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1.
J Med Virol ; 96(5): e29657, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38727035

RESUMO

The H1N1pdm09 virus has been a persistent threat to public health since the 2009 pandemic. Particularly, since the relaxation of COVID-19 pandemic mitigation measures, the influenza virus and SARS-CoV-2 have been concurrently prevalent worldwide. To determine the antigenic evolution pattern of H1N1pdm09 and develop preventive countermeasures, we collected influenza sequence data and immunological data to establish a new antigenic evolution analysis framework. A machine learning model (XGBoost, accuracy = 0.86, area under the receiver operating characteristic curve = 0.89) was constructed using epitopes, physicochemical properties, receptor binding sites, and glycosylation sites as features to predict the antigenic similarity relationships between influenza strains. An antigenic correlation network was constructed, and the Markov clustering algorithm was used to identify antigenic clusters. Subsequently, the antigenic evolution pattern of H1N1pdm09 was analyzed at the global and regional scales across three continents. We found that H1N1pdm09 evolved into around five antigenic clusters between 2009 and 2023 and that their antigenic evolution trajectories were characterized by cocirculation of multiple clusters, low-level persistence of former dominant clusters, and local heterogeneity of cluster circulations. Furthermore, compared with the seasonal H1N1 virus, the potential cluster-transition determining sites of H1N1pdm09 were restricted to epitopes Sa and Sb. This study demonstrated the effectiveness of machine learning methods for characterizing antigenic evolution of viruses, developed a specific model to rapidly identify H1N1pdm09 antigenic variants, and elucidated their evolutionary patterns. Our findings may provide valuable support for the implementation of effective surveillance strategies and targeted prevention efforts to mitigate the impact of H1N1pdm09.


Assuntos
Antígenos Virais , Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Influenza Humana/imunologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Aprendizado de Máquina , Evolução Molecular , Epitopos/genética , Epitopos/imunologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/virologia , COVID-19/imunologia , Pandemias/prevenção & controle , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , SARS-CoV-2/genética , SARS-CoV-2/imunologia
2.
Nat Commun ; 15(1): 3833, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714654

RESUMO

Antigenic characterization of circulating influenza A virus (IAV) isolates is routinely assessed by using the hemagglutination inhibition (HI) assays for surveillance purposes. It is also used to determine the need for annual influenza vaccine updates as well as for pandemic preparedness. Performing antigenic characterization of IAV on a global scale is confronted with high costs, animal availability, and other practical challenges. Here we present a machine learning model that accurately predicts (normalized) outputs of HI assays involving circulating human IAV H3N2 viruses, using their hemagglutinin subunit 1 (HA1) sequences and associated metadata. Each season, the model learns an updated nonlinear mapping of genetic to antigenic changes using data from past seasons only. The model accurately distinguishes antigenic variants from non-variants and adaptively characterizes seasonal dynamics of HA1 sites having the strongest influence on antigenic change. Antigenic predictions produced by the model can aid influenza surveillance, public health management, and vaccine strain selection activities.


Assuntos
Antígenos Virais , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Vírus da Influenza A Subtipo H3N2 , Influenza Humana , Aprendizado de Máquina , Estações do Ano , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/genética , Humanos , Influenza Humana/imunologia , Influenza Humana/virologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Antígenos Virais/imunologia , Antígenos Virais/genética , Testes de Inibição da Hemaglutinação , Variação Antigênica/genética , Vacinas contra Influenza/imunologia
3.
Viruses ; 16(4)2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38675907

RESUMO

Rotavirus A (RVA) is the leading cause of diarrhea requiring hospitalization in children and causes over 100,000 annual deaths in Sub-Saharan Africa. In order to generate next-generation vaccines against African RVA genotypes, a reverse genetics system based on a simian rotavirus strain was utilized here to exchange the antigenic capsid proteins VP4, VP7 and VP6 with those of African human rotavirus field strains. One VP4/VP7/VP6 (genotypes G9-P[6]-I2) triple-reassortant was successfully rescued, but it replicated poorly in the first cell culture passages. However, the viral titer was enhanced upon further passaging. Whole genome sequencing of the passaged virus revealed a single point mutation (A797G), resulting in an amino acid exchange (E263G) in VP4. After introducing this mutation into the VP4-encoding plasmid, a VP4 mono-reassortant as well as the VP4/VP7/VP6 triple-reassortant replicated to high titers already in the first cell culture passage. However, the introduction of the same mutation into the VP4 of other human RVA strains did not improve the rescue of those reassortants, indicating strain specificity. The results show that specific point mutations in VP4 can substantially improve the rescue and replication of recombinant RVA reassortants in cell culture, which may be useful for the development of novel vaccine strains.


Assuntos
Proteínas do Capsídeo , Vírus Reordenados , Rotavirus , Replicação Viral , Rotavirus/genética , Proteínas do Capsídeo/genética , Humanos , Vírus Reordenados/genética , Animais , Mutação , Linhagem Celular , Genética Reversa/métodos , Genótipo , Mutação Puntual , Infecções por Rotavirus/virologia , Genoma Viral , Antígenos Virais/genética , Antígenos Virais/imunologia
4.
Cell Host Microbe ; 32(5): 755-767.e4, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38653242

RESUMO

Kaposi sarcoma (KS) is the most common cancer in persons living with HIV. It is caused by KS-associated herpesvirus (KSHV). There exists no animal model for KS. Pronuclear injection of the 170,000-bp viral genome induces early-onset, aggressive angiosarcoma in transgenic mice. The tumors are histopathologically indistinguishable from human KS. As in human KS, all tumor cells express the viral latency-associated nuclear antigen (LANA). The tumors transcribe most viral genes, whereas endothelial cells in other organs only transcribe the viral latent genes. The tumor cells are of endothelial lineage and exhibit the same molecular pattern of pathway activation as KS, namely phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR, interleukin-10 (IL-10), and vascular endothelial growth factor (VEGF). The KSHV-induced tumors are more aggressive than Ha-ras-induced angiosarcomas. Overall survival is increased by prophylactic ganciclovir. Thus, whole-virus KSHV-transgenic mice represent an accurate model for KS and open the door for the genetic dissection of KS pathogenesis and evaluation of therapies, including vaccines.


Assuntos
Modelos Animais de Doenças , Hemangiossarcoma , Herpesvirus Humano 8 , Camundongos Transgênicos , Sarcoma de Kaposi , Animais , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/patogenicidade , Camundongos , Hemangiossarcoma/virologia , Hemangiossarcoma/genética , Hemangiossarcoma/patologia , Sarcoma de Kaposi/virologia , Sarcoma de Kaposi/patologia , Genoma Viral , Humanos , Antígenos Virais/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Ganciclovir/uso terapêutico , Ganciclovir/farmacologia , Interleucina-10/genética
5.
Emerg Microbes Infect ; 13(1): 2343909, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38616729

RESUMO

The recent emergence of a SARS-CoV-2 saltation variant, BA.2.87.1, which features 65 spike mutations relative to BA.2, has attracted worldwide attention. In this study, we elucidate the antigenic characteristics and immune evasion capability of BA.2.87.1. Our findings reveal that BA.2.87.1 is more susceptible to XBB-induced humoral immunity compared to JN.1. Notably, BA.2.87.1 lacks critical escaping mutations in the receptor binding domain (RBD) thus allowing various classes of neutralizing antibodies (NAbs) that were escaped by XBB or BA.2.86 subvariants to neutralize BA.2.87.1, although the deletions in the N-terminal domain (NTD), specifically 15-23del and 136-146del, compensate for the resistance to humoral immunity. Interestingly, several neutralizing antibody drugs have been found to restore their efficacy against BA.2.87.1, including SA58, REGN-10933 and COV2-2196. Hence, our results suggest that BA.2.87.1 may not become widespread until it acquires multiple RBD mutations to achieve sufficient immune evasion comparable to that of JN.1.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , Evasão da Resposta Imune , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Anticorpos Neutralizantes/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , COVID-19/imunologia , COVID-19/virologia , Anticorpos Antivirais/imunologia , Humanos , Mutação , Animais , Antígenos Virais/imunologia , Antígenos Virais/genética , Imunidade Humoral
6.
Biosci Rep ; 44(5)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38592735

RESUMO

The rotavirus capsid protein VP6 forms the middle of three protein layers and is responsible for many critical steps in the viral life cycle. VP6 as a structural protein can be used in various applications including as a subunit vaccine component. The head domain of VP6 (VP6H) contains key sequences that allow the protein to trimerize and that represent epitopes that are recognized by human antibodies in the viral particle. The domain is rich in ß-sheet secondary structures. Here, VP6H was solubilised from bacterial inclusion bodies and purified using a single affinity chromatography step. Spectral (far-UV circular dichroism and intrinsic tryptophan fluorescence) analysis revealed that the purified domain had native-like secondary and tertiary structures. The domain could maintain structure up to 44°C during thermal denaturation following which structural changes result in an intermediate forming and finally irreversible aggregation and denaturation. The chemical denaturation with urea and guanidinium hydrochloride produces intermediates that represent a loss in the cooperativity. The VP6H domain is stable and can fold to produce its native structure in the absence of the VP6 base domain but cannot be defined as an independent folding unit.


Assuntos
Antígenos Virais , Proteínas do Capsídeo , Rotavirus , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Antígenos Virais/química , Antígenos Virais/genética , Rotavirus/química , Desnaturação Proteica , Domínios Proteicos , Dicroísmo Circular , Dobramento de Proteína , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
8.
Emerg Microbes Infect ; 13(1): 2343910, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38618740

RESUMO

Japanese encephalitis (JE), caused by the Japanese encephalitis virus (JEV), is a highly threatening disease with no specific treatment. Fortunately, the development of vaccines has enabled effective defense against JE. However, re-emerging genotype V (GV) JEV poses a challenge as current vaccines are genotype III (GIII)-based and provide suboptimal protection. Given the isolation of GV JEVs from Malaysia, China, and the Republic of Korea, there is a concern about the potential for a broader outbreak. Under the hypothesis that a GV-based vaccine is necessary for effective defense against GV JEV, we developed a pentameric recombinant antigen using cholera toxin B as a scaffold and mucosal adjuvant, which was conjugated with the E protein domain III of GV by genetic fusion. This GV-based vaccine antigen induced a more effective immune response in mice against GV JEV isolates compared to GIII-based antigen and efficiently protected animals from lethal challenges. Furthermore, a bivalent vaccine approach, inoculating simultaneously with GIII- and GV-based antigens, showed protective efficacy against both GIII and GV JEVs. This strategy presents a promising avenue for comprehensive protection in regions facing the threat of diverse JEV genotypes, including both prevalent GIII and GI as well as emerging GV strains.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Genótipo , Vacinas contra Encefalite Japonesa , Vírus da Encefalite Japonesa (Espécie)/genética , Vírus da Encefalite Japonesa (Espécie)/imunologia , Vírus da Encefalite Japonesa (Espécie)/classificação , Animais , Encefalite Japonesa/prevenção & controle , Encefalite Japonesa/imunologia , Encefalite Japonesa/virologia , Vacinas contra Encefalite Japonesa/imunologia , Vacinas contra Encefalite Japonesa/administração & dosagem , Vacinas contra Encefalite Japonesa/genética , Camundongos , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Humanos , Camundongos Endogâmicos BALB C , Feminino , Antígenos Virais/imunologia , Antígenos Virais/genética , Eficácia de Vacinas , Toxina da Cólera/genética , Toxina da Cólera/imunologia
9.
Virol J ; 21(1): 94, 2024 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-38659036

RESUMO

BACKGROUND: The causative agents of diarrhea, rotavirus B (RVB) and rotavirus C (RVC) are common in adults and patients of all age groups, respectively. Due to the Rotavirus A (RVA) vaccination program, a significant decrease in the number of gastroenteritis cases has been observed globally. The replacement of RVA infections with RVB, RVC, or other related serogroups is suspected due to the possibility of reducing natural selective constraints due to RVA infections. The data available on RVB and RVC incidence are scant due to the lack of cheap and rapid commercial diagnostic assays and the focus on RVA infections. The present study aimed to develop real-time RT‒PCR assays using the data from all genomic RNA segments of human RVB and RVC strains available in the Gene Bank. RESULTS: Among the 11 gene segments, NSP3 and NSP5 of RVB and the VP6 gene of RVC were found to be suitable for real-time RT‒PCR (qRT‒PCR) assays. Fecal specimens collected from diarrheal patients were tested simultaneously for the presence of RVB (n = 192) and RVC (n = 188) using the respective conventional RT‒PCR and newly developed qRT‒PCR assays. All RVB- and RVC-positive specimens were reactive in their respective qRT‒PCR assays and had Ct values ranging between 23.69 and 41.97 and 11.49 and 36.05, respectively. All known positive and negative specimens for other viral agents were nonreactive, and comparative analysis showed 100% concordance with conventional RT‒PCR assays. CONCLUSIONS: The suitability of the NSP5 gene of RVB and the VP6 gene of RVC was verified via qRT‒PCR assays, which showed 100% sensitivity and specificity. The rapid qRT‒PCR assays developed will be useful diagnostic tools, especially during diarrheal outbreaks for testing non-RVA rotaviral agents and reducing the unnecessary use of antibiotics.


Assuntos
Diarreia , Fezes , Reação em Cadeia da Polimerase em Tempo Real , Infecções por Rotavirus , Rotavirus , Rotavirus/genética , Rotavirus/isolamento & purificação , Humanos , Infecções por Rotavirus/virologia , Infecções por Rotavirus/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Fezes/virologia , Diarreia/virologia , Diarreia/diagnóstico , Sensibilidade e Especificidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteínas não Estruturais Virais/genética , Antígenos Virais/genética , RNA Viral/genética , Proteínas do Capsídeo/genética , Genoma Viral/genética , Gastroenterite/virologia , Gastroenterite/diagnóstico
10.
Viruses ; 16(3)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38543842

RESUMO

Coxsackievirus A6 (CV-A6) has emerged as the predominant causative agent of hand, foot, and mouth disease (HFMD) in young children. Since the declaration of coronavirus disease 2019 (COVID-19) as a global pandemic, the incidence of infectious diseases, including HFMD, has decreased markedly. When social mitigation was relaxed during the COVID-19 pandemic in 2022, the re-emergence of HFMD was observed in Gwangju, South Korea, and seasonal characteristics of the disease appeared to have changed. To investigate the molecular characteristics of enterovirus (EV) associated with HFMD during 2022, 277 specimens were collected. Children aged younger than 5 years accounted for the majority of affected individuals. EV detection and genotyping were performed using real-time RT-PCR and nested RT-PCR followed by sequence analysis. The EV detection rate was found to be 82.3%, and the main genotype identified was CV-A6. Sixteen CV-A6 samples were selected for whole genome sequencing. According to phylogenetic analysis, all CV-A6 strains from this study belonged to the sub-genotype D3 clade based on VP1 sequences. Analysis of 3D polymerase phylogeny showed that only the recombinant RF-A group was identified. In conclusion, circulating EV types should be continuously monitored to understand pathogen emergence and evolution during the post-pandemic era.


Assuntos
Enterovirus , Doença de Mão, Pé e Boca , Criança , Humanos , Pré-Escolar , Doença de Mão, Pé e Boca/epidemiologia , Filogenia , Pandemias , Enterovirus/genética , Antígenos Virais/genética , Reação em Cadeia da Polimerase em Tempo Real , Genótipo , China/epidemiologia
11.
Microb Pathog ; 190: 106630, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38556102

RESUMO

Porcine circovirus type 2 (PCV2) is a globally prevalent infectious pathogen affecting swine, with its capsid protein (Cap) being the sole structural protein critical for vaccine development. Prior research has demonstrated that PCV2 Cap proteins produced in Escherichia coli (E. coli) can form virus-like particles (VLPs) in vitro, and nuclear localization signal peptides (NLS) play a pivotal role in stabilizing PCV2 VLPs. Recently, PCV2d has emerged as an important strain within the PCV2 epidemic. In this study, we systematically optimized the PCV2d Cap protein and successfully produced intact PCV2d VLPs containing NLS using E. coli. The recombinant PCV2d Cap protein was purified through affinity chromatography, yielding 7.5 mg of recombinant protein per 100 ml of bacterial culture. We augmented the conventional buffer system with various substances such as arginine, ß-mercaptoethanol, glycerol, polyethylene glycol, and glutathione to promote VLP assembly. The recombinant PCV2d Cap self-assembled into VLPs approximately 20 nm in diameter, featuring uniform distribution and exceptional stability in the optimized buffer. We developed the vaccine and immunized pigs and mice, evaluating the immunogenicity of the PCV2d VLPs vaccine by measuring PCV2-IgG, IL-4, TNF-α, and IFN-γ levels, comparing them to commercial vaccines utilizing truncated PCV2 Cap antigens. The HE staining and immunohistochemical tests confirmed that the PCV2 VLPs vaccine offered robust protection. The results revealed that animals vaccinated with the PCV2d VLPs vaccine exhibited high levels of PCV2 antibodies, with TNF-α and IFN-γ levels rapidly increasing at 14 days post-immunization, which were higher than those observed in commercially available vaccines, particularly in the mouse trial. This could be due to the fact that full-length Cap proteins can assemble into more stable PCV2d VLPs in the assembling buffer. In conclusion, our produced PCV2d VLPs vaccine elicited stronger immune responses in pigs and mice compared to commercial vaccines. The PCV2d VLPs from this study serve as an excellent candidate vaccine antigen, providing insights for PCV2d vaccine research.


Assuntos
Anticorpos Antivirais , Proteínas do Capsídeo , Circovirus , Escherichia coli , Proteínas Recombinantes , Vacinas de Partículas Semelhantes a Vírus , Animais , Circovirus/imunologia , Circovirus/genética , Suínos , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas de Partículas Semelhantes a Vírus/genética , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Camundongos , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genética , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Vacinas Virais/genética , Desenvolvimento de Vacinas , Antígenos Virais/imunologia , Antígenos Virais/genética , Imunoglobulina G/sangue , Análise Custo-Benefício , Feminino , Interferon gama/metabolismo , Imunogenicidade da Vacina
12.
J Appl Microbiol ; 135(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38471668

RESUMO

AIMS: Enteroviruses are significant human pathogens associated with a range of mild to severe diseases. This study aims to understand the diversity and genetic characterization of enteroviruses circulated in southwest China's border cities by using environmental surveillance. METHODS AND RESULTS: A total of 96 sewage samples were collected in three border cities and a port located in Yunnan Province, China from July 2020 to June 2022. After cell culture and VP1 sequencing, a total of 590 enterovirus isolates were identified, belonging to 21 types. All PV strains were Sabin-like with ≤6 nucleotide mutations in the VP1 coding region. Echovirus 6, echovirus 21 (a rare serotype in previous studies), and coxsackievirus B5 were the predominant serotypes, which accounted for 21.19%, 18.31%, and 13.39% of the total isolates, respectively. The prevalence of the common serotypes varied across different border cities and periods. Phylogenetic analysis revealed the presence of multiple evolutionary lineages for E21, E6, and E30, some of which formed distinct branches. CONCLUSIONS: High diversity of enteroviruses and distinct lineages of predominant serotypes circulated in southwest China's border cities.


Assuntos
Infecções por Enterovirus , Enterovirus , Humanos , Cidades , Filogenia , China/epidemiologia , Infecções por Enterovirus/epidemiologia , Enterovirus Humano B/genética , Antígenos Virais/genética , Monitoramento Ambiental/métodos
13.
Arch Virol ; 169(3): 44, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38341400

RESUMO

Foot-and-mouth disease is a highly contagious disease that affects cloven-hoofed animals. It has an important socio-economic impact on the livestock industry because it produces a drastic decrease of productivity. The disease has been successfully eradicated from some regions, including North America and Western Europe, but it is still endemic in developing countries. Agriculture plays an important role in the national economy of Vietnam, to which animal production contributes a great proportion. The concurrent circulation of foot-and-mouth disease virus (FMDV) serotypes O, A, and Asia 1 has been detected in recent years, but serotype O remains the most prevalent and is responsible for the highest numbers of outbreaks. Appropriate vaccine strain selection is an important element in the control of FMD and is necessary for the application of vaccination programs in FMD-affected regions. Here, we present updated information about the genetic and antigenic characteristics of circulating strains, collected from endemic outbreaks involving types O and A, between 2010 and 2019. Neutralizing assays showed a good in vitro match between type O strains and the monovalent O1 Campos vaccine strain. High r1 values were obtained (above 0.7) when testing a swine serum pool collected 21 days after vaccination, but the O/VTN/2/2019 strain was an exception. An EPP estimation resulted in a median neutralizing titre of about 1.65 log10, indicating that good protection could be achieved. For type A Asia SEA 97 lineage strains, acceptable individual neutralizing titres were obtained with estimated EPP values over 80% for different combinations of vaccine strains. Taking into account that the r1 value is one tool of a battery of tests that should be considered for estimating the cross-protection of a field strain against a vaccine strain, an in vivo challenge experiment was also performed, yielding a PD50 value of 8.0. The results indicate that South American strains could be potentially used for controlling outbreaks involving these lineages. This study demonstrates the importance of considering strain characteristics when choosing vaccine strains and controls.


Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Vacinas Virais , Animais , Suínos , Vietnã/epidemiologia , Vacinas Virais/genética , Febre Aftosa/epidemiologia , Febre Aftosa/prevenção & controle , Antígenos Virais/genética , Sorogrupo
14.
Virus Genes ; 60(2): 148-158, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38340271

RESUMO

Guinea Pig Herpes-Like Virus (GPHLV) is a virus isolated from leukemic guinea pigs with herpes virus-like morphology described by Hsiung and Kaplow in 1969. GPHLV transformed embryonic cells from Syrian hamsters or rats, which were tumorigenic in adult animals. Herein, we present the genomic sequence of GPHLV strain LK40 as a reference for future molecular analysis. GPHLV has a broad host tropism and replicates efficiently in Guinea pig, Cat, and Green African Monkey-derived cell lines. GPHLV has a GC content of 35.45%. The genome is predicted to encode at least 75 open-reading frames (ORFs) with 84% (63 ORFs) sharing homology to human Kaposi Sarcoma Associated Herpes Virus (KSHV). Importantly, GPHLV encodes homologues of the KSHV oncogenes, vBCL2 (ORF16), vPK (ORF36), viral cyclin (v-cyclin, ORF72), the latency associated nuclear antigen (LANA, ORF73), and vGPCR (ORF74). GPHLV is a Rhadinovirus of Cavia porcellus, and we propose the formal name of Caviid gamma herpesvirus 1 (CaGHV-1). GPHLV can be a novel small animal model of Rhadinovirus pathogenesis with broad host tropism.


Assuntos
Herpesviridae , Herpesvirus Humano 8 , Cricetinae , Cobaias , Humanos , Animais , Ratos , Chlorocebus aethiops , Antígenos Virais/genética , Mesocricetus , Ciclinas , Herpesvirus Humano 8/genética
15.
Cell Rep ; 43(3): 113888, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38416644

RESUMO

Higher-order genome structure influences the transcriptional regulation of cellular genes through the juxtaposition of regulatory elements, such as enhancers, close to promoters of target genes. While enhancer activation has emerged as an important facet of Kaposi sarcoma-associated herpesvirus (KSHV) biology, the mechanisms controlling enhancer-target gene expression remain obscure. Here, we discover that the KSHV genome tethering protein latency-associated nuclear antigen (LANA) potentiates enhancer-target gene expression in primary effusion lymphoma (PEL), a highly aggressive B cell lymphoma causally associated with KSHV. Genome-wide analyses demonstrate increased levels of enhancer RNA transcription as well as activating chromatin marks at LANA-bound enhancers. 3D genome conformation analyses identified genes critical for latency and tumorigenesis as targets of LANA-occupied enhancers, and LANA depletion results in their downregulation. These findings reveal a mechanism in enhancer-gene coordination and describe a role through which the main KSHV tethering protein regulates essential gene expression in PEL.


Assuntos
Herpesvirus Humano 8 , Sarcoma de Kaposi , Humanos , Herpesvirus Humano 8/fisiologia , Estudo de Associação Genômica Ampla , Antígenos Virais/genética , Antígenos Virais/metabolismo , Regiões Promotoras Genéticas/genética , Regulação da Expressão Gênica , Latência Viral
16.
Nat Commun ; 15(1): 1553, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378768

RESUMO

Ever-evolving SARS-CoV-2 variants of concern (VOCs) have diminished the effectiveness of therapeutic antibodies and vaccines. Developing a coronavirus vaccine that offers a greater breadth of protection against current and future VOCs would eliminate the need to reformulate COVID-19 vaccines. Here, we rationally engineer the sequence-conserved S2 subunit of the SARS-CoV-2 spike protein and characterize the resulting S2-only antigens. Structural studies demonstrate that the introduction of interprotomer disulfide bonds can lock S2 in prefusion trimers, although the apex samples a continuum of conformations between open and closed states. Immunization with prefusion-stabilized S2 constructs elicits broadly neutralizing responses against several sarbecoviruses and protects female BALB/c mice from mouse-adapted SARS-CoV-2 lethal challenge and partially protects female BALB/c mice from mouse-adapted SARS-CoV lethal challenge. These engineering and immunogenicity results should inform the development of next-generation pan-coronavirus therapeutics and vaccines.


Assuntos
COVID-19 , SARS-CoV-2 , Feminino , Animais , Humanos , Camundongos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Antígenos Virais/genética , Camundongos Endogâmicos BALB C , Glicoproteína da Espícula de Coronavírus/genética , Anticorpos Neutralizantes , Anticorpos Antivirais
17.
Int J Infect Dis ; 140: 113-118, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38307378

RESUMO

OBJECTIVES: Rotaviruses G1P[8] are epidemiologically relevant and are targeted by vaccines. The introduction of vaccines has altered rotavirus epidemiology. Hospital-based surveillance conducted in Sicily, Italy, showed a progressive decline in rotavirus prevalence since 2014, along with an increasing vaccine coverage (63.8% in 2020), and a marked decrease in circulation of G1P[8] strains. Surprisingly in 2021, G1P[8] viruses accounted for 90.5% (19/21) of rotavirus infections. This study aimed to understand if the increased activity of G1P[8]'s was related to virus-related peculiarities. DESIGN: In 2021, 266 patients <15 years of age were hospitalized with acute gastroenteritis (AGE) and included in rotavirus surveillance. Viral proteins (VP7 and VP4) genotyping and sequence data were generated from all rotavirus-positive samples. The genetic makeup of G1P[8] rotaviruses was investigated by full-genome sequencing. RESULTS: Peculiar G1P[8] rotaviruses, with VP7 and VP4 belonging to novel sub-lineages, circulated in 2021, accounting for 76.2% (16/21) of all rotavirus infections. On full-genome analysis, the novel G1P[8] variant displayed an intra-genotype (Wa-like) reassortant constellation, involving G12 and G1 strains, into a unique arrangement never observed before. The novel G1P[8] variant showed peculiar amino acid substitutions in 8-1 and 8-3 epitopes of the VP4 with respect to the Rotarix strain. CONCLUSIONS: Prompt identification of virus variants circulating in the human population is pivotal to understanding epidemiological trends and assessing vaccine efficacy.


Assuntos
Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Humanos , Rotavirus/genética , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Filogenia , Genoma Viral , Genótipo , Sicília , Proteínas do Capsídeo/genética , Antígenos Virais/genética
18.
Brief Bioinform ; 25(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38343322

RESUMO

Vaccination stands as the most effective and economical strategy for prevention and control of influenza. The primary target of neutralizing antibodies is the surface antigen hemagglutinin (HA). However, ongoing mutations in the HA sequence result in antigenic drift. The success of a vaccine is contingent on its antigenic congruence with circulating strains. Thus, predicting antigenic variants and deducing antigenic clusters of influenza viruses are pivotal for recommendation of vaccine strains. The antigenicity of influenza A viruses is determined by the interplay of amino acids in the HA1 sequence. In this study, we exploit the ability of convolutional neural networks (CNNs) to extract spatial feature representations in the convolutional layers, which can discern interactions between amino acid sites. We introduce PREDAC-CNN, a model designed to track antigenic evolution of seasonal influenza A viruses. Accessible at http://predac-cnn.cloudna.cn, PREDAC-CNN formulates a spatially oriented representation of the HA1 sequence, optimized for the convolutional framework. It effectively probes interactions among amino acid sites in the HA1 sequence. Also, PREDAC-CNN focuses exclusively on physicochemical attributes crucial for the antigenicity of influenza viruses, thereby eliminating unnecessary amino acid embeddings. Together, PREDAC-CNN is adept at capturing interactions of amino acid sites within the HA1 sequence and examining the collective impact of point mutations on antigenic variation. Through 5-fold cross-validation and retrospective testing, PREDAC-CNN has shown superior performance in predicting antigenic variants compared to its counterparts. Additionally, PREDAC-CNN has been instrumental in identifying predominant antigenic clusters for A/H3N2 (1968-2023) and A/H1N1 (1977-2023) viruses, significantly aiding in vaccine strain recommendation.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A , Vacinas , Vírus da Influenza A/genética , Vírus da Influenza A Subtipo H3N2/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Estações do Ano , Estudos Retrospectivos , Antígenos Virais/genética , Redes Neurais de Computação , Aminoácidos
19.
Bull Exp Biol Med ; 176(3): 354-358, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38342808

RESUMO

The influence of SARS-CoV-2 antigen on the cytokine-producing function of immune cells was studied. We observed suppression of the production of proinflammatory cytokines by 11-46% relative to the spontaneous level under the influence of SARS-CoV-2 antigen vaccine simulator, as well as when it was co-administered with cortisol (IL-6 by 1.8 times and IFNγ by 1.57 times) compared with control samples. IL-8 production was reduced by 1.72 times relative to its spontaneous level. IL-8 production was reduced by 1.72 times relative to its spontaneous level. Under conditions of SARS-CoV-2 stimulation with the vaccine antigen in vitro, an increase in the relative scaled expression of the VEGFA gene by 2.16 times relative to the spontaneous level was observed, which can be regarded as a model "cytokine storm" scenario. The obtained experimental data verify the ideas about the pathogenetic mechanisms of the COVID-19 and can contribute to the development of new approaches to the correction of its complications.


Assuntos
COVID-19 , Vacinas , Humanos , Vacinas contra COVID-19 , SARS-CoV-2/genética , Citocinas/genética , Interleucina-8 , COVID-19/prevenção & controle , Antígenos Virais/genética , Fator A de Crescimento do Endotélio Vascular/genética
20.
SLAS Discov ; 29(3): 100140, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38182043

RESUMO

The use of recombinant antibodies developed through phage display technology offers a promising approach for combating viral infectious diseases. By specifically targeting antigens on viral surfaces, these antibodies have the potential to reduce the severity of infections or even prevent them altogether. With the emergence of new and more virulent strains of viruses, it is crucial to develop innovative methods to counteract them. Phage display technology has proven successful in generating recombinant antibodies capable of targeting specific viral antigens, thereby providing a powerful tool to fight viral infections. In this mini-review article, we examine the development of these antibodies using phage display technology, and discuss the associated challenges and opportunities in developing novel treatments for viral infectious diseases. Furthermore, we provide an overview of phage display technology. As these methods continue to evolve and improve, novel and sophisticated tools based on phage display and peptide display systems are constantly emerging, offering exciting prospects for solving scientific, medical, and technological problems related to viral infectious diseases in the near future.


Assuntos
Técnicas de Visualização da Superfície Celular , Proteínas Recombinantes , Viroses , Humanos , Viroses/imunologia , Viroses/terapia , Técnicas de Visualização da Superfície Celular/métodos , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genética , Anticorpos Neutralizantes/imunologia , Biblioteca de Peptídeos , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/uso terapêutico , Animais , Antígenos Virais/imunologia , Antígenos Virais/genética
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