the detection of low-level HCV-RNA are crucial for obtaining reliable data on OCI.
Collapse
|
8
|
From Structural Studies to HCV Vaccine Design. Viruses 2021; 13:v13050833. [PMID: 34064532 PMCID: PMC8147963 DOI: 10.3390/v13050833] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) is a serious and growing public health problem despite recent developments of antiviral therapeutics. To achieve global elimination of HCV, an effective cross-genotype vaccine is needed. The failure of previous vaccination trials to elicit an effective cross-reactive immune response demands better vaccine antigens to induce a potent cross-neutralizing response to improve vaccine efficacy. HCV E1 and E2 envelope (Env) glycoproteins are the main targets for neutralizing antibodies (nAbs), which aid in HCV clearance and protection. Therefore, a molecular-level understanding of the nAb responses against HCV is imperative for the rational design of cross-genotype vaccine antigens. Here we summarize the recent advances in structural studies of HCV Env and Env-nAb complexes and how they improve our understanding of immune recognition of HCV. We review the structural data defining HCV neutralization epitopes and conformational plasticity of the Env proteins, and the knowledge applicable to rational vaccine design.
Collapse
|
9
|
Shi Y, Du L, Lv D, Li Y, Zhang Z, Huang X, Tang H. Emerging role and therapeutic application of exosome in hepatitis virus infection and associated diseases. J Gastroenterol 2021; 56:336-349. [PMID: 33665710 PMCID: PMC8005397 DOI: 10.1007/s00535-021-01765-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/23/2021] [Indexed: 02/05/2023]
Abstract
Hepatitis viruses are chief pathogens of hepatitis and end-stage liver diseases. Their replication and related pathogenic process highly rely on the host micro-environment and multiple cellular elements, including exosomes. Representing with a sort of cell-derived vesicle structure, exosomes were considered to be dispensable cellular components, even wastes. Along with advancing investigation, a specific profile of exosome in driving hepatitis viruses' infection and hepatic disease progression is revealed. Exosomes greatly affect the pathogenesis of hepatitis viruses by mediating their replication and modulating the host immune responses. The characteristics of host exosomes are markedly changed after infection with hepatitis viruses. Exosomes released from hepatitis virus-infected cells can carry viral nucleic or protein components, thereby acting as an effective subterfuge for hepatitis viruses by participating in viral transportation and immune escape. On the contrary, immune cell-derived exosomes contribute toward the innate antiviral immune defense and virus eradication. There is growing evidence supporting the application of exosomal biomarkers for predicting disease progress or therapeutic outcome, while exosomal nanoshuttles are regarded as promising therapeutic options based on their delivery properties and immune compatibility. In this review, we summarize the biogenesis and secretion mechanism of exosomes, review the recent findings pertaining to the role of exosomes in the interplay between hepatitis viruses and innate immune responses, and conclude their potential in further therapeutic application.
Collapse
Affiliation(s)
- Ying Shi
- Center of Infectious Diseases, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Wuhou District, Chengdu, 610041, Sichuan, China
- School of Medicine, University of Electronic Science and Technology of China, No. 4 Section 2, North Jianshe Road, Chengdu, 610054, Sichuan, China
- Department of Hepatobiliary Surgery and Cell Transplantation Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, No. 32 Western Section 2, 1st Ring Rd., Chengdu, 610072, Sichuan, China
| | - Lingyao Du
- Center of Infectious Diseases, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Wuhou District, Chengdu, 610041, Sichuan, China
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, No. 17 People's South Road, Chengdu, 610041, Sichuan, China
| | - Duoduo Lv
- Center of Infectious Diseases, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Wuhou District, Chengdu, 610041, Sichuan, China
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, No. 17 People's South Road, Chengdu, 610041, Sichuan, China
| | - Yan Li
- School of Medicine, University of Electronic Science and Technology of China, No. 4 Section 2, North Jianshe Road, Chengdu, 610054, Sichuan, China
- Department of Hepatobiliary Surgery and Cell Transplantation Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, No. 32 Western Section 2, 1st Ring Rd., Chengdu, 610072, Sichuan, China
| | - Zilong Zhang
- School of Medicine, University of Electronic Science and Technology of China, No. 4 Section 2, North Jianshe Road, Chengdu, 610054, Sichuan, China
- Department of Hepatobiliary Surgery and Cell Transplantation Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, No. 32 Western Section 2, 1st Ring Rd., Chengdu, 610072, Sichuan, China
| | - Xiaolun Huang
- School of Medicine, University of Electronic Science and Technology of China, No. 4 Section 2, North Jianshe Road, Chengdu, 610054, Sichuan, China
- Department of Hepatobiliary Surgery and Cell Transplantation Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, No. 32 Western Section 2, 1st Ring Rd., Chengdu, 610072, Sichuan, China
| | - Hong Tang
- Center of Infectious Diseases, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Wuhou District, Chengdu, 610041, Sichuan, China.
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, No. 17 People's South Road, Chengdu, 610041, Sichuan, China.
| |
Collapse
|
10
|
Castro-Sanchez P, Teagle AR, Prade S, Zamoyska R. Modulation of TCR Signaling by Tyrosine Phosphatases: From Autoimmunity to Immunotherapy. Front Cell Dev Biol 2020; 8:608747. [PMID: 33425916 PMCID: PMC7793860 DOI: 10.3389/fcell.2020.608747] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023] Open
Abstract
Early TCR signaling is dependent on rapid phosphorylation and dephosphorylation of multiple signaling and adaptor proteins, leading to T cell activation. This process is tightly regulated by an intricate web of interactions between kinases and phosphatases. A number of tyrosine phosphatases have been shown to modulate T cell responses and thus alter T cell fate by negatively regulating early TCR signaling. Mutations in some of these enzymes are associated with enhanced predisposition to autoimmunity in humans, and mouse models deficient in orthologous genes often show T cell hyper-activation. Therefore, phosphatases are emerging as potential targets in situations where it is desirable to enhance T cell responses, such as immune responses to tumors. In this review, we summarize the current knowledge about tyrosine phosphatases that regulate early TCR signaling and discuss their involvement in autoimmunity and their potential as targets for tumor immunotherapy.
Collapse
Affiliation(s)
- Patricia Castro-Sanchez
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Alexandra R Teagle
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Sonja Prade
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Rose Zamoyska
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
11
|
Tzarum N, Giang E, Kadam RU, Chen F, Nagy K, Augestad EH, Velázquez-Moctezuma R, Keck ZY, Hua Y, Stanfield RL, Dreux M, Prentoe J, Foung SKH, Bukh J, Wilson IA, Law M. An alternate conformation of HCV E2 neutralizing face as an additional vaccine target. SCIENCE ADVANCES 2020; 6:eabb5642. [PMID: 32754640 PMCID: PMC7380959 DOI: 10.1126/sciadv.abb5642] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/12/2020] [Indexed: 05/11/2023]
Abstract
To achieve global elimination of hepatitis C virus (HCV), an effective cross-genotype vaccine is needed. The HCV envelope glycoprotein E2 is the main target for neutralizing antibodies (nAbs), which aid in HCV clearance and protection. E2 is structurally flexible and functions in engaging host receptors. Many nAbs bind to the "neutralizing face" on E2, including several broadly nAbs encoded by the VH1-69 germline gene family that bind to a similar conformation (A) of this face. Here, a previously unknown conformation (B) of the neutralizing face is revealed in crystal structures of two of four additional E2-VH1-69 nAb complexes. In this conformation, the E2 front-layer region is displaced upon antibody binding, exposing residues in the back layer for direct antibody interaction. This E2 B structure may represent another conformational state in the viral entry process that is susceptible to antibody neutralization and thus provide a new target for rational vaccine development.
Collapse
Affiliation(s)
- Netanel Tzarum
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Erick Giang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Rameshwar U. Kadam
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Fang Chen
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kenna Nagy
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Elias H. Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rodrigo Velázquez-Moctezuma
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yuanzi Hua
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Robyn L. Stanfield
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Marlene Dreux
- CIRI, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, École Normale Supérieure de Lyon, Univ Lyon, F-69007, Lyon, France
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Steven K. H. Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Corresponding author. (M.L.); (I.A.W.)
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Corresponding author. (M.L.); (I.A.W.)
| |
Collapse
|
12
|
Welch JL, Kaufman TM, Stapleton JT, Okeoma CM. Semen exosomes inhibit HIV infection and HIV-induced proinflammatory cytokine production independent of the activation state of primary lymphocytes. FEBS Lett 2019; 594:695-709. [PMID: 31665815 DOI: 10.1002/1873-3468.13653] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 10/09/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022]
Abstract
Semen exosomes (SE) inhibit HIV infection. However, the effect of SE on cell activation and inflammation remains unknown. We characterized the response of peripheral blood mononuclear cells (PBMCs) from HIV-uninfected and antiretroviral therapy-suppressed HIV-infected (HIV+) subjects to SE. Quiescent PBMCs or T-cell receptor (TCR)-activated PBMCs from HIV- and HIV+ donors were stimulated with SE in the presence/absence of ex vivo HIV infection. In HIV-infected PBMCs, SE did not reactivate HIV, did not induce lymphoblast development, nor increase CD69+/CD25+ numbers. Furthermore, SE inhibited de novo HIV infection without altering cell activation. SE also asynchronously downregulated HIV-inducible IL1β, IL8, and TNFα and upregulated CXCL10. These data suggest that SE inhibits HIV infection and production of HIV-induced proinflammatory cytokines while preserving lymphocyte activation.
Collapse
Affiliation(s)
- Jennifer L Welch
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Medical Service, Iowa City Veterans Affairs Medical Center, IA, USA
| | - Thomas M Kaufman
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Medical Service, Iowa City Veterans Affairs Medical Center, IA, USA
| | - Jack T Stapleton
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Medical Service, Iowa City Veterans Affairs Medical Center, IA, USA
| | - Chioma M Okeoma
- Department of Pharmacology, Stony Brook University Renaissance School of Medicine, NY, USA
| |
Collapse
|
13
|
Welch JL, Stapleton JT, Okeoma CM. Vehicles of intercellular communication: exosomes and HIV-1. J Gen Virol 2019; 100:350-366. [PMID: 30702421 PMCID: PMC7011712 DOI: 10.1099/jgv.0.001193] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 11/15/2018] [Indexed: 12/20/2022] Open
Abstract
The terms extracellular vesicles, microvesicles, oncosomes, or exosomes are often used interchangeably as descriptors of particles that are released from cells and comprise a lipid membrane that encapsulates nucleic acids and proteins. Although these entities are defined based on a specific size range and/or mechanism of release, the terminology is often ambiguous. Nevertheless, these vesicles are increasingly recognized as important modulators of intercellular communication. The generic characterization of extracellular vesicles could also be used as a descriptor of enveloped viruses, highlighting the fact that extracellular vesicles and enveloped viruses are similar in both composition and function. Their high degree of similarity makes differentiating between vesicles and enveloped viruses in biological specimens particularly difficult. Because viral particles and extracellular vesicles are produced simultaneously in infected cells, it is necessary to separate these populations to understand their independent functions. We summarize current understanding of the similarities and differences of extracellular vesicles, which henceforth we will refer to as exosomes, and the enveloped retrovirus, HIV-1. Here, we focus on the presence of these particles in semen, as these are of particular importance during HIV-1 sexual transmission. While there is overlap in the terminology and physical qualities between HIV-1 virions and exosomes, these two types of intercellular vehicles may differ depending on the bio-fluid source. Recent data have demonstrated that exosomes from human semen serve as regulators of HIV-1 infection that may contribute to the remarkably low risk of infection per sexual exposure.
Collapse
Affiliation(s)
- Jennifer L. Welch
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 200 Hawkins Drive, Iowa City, IA 52242-1109, USA
- Medical Service, Iowa City Veterans Affairs Medical Center, University of Iowa, 604 Highway 6, Iowa City, IA 52246-2208, USA
| | - Jack T. Stapleton
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 200 Hawkins Drive, Iowa City, IA 52242-1109, USA
- Medical Service, Iowa City Veterans Affairs Medical Center, University of Iowa, 604 Highway 6, Iowa City, IA 52246-2208, USA
| | - Chioma M. Okeoma
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
- Department of Pharmacologic Sciences, Basic Sciences Tower, Rm 8-142, Stony Brook, University School of Medicine, Stony Brook, NY 11794-8651, USA
| |
Collapse
|
14
|
McLinden JH, Bhattarai N, Stapleton JT, Chang Q, Kaufman TM, Cassel SL, Sutterwala FS, Haim H, Houtman JC, Xiang J. Yellow Fever Virus, but Not Zika Virus or Dengue Virus, Inhibits T-Cell Receptor-Mediated T-Cell Function by an RNA-Based Mechanism. J Infect Dis 2017; 216:1164-1175. [PMID: 28968905 PMCID: PMC5853456 DOI: 10.1093/infdis/jix462] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 08/13/2017] [Indexed: 01/03/2023] Open
Abstract
The Flavivirus genus within the Flaviviridae family is comprised of many important human pathogens including yellow fever virus (YFV), dengue virus (DENV), and Zika virus (ZKV), all of which are global public health concerns. Although the related flaviviruses hepatitis C virus and human pegivirus (formerly named GBV-C) interfere with T-cell receptor (TCR) signaling by novel RNA and protein-based mechanisms, the effect of other flaviviruses on TCR signaling is unknown. Here, we studied the effect of YFV, DENV, and ZKV on TCR signaling. Both YFV and ZKV replicated in human T cells in vitro; however, only YFV inhibited TCR signaling. This effect was mediated at least in part by the YFV envelope (env) protein coding RNA. Deletion mutagenesis studies demonstrated that expression of a short, YFV env RNA motif (vsRNA) was required and sufficient to inhibit TCR signaling. Expression of this vsRNA and YFV infection of T cells reduced the expression of a Src-kinase regulatory phosphatase (PTPRE), while ZKV infection did not. YFV infection in mice resulted in impaired TCR signaling and PTPRE expression, with associated reduction in murine response to experimental ovalbumin vaccination. Together, these data suggest that viruses within the flavivirus genus inhibit TCR signaling in a species-dependent manner.
Collapse
Affiliation(s)
- James H McLinden
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Nirjal Bhattarai
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Jack T Stapleton
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
- Department of Microbiology, University of Iowa, Iowa City
| | - Qing Chang
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Thomas M Kaufman
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Suzanne L Cassel
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Fayyaz S Sutterwala
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Hillel Haim
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Jon C Houtman
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
- Department of Microbiology, University of Iowa, Iowa City
| | - Jinhua Xiang
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| |
Collapse
|
15
|
Baer A, Colon-Moran W, Xiang J, Stapleton JT, Bhattarai N. Src-family kinases negatively regulate NFAT signaling in resting human T cells. PLoS One 2017; 12:e0187123. [PMID: 29073235 PMCID: PMC5658144 DOI: 10.1371/journal.pone.0187123] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/13/2017] [Indexed: 01/30/2023] Open
Abstract
T cell signaling is required for activation of both natural and therapeutic T cells including chimeric antigen receptor (CAR) T cells. Identification of novel factors and pathways regulating T cell signaling may aid in development of effective T cell therapies. In resting human T cells, the majority of Src-family of tyrosine kinases (SFKs) are inactive due to phosphorylation of a conserved carboxy-terminal tyrosine residue. Recently, a pool of enzymatically active SFKs has been identified in resting T cells; however, the significance of these is incompletely understood. Here, we characterized the role of active SFKs in resting human T cells. Pharmacologic inhibition of active SFKs enhanced distal TCR signaling as measured by IL-2 release and CD25 surface expression following TCR-independent activation. Mechanistically, inhibition of the active pool of SFKs induced nuclear translocation of NFAT1, and enhanced NFAT1-dependent signaling in resting T cells. The negative regulation of NFAT1 signaling was in part mediated by the Src-kinase Lck as human T cells lacking Lck had increased levels of nuclear NFAT1 and demonstrated enhanced NFAT1-dependent gene expression. Inhibition of active SFKs in resting primary human T cells also increased nuclear NFAT1 and enhanced NFAT1-dependent signaling. Finally, the calcineurin inhibitor FK506 and Cyclosporin A reversed the effect of SFKs inhibition on NFAT1. Together, these data identified a novel role of SFKs in preventing aberrant NFAT1 activation in resting T cells, and suggest that maintaining this pool of active SFKs in therapeutic T cells may increase the efficacy of T cell therapies.
Collapse
Affiliation(s)
- Alan Baer
- Division of Cellular and Gene Therapies, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland
| | - Winston Colon-Moran
- Division of Cellular and Gene Therapies, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland
| | - Jinhua Xiang
- Research Service, Iowa City Veterans Affairs Medical Center, and the Department of Internal Medicine, University of Iowa, Iowa City, IA
| | - Jack T. Stapleton
- Research Service, Iowa City Veterans Affairs Medical Center, and the Department of Internal Medicine, University of Iowa, Iowa City, IA
| | - Nirjal Bhattarai
- Division of Cellular and Gene Therapies, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland
- * E-mail:
| |
Collapse
|
16
|
Abstract
Hepatitis C virus (HCV) infects more than 170 million people worldwide and is the main cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Although the newly developed direct-acting antivirals (DAAs) have transformed the treatment of HCV infection, controlling HCV infection on a global scale remains a challenge because of the high cost, low resistance barrier of DAAs and lack of HCV vaccine. The host immune responses associated with HCV infection, especially HCV-specific T cellular immunity, determine the outcome of HCV infection: either acute or chronic infection. It is important to fully interpret the immunopathogenesis of HCV infection and consequently to exploit effective strategies to eliminate HCV. Here, we review the current progress in HCV immunology, which will deepen our understanding of the spectrum of HCV infection and immunity in humans.
Collapse
Affiliation(s)
- Jijing Shi
- Department of Infectious Diseases, Beijing 302 Hospital, Beijing, 100039, China
| | - Yuanyuan Li
- Department of Infectious Diseases, Beijing 302 Hospital, Beijing, 100039, China
| | | | - Xuexiu Zhang
- Department of Gastroenterology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 460000, China
| | - Fu-Sheng Wang
- Department of Infectious Diseases, Beijing 302 Hospital, Beijing, 100039, China.
| |
Collapse
|
17
|
Graft Versus Host Disease After Liver Transplantation in Adults: A Case series, Review of Literature, and an Approach to Management. Transplantation 2017; 100:2661-2670. [PMID: 27495762 DOI: 10.1097/tp.0000000000001406] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Graft-versus-host-disease (GVHD) after liver transplantation (LT) is a deadly complication with very limited data on risk factors, diagnosis and management. We report a case series and a comprehensive review of the literature. METHODS Data were systematically extracted from reports of GVHD after LT, and from the United Network for Organ Sharing database. Group comparisons were performed. RESULTS One hundred fifty-six adult patients with GVHD after LT have been reported. Median time to GVHD onset was 28 days. Clinical features were skin rash (92%), pancytopenia (78%), and diarrhea (65%). Six-month mortality with GVHD after LT was 73%. Sepsis was the most common cause of death (60%). Enterobacter bacteremia, invasive aspergillosis, and disseminated Candida infections were frequently reported. Recipient age over 50 years is a risk factor for GVHD after LT. Hepatocellular carcinoma was overrepresented, whereas chronic hepatitis C was underrepresented, in reported United States GVHD cases relative to all United Network for Organ Sharing database LT cases. Mortality rate with treatment of GVHD after LT was 84% with high-dose steroids alone, 75% to 100% with regimens using dose increases of calcineurin inhibitors, and 55% with IL-2 antagonists. Mortality was 25% in small case series using the CD2-blocker alefacept or TNF-α antagonists. CONCLUSIONS Age older than 50 years and hepatocellular carcinoma appear to be risk factors for GVHD. Hepatitis C may be protective. High-dose steroids and calcineurin inhibitors are ineffective in the treatment of GVHD after LT. CD2-blockers and TNF-α antagonists appear promising. We propose a diagnostic algorithm to assist clinicians in managing adults with GVHD after LT.
Collapse
|
18
|
Hepatitis C virus infection inhibits a Src-kinase regulatory phosphatase and reduces T cell activation in vivo. PLoS Pathog 2017; 13:e1006232. [PMID: 28235043 PMCID: PMC5342304 DOI: 10.1371/journal.ppat.1006232] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/08/2017] [Accepted: 02/12/2017] [Indexed: 12/31/2022] Open
Abstract
Among human RNA viruses, hepatitis C virus (HCV) is unusual in that it causes persistent infection in the majority of infected people. To establish persistence, HCV evades host innate and adaptive immune responses by multiple mechanisms. Recent studies identified virus genome-derived small RNAs (vsRNAs) in HCV-infected cells; however, their biological significance during human HCV infection is unknown. One such vsRNA arising from the hepatitis C virus (HCV) E2 coding region impairs T cell receptor (TCR) signaling by reducing expression of a Src-kinase regulatory phosphatase (PTPRE) in vitro. Since TCR signaling is a critical first step in T cell activation, differentiation, and effector function, its inhibition may contribute towards HCV persistence in vivo. The effect of HCV infection on PTPRE expression in vivo has not been examined. Here, we found that PTPRE levels were significantly reduced in liver tissue and peripheral blood mononuclear cells (PBMCs) obtained from HCV-infected humans compared to uninfected controls. Loss of PTPRE expression impaired antigen-specific TCR signaling, and curative HCV therapy restored PTPRE expression in PBMCs; restoring antigen-specific TCR signaling defects. The extent of PTPRE expression correlated with the amount of sequence complementarity between the HCV E2 vsRNA and the PTPRE 3' UTR target sites. Transfection of a hepatocyte cell line with full-length HCV RNA or with synthetic HCV vsRNA duplexes inhibited PTPRE expression, recapitulating the in vivo observation. Together, these data demonstrate that HCV infection reduces PTPRE expression in the liver and PBMCs of infected humans, and suggest that the HCV E2 vsRNA is a novel viral factor that may contribute towards viral persistence.
Collapse
|
19
|
Mele D, Mantovani S, Oliviero B, Grossi G, Ludovisi S, Mondelli MU, Varchetta S. Hepatitis C virus inhibits CD4 T cell function via binding to Toll-like receptor 7. Antiviral Res 2016; 137:108-111. [PMID: 27876497 DOI: 10.1016/j.antiviral.2016.11.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/21/2016] [Accepted: 11/07/2016] [Indexed: 12/31/2022]
Abstract
Toll-like receptor 7 (TLR7) is a ssRNA receptor that activates dendritic cells and macrophages upon ssRNA binding; however, little is known of its role in CD4+ T cells. We show here that hepatitis C virus (HCV) induces a dose dependent inhibition of cytokine production and expression of activation markers in CD4 T cells, which were restored by a TLR7-specific antagonist. These findings indicate that HCV induces CD4 T cell impairment via TLR7 which may contribute to failure of virus eradication, casting doubts on the use of TLR7 agonists to boost innate immunity in chronic RNA virus infections.
Collapse
Affiliation(s)
- Dalila Mele
- Division of Infectious Diseases and Immunology, Department of Medical Sciences and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
| | - Stefania Mantovani
- Division of Infectious Diseases and Immunology, Department of Medical Sciences and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
| | - Barbara Oliviero
- Division of Infectious Diseases and Immunology, Department of Medical Sciences and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
| | - Giulia Grossi
- Division of Infectious Diseases and Immunology, Department of Medical Sciences and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
| | - Serena Ludovisi
- Internal Medicine and Hepatology Unit, Humanitas Research Hospital, Rozzano, Milan, Italy.
| | - Mario U Mondelli
- Division of Infectious Diseases and Immunology, Department of Medical Sciences and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.
| | - Stefania Varchetta
- Division of Infectious Diseases and Immunology, Department of Medical Sciences and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
| |
Collapse
|
20
|
Quarleri JF, Oubiña JR. Hepatitis C virus strategies to evade the specific-T cell response: a possible mission favoring its persistence. Ann Hepatol 2016; 15:17-26. [PMID: 26626636 DOI: 10.5604/16652681.1184193] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hepatitis C virus (HCV) is a small, enveloped RNA virus. The number of HCV-infected individuals worldwide is estimated to be approximately 200 million. The vast majority of HCV infections persist, with up to 80% of all cases leading to chronic hepatitis associated with liver fibrosis, cirrhosis, and hepatocellular carcinoma. The interaction between HCV and the host have a pivotal role in viral fitness, persistence, pathogenicity, and disease progression. The control of HCV infection requires both effective innate and adaptive immune responses. The HCV clearance during acute infection is associated with an early induction of the innate and a delayed initiation of the adaptive immune responses. However, in the vast majority of acute HCV infections, these responses are overcome and the virus persistence almost inexorably occurs. Recently, several host- and virus-related mechanisms responsible for the failure of both the innate and the adaptive immune responses have been recognized. Among the latter, the wide range of escape mutations to evade the specific-T-and B-cell responses as well as the T cell anergy and the CD8+ T cell exhaustion together with the interference with its function after prolonged virus exposure hold a pivotal role. Other HCV strategies include the modification or manipulation of molecules playing key roles in the induction of the interferon response and its induced effector proteins. In this review, we attempt to gain insights on the main T cell immune evasion strategies used by the virus in order to favor its persistence.
Collapse
Affiliation(s)
- Jorge Fabián Quarleri
- Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Universidad de Buenos Aires-CONICET, Argentina
| | - José Raúl Oubiña
- Instituto de Microbiología y Parasitología Médica (IMPAM), Universidad de Buenos Aires-CONICET, Argentina
| |
Collapse
|
21
|
Abstract
Extracellular vesicles (EVs) released by various cells are small phospholipid membrane-enclosed entities that can carry miRNA. They are now central to research in many fields of biology because they seem to constitute a new system of cell-cell communication. Physical and chemical characteristics of many EVs, as well as their biogenesis pathways, resemble those of retroviruses. Moreover, EVs generated by virus-infected cells can incorporate viral proteins and fragments of viral RNA, being thus indistinguishable from defective (noninfectious) retroviruses. EVs, depending on the proteins and genetic material incorporated in them, play a significant role in viral infection, both facilitating and suppressing it. Deciphering the mechanisms of EV-cell interactions may facilitate the design of EVs that inhibit viral infection and can be used as vehicles for targeted drug delivery.
Collapse
|
22
|
Abstract
The past decade has seen tremendous progress in understanding hepatitis C virus (HCV) biology and its related disease, hepatitis C. Major advances in characterizing viral replication have led to the development of direct-acting anti-viral therapies that have considerably improved patient treatment outcome and can even cure chronic infection. However, the high cost of these treatments, their low barrier to viral resistance, and their inability to prevent HCV-induced liver cancer, along with the absence of an effective HCV vaccine, all underscore the need for continued efforts to understand the biology of this virus. Moreover, beyond informing therapies, enhanced knowledge of HCV biology is itself extremely valuable for understanding the biology of related viruses, such as dengue virus, which is becoming a growing global health concern. Major advances have been realized over the last few years in HCV biology and pathogenesis, such as the discovery of the envelope glycoprotein E2 core structure, the generation of the first mouse model with inheritable susceptibility to HCV, and the characterization of virus-host interactions that regulate viral replication or innate immunity. Here, we review the recent findings that have significantly advanced our understanding of HCV and highlight the major challenges that remain.
Collapse
Affiliation(s)
- Florian Douam
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ, 08544, USA
| | - Qiang Ding
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ, 08544, USA
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ, 08544, USA
| |
Collapse
|