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1.
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
2.
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
3.
Viruses ; 13(8)2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34452505

RESUMO

Viral infection is a global public health threat causing millions of deaths. A suitable small animal model is essential for viral pathogenesis and host response studies that could be used in antiviral and vaccine development. The tree shrew (Tupaia belangeri or Tupaia belangeri chinenesis), a squirrel-like non-primate small mammal in the Tupaiidae family, has been reported to be susceptible to important human viral pathogens, including hepatitis viruses (e.g., HBV, HCV), respiratory viruses (influenza viruses, SARS-CoV-2, human adenovirus B), arboviruses (Zika virus and dengue virus), and other viruses (e.g., herpes simplex virus, etc.). The pathogenesis of these viruses is not fully understood due to the lack of an economically feasible suitable small animal model mimicking natural infection of human diseases. The tree shrew model significantly contributes towards a better understanding of the infection and pathogenesis of these important human pathogens, highlighting its potential to be used as a viable viral infection model of human viruses. Therefore, in this review, we summarize updates regarding human viral infection in the tree shrew model, which highlights the potential of the tree shrew to be utilized for human viral infection and pathogenesis studies.


Assuntos
Modelos Animais de Doenças , Tupaia , Viroses , Infecções por Adenoviridae/imunologia , Infecções por Adenoviridae/virologia , Animais , COVID-19/virologia , Dengue/imunologia , Dengue/patologia , Dengue/virologia , Infecções por HIV/virologia , Hepatite B/imunologia , Hepatite B/virologia , Hepatite C/imunologia , Hepatite C/patologia , Hepatite C/virologia , Herpes Simples/patologia , Herpes Simples/virologia , Humanos , Influenza Humana/imunologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/patologia , Infecção por Zika virus/virologia
4.
Int J Mol Sci ; 22(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206987

RESUMO

Hepatitis C virus (HCV) is one of the main triggers of chronic liver disease. Despite tremendous progress in the HCV field, there is still no vaccine against this virus. Potential vaccines can be based on its recombinant proteins. To increase the humoral and, especially, cellular immune response to them, more effective adjuvants are needed. Here, we evaluated a panel of compounds as potential adjuvants using the HCV NS5B protein as an immunogen. These compounds included inhibitors of polyamine biosynthesis and urea cycle, the mTOR pathway, antioxidants, and cellular receptors. A pronounced stimulation of cell proliferation and interferon-γ (IFN-γ) secretion in response to concanavalin A was shown for antioxidant N-acetylcysteine (NAC), polyamine biosynthesis inhibitor 2-difluoromethylornithine (DFMO), and TLR9 agonist CpG ODN 1826 (CpG). Their usage during the immunization of mice with the recombinant NS5B protein significantly increased antibody titers, enhanced lymphocyte proliferation and IFN-γ production. NAC and CpG decreased relative Treg numbers; CpG increased the number of myeloid-derived suppressor cells (MDSCs), whereas neither NAC nor DFMO affected MDSC counts. NAC and DFMO suppressed NO and interleukin 10 (IL-10) production by splenocytes, while DFMO increased the levels of IL-12. This is the first evidence of immunomodulatory activity of NAC and DFMO during prophylactic immunization against infectious diseases.


Assuntos
Acetilcisteína/farmacologia , Adjuvantes Imunológicos/farmacologia , Eflornitina/farmacologia , Hepatite C/imunologia , Imunidade Ativa/efeitos dos fármacos , Proteínas não Estruturais Virais/imunologia , Animais , Proliferação de Células , Células Cultivadas , Feminino , Imunogenicidade da Vacina/efeitos dos fármacos , Interferon gama/metabolismo , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Camundongos , Camundongos Endogâmicos DBA , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/imunologia , Óxido Nítrico/metabolismo , Oligodesoxirribonucleotídeos/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Vacinas contra Hepatite Viral/imunologia
5.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204438

RESUMO

Hepatitis C virus (HCV) is associated with various liver diseases. Chronic HCV infection is characterized by an abnormal host immune response. Therefore, it is speculated that to suppress HCV, a well-regulated host immune response is necessary. 2-O-methylhonokiol was identified by the screening of anti-HCV compounds using Renilla luciferase assay in Huh 7.5/Con 1 genotype 1b replicon cells. Here, we investigated the mechanism by which 2-O-methylhonokiol treatment inhibits HCV replication using real-time PCR. Our data shows that treatment with 2-O-methylhonokiol activated innate immune responses via nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) pathway. Additionally, the immunoprecipitation result shows that treatment with 2-O-methylhonokiol augmented tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) by preventing p62 from binding to TRAF6, resulting in reduced autophagy caused by HCV. Finally, we reproduced our data with the conditioned media from 2-O-methylhonokiol-treated cells. These findings strongly suggest that 2-O-methylhonokiol enhances the host immune response and suppresses HCV replication via TRAF6-mediated NF-kB activation.


Assuntos
Hepacivirus/fisiologia , Hepatite C/metabolismo , Hepatite C/virologia , Interações Hospedeiro-Patógeno , NF-kappa B/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo , Replicação Viral , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linhagem Celular , Células Cultivadas , Hepatite C/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata , Modelos Biológicos , Estrutura Molecular
6.
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
7.
Viruses ; 13(5)2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946211

RESUMO

Direct-acting antiviral agents have proven highly effective at treating existing hepatitis C infections but despite their availability most countries will not reach the World Health Organization targets for elimination of HCV by 2030. A prophylactic vaccine remains a high priority. Whilst early vaccines focused largely on generating T cell immunity, attention is now aimed at vaccines that generate humoral immunity, either alone or in combination with T cell-based vaccines. High-resolution structures of hepatitis C viral glycoproteins and their interaction with monoclonal antibodies isolated from both cleared and chronically infected people, together with advances in vaccine technologies, provide new avenues for vaccine development.


Assuntos
Bioengenharia , Hepacivirus/imunologia , Hepatite C/imunologia , Hepatite C/prevenção & controle , Interações Hospedeiro-Patógeno/imunologia , Imunidade Humoral , Vacinas contra Hepatite Viral/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos Virais/química , Antígenos Virais/imunologia , Epitopos/química , Epitopos/imunologia , Anticorpos Anti-Hepatite C/imunologia , Humanos , Modelos Moleculares , Pesquisa , Relação Estrutura-Atividade , Vacinologia , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/imunologia , Vacinas contra Hepatite Viral/classificação
8.
J Immunol ; 206(8): 1932-1942, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33789981

RESUMO

The cell has several mechanisms to sense and neutralize stress. Stress-related stimuli activate pathways that counteract danger, support cell survival, and activate the inflammatory response. We use human cells to show that these processes are modulated by EGOT, a long noncoding RNA highly induced by viral infection, whose inhibition results in increased levels of antiviral IFN-stimulated genes (ISGs) and decreased viral replication. We now show that EGOT is induced in response to cell stress, viral replication, or the presence of pathogen-associated molecular patterns via the PI3K/AKT, MAPKs, and NF-κB pathways, which lead to cell survival and inflammation. Transcriptome analysis and validation experiments show that EGOT modulates PI3K/AKT and NF-κB responses. On the one hand, EGOT inhibition decreases expression of PI3K/AKT-induced cellular receptors and cell proliferation. In fact, EGOT levels are increased in several tumors. On the other hand, EGOT inhibition results in decreased levels of key NF-κB target genes, including those required for inflammation and ISGs in those cells that build an antiviral response. Mechanistically, EGOT depletion decreases the levels of the key coactivator TBLR1, essential for transcription by NF-κB. In summary, EGOT is induced in response to stress and may function as a switch that represses ISG transcription until a proper antiviral or stress response is initiated. EGOT then helps PI3K/AKT, MAPKs, and NF-κB pathways to activate the antiviral response, cell inflammation, and growth. We believe that modulation of EGOT levels could be used as a therapy for the treatment of certain viral infections, immune diseases, and cancer.


Assuntos
Hepacivirus/fisiologia , Hepatite C/imunologia , Inflamação/genética , RNA Longo não Codificante/genética , Estresse Fisiológico/imunologia , Processos de Crescimento Celular , Linhagem Celular , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais
9.
Viruses ; 13(2)2021 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672697

RESUMO

Hepatitis C virus remains a global threat, despite the availability of highly effective direct-acting antiviral (DAA) drugs. With thousands of new infections annually, the need for a prophylactic vaccine is evident. However, traditional vaccine design has been unable to provide effective vaccines so far. Therefore, alternative strategies need to be investigated. In this work, a chemistry-based approach is explored towards fully synthetic peptide-based vaccines using epitope mimicry, by focusing on highly effective and conserved amino acid sequences in HCV, which, upon antibody binding, inhibit its bio-activity. Continuous and discontinuous epitope mimics were both chemically synthesized based on the HCV-E2 glycoprotein while using designed fully synthetic cyclic peptides. These cyclic epitope mimics were assembled on an orthogonally protected scaffold. The scaffolded epitope mimics have been assessed in immunization experiments to investigate the elicitation of anti-HCV-E2 glycoprotein antibodies. The neutralizing potential of the elicited antibodies was investigated, representing a first step in employing chemically synthesized epitope mimics as a novel strategy towards vaccine design.


Assuntos
Epitopos/química , Hepacivirus/imunologia , Hepatite C/imunologia , Vacinas Sintéticas/química , Proteínas do Envelope Viral/síntese química , Anticorpos Antivirais/imunologia , Desenho de Fármacos , Epitopos/genética , Epitopos/imunologia , Hepacivirus/química , Hepacivirus/genética , Hepatite C/prevenção & controle , Hepatite C/virologia , Humanos , Mimetismo Molecular , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/química , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Envelope Viral/administração & dosagem , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia
10.
Immunity ; 54(4): 781-796.e4, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33675683

RESUMO

Human IGHV1-69-encoded broadly neutralizing antibodies (bnAbs) that target the hepatitis C virus (HCV) envelope glycoprotein (Env) E2 are important for protection against HCV infection. An IGHV1-69 ortholog gene, VH1.36, is preferentially used for bnAbs isolated from HCV Env-immunized rhesus macaques (RMs). Here, we studied the genetic, structural, and functional properties of VH1.36-encoded bnAbs generated by vaccination, in comparison to IGHV1-69-encoded bnAbs from HCV patients. Global B cell repertoire analysis confirmed the expansion of VH1.36-derived B cells in immunized animals. Most E2-specific, VH1.36-encoded antibodies cross-neutralized HCV. Crystal structures of two RM bnAbs with E2 revealed that the RM bnAbs engaged conserved E2 epitopes using similar molecular features as human bnAbs but with a different binding mode. Longitudinal analyses of the RM antibody repertoire responses during immunization indicated rapid lineage development of VH1.36-encoded bnAbs with limited somatic hypermutation. Our findings suggest functional convergence of a germline-encoded bnAb response to HCV Env with implications for vaccination in humans.


Assuntos
Anticorpos Neutralizantes/imunologia , Células Germinativas/imunologia , Glicoproteínas/imunologia , Hepacivirus/imunologia , Hepatite C/imunologia , Macaca mulatta/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Linfócitos B/imunologia , Células CHO , Linhagem Celular , Cricetulus , Epitopos/imunologia , Células HEK293 , Hepatite C/virologia , Humanos , Estudos Longitudinais , Macaca mulatta/virologia , Receptores de Antígenos de Linfócitos B/imunologia , Vacinação/métodos
11.
Theranostics ; 11(7): 3489-3501, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33537099

RESUMO

The rapid development and remarkable success of checkpoint inhibitors have provided significant breakthroughs in cancer treatment, including hepatocellular carcinoma (HCC). However, only 15-20% of HCC patients can benefit from checkpoint inhibitors. Cancer stem cells (CSCs) are responsible for recurrence, metastasis, and local and systemic therapy resistance in HCC. Accumulating evidence has suggested that HCC CSCs can create an immunosuppressive microenvironment through certain intrinsic and extrinsic mechanisms, resulting in immune evasion. Intrinsic evasion mechanisms mainly include activation of immune-related CSC signaling pathways, low-level expression of antigen presenting molecules, and high-level expression of immunosuppressive molecules. External evasion mechanisms are mainly related to HBV/HCV infection, alcoholic/nonalcoholic steatohepatitis, hypoxia stimulation, abnormal angiogenesis, and crosstalk between CSCs and immune cells. A better understanding of the complex mechanisms of CSCs involved in immune evasion will contribute to therapies for HCC. Here we will outline the detailed mechanisms of immune evasion for CSCs, and provide an overview of the current immunotherapies targeting CSCs in HCC.


Assuntos
Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/terapia , Proteínas de Neoplasias/genética , Recidiva Local de Neoplasia/terapia , Células-Tronco Neoplásicas/efeitos dos fármacos , Evasão Tumoral/efeitos dos fármacos , Apresentação do Antígeno/efeitos dos fármacos , Antineoplásicos Imunológicos/uso terapêutico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/patologia , Fígado Gorduroso/genética , Fígado Gorduroso/imunologia , Fígado Gorduroso/patologia , Fígado Gorduroso/terapia , Regulação Neoplásica da Expressão Gênica , Hepatite B/genética , Hepatite B/imunologia , Hepatite B/patologia , Hepatite B/terapia , Hepatite C/genética , Hepatite C/imunologia , Hepatite C/patologia , Hepatite C/terapia , Humanos , Fatores Imunológicos/uso terapêutico , Imunoterapia/métodos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/imunologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/imunologia , Recidiva Local de Neoplasia/patologia , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/imunologia , Neovascularização Patológica/patologia , Neovascularização Patológica/prevenção & controle , Transdução de Sinais , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
12.
J Immunol Res ; 2021: 3108157, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33532506

RESUMO

Currently, no vaccine to prevent hepatitis C virus (HCV) infection is available. A major challenge in developing an HCV vaccine is the high diversity of HCV sequences. The purpose of immunization with viral glycoproteins is to induce a potent and long-lasting cellular and humoral immune response. However, this strategy only achieves limited protection, and antigen selection plays a crucial role in vaccine design. In this study, we investigated the humoral immune responses induced by intraperitoneal injection of keyhole limpet hemocyanin conjugated with 4 highly conserved peptides, including amino acids [aa]317-325 from E1 and aa418-429, aa502-518, and aa685-693 from E2, or 3 peptides from hypervariable region 1 (HVR1) of E2, including the N terminus of HVR1 (N-HVR1, aa384-396), C terminus of HVR1 (C-HVR1, aa397-410), and HVR1 in BALB/c mice. The neutralizing activity against HCV genotypes 1-6 was assessed using the cell culture HCV (HCVcc) system. The results showed that the 4 conserved peptides efficiently induced antibodies with potent neutralizing activity against 3 or 4 genotypes. Antibodies induced by aa685-693 conferred potent protection (>50%) against genotypes 2, 4, and 5. Peptide N-HVR1 elicited antibodies with the most potent neutralization activities against 3 HCV genotypes: TNcc(1a), S52(3a), and ED43(4a). These findings suggested that peptides within HCV glycoproteins could serve as potent immunogens for vaccine design and development.


Assuntos
Anticorpos Neutralizantes/imunologia , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/imunologia , Hepatite C/imunologia , Proteínas do Envelope Viral/imunologia , Vacinas contra Hepatite Viral/imunologia , Adjuvantes Imunológicos , Sequência de Aminoácidos , Animais , Linhagem Celular , Feminino , Genótipo , Hemocianinas , Hepacivirus/genética , Humanos , Soros Imunes/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Peptídeos/química , Peptídeos/imunologia , Vacinas Conjugadas/imunologia
13.
Diagn Microbiol Infect Dis ; 100(1): 115311, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33524728

RESUMO

Centers for Disease Control guidelines recommend hepatitis C virus (HCV) RNA testing of all HCV IgG-reactive samples, although earlier studies found that IgG-reactive samples with low indices were negative in qualitative RNA assays. To determine if previous study results could be confirmed using current real-time RT-PCR technology, we investigated the relationship between HCV IgG index (Ortho VITROS) and quantitative HCV RNA results (cobas HCV) for 2368 consecutive IgG-reactive sera. Results were segregated into Low (1.00-16.0), Medium (16.1-30.0), and High (>30.0) IgG index groups. Although median viral load (VL) of RNA-positive samples was similar in all 3 groups, the percentage with low VL (1.18-4.16 log IU/mL) was increased for the Low group. Further analysis of the Low group revealed that 23 of 370 (6%) samples with IgG indices ≤8.00 were RNA-positive, and 13/23 (57%) had low VL. Our analysis supports the Centers for Disease Control recommendation to test all HCV IgG-reactive sera for HCV RNA.


Assuntos
Hepacivirus , Hepatite C , RNA Viral , Reação em Cadeia da Polimerase em Tempo Real/métodos , Carga Viral/métodos , Feminino , Hepacivirus/genética , Hepacivirus/imunologia , Hepatite C/diagnóstico , Hepatite C/imunologia , Hepatite C/virologia , Anticorpos Anti-Hepatite C/sangue , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , RNA Viral/genética
14.
Sci Rep ; 11(1): 1551, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33452360

RESUMO

Viral hepatitis leads to immune-mediated liver injury. The rate of disease progression varies between individuals. We aimed to phenotype immune cells associated with preservation of normal liver function during hepatitis C virus (HCV) infection. Clinical data and specimens were obtained from 19 HCV-infected patients undergoing liver transplantation. Liver and peripheral blood mononuclear cells were isolated and eight subsets of innate immune cells were delineated by multiparameter flow cytometry. Cytokine assays and microarrays were performed. Intrahepatic CD56Bright/CD16- natural killer (NK) cells comprised the only subset correlating with better liver function, i.e., lower bilirubin (p = 0.0002) and lower model for end stage of liver disease scores (p = 0.03). The signature of liver NK cells from HCV-infected patients included genes expressed by NK cells in normal liver and by decidual NK cells. Portal vein blood had a higher concentration of interleukin (IL)-10 than peripheral blood (p = 0.03). LMCs were less responsive to toll-like receptor (TLR) stimulation than PBMCs, with fewer pro-inflammatory gene-expression pathways up-regulated after in vitro exposure to lipopolysaccharide and a TLR-7/8 agonist. Hepatic CD56Bright/CD16- NK cells may be critical for maintaining liver homeostasis. Portal vein IL-10 may prime inhibitory pathways, attenuating TLR signaling and reducing responsiveness to pro-inflammatory stimuli.


Assuntos
Hepatite C/imunologia , Células Matadoras Naturais/metabolismo , Fígado/patologia , Idoso , Progressão da Doença , Feminino , Citometria de Fluxo/métodos , Hepacivirus/patogenicidade , Hepatite C/metabolismo , Hepatite C/fisiopatologia , Humanos , Imunidade Inata/imunologia , Imunidade Inata/fisiologia , Imunofenotipagem , Células Matadoras Naturais/patologia , Leucócitos Mononucleares/metabolismo , Fígado/imunologia , Testes de Função Hepática/métodos , Masculino , Pessoa de Meia-Idade
15.
Clin Pharmacol Ther ; 109(4): 829-840, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33410134

RESUMO

Modern viral kinetic modeling and its application to therapeutics is a field that attracted the attention of the medical, pharmaceutical, and modeling communities during the early days of the AIDS epidemic. Its successes led to applications of modeling methods not only to HIV but a plethora of other viruses, such as hepatitis C virus (HCV), hepatitis B virus and cytomegalovirus, which along with HIV cause chronic diseases, and viruses such as influenza, respiratory syncytial virus, West Nile virus, Zika virus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which generally cause acute infections. Here we first review the historical development of mathematical models to understand HIV and HCV infections and the effects of treatment by fitting the models to clinical data. We then focus on recent efforts and contributions of applying these models towards understanding SARS-CoV-2 infection and highlight outstanding questions where modeling can provide crucial insights and help to optimize nonpharmaceutical and pharmaceutical interventions of the coronavirus disease 2019 (COVID-19) pandemic. The review is written from our personal perspective emphasizing the power of simple target cell limited models that provided important insights and then their evolution into more complex models that captured more of the virology and immunology. To quote Albert Einstein, "Everything should be made as simple as possible, but not simpler," and this idea underlies the modeling we describe below.


Assuntos
COVID-19/epidemiologia , COVID-19/terapia , Modelos Teóricos , Antirretrovirais/uso terapêutico , COVID-19/imunologia , COVID-19/prevenção & controle , Doenças Transmissíveis/epidemiologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/imunologia , Hepatite C/epidemiologia , Hepatite C/imunologia , Humanos , Pandemias , SARS-CoV-2 , Carga Viral
16.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33431677

RESUMO

Hepatitis C virus (HCV) is a major worldwide health burden, and a preventive vaccine is needed for global control or eradication of this virus. A substantial hurdle to an effective HCV vaccine is the high variability of the virus, leading to immune escape. The E1E2 glycoprotein complex contains conserved epitopes and elicits neutralizing antibody responses, making it a primary target for HCV vaccine development. However, the E1E2 transmembrane domains that are critical for native assembly make it challenging to produce this complex in a homogenous soluble form that is reflective of its state on the viral envelope. To enable rational design of an E1E2 vaccine, as well as structural characterization efforts, we have designed a soluble, secreted form of E1E2 (sE1E2). As with soluble glycoprotein designs for other viruses, it incorporates a scaffold to enforce assembly in the absence of the transmembrane domains, along with a furin cleavage site to permit native-like heterodimerization. This sE1E2 was found to assemble into a form closer to its expected size than full-length E1E2. Preservation of native structural elements was confirmed by high-affinity binding to a panel of conformationally specific monoclonal antibodies, including two neutralizing antibodies specific to native E1E2 and to its primary receptor, CD81. Finally, sE1E2 was found to elicit robust neutralizing antibodies in vivo. This designed sE1E2 can both provide insights into the determinants of native E1E2 assembly and serve as a platform for production of E1E2 for future structural and vaccine studies, enabling rational optimization of an E1E2-based antigen.


Assuntos
Hepacivirus/efeitos dos fármacos , Anticorpos Anti-Hepatite C/biossíntese , Hepatite C/prevenção & controle , Proteínas do Envelope Viral/imunologia , Vacinas contra Hepatite Viral/imunologia , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Neutralizantes/biossíntese , Mapeamento de Epitopos , Epitopos/química , Epitopos/imunologia , Feminino , Expressão Gênica , Hepacivirus/imunologia , Hepacivirus/patogenicidade , Hepatite C/imunologia , Hepatite C/patologia , Hepatite C/virologia , Humanos , Imunogenicidade da Vacina , Camundongos , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Engenharia de Proteínas/métodos , Multimerização Proteica , Receptores Virais/genética , Receptores Virais/imunologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Solubilidade , Tetraspanina 28/genética , Tetraspanina 28/imunologia , Vacinação , Proteínas do Envelope Viral/administração & dosagem , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Vacinas contra Hepatite Viral/administração & dosagem , Vacinas contra Hepatite Viral/química , Vacinas contra Hepatite Viral/genética
17.
J Virol ; 95(4)2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33208444

RESUMO

MicroRNA let-7b expression is induced by infection of hepatitis C virus (HCV) and is involved in the regulation of HCV replication by directly targeting the HCV genome. The current study demonstrated that let-7b directly targets negative regulators of type I interferon (IFN) signaling thereby limiting HCV replication in the early stage of HCV infection. Let-7b-regulated genes which are involved in host cellular responses to HCV infection were unveiled by microarray profiling and bioinformatic analyses, followed by various molecular and cellular assays using Huh7 cells expressing wild-type (WT) or the seed region-mutated let-7b. Let-7b targeted the cytokine signaling 1 (SOCS1) protein, a negative regulator of JAK/STAT signaling, which then enhanced STAT1-Y701 phosphorylation leading to increased expression of the downstream interferon-stimulated genes (ISGs). Let-7b augmented retinoic acid-inducible gene I (RIG-I) signaling, but not MDA5, to phosphorylate and nuclear translocate IRF3 leading to increased expression of IFN-ß. Let-7b directly targeted the ATG12 and IκB kinase alpha (IKKα) transcripts and reduced the interaction of the ATG5-ATG12 conjugate and RIG-I leading to increased expression of IFN, which may further stimulate JAK/STAT signaling. Let-7b induced by HCV infection elicits dual effects on IFN expression and signaling, along with targeting the coding sequences of NS5B and 5' UTR of the HCV genome, and limits HCV RNA accumulation in the early stage of HCV infection. Controlling let-7b expression is thereby crucial in the intervention of HCV infection.IMPORTANCE HCV is a leading cause of liver disease, with an estimated 71 million people infected worldwide. During HCV infection, type I interferon (IFN) signaling displays potent antiviral and immunomodulatory effects. Host factors, including microRNAs (miRNAs), play a role in upregulating IFN signaling to limit HCV replication. Let-7b is a liver-abundant miRNA that is induced by HCV infection and targets the HCV genome to suppress HCV RNA accumulation. In this study, we demonstrated that let-7b, as a positive regulator of type I IFN signaling, plays dual roles against HCV replication by increasing the expression of IFN and interferon-sensitive response element (ISRE)-driven interferon-stimulated genes (ISGs) in the early stage of HCV infection. This study sheds new insight into understanding the role of let-7b in combatting HCV infection. Clarifying IFN signaling regulated by miRNA during the early phase of HCV infection may help researchers understand the initial defense mechanisms to other RNA viruses.


Assuntos
Hepatite C/imunologia , Interferon Tipo I/metabolismo , MicroRNAs/fisiologia , RNA Viral/metabolismo , Replicação Viral , Regiões 5' não Traduzidas , Células HEK293 , Interações entre Hospedeiro e Microrganismos , Humanos , Proteína 1 Supressora da Sinalização de Citocina/metabolismo , Proteínas não Estruturais Virais/genética
18.
Nat Rev Cardiol ; 18(3): 169-193, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33046850

RESUMO

Inflammatory cardiomyopathy, characterized by inflammatory cell infiltration into the myocardium and a high risk of deteriorating cardiac function, has a heterogeneous aetiology. Inflammatory cardiomyopathy is predominantly mediated by viral infection, but can also be induced by bacterial, protozoal or fungal infections as well as a wide variety of toxic substances and drugs and systemic immune-mediated diseases. Despite extensive research, inflammatory cardiomyopathy complicated by left ventricular dysfunction, heart failure or arrhythmia is associated with a poor prognosis. At present, the reason why some patients recover without residual myocardial injury whereas others develop dilated cardiomyopathy is unclear. The relative roles of the pathogen, host genomics and environmental factors in disease progression and healing are still under discussion, including which viruses are active inducers and which are only bystanders. As a consequence, treatment strategies are not well established. In this Review, we summarize and evaluate the available evidence on the pathogenesis, diagnosis and treatment of myocarditis and inflammatory cardiomyopathy, with a special focus on virus-induced and virus-associated myocarditis. Furthermore, we identify knowledge gaps, appraise the available experimental models and propose future directions for the field. The current knowledge and open questions regarding the cardiovascular effects associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are also discussed. This Review is the result of scientific cooperation of members of the Heart Failure Association of the ESC, the Heart Failure Society of America and the Japanese Heart Failure Society.


Assuntos
Cardiomiopatias/fisiopatologia , Inflamação/fisiopatologia , Miocardite/fisiopatologia , Viroses/fisiopatologia , Animais , Antivirais/uso terapêutico , Autoimunidade/imunologia , Biópsia , COVID-19/fisiopatologia , COVID-19/terapia , Cardiomiopatias/diagnóstico , Cardiomiopatias/imunologia , Cardiomiopatias/terapia , Cardiomiopatia Dilatada , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/terapia , Infecções por Coxsackievirus/imunologia , Infecções por Coxsackievirus/fisiopatologia , Infecções por Coxsackievirus/terapia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/fisiopatologia , Infecções por Citomegalovirus/terapia , Modelos Animais de Doenças , Infecções por Echovirus/imunologia , Infecções por Echovirus/fisiopatologia , Infecções por Echovirus/terapia , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/fisiopatologia , Infecções por Vírus Epstein-Barr/terapia , Eritema Infeccioso/imunologia , Eritema Infeccioso/fisiopatologia , Eritema Infeccioso/terapia , Infecções por HIV/fisiopatologia , Hepatite C/imunologia , Hepatite C/fisiopatologia , Hepatite C/terapia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Inflamação/diagnóstico , Inflamação/imunologia , Inflamação/terapia , Influenza Humana/imunologia , Influenza Humana/fisiopatologia , Influenza Humana/terapia , Leucócitos/imunologia , Miocardite/diagnóstico , Miocardite/imunologia , Miocardite/terapia , Miocárdio/patologia , Prognóstico , Infecções por Roseolovirus/imunologia , Infecções por Roseolovirus/fisiopatologia
19.
J Med Virol ; 93(6): 3730-3737, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33368401

RESUMO

Female sex workers (FSWs) represent a high vulnerability group for the acquisition of sexual and parenteral infections such as hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. The present study aimed to determine the prevalence of serological markers and risk factors associated with exposure to HBV and HCV among FSWs in the state of Pará, Brazil. A cross-sectional study using principles of the time location sampling (TLS) method was conducted in four cities (Belém, Bragança, Barcarena, and Augusto Corrêa) of the state of Pará, from 2005 to 2006. In total, 365 FSWs were interviewed using a standardized questionnaire. Blood samples were collected and tested for serological markers of exposure to HBV and HCV using an enzyme immunoassay. The overall prevalence of exposure to HBV and HCV was 36.7% and 7.7%, respectively. The prevalence of surface antigen of HBV was 3.0%. The prevalence of anti-HBc and anti-HBc+ anti-HBs antibodies were 6.3% and 27.4%. Very few (4.7%) FSWs had vaccine immunity against HBV (anti-HBs antibodies only). The prevalence of anti-HCV antibodies was 7.7%. Low monthly income, drug usage, and unprotected sex were some of the social characteristics associated with exposure to the viruses using different analysis. The seroprevalence of HBV and HCV infections among FSWs in four cities of the state of Pará is high when compared to the general population of Brazil, but similar to those found in FSWs in other nondeveloped countries. The prevalence of HBV was higher in Belém, while the prevalence of HCV was higher in the other three cities, highlighting the importance of establishing control and prevention programs to reduce the risk of acquiring these viruses in Pará.


Assuntos
Hepatite B/epidemiologia , Hepatite B/imunologia , Hepatite C/epidemiologia , Hepatite C/imunologia , Profissionais do Sexo/estatística & dados numéricos , Adolescente , Adulto , Idoso , Brasil/epidemiologia , Cidades/epidemiologia , Estudos Transversais , Feminino , Hepacivirus/imunologia , Hepatite B/sangue , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/imunologia , Hepatite C/sangue , Anticorpos Anti-Hepatite C/sangue , Humanos , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Estudos Soroepidemiológicos , Adulto Jovem
20.
Clin Exp Immunol ; 204(1): 107-124, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33314121

RESUMO

Natural killer (NK) cell functions are regulated by diverse inhibitory and activating receptors, including killer cell immunoglobulin-like receptors (KIR), which interact with human leukocyte antigen (HLA) class I molecules. Some KIR/HLA genetic combinations were reported associated with spontaneous clearance (SC) of hepatitis C virus (HCV) but with discordant results, possibly reflecting KIR and/or HLA gene polymorphism according to populations. KIR/HLA genetic combinations associated with both an exhaustive NK and T cell repertoire were investigated in a cohort of HIV-HCV co-infected individuals with either SC (n = 68) or chronic infection (CI, n = 163) compared to uninfected blood donors [controls (Ctrl), n = 100]. Multivariate analysis showed that the HLA C2C2 environment was associated with SC only in European HIV-HCV co-infected individuals [odds ratio (OR) = 4·30, 95% confidence interval = 1·57-12·25, P = 0·005]. KIR2D+ NK cell repertoire and potential of degranulation of KIR2DL1/S1+ NK cells were similar in the SC European cohort compared to uninfected individuals. In contrast, decreased frequencies of KIR2DS1+ and KIR2DL2+ NK cells were detected in the CI group of Europeans compared to SC and a decreased frequency of KIR2DL1/S1+ NK cells compared to controls. Regarding T cells, higher frequencies of DNAX accessory molecule-1 (DNAM-1)+ and CD57+ T cells were observed in SC in comparison to controls. Interestingly, SC subjects emphasized increased frequencies of KIR2DL2/L3/S2+ T cells compared to CI subjects. Our study underlines that the C2 environment may activate efficient KIR2DL1+ NK cells in a viral context and maintain a KIR2DL2/L3/S2+ mature T cell response in the absence of KIR2DL2 engagement with its cognate ligands in SC group of HCV-HIV co-infected European patients.


Assuntos
Coinfecção/imunologia , Infecções por HIV/imunologia , Antígenos HLA-C/imunologia , Hepatite C/imunologia , Adulto , Células Cultivadas , Feminino , Citometria de Fluxo/métodos , França , Genótipo , Antígenos HLA-C/genética , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Masculino , Pessoa de Meia-Idade , Receptores KIR/genética , Receptores KIR/imunologia , Receptores KIR2DL1/genética , Receptores KIR2DL1/imunologia , Receptores KIR2DL2/genética , Receptores KIR2DL2/imunologia , Receptores KIR2DL3/genética , Receptores KIR2DL3/imunologia , Remissão Espontânea , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
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