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1.
Viruses ; 13(10)2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34696506

RESUMO

Infections with viral pathogens are widespread and can cause a variety of different diseases. In-depth knowledge about viral triggers initiating an immune response is necessary to decipher viral pathogenesis. Inflammasomes, as part of the innate immune system, can be activated by viral pathogens. However, viral structural components responsible for inflammasome activation remain largely unknown. Here we analyzed glycoproteins derived from SARS-CoV-1/2, HCMV and HCV, required for viral entry and fusion, as potential triggers of NLRP3 inflammasome activation and pyroptosis in THP-1 macrophages. All tested glycoproteins were able to potently induce NLRP3 inflammasome activation, indicated by ASC-SPECK formation and secretion of cleaved IL-1ß. Lytic cell death via gasdermin D (GSDMD), pore formation, and pyroptosis are required for IL-1ß release. As a hallmark of pyroptosis, we were able to detect cleavage of GSDMD and, correspondingly, cell death in THP-1 macrophages. CRISPR-Cas9 knockout of NLRP3 and GSDMD in THP-1 macrophages confirmed and strongly support the evidence that viral glycoproteins can act as innate immunity triggers. With our study, we decipher key mechanisms of viral pathogenesis by showing that viral glycoproteins potently induce innate immune responses. These insights could be beneficial in vaccine development and provide new impulses for the investigation of vaccine-induced innate immunity.


Assuntos
Imunidade Inata/imunologia , Inflamassomos/imunologia , Macrófagos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteínas do Envelope Viral/imunologia , Proteínas Virais de Fusão/imunologia , Linhagem Celular Tumoral , Citomegalovirus/imunologia , Hepacivirus/imunologia , Humanos , Interleucina-1beta/biossíntese , Interleucina-1beta/imunologia , Piroptose/imunologia , Vírus da SARS/imunologia , SARS-CoV-2/imunologia , Células THP-1
2.
Front Immunol ; 12: 654998, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34531848

RESUMO

HCV core protein is the first structural protein synthesized during hepatitis C virus (HCV) infection and replication. It is released from virus infected liver cells and mediates multiple functions to affect host cell response. The innate immune response is the first line of defense against viral infection. After HCV infection, Kupffer cells (KCs) which are liver macrophages play an important role in host innate immune response. Kupffer cells act as phagocytes and release different cytokines and chemokines to counter viral infection and regulate inflammation and fibrosis in liver. Earlier, we have demonstrated that HCV core protein interacts with gC1qR and activates MAPK, NF-κB and PI3K/AKT pathways in macrophages. In this study, we explored the effect of HCV core protein on CCL2 and CXCL10 expression in macrophages and the signaling pathways involved. Upon silencing of gC1qR, we observed a significant decrease expression of CCL2 and CXCL10 in macrophages in the presence of HCV core protein. Inhibiting NF-κB pathway, but not P38, JNK, ERK and AKT pathways greatly reduced the expression of CCL2 and CXCL10. Therefore, our results indicate that interaction of HCV core protein with gC1qR could induce CCL2 and CXCL10 secretion in macrophages via NF-κB signaling pathway. These findings may shed light on the understanding of how leukocytes migrate into the liver and exaggerate host-derived immune responses and may provide novel therapeutic targets in HCV chronic inflammation.


Assuntos
Quimiocina CCL2/imunologia , Quimiocina CXCL10/imunologia , Hepacivirus/imunologia , Macrófagos/imunologia , NF-kappa B/imunologia , Transdução de Sinais/imunologia , Proteínas do Core Viral/imunologia , Animais , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Expressão Gênica/imunologia , Hepacivirus/metabolismo , Hepacivirus/fisiologia , Hepatite C/imunologia , Hepatite C/metabolismo , Hepatite C/virologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Macrófagos do Fígado/imunologia , Macrófagos do Fígado/metabolismo , Macrófagos do Fígado/virologia , Macrófagos/metabolismo , Macrófagos/virologia , Camundongos , Camundongos Endogâmicos BALB C , Células RAW 264.7 , Células THP-1 , Proteínas do Core Viral/metabolismo
3.
Cells ; 10(9)2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34571900

RESUMO

Iron is crucial to the regulation of the host innate immune system and the outcome of many infections. Hepatitis C virus (HCV), one of the major viral human pathogens that depends on iron to complete its life cycle, is highly skilled in evading the immune system. This study presents the construction and validation of a physiologically relevant triple-cell co-culture model that was used to investigate the input of iron in HCV infection and the interplay between HCV, iron, and determinants of host innate immunity. We recorded the expression patterns of key proteins of iron homeostasis involved in iron import, export and storage and examined their relation to the iron regulatory hormone hepcidin in hepatocytes, enterocytes and macrophages in the presence and absence of HCV. We then assessed the transcriptional profiles of pro-inflammatory cytokines Interleukin-6 (IL-6) and interleukin-15 (IL-15) and anti-inflammatory interleukin-10 (IL-10) under normal or iron-depleted conditions and determined how these were affected by infection. Our data suggest the presence of a link between iron homeostasis and innate immunity unfolding among liver, intestine, and macrophages, which could participate in the deregulation of innate immune responses observed in early HCV infection. Coupled with iron-assisted enhanced viral propagation, such a mechanism may be important for the establishment of viral persistence and the ensuing chronic liver disease.


Assuntos
Enterócitos/patologia , Hepatite C/patologia , Hepatócitos/patologia , Homeostase , Imunidade Inata , Ferro/metabolismo , Macrófagos/patologia , Técnicas de Cocultura , Citocinas/metabolismo , Enterócitos/imunologia , Enterócitos/metabolismo , Enterócitos/virologia , Hepacivirus/imunologia , Hepacivirus/metabolismo , Hepatite C/imunologia , Hepatite C/metabolismo , Hepatite C/virologia , Hepatócitos/imunologia , Hepatócitos/metabolismo , Hepatócitos/virologia , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/virologia
4.
CMAJ Open ; 9(3): E897-E906, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34584004

RESUMO

BACKGROUND: Colonization and marginalization have affected the risk for and experience of hepatitis C virus (HCV) infection for First Nations people in Canada. In partnership with the Ontario First Nations HIV/AIDS Education Circle, we estimated the publicly borne health care costs associated with HCV infection among Status First Nations people in Ontario. METHODS: In this retrospective matched cohort study, we used linked health administrative databases to identify Status First Nations people in Ontario who tested positive for HCV antibodies or RNA between 2004 and 2014, and Status First Nations people who had no HCV testing records or only a negative test result (control group, matched 2:1 to case participants). We estimated total and net costs (difference between case and control participants) for 4 phases of care: prediagnosis (6 mo before HCV infection diagnosis), initial (after diagnosis), late (liver disease) and terminal (6 mo before death), until death or Dec. 31, 2017, whichever occurred first. We stratified costs by sex and residence within or outside of First Nations communities. All costs were measured in 2018 Canadian dollars. RESULTS: From 2004 to 2014, 2197 people were diagnosed with HCV infection. The mean net total costs per 30 days of HCV infection were $348 (95% confidence interval [CI] $277 to $427) for the prediagnosis phase, $377 (95% CI $288 to $470) for the initial phase, $1768 (95% CI $1153 to $2427) for the late phase and $893 (95% CI -$1114 to $3149) for the terminal phase. After diagnosis of HCV infection, net costs varied considerably among those who resided within compared to outside of First Nations communities. Net costs were higher for females than for males except in the terminal phase. INTERPRETATION: The costs per 30 days of HCV infection among Status First Nations people in Ontario increased substantially with progression to advanced liver disease and finally to death. These estimates will allow for planning and evaluation of provincial and territorial population-specific hepatitis C control efforts.


Assuntos
Custos de Cuidados de Saúde/estatística & dados numéricos , Hepacivirus , Hepatite C Crônica , Estudos de Casos e Controles , Bases de Dados Factuais/estatística & dados numéricos , Progressão da Doença , Feminino , Alocação de Recursos para a Atenção à Saúde/economia , Alocação de Recursos para a Atenção à Saúde/estatística & dados numéricos , Hepacivirus/genética , Hepacivirus/imunologia , Hepacivirus/isolamento & purificação , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/economia , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/fisiopatologia , Humanos , Canadenses Indígenas/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Ontário/epidemiologia , Estudos Retrospectivos , Análise de Sequência de RNA/estatística & dados numéricos , Testes Sorológicos/estatística & dados numéricos
5.
Nat Commun ; 12(1): 4882, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385466

RESUMO

Genetic variants of the interferon lambda (IFNL) gene locus are strongly associated with spontaneous and IFN treatment-induced clearance of hepatitis C virus (HCV) infections. Individuals with the ancestral IFNL4-dG allele are not able to clear HCV in the acute phase and have more than a 90% probability to develop chronic hepatitis C (CHC). Paradoxically, the IFNL4-dG allele encodes a fully functional IFNλ4 protein with antiviral activity against HCV. Here we describe an effect of IFNλ4 on HCV antigen presentation. Only minor amounts of IFNλ4 are secreted, because the protein is largely retained in the endoplasmic reticulum (ER) where it induces ER stress. Stressed cells are significantly weaker activators of HCV specific CD8+ T cells than unstressed cells. This is not due to reduced MHC I surface presentation or extracellular IFNλ4 effects, since T cell responses are restored by exogenous loading of MHC with HCV antigens. Rather, IFNλ4 induced ER stress impairs HCV antigen processing and/or loading onto the MHC I complex. Our results provide a potential explanation for the IFNλ4-HCV paradox.


Assuntos
Apresentação do Antígeno/imunologia , Linfócitos T CD8-Positivos/imunologia , Hepacivirus/imunologia , Interleucinas/imunologia , Ativação Linfocitária/imunologia , Células A549 , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Linhagem Celular Tumoral , Regulação da Expressão Gênica/imunologia , Genótipo , Células Hep G2 , Hepacivirus/genética , Hepacivirus/fisiologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Interleucinas/genética , Interleucinas/metabolismo
6.
J Med Virol ; 93(11): 6116-6123, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34375002

RESUMO

Virus invasion activates the host's innate immune response, inducing the production of numerous cytokines and interferons to eliminate pathogens. Except for viral DNA/RNA, viral proteins are also targets of pattern recognition receptors. Membrane-bound receptors such as Toll-like receptor (TLR)1, TLR2, TLR4, TLR6, and TLR10 relate to the recognition of viral proteins. Distinct TLRs perform both protective and detrimental roles for a specific virus. Here, we review viral proteins serving as pathogen-associated molecular patterns and their corresponding TLRs. These viruses are all enveloped, including respiratory syncytial virus, hepatitis C virus, measles virus, herpesvirus human immunodeficiency virus, and coronavirus, and can encode proteins to activate innate immunity in a TLR-dependent way. The TLR-viral protein relationship plays an important role in innate immunity activation. A detailed understanding of their pathways contributes to a novel direction for vaccine development.


Assuntos
Imunidade Inata , Padrões Moleculares Associados a Patógenos/metabolismo , Receptores Toll-Like/imunologia , Receptores Toll-Like/metabolismo , Proteínas Virais/metabolismo , Viroses/imunologia , Vírus/imunologia , Animais , HIV/imunologia , HIV/metabolismo , HIV/patogenicidade , Hepacivirus/imunologia , Hepacivirus/metabolismo , Hepacivirus/patogenicidade , Herpesviridae/imunologia , Herpesviridae/metabolismo , Herpesviridae/patogenicidade , Humanos , Vírus do Sarampo/imunologia , Vírus do Sarampo/metabolismo , Vírus do Sarampo/patogenicidade , Padrões Moleculares Associados a Patógenos/química , Vírus Sinciciais Respiratórios/imunologia , Vírus Sinciciais Respiratórios/metabolismo , Vírus Sinciciais Respiratórios/patogenicidade , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Proteínas Virais/química , Viroses/virologia , Vírus/metabolismo , Vírus/patogenicidade
7.
Viruses ; 13(7)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34372558

RESUMO

Thirty years after its discovery, the hepatitis C virus (HCV) remains a leading cause of liver disease worldwide. Given that many countries continue to experience high rates of transmission despite the availability of potent antiviral therapies, an effective vaccine is seen as critical for the elimination of HCV. The recent failure of the first vaccine efficacy trial for the prevention of chronic HCV confirmed suspicions that this virus will be a challenging vaccine target. Here, we examine the published data from this first efficacy trial along with the earlier clinical and pre-clinical studies of the vaccine candidate and then discuss three key research directions expected to be important in ongoing and future HCV vaccine development. These include the following: 1. design of novel immunogens that generate immune responses to genetically diverse HCV genotypes and subtypes, 2. strategies to elicit broadly neutralizing antibodies against envelope glycoproteins in addition to cytotoxic and helper T cell responses, and 3. consideration of the unique immunological status of individuals most at risk for HCV infection, including those who inject drugs, in vaccine platform development and early immunogenicity trials.


Assuntos
Hepacivirus/genética , Hepatite C/prevenção & controle , Vacinas contra Hepatite Viral/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Hepacivirus/imunologia , Hepacivirus/patogenicidade , Hepatite C/virologia , Anticorpos Anti-Hepatite C/imunologia , Antígenos da Hepatite C/imunologia , Humanos , Proteínas do Envelope Viral/genética , Vacinas contra Hepatite Viral/farmacologia
8.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360889

RESUMO

Despite extensive research, there is still no vaccine against the hepatitis C virus (HCV). The aim of this study was to investigate whether MSCs can exhibit adjuvant properties during DNA vaccination against hepatitis C. We used the pcNS3-NS5B plasmid encoding five nonstructural HCV proteins and MSCs derived from mice bone marrow. Five groups of DBA mice were immunized with the plasmid and/or MSCs in a different order. Group 1 was injected with the plasmid twice at intervals of 3 weeks; Group 2 with the plasmid, and after 24 h with MSCs; Group 3 with MSCs followed by the plasmid the next day; Group 4 with only MSCs; and Group 5 with saline. When the MSCs were injected prior to DNA immunization, the cell immune response to HCV proteins assessed by the level of IFN-γ synthesis was markedly increased compared to DNA alone. In contrast, MSCs injected after DNA suppressed the immune response. Apparently, the high level of proinflammatory cytokines detected after DNA injection promotes the conversion of MSCs introduced later into the immunosuppressive MSC2. The low level of cytokines in mice before MSC administration promotes the high immunostimulatory activity of MSC1 in response to a DNA vaccine. Thus, when administered before DNA, MSCs are capable of exhibiting promising adjuvant properties.


Assuntos
Genes Virais/imunologia , Hepacivirus/genética , Hepacivirus/imunologia , Hepatite C/prevenção & controle , Imunidade Celular , Células-Tronco Mesenquimais/imunologia , Vacinação/métodos , Vacinas de DNA/administração & dosagem , Proteínas não Estruturais Virais/genética , Animais , Linhagem Celular Tumoral , Citocinas/metabolismo , Feminino , Hepatite C/imunologia , Hepatite C/virologia , Humanos , Camundongos , Camundongos Endogâmicos DBA , Plasmídeos/genética , Linfócitos T/imunologia , Transfecção , Resultado do Tratamento , Vacinas de DNA/imunologia
9.
J Immunol ; 207(4): 1180-1193, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34341170

RESUMO

Hepatitis C virus (HCV) infection resolves spontaneously in ∼25% of acutely infected humans where viral clearance is mediated primarily by virus-specific CD8+ T cells. Previous cross-sectional analysis of the CD8+ TCR repertoire targeting two immunodominant HCV epitopes reported widespread use of public TCRs shared by different subjects, irrespective of infection outcome. However, little is known about the evolution of the public TCR repertoire during acute HCV and whether cross-reactivity to other Ags can influence infectious outcome. In this article, we analyzed the CD8+ TCR repertoire specific to the immunodominant and cross-reactive HLA-A2-restricted nonstructural 3-1073 epitope during acute HCV in humans progressing to either spontaneous resolution or chronic infection and at ∼1 y after viral clearance. TCR repertoire diversity was comparable among all groups with preferential usage of the TCR-ß V04 and V06 gene families. We identified a set of 13 public clonotypes in HCV-infected humans independent of infection outcome. Six public clonotypes used the V04 gene family. Several public clonotypes were long-lived in resolvers and expanded on reinfection. By mining publicly available data, we identified several low-frequency CDR3 sequences in the HCV-specific repertoire matching human TCRs specific for other HLA-A2-restricted epitopes from melanoma, CMV, influenza A, EBV, and yellow fever viruses, but they were of low frequency and limited cross-reactivity. In conclusion, we identified 13 new public human CD8+ TCR clonotypes unique to HCV that expanded during acute infection and reinfection. The low frequency of cross-reactive TCRs suggests that they are not major determinants of infectious outcome.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Hepacivirus/imunologia , Hepatite C/imunologia , Reinfecção/imunologia , Células Clonais/imunologia , Estudos Transversais , Epitopos de Linfócito T/imunologia , Antígeno HLA-A2/imunologia , Humanos , Epitopos Imunodominantes/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia
10.
PLoS One ; 16(7): e0255336, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34329365

RESUMO

Yearly, about 1.5 million people become chronically infected with hepatitis C virus (HCV) and for the 71 million with chronic HCV infection about 400,000 die from related morbidities, including liver cirrhosis and cancer. Effective treatments exist, but challenges including cost-of-treatment and wide-spread undiagnosed infection, necessitates the development of vaccines. Vaccines should induce neutralizing antibodies (NAbs) against the HCV envelope (E) transmembrane glycoprotein 2, E2, which partly depends on its interaction partner, E1, for folding. Here, we generated three soluble HCV envelope protein antigens with the transmembrane regions deleted (i.e., fused peptide backbones), termed sE1E2 (E1 followed by E2), sE2E1 (E2 followed by E1), and sE21E (E2 followed by inverted E1). The E1 inversion for sE21E positions C-terminal residues of E1 near C-terminal residues of E2, which is in analogy to how they likely interact in native E1/E2 complexes. Probing conformational E2 epitope binding using HCV patient-derived human monoclonal antibodies, we show that sE21E was superior to sE2E1, which was consistently superior to sE1E2. This correlated with improved induction of NAbs by sE21E compared with sE2E1 and especially compared with sE1E2 in female BALB/c mouse immunizations. The deletion of the 27 N-terminal amino acids of E2, termed hypervariable region 1 (HVR1), conferred slight increases in antigenicity for sE2E1 and sE21E, but severely impaired induction of antibodies able to neutralize in vitro viruses retaining HVR1. Finally, comparing sE21E with sE2 in mouse immunizations, we show similar induction of heterologous NAbs. In summary, we find that C-terminal E2 fusion of E1 or 1E is superior to N-terminal fusion, both in terms of antigenicity and the induction of heterologous NAbs. This has relevance when designing HCV E1E2 vaccine antigens.


Assuntos
Antígenos Virais , Hepacivirus , Anticorpos Anti-Hepatite C/imunologia , Proteínas do Envelope Viral , Vacinas contra Hepatite Viral , Animais , Antígenos Virais/genética , Antígenos Virais/imunologia , Antígenos Virais/farmacologia , Avaliação de Medicamentos , Feminino , Células HEK293 , Hepacivirus/genética , Hepacivirus/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Solubilidade , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/farmacologia , Vacinas contra Hepatite Viral/genética , Vacinas contra Hepatite Viral/imunologia , Vacinas contra Hepatite Viral/farmacologia
11.
Nat Immunol ; 22(8): 1030-1041, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34312544

RESUMO

T cell exhaustion is associated with failure to clear chronic infections and malignant cells. Defining the molecular mechanisms of T cell exhaustion and reinvigoration is essential to improving immunotherapeutic modalities. Here we confirmed pervasive phenotypic, functional and transcriptional differences between memory and exhausted antigen-specific CD8+ T cells in human hepatitis C virus (HCV) infection before and after treatment. After viral cure, phenotypic changes in clonally stable exhausted T cell populations suggested differentiation toward a memory-like profile. However, functionally, the cells showed little improvement, and critical transcriptional regulators remained in the exhaustion state. Notably, T cells from chronic HCV infection that were exposed to antigen for less time because of viral escape mutations were functionally and transcriptionally more similar to memory T cells from spontaneously resolved HCV infection. Thus, the duration of T cell stimulation impacts exhaustion recovery, with antigen removal after long-term exhaustion being insufficient for the development of functional T cell memory.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Hepacivirus/imunologia , Hepatite C Crônica/imunologia , Memória Imunológica/imunologia , Antivirais/uso terapêutico , Diferenciação Celular/imunologia , Epitopos/genética , Hepatite C Crônica/tratamento farmacológico , Humanos , Fenótipo
13.
Nat Immunol ; 22(8): 1020-1029, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34312547

RESUMO

T cell exhaustion is an induced state of dysfunction that arises in response to chronic infection and cancer. Exhausted CD8+ T cells acquire a distinct epigenetic state, but it is not known whether that chromatin landscape is fixed or plastic following the resolution of a chronic infection. Here we show that the epigenetic state of exhaustion is largely irreversible, even after curative therapy. Analysis of chromatin accessibility in HCV- and HIV-specific responses identifies a core epigenetic program of exhaustion in CD8+ T cells, which undergoes only limited remodeling before and after resolution of infection. Moreover, canonical features of exhaustion, including super-enhancers near the genes TOX and HIF1A, remain 'epigenetically scarred.' T cell exhaustion is therefore a conserved epigenetic state that becomes fixed and persists independent of chronic antigen stimulation and inflammation. Therapeutic efforts to reverse T cell exhaustion may require new approaches that increase the epigenetic plasticity of exhausted T cells.


Assuntos
Antígenos Virais/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Hepacivirus/imunologia , Hepatite C Crônica/imunologia , Memória Imunológica/imunologia , 2-Naftilamina/uso terapêutico , Anilidas/uso terapêutico , Antivirais/uso terapêutico , Cromatina/metabolismo , Ciclopropanos/uso terapêutico , Epigênese Genética/genética , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Proteínas de Grupo de Alta Mobilidade/genética , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Lactamas Macrocíclicas/uso terapêutico , Prolina/análogos & derivados , Prolina/uso terapêutico , Ribavirina/uso terapêutico , Ritonavir/uso terapêutico , Sulfonamidas/uso terapêutico , Uracila/análogos & derivados , Uracila/uso terapêutico , Valina/uso terapêutico
14.
Viruses ; 13(6)2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070543

RESUMO

Development of preventive vaccines against hepatitis C virus (HCV) remains one of the main strategies in achieving global elimination of the disease. The effort is focused on the quest for vaccines capable of inducing protective cross-neutralizing humoral and cellular immune responses, which in turn dictate the need for rationally designed cross-genotype vaccine antigens and potent immunoadjuvants systems. This review provides an assessment of the current state of knowledge on immunopotentiating compounds and vaccine delivery systems capable of enhancing HCV antigen-specific immune responses, while focusing on the synergy and interplay of two modalities. Structural, physico-chemical, and biophysical features of these systems are discussed in conjunction with the analysis of their in vivo performance. Extreme genetic diversity of HCV-a well-known hurdle in the development of an HCV vaccine, may also present a challenge in a search for an effective immunoadjuvant, as the effort necessitates systematic and comparative screening of rationally designed antigenic constructs. The progress may be accelerated if the preference is given to well-defined molecular immunoadjuvants with greater formulation flexibility and adaptability, including those capable of spontaneous self-assembly behavior, while maintaining their robust immunopotentiating and delivery capabilities.


Assuntos
Sistemas de Liberação de Medicamentos , Hepacivirus/imunologia , Hepatite C/prevenção & controle , Imunogenicidade da Vacina , Vacinas contra Hepatite Viral/imunologia , Adjuvantes Imunológicos , Animais , Ensaios Clínicos como Assunto , Composição de Medicamentos , Hepatite C/imunologia , Humanos , Nanopartículas , Vacinas contra Hepatite Viral/administração & dosagem , Vacinas contra Hepatite Viral/química
15.
Curr Opin Virol ; 49: 92-101, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34091143

RESUMO

The molecular mechanisms of hepatitis C virus (HCV) persistence and pathogenesis are poorly understood. The design of an effective HCV vaccine is challenging despite a robust humoral immune response against closely related strains of HCV. This is primarily because of the huge genetic diversity of HCV and the molecular evolution of various virus escape mechanisms. These mechanisms are steered by the presence of a high mutational rate in HCV, structural plasticity of the immunodominant regions on the virion surface of diverse HCV genotypes, and constant amino acid substitutions on key structural components of HCV envelope glycoproteins. Here, we review the molecular basis of neutralizing antibody (nAb)-mediated immune response against diverse HCV variants, HCV-steered humoral immune evasion strategies and explore the essential structural elements to consider for designing a universal HCV vaccine. Structural perspectives on key escape pathways mediated by a point mutation within the epitope, allosteric modulation of the epitope by distant mutations and glycan shift on envelope glycoproteins will be highlighted (abstract graphic).


Assuntos
Hepacivirus/imunologia , Hepatite C Crônica/imunologia , Hepatite C Crônica/virologia , Evasão da Resposta Imune , Proteínas do Envelope Viral/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos Virais/química , Antígenos Virais/genética , Antígenos Virais/imunologia , Epitopos , Variação Genética , Hepacivirus/química , Hepacivirus/genética , Anticorpos Anti-Hepatite C/imunologia , Humanos , Imunidade Humoral , Epitopos Imunodominantes , Mutação , Conformação Proteica , Domínios Proteicos , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética
16.
BMC Infect Dis ; 21(1): 508, 2021 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-34059011

RESUMO

BACKGROUND: Hepatitis B and C infections and transmission are a serious challenge to all healthcare systems. We studied seroprevalence rates of Transfusion Transmitted Diseases (TTD) among blood bank donors in Jordan from 2014 to 2019 as a follow-up study of our previously published work. In addition, we wanted to explore the efficacy of the mandatory vaccination of infants against hepatitis B virus (HBV) which was implemented by the Ministry of Health since 1995 for the eradication of HBV infection in Jordan. METHODS: We reviewed blood bank donors' records at King Hussein Cancer Center (KHCC) from January 1st, 2014, until December 31st, 2019. Results of seropositivity prevalence rates for HBsAg, anti-HBcore, and anti-HCV, using Enzyme-Linked ImmunoSorbent Assay (ELISA) were compared to seropositivity rates from our previously published data. In addition, our results were compared to data obtained from other blood banks in Jordan, as well as compared to published information from blood banks in neighboring countries. RESULTS: The prevalence rates (%) of seropositive blood donors for viral hepatitis for the years 2014, 2015, 2016, 2017, 2018, and 2019, were as follows: HBsAg rates were 0.3386, 0.2108, 0.1801, 0.1898, 0.2068, and 0.2741; anti-HBcore rates were 4.1112, 3.2271, 2.9748, 2.8405, 2.6879 and 3.0986; and anti-HCV rates were 0.1129, 0.0486, 0.0548, 0.0654, 0.0782, and 0.0839, respectively. There was a significant increase in the prevalence of HBsAg, Anti-HBcore and Anti-HCV antibodies in 2019 (one sample z-score test, p < 0.00001). CONCLUSIONS: Prevalence rates of hepatitis B and C infections among Jordanian blood bank donors showed a steady decline between 2009 and 2017, and these rates were much lower in Jordan than in neighboring countries. However, an increase in the prevalence rates of hepatitis B and C infections among blood bank donors was documented in 2019. While the reasons for this increase are not clear yet, these findings highlight the importance of renewed efforts to increase public health awareness of HBV and implement effective measures to prevent the transmission and infection with HBV, including national vaccination programs.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Reação Transfusional/epidemiologia , Bancos de Sangue/estatística & dados numéricos , Hepacivirus/imunologia , Hepacivirus/isolamento & purificação , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/imunologia , Vírus da Hepatite B/isolamento & purificação , Hepatite C/diagnóstico , Hepatite C/epidemiologia , Hepatite C/prevenção & controle , Anticorpos Anti-Hepatite C/sangue , Humanos , Jordânia/epidemiologia , Prevalência , Estudos Soroepidemiológicos , Reação Transfusional/sangue , Reação Transfusional/prevenção & controle , Reação Transfusional/virologia , Vacinas contra Hepatite Viral/administração & dosagem
17.
West J Emerg Med ; 22(3): 719-725, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34125052

RESUMO

INTRODUCTION: In 2019 the United States Preventive Services Task Force (USPSTF) released draft guidelines recommending universal hepatitis C virus (HCV) screening for individuals aged 18-79. We aimed to assess the efficacy of an emergency department-based HCV screening program, by comparing screening practices before and after its implementation. METHODS: We performed a retrospective cohort analysis of two temporally matched, 11-month study periods, corresponding to before and after the implementation of a best practice advisory (BPA). Patients were screened for anti-HCV antibody (Ab), and positive results were followed by HCV viral load (VL) testing. The primary implementation outcome was ED testing volume (number of tests performed/month). The primary screening outcomes were the seroprevalence of anti-HCV Ab and HCV VL. We describe data with simple descriptive statistics. RESULTS: The median age of patients was similar between periods (pre: 50 years [interquartile range [IQR] 34-62], post: 47 years [IQR 33-59]). Patients screened were more likely to be males in the pre-BPA period (Male, pre: 60%, post: 49%). During the pre-BPA study period, a total of 69,604 patients were seen in the ED, and 218 unique patients were screened for HCV (mean 19.8 tests/month). During the post-BPA study period, a total of 68,225 patients were seen in the ED, and 14,981 unique patients were screened for HCV (mean 1361.9 tests/month). Anti-HCV Ab seroprevalence was 23% (51/218) and 9% (1340/14,981) in the pre-BPA and post-BPA periods, respectively. In the pre-BPA period, six patients with a positive anti-HCV Ab level had follow-up VL testing (detectable in three). In the post-BPA period, reflex VL testing was performed in most patients (91%, 1225/1,340), and there were 563 patients with detectable VLs, indicating active infection. CONCLUSION: Our study shows that using a universal BPA-driven screening protocol can dramatically increase the number of patients screened for HCV and increase the number of new HCV diagnoses.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Hepatite C/diagnóstico , Programas de Rastreamento/métodos , Adulto , Feminino , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/isolamento & purificação , Humanos , Masculino , Programas de Rastreamento/estatística & dados numéricos , Pessoa de Meia-Idade , Estudos Retrospectivos , Estudos Soroepidemiológicos , Estados Unidos
18.
J Immunol Methods ; 495: 113087, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34147479

RESUMO

Lack of a simple, high throughput antibody-dependent cellular phagocytosis (ADCP) assay has limited our understanding of its potential role of in hepatitis C (HCV) infection. Here, we optimised a flow-cytometry based ADCP assay using HCV envelope (E2)-protein coated microbeads that were opsonised with anti-E2 monoclonal IgG antibody (αE2 mAb) and the THP-1 monocyte cell line as effector cells. We found 1.5 × 109/ml microbeads opsonised with 5 µg/ml αE2 mAb and 1.6 × 106/ml THP-1 cells were optimal conditions to distinguish between healthy controls and patients with HCV. This optimised assay was then used to investigate ADCP in plasma obtained from 72 patients with chronic HCV infection and 15 healthy controls. We found that 75% of patients with genotype 1 and 87% of patients with genotype 3 HCV infection had significantly higher levels of ADCP compared to healthy controls. In patients, there was a significant correlation between increase in ADCP and higher concentrations of anti-E2 IgG antibodies in the plasma. Taken together, we established a simple, quick and high throughput ADCP assay for HCV infection that can readily be used for screening of large cohorts of patients and investigation of the role of ADCP in the pathogenesis or protection from this disease.


Assuntos
Citometria de Fluxo , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/imunologia , Hepatite C/diagnóstico , Imunoglobulina G/imunologia , Fagocitose , Proteínas do Envelope Viral/imunologia , Estudos de Casos e Controles , Genótipo , Hepacivirus/genética , Hepatite C/sangue , Hepatite C/imunologia , Hepatite C/virologia , Anticorpos Anti-Hepatite C/sangue , Ensaios de Triagem em Larga Escala , Interações Hospedeiro-Patógeno , Humanos , Imunoglobulina G/sangue , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Células THP-1 , Proteínas do Envelope Viral/genética , Fluxo de Trabalho
19.
J Virol ; 95(17): e0095221, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34160260

RESUMO

Hepatitis C virus (HCV) regulates many cellular genes in modulating the host immune system for benefit of viral replication and long-term persistence in a host for chronic infection. Long noncoding RNAs (lncRNAs) play an important role in the regulation of many important cellular processes, including immune responses. We recently reported that HCV infection downregulates lncRNA Linc-Pint (long intergenic non-protein-coding RNA p53-induced transcript) expression, although the mechanism of repression and functional consequences are not well understood. In this study, we demonstrate that HCV infection of hepatocytes transcriptionally reduces Linc-Pint expression through CCAAT/enhancer binding protein ß (C/EBP-ß). Subsequently, we observed that the overexpression of Linc-Pint significantly upregulates interferon alpha (IFN-α) and IFN-ß expression in HCV-replicating hepatocytes. Using unbiased proteomics, we identified that Linc-Pint associates with DDX24, which enables RIP1 to interact with IFN-regulatory factor 7 (IRF7) of the IFN signaling pathway. We furthermore observed that IFN-α14 promoter activity was enhanced in the presence of Linc-Pint. Together, these results demonstrated that Linc-Pint acts as a positive regulator of host innate immune responses, especially IFN signaling. HCV-mediated downregulation of Linc-Pint expression appears to be one of the mechanisms by which HCV may evade innate immunity for long-term persistence and chronicity. IMPORTANCE The mechanism by which lncRNA regulates the host immune response during HCV infection is poorly understood. We observed that Linc-Pint was transcriptionally downregulated by HCV. Using a chromatin immunoprecipitation (ChIP) assay, we showed inhibition of transcription factor C/EBP-ß binding to the Linc-Pint promoter in the presence of HCV infection. We further identified that Linc-Pint associates with DDX24 for immunomodulatory function. The overexpression of Linc-Pint reduces DDX24 expression, which in turn results in the disruption of DDX24-RIP1 complex formation and the activation of IRF7. The induction of IFN-α14 promoter activity in the presence of Linc-Pint further confirms our observation. Together, our results suggest that Linc-Pint acts as a positive regulator of host innate immune responses. Downregulation of Linc-Pint expression by HCV helps in escaping the innate immune system for the development of chronicity.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Hepacivirus/imunologia , Hepatite C/imunologia , Imunidade Inata/imunologia , Interferon-alfa/metabolismo , Interferon beta/metabolismo , RNA Longo não Codificante/antagonistas & inibidores , Proteína beta Intensificadora de Ligação a CCAAT/genética , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Hepatite C/metabolismo , Hepatite C/virologia , Hepatócitos/imunologia , Hepatócitos/metabolismo , Hepatócitos/virologia , Humanos , Interferon-alfa/genética , Interferon beta/genética , RNA Longo não Codificante/genética , Replicação Viral
20.
PLoS One ; 16(6): e0252976, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34111200

RESUMO

BACKGROUND: Chronic hepatitis C virus infection (HCV) is a common infectious disease that affects more than 2.7 million people in the US. Because the emergency department (ED) can present an ideal opportunity to screen patients who may not otherwise get routine screening, we implemented a risk-based screening program for ED patients and established a system to facilitate linkage to care. METHODS AND FINDINGS: A risk-based screening algorithm for HCV was programmed to trigger an alert in Epic electronic medical record system. Patients identified between August 2018 and April 2020 in the ED were tested for HCV antibody reflex to HCV RNA. Patients with a positive screening test were contacted for the confirmatory test result and to establish medical care for HCV treatment. Patient characteristics including age, sex, self-awareness of HCV infection, history of previous HCV treatment, history of opioids use, history of tobacco use, and types of insurance were obtained. A total of 4,525 patients underwent a screening test, of whom 131 patients (2.90%) were HCV antibody positive and 43 patients (0.95%) were HCV RNA positive, indicating that only 33% of patients with positive screening test had chronic HCV infection. The rate of chronic infection was higher in males as compared to females (1.34% vs 0.60%, p = 0.01). Patients with history of opioid use or history of tobacco use were found to have a lower rate of spontaneous clearance than patients without each history (opioids: 48.6% vs 72.0%, p = 0.02; tobacco: 56.6% vs 80.5%, p = 0.01). Among 43 patients who were diagnosed with chronic hepatitis C, 26 were linked to a clinical setting that can address chronic HCV infection, with linkage to care rate of 60.5%. The most common barrier to this was inability to contact patients after discharge from the ED. CONCLUSIONS: A streamlined EMR system for HCV screening and subsequent linkage to care from the ED can be successfully implemented. A retrospective review suggests that male sex is related to chronic HCV infection, and history of opioid use or history of tobacco use is related to lower HCV spontaneous clearance.


Assuntos
Hepacivirus/genética , Anticorpos Anti-Hepatite C/análise , Hepatite C Crônica/epidemiologia , Programas de Rastreamento/métodos , RNA Viral/genética , Algoritmos , Gerenciamento Clínico , Serviço Hospitalar de Emergência , Feminino , Hepacivirus/imunologia , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/imunologia , Hospitais Comunitários , Humanos , Masculino , Estudos Retrospectivos , Medição de Risco , Caracteres Sexuais , Estados Unidos/epidemiologia
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