RESUMO
The emergence of Zika virus (ZIKV) and its association with congenital malformations has prompted the rapid development of vaccines. Although efficacy with multiple viral vaccine platforms has been established in animals, no study has addressed protection during pregnancy. We tested in mice two vaccine platforms, a lipid nanoparticle-encapsulated modified mRNA vaccine encoding ZIKV prM and E genes and a live-attenuated ZIKV strain encoding an NS1 protein without glycosylation, for their ability to protect against transmission to the fetus. Vaccinated dams challenged with a heterologous ZIKV strain at embryo day 6 (E6) and evaluated at E13 showed markedly diminished levels of viral RNA in maternal, placental, and fetal tissues, which resulted in protection against placental damage and fetal demise. As modified mRNA and live-attenuated vaccine platforms can restrict in utero transmission of ZIKV in mice, their further development in humans to prevent congenital ZIKV syndrome is warranted.
Assuntos
Vacinas Virais/administração & dosagem , Infecção por Zika virus/imunologia , Infecção por Zika virus/prevenção & controle , Zika virus/fisiologia , Aedes/virologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Células Sanguíneas/virologia , Embrião de Mamíferos/virologia , Feminino , Feto/virologia , Humanos , Lipídeos/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Organismos Livres de Patógenos Específicos , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Vacinas Virais/imunologia , Infecção por Zika virus/virologiaRESUMO
c-FLIP functions as a dual regulator of apoptosis and inflammation, yet its implications in Zika virus (ZIKV) infection remain partially understood, especially in the context of ZIKV-induced congenital Zika syndrome (CZS) where both apoptosis and inflammation play pivotal roles. Our findings demonstrate that c-FLIP promotes ZIKV infection in placental cells and myeloid-derived macrophages, involving inflammation and caspase-8/3-mediated apoptosis. Moreover, our observations reveal that c-FLIP augments ZIKV infection in multiple tissues, including blood cell, spleen, uterus, testis, and the brain of mice. Notably, the partial deficiency of c-FLIP provides protection to embryos against ZIKV-induced CZS, accompanied by a reduction in caspase-3-mediated apoptosis. Additionally, we have found a distinctive parental effect of c-FLIP influencing ZIKV replication in fetal heads. In summary, our study reveals the critical role of c-FLIP as a positive regulator in caspase-8/3-mediated apoptosis during ZIKV infection, significantly contributing to the development of CZS.
Assuntos
Apoptose , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD , Caspase 3 , Caspase 8 , Infecção por Zika virus , Zika virus , Infecção por Zika virus/virologia , Infecção por Zika virus/metabolismo , Infecção por Zika virus/patologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Animais , Camundongos , Caspase 8/metabolismo , Feminino , Humanos , Caspase 3/metabolismo , Gravidez , Placenta/virologia , Placenta/metabolismo , Placenta/patologia , Camundongos Endogâmicos C57BL , Replicação Viral , Camundongos KnockoutRESUMO
Whether the immune imprinting caused by severe acute respiratory syndrome coronavirus (SARS-CoV) affects the efficiency of SARS-CoV-2 vaccination has attracted global concern. Little is known about the dynamic changes of antibody response in SARS convalescents inoculated with three doses of inactivated SARS-CoV-2 vaccine although lack of cross-neutralizing antibody response to SARS-CoV-2 in SARS survivors has been reported. We longitudinally examined the neutralizing antibodies (nAbs) against SARS-CoV and SARS-CoV-2 as well as spikes binding IgA, IgG, IgM, IgG1, and IgG3 antibodies in 9 SARS-recovered donors and 21 SARS-naïve donors. Stably higher nAbs and spike antigens-specific IgA, IgG antibodies against SARS-CoV-2 were observed in SARS-recovered donors compared with SARS-naïve donors during the period with two doses of BBIBP-CorV vaccination. However, the third-dose BBIBP-CorV stimulated a sharply and shortly higher increase of nAbs in SARS-naïve donors than in SARS-recovered donors. It is worth noting that, regardless of prior SARS infection, the Omicron subvariants were found to subvert immune responses. Moreover, certain subvariants such as BA.2, BA.2.75, or BA.5 exhibited a high degree of immune evasion in SARS survivors. Interestingly, BBIBP-CorV recalled higher nAbs against SARS-CoV compared with SARS-CoV-2 in SARS-recovered donors. In SARS survivors, a single dose of inactivated SARS-CoV-2 vaccine provoked immune imprinting for the SARS antigen, providing protection against wild-type SARS-CoV-2, and the earlier variants of concern (VOCs) including Alpha, Beta, Gamma, and Delta but not against Omicron subvariants. As such, it is important to evaluate the type and dosage of SARS-CoV-2 vaccine for SARS survivors.
Assuntos
COVID-19 , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Humanos , Vacinas contra COVID-19 , Formação de Anticorpos , COVID-19/prevenção & controle , SARS-CoV-2 , Anticorpos Neutralizantes , Imunoglobulina G , Imunoglobulina A , Anticorpos AntiviraisRESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is ongoing and multiple studies have elucidated its pathogenesis, however, the related- microbiome imbalance caused by SARS-CoV-2 is still not clear. In this study, we have comprehensively compared the microbiome composition and associated function alterations in the oropharyngeal swabs of healthy controls and coronavirus disease 2019 (COVID-19) patients with moderate or severe symptoms by metatranscriptomic sequencing. We did observe a reduced microbiome alpha-diversity but significant enrichment of opportunistic microorganisms in patients with COVID-19 compared with healthy controls, and the microbial homeostasis was rebuilt following the recovery of COVID-19 patients. Correspondingly, less functional genes in multiple biological processes and weakened metabolic pathways such as carbohydrate metabolism, energy metabolism were also observed in COVID-19 patients. We only found higher relative abundance of limited genera such as Lachnoanaerobaculum between severe patients and moderate patients while no worthy-noting microbiome diversity and function alteration were observed. Finally, we noticed that the co-occurrence of antibiotic resistance and virulence was closely related to the microbiome alteration caused by SRAS-CoV-2. Overall, our findings demonstrate that microbial dysbiosis may enhance the pathogenesis of SARS-CoV-2 and the antibiotics treatment should be critically considered.
Assuntos
COVID-19 , Microbiota , Humanos , SARS-CoV-2 , Disbiose , Resistência Microbiana a MedicamentosRESUMO
Zika virus (ZIKV) infects pregnant women and causes devastating congenital zika syndrome (CZS). How the virus is vertically transmitted to the fetus and induces neuronal loss remains unclear. We previously reported that Pellino (Peli)1, an E3 ubiquitin ligase, promotes p38MAPK activation in microglia and induction of lethal encephalitis by facilitating the replication of West Nile virus (WNV), a closely related flavivirus. Here, we found that Peli1 expression was induced on ZIKV-infected human monocytic cells, peripheral blood mononuclear cells, human first-trimester placental trophoblasts, and neural stem cell (hNSC)s. Peli1 mediates ZIKV cell attachment, entry and viral translation and its expression is confined to the endoplasmic reticulum. Moreover, Peli1 mediated inflammatory cytokine and chemokine responses and induced cell death in placental trophoblasts and hNSCs. ZIKV-infected pregnant mice lacking Peli1 signaling had reduced placental inflammation and tissue damage, which resulted in attenuated congenital abnormalities. Smaducin-6, a membrane-tethered Smad6-derived peptide, blocked Peli1-mediated NF-κB activation but did not have direct effects on ZIKV infection. Smaducin-6 reduced inflammatory responses and cell death in placental trophoblasts and hNSCs, and diminished placental inflammation and damage, leading to attenuated congenital malformations in mice. Collectively, our results reveal a novel role of Peli1 in flavivirus pathogenesis and suggest that Peli1 promotes ZIKV vertical transmission and neuronal loss by mediating inflammatory cytokine responses and induction of cell death. Our results also identify Smaducin-6 as a potential therapeutic candidate for treatment of CZS.
Assuntos
Síndrome de Guillain-Barré , Proteínas Nucleares/antagonistas & inibidores , Peptídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Infecção por Zika virus , Zika virus/metabolismo , Animais , Linhagem Celular , Feminino , Síndrome de Guillain-Barré/tratamento farmacológico , Síndrome de Guillain-Barré/genética , Síndrome de Guillain-Barré/metabolismo , Síndrome de Guillain-Barré/patologia , Humanos , Masculino , Camundongos , Camundongos Knockout , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Transdução de Sinais/genética , Trofoblastos/metabolismo , Trofoblastos/patologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Zika virus/genética , Infecção por Zika virus/tratamento farmacológico , Infecção por Zika virus/genética , Infecção por Zika virus/metabolismo , Infecção por Zika virus/patologiaRESUMO
Innate regulation through TLR signaling has been shown to be important for promoting T cell subset development and function. However, limited information is known about whether differential TLR signaling can selectively inhibit Th17 and/or Th1 cells, which are important for controlling excessive inflammation and autoimmune responses. In this article, we demonstrate that activation of TLR7 signaling in T cells can inhibit Th17 cell differentiation from naive T cells and IL-17 production in established Th17 cells. We further report that downregulation of STAT3 signaling is responsible for TLR7-mediated inhibition of Th17 cells due to induction of suppressor of cytokine signaling 3 and 5. TLR7-mediated suppression of Th17 cells does not require dendritic cell involvement. In addition, we show that TLR7 signaling can suppress Th1 cell development and function through a mechanism different from Th17 cell suppression. Importantly, our complementary in vivo studies demonstrate that treatment with the TLR7 ligand imiquimod can inhibit Th1 and Th17 cells, resulting in the prevention of, and an immunotherapeutic reduction in, experimental autoimmune encephalomyelitis. These studies identify a new strategy to manipulate Th17/Th1 cells through TLR7 signaling, with important implications for successful immunotherapy against autoimmune and inflammatory diseases.
Assuntos
Autoimunidade/imunologia , Glicoproteínas de Membrana/metabolismo , Transdução de Sinais/imunologia , Células Th17/imunologia , Receptor 7 Toll-Like/metabolismo , Aminoquinolinas/administração & dosagem , Animais , Diferenciação Celular , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/fisiopatologia , Encefalomielite Autoimune Experimental/prevenção & controle , Encefalomielite Autoimune Experimental/terapia , Humanos , Imiquimode , Imunoterapia , Inflamação/terapia , Interleucina-17/biossíntese , Interleucina-17/imunologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos , Fator de Transcrição STAT3/metabolismo , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/imunologia , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th17/efeitos dos fármacos , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/imunologiaRESUMO
The use of pathogen recognition receptor (PRR) agonists and the molecular mechanisms involved have been the major focus of research in individual vaccine development. West Nile virus (WNV) nonstructural (NS) 4B-P38G mutant has several features for an ideal vaccine candidate, including significantly reduced neuroinvasiveness, induction of strong adaptive immunity, and protection of mice from wild-type (WT) WNV infection. Here, we determined the role of mitochondrial antiviral signaling protein (MAVS), the adaptor protein for RIG-I-like receptor in regulating host immunity against the NS4B-P38G vaccine. We found that Mavs-/- mice were more susceptible to NS4B-P38G priming than WT mice. Mavs-/- mice had a transiently reduced production of antiviral cytokines and an impaired CD4+ T cell response in peripheral organs. However, antibody and CD8+ T cell responses were minimally affected. NS4B-P38G induced lower type I interferon (IFN), IFN-stimulating gene, and proinflammatory cytokine responses in Mavs-/- dendritic cells and subsequently compromised the antigen-presenting capacity for CD4+ T cells. Interestingly, Mavs-/- mice surviving NS4B-P38G priming were all protected from a lethal WT WNV challenge. NS4B-P38G-primed Mavs-/- mice exhibited equivalent levels of protective CD4+ T cell recall response, a modestly reduced WNV-specific IgM production, but more robust CD8+ T cell recall response. Taken together, our results suggest that MAVS is essential for boosting optimal primary CD4+ T cell responses upon NS4B-P38G vaccination and yet is dispensable for host protection and recall T cell responses during secondary WT WNV infection.IMPORTANCE The production of innate cytokines induced by the recognition of pathogen recognition receptors (PRRs) via their cognate ligands are critical for enhancing antigen-presenting cell functions and influencing T cell responses during microbial infection. The use of PRR agonists and the underlying molecular mechanisms have been the major focus in individual vaccine development. Here, we determined the role of mitochondrial antiviral-signaling protein (MAVS), the adaptor protein for RIG-I like receptor in regulating host immunity against the live attenuated West Nile virus (WNV) vaccine strain, the nonstructural (NS) 4B-P38G mutant. We found that MAVS is important for boosting optimal primary CD4+ T cell response during NS4B-P38G vaccination. However, MAVS is dispensable for memory T cell development and host protection during secondary wild-type WNV infection. Overall, these results may be utilized as a paradigm to aid in the rational development of other efficacious live attenuated flavivirus vaccines.
Assuntos
Imunidade Adaptativa , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos T CD4-Positivos/imunologia , Imunidade Inata , Vacinas contra o Vírus do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/imunologia , Proteínas Adaptadoras de Transdução de Sinal/deficiência , Animais , Anticorpos Antivirais/sangue , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Camundongos , Camundongos KnockoutRESUMO
UNLABELLED: The elderly are known to have enhanced susceptibility to infections and an impaired capacity to respond to vaccination. West Nile virus (WNV), a mosquito-borne flavivirus, has induced severe neurological symptoms, mostly in the elderly population. No vaccines are available for human use. Recent work showed that an attenuated WNV, a nonstructural (NS) 4B-P38G mutant, induced no lethality but strong immune responses in young (6- to 10-week-old) mice. While studying protective efficacy, we found unexpectedly that old (21- to 22-month) mice were susceptible to WNV NS4B-P38G mutant infection but were protected from subsequent lethal wild-type WNV challenge. Compared to responses in young mice, the NS4B-P38G mutant triggered higher inflammatory cytokine and interleukin-10 (IL-10) production, a delayed γδ T cell expansion, and lower antibody and WNV-specific T cell responses in old mice. Toll-like receptor 7 (TLR7) is expressed on multiple types of cells. Impaired TLR7 signaling in old mice led to dendritic cell (DC) antigen-presenting function compromise and a reduced γδ T cell and regulatory T cell (Treg) expansion during NS4B-P38G mutant infection. R848, a TLR7 agonist, decreased host vulnerability in NS4B-P38G-infected old mice by enhancing γδ T cell and Treg expansion and the antigen-presenting capacity of DCs, thereby promoting T cell responses. In summary, our results suggest that dysregulation of TLR7 partially contributes to impaired innate and adaptive T cell responses and an enhanced vulnerability in old mice during WNV NS4B-P38G mutant infection. R848 increases the safety and efficacy during immunization of old mice with the WNV NS4B-P38G mutant. IMPORTANCE: The elderly are known to have enhanced susceptibility to infections and an impaired capacity to respond to vaccination. West Nile virus (WNV), an emerging mosquito-borne flavivirus, has induced severe neurological symptoms more frequently in the elderly population. No vaccines are available for human use. Here, we used an aged mouse model to investigate the protective efficacy of an attenuated WNV, the nonstructural 4B-P38G mutant, which was previously shown to induce no lethality but strong immune responses in young adult mice. Studies that contribute to a mechanistic understanding of immune defects in the elderly will allow the development of strategies to improve responses to infectious diseases and to increase vaccine efficacy and safety in aging individuals.
Assuntos
Imunidade Adaptativa , Resistência à Doença , Imunidade Inata , Linfócitos T/imunologia , Receptor 7 Toll-Like/metabolismo , Febre do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/imunologia , Fatores Etários , Animais , Histocitoquímica , Camundongos Endogâmicos C57BL , Análise de Sobrevida , Carga Viral , Febre do Nilo Ocidental/patologiaRESUMO
Precise regulation of innate immunity is crucial for maintaining optimal immune responses against infections. Whereas positive regulation of IFN signaling elicits rapid type I IFNs, negative regulation is equally important in preventing the production of superfluous IFNs that can be hazardous to the host. The positive regulators of IFN pathway are known to be the main targets of viruses to antagonize the innate immune system. Whether viruses target the negative regulators of IFN pathway remains to be fully investigated. In this study, we report that the structural protein VP2 of human Bocavirus modulates IFN pathway by targeting the ring finger protein 125 (RNF125), a negative regulator of type I IFN signaling, which conjugates Lys(48)-linked ubiquitination to retinoic acid-inducible gene-I (RIG-I) and subsequently leads to the proteasome-dependent degradation of RIG-I. VP2 not only upregulated Sendai virus (SeV)-induced IFNB promoter activity, but also enhanced SeV-induced IFN-ß production at both mRNA and protein levels. In agreement, the level of Ser(396)-phosphorylated IFN regulatory factor 3 stimulated by SeV was enhanced in the presence of VP2. Furthermore, VP2 was demonstrated to physically interact with RNF125, resulting in the reduction of RNF125-mediated ubiquitination and proteasome-dependent degradation of RIG-I. Additional study indicated that endogenous RIG-I degradation was decreased in VP2-expressing cells. Our study delineates a unique phenomenon for aberrant activation of IFN regulatory factor 3 pathway and may represent a new mechanism underlying viral manipulation of the host immune system.
Assuntos
Proteínas do Capsídeo/metabolismo , RNA Helicases DEAD-box/metabolismo , Bocavirus Humano , Interferon beta/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Linhagem Celular , Proteína DEAD-box 58 , Células HEK293 , Células HeLa , Humanos , Imunidade Inata , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/genética , Fosforilação , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Imunológicos , Vírus Sendai , Transdução de Sinais , UbiquitinaçãoRESUMO
Human bocavirus (HBoV) mainly infects young children. Although many infected children suffer from respiratory or gastroenteric tract diseases, an association between HBoV and these diseases is not definite. Because modulation of type I IFN is crucial for viruses to establish efficient replication, in this study, we tested whether HBoV modulates type I IFN production. We observed that a nearly full-length HBoV clone significantly reduced both Sendai virus (SeV)- and poly(deoxyadenylic-thymidylic) acid-induced IFN-ß production. Further study showed that NP1 blocked IFN-ß activation in response to SeV, poly(deoxyadenylic-thymidylic) acid, and IFN-ß pathway inducers, including retinoic acid-inducible protein I, mitochondrial antiviral signaling protein, inhibitor of κB kinase ε, and TANK-binding kinase 1. In addition, NP1 interfered with IRF-3-responsive PRD(III-I) promoter activated by SeV and a constitutively active mutant of IRF-3 (IRF-3/5D). Although NP1 suppressed the IRF-3 pathway, it did not affect IRF-3 activation processes, including phosphorylation, dimerization, and nuclear translocation. Coimmunoprecipitation assays confirmed the interaction between NP1 and IRF-3. Additional deletion mutagenesis and coimmunoprecipitation assays revealed that NP1 bound to the DNA-binding domain of IRF-3, resulting in the interruption of an association between IRF-3 and IFNB promoter. Altogether, our results indicate that HBoV NP1 blocks IFN production through a unique mechanism. To our knowledge, this is the first study to investigate the modulation of innate immunity by HBoV. Our findings suggest a potential immune-evasion mechanism used by HBoV and provide a basis for better understanding HBoV pathogenesis.
Assuntos
Bocavirus/imunologia , Interações Hospedeiro-Patógeno , Fator Regulador 3 de Interferon/antagonistas & inibidores , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/antagonistas & inibidores , Interferon beta/biossíntese , Regiões Promotoras Genéticas/imunologia , Proteínas não Estruturais Virais/fisiologia , Linhagem Celular Tumoral , Células HEK293 , Humanos , Interferon beta/genética , Transdução de Sinais/imunologiaRESUMO
Influenza remains a global health concern due to its potential to cause pandemics as a result of rapidly mutating influenza virus strains. Existing vaccines often struggle to keep up with these rapidly mutating flu viruses. Therefore, the development of a broad-spectrum peptide vaccine that can stimulate an optimal antibody response has emerged as an innovative approach to addressing the influenza threat. In this study, an immunoinformatic approach was employed to rapidly predict immunodominant epitopes from different antigens, aiming to develop an effective multiepitope influenza vaccine (MEV). The immunodominant B-cell linear epitopes of seasonal influenza strains hemagglutinin (HA) and neuraminidase (NA) were predicted using an antibody-peptide microarray, involving a human cohort including vaccinees and infected patients. On the other hand, bioinformatics tools were used to predict immunodominant cytotoxic T-cell (CTL) and helper T-cell (HTL) epitopes. Subsequently, these epitopes were evaluated by various immunoinformatic tools. Epitopes with high antigenicity, high immunogenicity, non-allergenicity, non-toxicity, as well as exemplary conservation were then connected in series with appropriate linkers and adjuvants to construct a broad-spectrum MEV. Moreover, the structural analysis revealed that the MEV candidates exhibited good stability, and the docking results demonstrated their strong affinity to Toll-like receptors 4 (TLR4). In addition, molecular dynamics simulation confirmed the stable interaction between TLR4 and MEVs. Three injections with MEVs showed a high level of B-cell and T-cell immune responses according to the immunological simulations in silico. Furthermore, in-silico cloning was performed, and the results indicated that the MEVs could be produced in considerable quantities in Escherichia coli (E. coli). Based on these findings, it is reasonable to create a broad-spectrum MEV against different subtypes of influenza A and B viruses in silico.
Assuntos
Vacinas contra Influenza , Influenza Humana , Orthomyxoviridae , Humanos , Receptor 4 Toll-Like , Influenza Humana/prevenção & controle , Escherichia coli , Simulação de Acoplamento Molecular , Epitopos de Linfócito T/química , Vacinas de Subunidades Antigênicas , Epitopos de Linfócito B , Biologia Computacional/métodosRESUMO
BACKGROUND: Influenza viruses pose a persistent threat to global public health, necessitating the development of innovative and broadly effective vaccines. METHODS: This study focuses on a multiepitope vaccine (MEV) designed to provide broad-spectrum protection against different influenza viruses. The MEV, containing 19 B-cell linear epitopes, 7 CD4+ T cells, and 11 CD8+ T cells epitopes identified through enzyme-linked immunospot assay (ELISPOT) in influenza viruses infected mice, was administered through a regimen of two doses of DNA vaccine followed by one dose of a protein vaccine in C57BL/6 female mice. FINDINGS: Upon lethal challenge with both seasonal circulating strains (H1N1, H3N2, BV, and BY) and historical strains (H1N1-PR8 and H3N2-X31), MEV demonstrated substantial protection against different influenza seasonal strains, with partial efficacy against historical strains. Notably, the increased germinal centre B cells and antibody-secreting cells, along with robust T cell immune responses, highlighted the comprehensive immune defence elicited by MEV. Elevated hemagglutinin inhibition antibody was also observed against seasonal circulating and historical strains. Additionally, mice vaccinated with MEV exhibited significantly lower counts of inflammatory cells in the lungs compared to negative control groups. INTERPRETATION: Our results demonstrated the efficacy of a broad-spectrum MEV against influenza viruses in mice. Conducting long-term studies to evaluate the durability of MEV-induced immune responses and explore its potential application in diverse populations will offer valuable insights for the continued advancement of this promising vaccine. FUNDING: Funding bodies are described in the Acknowledgments section.
Assuntos
Epitopos de Linfócito B , Vírus da Influenza B , Vacinas contra Influenza , Infecções por Orthomyxoviridae , Animais , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/administração & dosagem , Camundongos , Vírus da Influenza B/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/imunologia , Feminino , Epitopos de Linfócito B/imunologia , Vírus da Influenza A/imunologia , Anticorpos Antivirais/imunologia , Epitopos de Linfócito T/imunologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Vacinas de DNA/imunologia , Vacinas de DNA/administração & dosagem , Estações do Ano , Vírus da Influenza A Subtipo H3N2/imunologia , HumanosRESUMO
Companion animals such as cats and dogs harbor diverse microbial communities that can potentially impact human health due to close and frequent contact. To better characterize their total infectomes and assess zoonotic risks, we characterized the overall infectomes of companion animals (cats and dogs) and evaluated their potential zoonotic risks. Meta-transcriptomic analyses were performed on 239 samples from cats and dogs collected across China, identifying 24 viral species, 270 bacterial genera, and two fungal genera. Differences in the overall microbiome and infectome composition were compared across different animal species (cats or dogs), sampling sites (rectal or oropharyngeal), and health status (healthy or diseased). Diversity analyses revealed that viral abundance was generally higher in diseased animals compared to healthy ones, while differences in microbial composition were mainly driven by sampling site, followed by animal species and health status. Disease association analyses validated the pathogenicity of known pathogens and suggested potential pathogenic roles of previously undescribed bacteria and newly discovered viruses. Cross-species transmission analyses identified seven pathogens shared between cats and dogs, such as alphacoronavirus 1, which was detected in both oropharyngeal and rectal swabs albeit with differential pathogenicity. Further analyses showed that some viruses, like alphacoronavirus 1, harbored multiple lineages exhibiting distinct pathogenicity, tissue, or host preferences. Ultimately, a systematic evolutionary screening identified 27 potential zoonotic pathogens in this sample set, with far more bacterial than viral species, implying potential health threats to humans. Overall, our meta-transcriptomic analysis reveals a landscape of actively transcribing microorganisms in major companion animals, highlighting key pathogens, those with the potential for cross-species transmission, and possible zoonotic threats. IMPORTANCE: This study provides a comprehensive characterization of the entire community of infectious microbes (viruses, bacteria, and fungi) in companion animals like cats and dogs, termed the "infectome." By analyzing hundreds of samples from across China, the researchers identified numerous known and novel pathogens, including 27 potential zoonotic agents that could pose health risks to both animals and humans. Notably, some of these zoonotic pathogens were detected even in apparently healthy pets, highlighting the importance of surveillance. The study also revealed key microbial factors associated with respiratory and gastrointestinal diseases in pets, as well as potential cross-species transmission events between cats and dogs. Overall, this work sheds light on the complex microbial landscapes of companion animals and their potential impacts on animal and human health, underscoring the need for monitoring and management of these infectious agents.
Assuntos
Bactérias , Doenças do Gato , Doenças do Cão , Animais de Estimação , Zoonoses , Animais , Gatos , Cães , Animais de Estimação/virologia , Animais de Estimação/microbiologia , Humanos , Doenças do Cão/microbiologia , Doenças do Cão/virologia , Doenças do Cão/transmissão , Zoonoses/microbiologia , Zoonoses/virologia , Zoonoses/transmissão , Doenças do Gato/virologia , Doenças do Gato/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Microbiota/genética , China , Vírus/classificação , Vírus/genética , Vírus/isolamento & purificação , Vírus/patogenicidade , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/patogenicidade , Perfilação da Expressão Gênica , TranscriptomaRESUMO
Human bocavirus (HBoV), closely related to canine minute virus (MVC) and bovine parvovirus (BPV), is a new member of the Bocavirus genus within the Parvoviridae family. The non-structural protein NP1 of HBoV is a nuclear localized protein and plays an important role in DNA replication as well as in the evasion of host innate immunity. In the current study, we provide the first evidence that NP1 possesses a non-classical nuclear localization signal (ncNLS) (amino acids 7-50). Embedded within this ncNLS is a classical bipartite nuclear localization signal (cNLS) (amino acids 14-28), capable of transporting a heterologous cytoplasmic protein ß-galactosidase fusion protein (ß-gal-EGFP) to the nucleus via the classical importin α/ß1-mediated pathway. Amino acids 7-50 containing the cNLS and the ncNLS of NP1 or full-length NP1 interact with importin α1, importin ß1 and importin ß1Δ, which lacks the importin α binding domain, indicating that the nuclear import of NP1 is through both conventional importin α/ß1 heterodimer- and non-classical importinß1-mediated pathways. Given that the arrangement of a cNLS embedded within an ncNLS is unusual in viral proteins, our data together reveal a novel molecular mechanism underlying the nuclear import of HBoV NP1, providing a basis for further understanding its biological function.
Assuntos
Núcleo Celular/metabolismo , Bocavirus Humano/genética , Sinais de Localização Nuclear , Infecções por Parvoviridae/virologia , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo , Transporte Ativo do Núcleo Celular , Motivos de Aminoácidos , Sequência de Aminoácidos , Linhagem Celular , Núcleo Celular/virologia , Bocavirus Humano/química , Bocavirus Humano/metabolismo , Humanos , Infecções por Parvoviridae/metabolismo , Proteínas não Estruturais Virais/genética , beta Carioferinas/metabolismoRESUMO
West Nile virus (WNV), a mosquito-borne neurotropic flavivirus, has become the leading cause of vector-borne viral encephalitis in the United States for the past decades. The murine model of WNV infection is an effective in vivo experimental model to investigate WNV neuropathogenesis in humans. Here, we describe several laboratory protocols to study WNV infection and the virus-induced inflammation in the brain in both in vitro and in vivo murine models.
Assuntos
Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Camundongos , Humanos , Modelos Animais de Doenças , Mosquitos Vetores , Encéfalo/patologia , Inflamação/patologiaRESUMO
The development of a universal influenza vaccine to elicit broad immune responses is essential in reducing disease burden and pandemic impact. In this study, the mosaic vaccine design strategy and genetic algorithms were utilized to optimize the seasonal influenza A virus (H1N1, H3N2) hemagglutinin (HA) and neuraminidase (NA) antigens, which also contain most potential T-cell epitopes. These mosaic immunogens were then expressed as virus-like particles (VLPs) using the baculovirus expression system. The immunogenicity and protection effectiveness of the mosaic VLPs were compared to the commercial quadrivalent inactivated influenza vaccine (QIV) in the mice model. Strong cross-reactive antibody responses were observed in mice following two doses of vaccination with the mosaic VLPs, with HI titers higher than 40 in 15 of 16 tested strains as opposed to limited cross HI antibody levels with QIV vaccination. After a single vaccination, mice also show a stronger level of cross-reactive antibody responses than the QIV. The QIV vaccinations only elicited NI antibodies to a small number of vaccine strains, and not even strong NI antibodies to its corresponding vaccine components. In contrast, the mosaic VLPs caused robust NI antibodies to all tested seasonal influenza virus vaccine strains. Here, we demonstrated the mosaic vaccines induces stronger cross-reactive antibodies and robust more T-cell responses compared to the QIV. The mosaic VLPs also provided protection against challenges with ancestral influenza A viruses of both H1 and H3 subtypes. These findings indicated that the mosaic VLPs were a promising strategy for developing a broad influenza vaccine in future.
RESUMO
A single-nucleotide polymorphism (SNP) rs12252-C of interferon-induced transmembrane protein 3 (IFITM3), resulting in a truncated IFITM3 protein lacking 21 N-terminus amino acids, is associated with severe influenza infection in the Chinese population. However, the effect of IFITM3 rs12252-C on influenza vaccination and the underlying mechanism is poorly understood. Here, we constructed a mouse model with a deletion of 21 amino acids at the N-terminus (NΔ21) of IFITM3 and then compared the antibody response between Quadrivalent influenza vaccine (QIV) immunized wild-type (WT) mice and NΔ21 mice. Significantly higher levels of haemagglutination inhibition (HI) titre, neutralizing antibodies (NAb), and immunoglobulin G (IgG) to H1N1, H3N2, B/Victory, and B/Yamagata viruses were observed in NΔ21 mice compared to WT mice. Correspondingly, the numbers of splenic germinal centre (GC) B cells, plasma cells, memory B cells, QIV-specific IgG+ antibody-secreting cells (ASC), and T follicular helper cells (TFH) in NΔ21 mice were higher compared with WT mice. Moreover, the 21-amino-acid deletion caused IFITM3 translocation from the endocytosis compartment to the periphery of cells, which also prevented the degradation of a co-stimulatory molecule of B cell receptor (BCR) CD81 on the cell surface. More importantly, a more interaction was observed between NΔ21 protein and CD81 compared to the interaction between IFITM3 and CD81. Overall, our study revealed a potential mechanism of NΔ21 protein enhancing humoral immune response by relocation to prevent the degradation of CD81, providing insight into SNP affecting influenza vaccination.
Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Animais , Camundongos , Humanos , Imunidade Humoral , Vírus da Influenza A Subtipo H3N2/genética , Imunoglobulina G , Aminoácidos , Anticorpos AntiviraisRESUMO
The re-emergence of Zika virus (ZIKV) remains a major public health threat that has raised worldwide attention. Accumulating evidence suggests that ZIKV can cause serious pathological changes to the human nervous system, including microcephaly in newborns. Recent studies suggest that metformin, an established treatment for diabetes may play a role in viral infection; however, little is known about the interactions between ZIKV infection and metformin administration. Using fluorescent ZIKV by flow cytometry and immunofluorescence imaging, we found that ZIKV can infect microglia in a dose-dependent manner. Metformin diminished ZIKV replication without the alteration of viral entry and phagocytosis. Our study demonstrated that metformin downregulated ZIKV-induced inflammatory response in microglia in a time- and dose-dependent manner. Our RNA-Seq and qRT-PCR analysis found that type I and III interferons (IFN), such as IFNα2, IFNß1 and IFNλ3 were upregulated in ZIKV-infected cells by metformin treatment, accompanied with the downregulation of GBP4, OAS1, MX1 and ISG15. Together, our results suggest that metformin-mediated modulation in multiple pathways may attribute to restraining ZIKV infection in microglia, which may provide a potential tool to consider for use in unique clinical circumstances.
Assuntos
Metformina , Infecção por Zika virus , Zika virus , Recém-Nascido , Humanos , Microglia , Regulação para Baixo , Replicação ViralRESUMO
Background: Pre-existing cross-reactive immunity among different coronaviruses, also termed immune imprinting, may have a comprehensive impact on subsequent SARS-CoV-2 infection and COVID-19 vaccination effectiveness. Here, we aim to explore the interplay between pre-existing seasonal coronaviruses (sCoVs) antibodies and the humoral immunity induced by COVID-19 vaccination. Methods: We first collected serum samples from healthy donors prior to COVID-19 pandemic and individuals who had received COVID-19 vaccination post-pandemic in China, and the levels of IgG antibodies against sCoVs and SARS-CoV-2 were detected by ELISA. Wilcoxon rank sum test and chi-square test were used to compare the difference in magnitude and seropositivity rate between two groups. Then, we recruited a longitudinal cohort to collect serum samples before and after COVID-19 vaccination. The levels of IgG antibodies against SARS-CoV-2 S, S1, S2 and N antigen were monitored. Association between pre-existing sCoVs antibody and COVID-19 vaccination-induced antibodies were analyzed by Spearman rank correlation. Results: 96.0% samples (339/353) showed the presence of IgG antibodies against at least one subtype of sCoVs. 229E and OC43 exhibited the highest seroprevalence rates at 78.5% and 72.0%, respectively, followed by NL63 (60.9%) and HKU1 (52.4%). The levels of IgG antibodies against two ß coronaviruses (OC43 and HKU1) were significantly higher in these donors who had inoculated with COVID-19 vaccines compared to pre-pandemic healthy donors. However, we found that COVID-19 vaccine-induced antibody levels were not significant different between two groups with high levelor low level of pre-existing sCoVs antibody among the longitudinal cohort. Conclusion: We found a high prevalence of antibodies against sCoVs in Chinese population. The immune imprinting by sCoVs could be reactivated by COVID-19 vaccination, but it did not appear to be a major factor affecting the immunogenicity of COVID-19 vaccine. These findings will provide insights into understanding the impact of immune imprinting on subsequent multiple shots of COVID-19 vaccines.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , Pandemias , Estações do Ano , Estudos Soroepidemiológicos , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2 , Imunoglobulina GRESUMO
The mechanism by which Zika virus (ZIKV) causes severe birth defects in pregnant women remains unclear. Cell tropisms in placenta and brain play a crucial role in ZIKV pathogenesis, leading to congenital Zika syndrome (CZS). To identify the host factors involved in ZIKV infection, we compared the transcriptional profiles of ZIKV-infected human first-trimester placental trophoblast cells HTR8/SVneo and a human glioblastoma astrocytoma cell line U251. Our results demonstrated that ZIKV exhibited lower rates of mRNA replication and protein expression in HTR8 than in U251 cells, while showing a higher release of infectious viral particles. However, a greater number of differentially expressed genes (DEGs) were found in ZIKV-infected U251 cells than in ZIKV-infected HTR8 cells. Several of these DEGs were enriched in distinct biological processes related to the characteristics of each cell type that may contribute to foetal damage. Both cell types exhibited activation of common interferons, inflammatory cytokines, and chemokine production upon ZIKV infection. Moreover, the neutralization of tumour necrosis factor-alpha (TNF-α) promoted ZIKV infection in both trophoblasts and glioblastoma astrocytoma cells. Overall, we identified multiple DEGs associated with ZIKV pathogenesis.