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1.
Front Microbiol ; 15: 1392814, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38962133

RESUMO

Alphaherpesviruses, categorized as viruses with linear DNA composed of two complementary strands, can potentially to induce diseases in both humans and animals as pathogens. Mature viral particles comprise of a core, capsid, tegument, and envelope. While herpesvirus infection can elicit robust immune and inflammatory reactions in the host, its persistence stems from its prolonged interaction with the host, fostering a diverse array of immunoescape mechanisms. In recent years, significant advancements have been achieved in comprehending the immunoescape tactics employed by alphaherpesviruses, including pseudorabies virus (PRV), herpes simplex virus (HSV), varicella-zoster virus (VZV), feline herpesvirus (FeHV), equine herpesvirus (EHV), and caprine herpesvirus type I (CpHV-1). Researchers have unveiled the intricate adaptive mechanisms existing between viruses and their natural hosts. This review endeavors to illuminate the research advancements concerning the immunoescape mechanisms of alphaherpesviruses by delineating the pertinent proteins and genes involved in virus immunity. It aims to furnish valuable insights for further research on related mechanisms and vaccine development, ultimately contributing to virus control and containment efforts.

2.
Front Mol Biosci ; 11: 1375360, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38962282

RESUMO

Background: High altitude de-acclimatization (HADA) is gradually becoming a public health concern as millions of individuals of different occupations migrate to high-altitude areas for work due to economic growth in plateau areas. HADA affects people who return to lower elevations after exposure to high altitudes. It causes significant physiological and functional changes that can negatively impact health and even endanger life. However, uncertainties persist about the detailed mechanisms underlying HADA. Methods: We established a population cohort of individuals with HADA and assessed variations in metabolite composition. Plasm samples of four groups, including subjects staying at plain (P) and high altitude (H) as well as subjects suffering from HADA syndrome with almost no reaction (r3) and mild-to-moderate reaction (R3) after returning to plain from high altitude, were collected and analyzed by Liquid Chromatography-Mass Spectrometry metabolomic. Multivariate statistical analyses were used to explore significant differences and potential clinical prospect of metabolites. Result: Although significantly different on current HADAS diagnostic symptom score, there were no differences in 17 usual clinical indices between r3 and R3. Further multivariate analyses showed isolated clustering distribution of the metabolites among the four groups, suggesting significant differences in their metabolic characteristics. Through K-means clustering analysis, we identified 235 metabolites that exhibited patterns of abundance change consistent with phenotype of HADA syndrome. Pathway enrichment analysis indicated a high influence of polyunsaturated fatty acids under high-altitude conditions. We compared the metabolites between R3 and r3 and found 107 metabolites with differential abundance involved in lipid metabolism and oxidation, suggesting their potential role in the regulation of oxidative stress homeostasis. Among them, four metabolites might play a key role in the occurrence of HADA, including 11-beta-hydroxyandrosterone-3-glucuronide, 5-methoxyindoleacetate, 9,10-epoxyoctadecenoic acid, and PysoPC (20:5). Conclusion: We observed the dynamic variation in the metabolic process of HADA. Levels of four metabolites, which might be provoking HADA mediated through lipid metabolism and oxidation, were expected to be explore prospective indices for HADA. Additionally, metabolomics was more efficient in identifying environmental risk factors than clinical examination when dramatic metabolic disturbances underlying the difference in symptoms were detected, providing new insights into the molecular mechanisms of HADAS.

3.
Emerg Microbes Infect ; 13(1): 2377599, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38973388

RESUMO

African swine fever virus (ASFV) is the causative agent of African swine fever (ASF), a highly contagious disease that can kill up to 100% of domestic pigs and wild boars. It has been shown that the pigs inoculated with some ASF vaccine candidates display more severe clinical signs and die earlier than do pigs not immunized. We hypothesize that antibody-dependent enhancement (ADE) of ASFV infection may be caused by the presence of some unidentified antibodies. In this study, we found that the ASFV-encoded structural protein A137R (pA137R) can be recognized by the anti-ASFV positive sera, indicating that the anti-pA137R antibodies are induced in the ASFV-infected pigs. Interestingly, our results demonstrated that the anti-pA137R antibodies produced in rabbits or pigs enhanced viral replication of different ASFV strains in primary porcine alveolar macrophages (PAMs), the target cells of ASFV. Mechanistic investigations revealed that anti-pA137R antibodies were able to promote the attachment of ASFV to PAMs and two types of Fc gamma receptors (FcγRs), FcγRII and FcγRIII, mediated the ADE of ASFV infection. Taken together, anti-pA137R antibodies are able to drive ASFV ADE in PAMs. These findings shed new light on the roles of anti-ASFV antibodies and have implications for the pathophysiology of the disease and the development of ASF vaccines.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Anticorpos Antivirais , Anticorpos Facilitadores , Macrófagos Alveolares , Receptores de IgG , Animais , Vírus da Febre Suína Africana/imunologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/virologia , Suínos , Febre Suína Africana/virologia , Febre Suína Africana/imunologia , Anticorpos Antivirais/imunologia , Receptores de IgG/imunologia , Replicação Viral , Coelhos
4.
Viruses ; 16(6)2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38932205

RESUMO

African swine fever (ASF) is a contagious viral disease affecting pigs and wild boars. It typically presents as a hemorrhagic fever but can also manifest in various forms, ranging from acute to asymptomatic. ASF has spread extensively globally, significantly impacting the swine industry. The complex and highly variable character of the ASFV genome makes vaccine development and disease surveillance extremely difficult. The overall trend in ASFV evolution is towards decreased virulence and increased transmissibility. Factors such as gene mutation, viral recombination, and the strain-specificity of virulence-associated genes facilitate viral variations. This review deeply discusses the influence of these factors on viral immune evasion, pathogenicity, and the ensuing complexities encountered in vaccine development, disease detection, and surveillance. The ultimate goal of this review is to thoroughly explore the genetic evolution patterns and variation mechanisms of ASFV, providing a theoretical foundation for advancement in vaccine and diagnostic technologies.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Variação Genética , Genoma Viral , Vírus da Febre Suína Africana/genética , Animais , Suínos , Febre Suína Africana/virologia , Virulência , Vacinas Virais/imunologia , Vacinas Virais/genética , Evolução Molecular , Evasão da Resposta Imune/genética , Mutação , Desenvolvimento de Vacinas
5.
Viruses ; 16(6)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38932241

RESUMO

African swine fever (ASF) is an acute, hemorrhagic, highly contagious disease in pigs caused by African swine fever virus (ASFV). Our previous study identified that the ASFV MGF300-2R protein functions as a virulence factor and found that MGF300-2R degrades IKKß via selective autophagy. However, the E3 ubiquitin ligase responsible for IKKß ubiquitination during autophagic degradation still remains unknown. In order to solve this problem, we first pulled down 328 proteins interacting with MGF300-2R through immunoprecipitation-mass spectrometry. Next, we analyzed and confirmed the interaction between the E3 ubiquitin ligase TRIM21 and MGF300-2R and demonstrated the catalytic role of TRIM21 in IKKß ubiquitination. Finally, we indicated that the degradation of IKKß by MGF300-2R was dependent on TRIM21. In summary, our results indicate TRIM21 is the E3 ubiquitin ligase involved in the degradation of IKKß by MGF300-2R, thereby augmenting our understanding of the functions of MGF300-2R and offering insights into the rational design of live attenuated vaccines and antiviral strategies against ASF.


Assuntos
Vírus da Febre Suína Africana , Quinase I-kappa B , Ribonucleoproteínas , Ubiquitina-Proteína Ligases , Ubiquitinação , Proteínas Virais , Animais , Vírus da Febre Suína Africana/metabolismo , Vírus da Febre Suína Africana/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Suínos , Quinase I-kappa B/metabolismo , Ribonucleoproteínas/metabolismo , Ribonucleoproteínas/genética , Proteínas Virais/metabolismo , Proteínas Virais/genética , Febre Suína Africana/virologia , Febre Suína Africana/metabolismo , Humanos , Células HEK293 , Interações Hospedeiro-Patógeno , Fatores de Virulência/metabolismo , Autofagia , Ligação Proteica
6.
Vaccines (Basel) ; 12(6)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38932358

RESUMO

Classical swine fever (CSF), caused by the classical swine fever virus (CSFV), results in significant economic losses to the swine industry in many countries. Vaccination represents the primary strategy to control CSF and the CSFV E2 protein is known as the major protective antigen. However, the E2 protein expressed or presented by different systems elicits distinct immune responses. In this study, we established a stable CHO cell line to express the E2 protein and delivered it using self-assembled ferritin nanoparticles (NPs). Subsequently, we compared the adaptive immune responses induced by the E2-ferritin NPs and the monomeric E2 protein produced by the CHO cells or a baculovirus expression system. The results revealed that the NP-delivered E2 protein elicited higher titers of neutralizing antibodies than did the monomeric E2 protein in pigs. Importantly, only the NP-delivered E2 protein significantly induced CSFV-specific IFN-γ-secreting cells. Furthermore, all the pigs inoculated with the E2-ferritin NPs were completely protected from a lethal CSFV challenge infection. These findings demonstrate the ability of the E2-ferritin NPs to protect pigs against the lethal CSFV challenge by eliciting robust humoral and cellular immune responses.

7.
Int J Biol Macromol ; 271(Pt 1): 132666, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38806081

RESUMO

Elongation of very long-chain fatty acids protein 6 (ELOVL6) plays a pivotal role in the synthesis of endogenous fatty acids, influencing energy balance and metabolic diseases. The primary objective of this study was to discover the molecular attributes and regulatory roles of ELOVL6 in male Nile tilapia, Oreochromis niloticus. The full-length cDNA of elovl6 was cloned from male Nile tilapia, and was determined to be 2255-bp long, including a 5'-untranslated region of 193 bp, a 3'-untranslated region of 1252 bp, and an open reading frame of 810 bp encoding 269 amino acids. The putative protein had typical features of ELOVL proteins. The transcript levels of elovl6 differed among various tissues and among fish fed with different dietary lipid sources. Knockdown of elovl6 in Nile tilapia using antisense RNA technology resulted in significant alterations in hepatic morphology, long-chain fatty acid synthesis, and fatty acid oxidation, and led to increased fat deposition in the liver and disrupted glucose/lipid metabolism. A comparative transcriptomic analysis (elovl6 knockdown vs. the negative control) identified 5877 differentially expressed genes with significant involvement in key signaling pathways including the peroxisome proliferator-activated receptor signaling pathway, fatty acid degradation, glycolysis/gluconeogenesis, and the insulin signaling pathway, all of which are crucial for lipid and glucose metabolism. qRT-PCR analyses verified the transcript levels of 13 differentially expressed genes within these pathways. Our findings indicate that elovl6 knockdown in male tilapia impedes oleic acid synthesis, culminating in aberrant nutrient metabolism.


Assuntos
Ciclídeos , Elongases de Ácidos Graxos , Animais , Masculino , Elongases de Ácidos Graxos/genética , Elongases de Ácidos Graxos/metabolismo , Ciclídeos/genética , Ciclídeos/metabolismo , Metabolismo dos Lipídeos/genética , Inativação Gênica , Fígado/metabolismo , Nutrientes/metabolismo , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Sequência de Aminoácidos , Clonagem Molecular , Acetiltransferases/genética , Acetiltransferases/metabolismo , Técnicas de Silenciamento de Genes
8.
Emerg Microbes Infect ; 13(1): 2333381, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38501350

RESUMO

African swine fever (ASF) is a highly contagious, often fatal viral disease caused by African swine fever virus (ASFV), which imposes a substantial economic burden on the global pig industry. When screening for the virus replication-regulating genes in the left variable region of the ASFV genome, we observed a notable reduction in ASFV replication following the deletion of the MGF300-4L gene. However, the role of MGF300-4L in ASFV infection remains unexplored. In this study, we found that MGF300-4L could effectively inhibit the production of proinflammatory cytokines IL-1ß and TNF-α, which are regulated by the NF-κB signaling pathway. Mechanistically, we demonstrated that MGF300-4L interacts with IKKß and promotes its lysosomal degradation via the chaperone-mediated autophagy. Meanwhile, the interaction between MGF300-4L and IκBα competitively inhibits the binding of the E3 ligase ß-TrCP to IκBα, thereby inhibiting the ubiquitination-dependent degradation of IκBα. Remarkably, although ASFV encodes other inhibitors of NF-κB, the MGF300-4L gene-deleted ASFV (Del4L) showed reduced virulence in pigs, indicating that MGF300-4L plays a critical role in ASFV pathogenicity. Importantly, the attenuation of Del4L was associated with a significant increase in the production of IL-1ß and TNF-α early in the infection of pigs. Our findings provide insights into the functions of MGF300-4L in ASFV pathogenicity, suggesting that MGF300-4L could be a promising target for developing novel strategies and live attenuated vaccines against ASF.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Quinase I-kappa B , Inibidor de NF-kappaB alfa , Animais , Vírus da Febre Suína Africana/fisiologia , Quinase I-kappa B/genética , Quinase I-kappa B/farmacologia , NF-kappa B/genética , Inibidor de NF-kappaB alfa/genética , Inibidor de NF-kappaB alfa/farmacologia , Suínos , Fator de Necrose Tumoral alfa/genética , Virulência
9.
Virol J ; 21(1): 53, 2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38438894

RESUMO

BACKGROUND: Atypical porcine pestivirus (APPV) is a newly discovered swine pestivirus, which can cause congenital tremor and high mortality in newborn piglets and subclinical infection in adult pigs, leading to significant impacts on the pig industry. Currently, there is no approved serological method to assess APPV infection status in pig farms. METHODS: In this study, the envelope glycoprotein E2 of APPV was highly expressed in suspension HEK293 cells, and further an indirect enzyme-linked immunosorbent assay based on the recombinant E2 protein (E2-iELISA) was developed and evaluated. RESULTS: The reaction parameters of the E2-iELISA were optimized, and the cutoff value was determined to be 0.2 by analyzing S/P values of 165 negative sera against APPV that were confirmed by virus neutralization test (VNT). Specificity test showed that the method had no cross-reaction with other common swine viruses. The E2-iELISA was evaluated using a panel of swine sera, and showed high sensitivity (113/120, 94.2%) and specificity (65/70, 92.9%), and the agreement rate with VNT was 93.7% (178/190). Subsequently, the E2-iELISA was utilized to investigate the seroprevalence of APPV in pig herds of China. When detecting 1368 pig serum samples collected from nine provinces in China, the overall seroprevalence of APPV was 73.9% (1011/1368). CONCLUSION: Our findings suggest that the E2-iELISA is specific and sensitive, and could be a valuable tool for serological surveillance of APPV infection in pigs.


Assuntos
Infecções Assintomáticas , Pestivirus , Humanos , Adulto , Animais , Suínos , Células HEK293 , Estudos Soroepidemiológicos , Ensaio de Imunoadsorção Enzimática
10.
J Med Chem ; 67(5): 3571-3589, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38385264

RESUMO

PAR4 is a promising antithrombotic target with potential for separation of efficacy from bleeding risk relative to current antiplatelet therapies. In an effort to discover a novel PAR4 antagonist chemotype, a quinoxaline-based HTS hit 3 with low µM potency was identified. Optimization of the HTS hit through the use of positional SAR scanning and the design of conformationally constrained cores led to the discovery of a quinoxaline-benzothiazole series as potent and selective PAR4 antagonists. The lead compound 48, possessing a 2 nM IC50 against PAR4 activation by γ-thrombin in platelet-rich plasma (PRP) and greater than 2500-fold selectivity versus PAR1, demonstrated robust antithrombotic efficacy and minimal bleeding in the cynomolgus monkey models.


Assuntos
Fibrinolíticos , Trombose , Animais , Fibrinolíticos/farmacologia , Fibrinolíticos/uso terapêutico , Macaca fascicularis , Quinoxalinas/farmacologia , Quinoxalinas/uso terapêutico , Receptores de Trombina , Trombina , Hemorragia , Trombose/tratamento farmacológico , Trombose/prevenção & controle , Receptor PAR-1 , Plaquetas , Agregação Plaquetária
11.
Front Cell Infect Microbiol ; 13: 1289170, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38125906

RESUMO

Autophagy selectively degrades viral particles or cellular components, either facilitating or inhibiting viral replication. Conversely, most viruses have evolved strategies to escape or exploit autophagy. Moreover, autophagy collaborates with the pattern recognition receptor signaling, influencing the expression of adaptor molecules involved in the innate immune response and regulating the expression of interferons (IFNs). The intricate relationship between autophagy and IFNs plays a critical role in the host cell defense against microbial invasion. Therefore, it is important to summarize the interactions between viral infections, autophagy, and the host defense mechanisms against viruses. This review specifically focuses on the interactions between autophagy and IFN pathways during viral infections, providing a comprehensive summary of the molecular mechanisms utilized or evaded by different viruses.


Assuntos
Viroses , Vírus , Humanos , Interações Hospedeiro-Patógeno , Interferons , Imunidade Inata , Autofagia , Replicação Viral
12.
Sheng Wu Gong Cheng Xue Bao ; 39(12): 4759-4772, 2023 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-38147979

RESUMO

Cell-mediated immune response is an important part of machinery in maintaining the body's homeostasis. After the innate immune system selectively activates the adaptive immune system, the cell-mediated immunity exerts its killing and clearance functions. Therefore, evaluating the level of cell-mediated immune response is crucial in the diagnosis and treatment of cancer, monitoring the immune status after organ transplantation, diagnosing and preventing viral diseases, and evaluating the effectiveness of vaccines and other areas. From the initial overall assessment of the immune effects in vivo to the precise detection of the number and function of multiple immune cells, the evaluation methods of cell-mediated immune response have greatly advanced. However, cell-mediated immune response involves multiple levels in the body, and it's difficult to choose the numerous detection methods available. The article systematically compares the evaluation methods of cell-mediated immune response at four different levels: the organism, the tissue and organ, the immune cells and the immune molecules, with the aim to facilitate the applications of related technologies.


Assuntos
Imunidade Celular , Neoplasias , Humanos , Neoplasias/diagnóstico , Neoplasias/terapia , Imunidade Inata
13.
Viruses ; 15(11)2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-38005827

RESUMO

Atypical porcine pestivirus (APPV) is a recently discovered and very divergent species of the genus Pestivirus within the family Flaviviridae, which causes congenital tremor (CT) in newborn piglets. In this study, an APPV epidemiological investigation was conducted by studying 975 swine samples (562 tissue and 413 serum samples) collected from different parts of China from 2017 to 2021. The results revealed that the overall positive rate of the APPV genome was 7.08% (69/975), among which 50.7% (35/69) of the samples tested positive for one or more other common swine viruses, especially porcine circovirus type 2 (PCV2) with a coinfection rate of 36.2% (25/69). Subsequently, a novel APPV strain, named China/HLJ491/2017, was isolated in porcine kidney (PK)-15 cells for the first time from a weaned piglet that was infected with both APPV and PCV2. The new APPV isolate was confirmed by RT-PCR, sequencing, immunofluorescence assay, and transmission electron microscopy. After clearing PCV2, a pure APPV strain was obtained and further stably propagated in PK-15 cells for more than 30 passages. Full genome sequencing and phylogenetic analysis showed that the China/HLJ491/2017 strain was classified as genotype 2, sharing 80.8 to 97.6% of its nucleotide identity with previously published APPV strains. In conclusion, this study enhanced our knowledge of this new pestivirus and the successful isolation of the APPV strain provides critical material for the investigation of the biological and pathogenic properties of this emerging virus, as well as the development of vaccines and diagnostic reagents.


Assuntos
Infecções por Pestivirus , Pestivirus , Doenças dos Suínos , Animais , Suínos , Infecções por Pestivirus/epidemiologia , Infecções por Pestivirus/veterinária , Infecções por Pestivirus/congênito , Filogenia , China/epidemiologia
14.
J Biol Chem ; 299(11): 105347, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37838171

RESUMO

The pseudorabies virus (PRV) TJ strain, a variant of PRV, induces more severe neurological symptoms and higher mortality in piglets and mice than the PRV SC strain isolated in 1980. However, the mechanism underlying responsible for the discrepancy in virulence between these strains remains unclear. Our study investigated the differences in neurotropism between PRV TJ and PRV SC using both in vitro and in vivo models. We discovered that PRV TJ enters neural cells more efficiently than PRV SC. Furthermore, we found that PRV TJ has indistinguishable genomic DNA replication capability and axonal retrograde transport dynamics compared to the PRV SC. To gain deeper insights into the mechanisms underlying these differences, we constructed gene-interchanged chimeric virus constructs and assessed the affinity between envelope glycoprotein B, C, and D (gD) and corresponding receptors. Our findings confirmed that mutations in these envelope proteins, particularly gD, significantly contributed to the heightened attachment and penetration capabilities of PRV TJ. Our study revealed the critical importance of the gDΔR278/P279 and gDV338A in facilitating viral invasion. Furthermore, our observations indicated that mutations in envelope proteins have a more significant impact on viral invasion than on virulence in the mouse model. Our findings provide valuable insights into the roles of natural mutations on the PRV envelope glycoproteins in cell tropism, which sheds light on the relationship between cell tropism and clinical symptoms and offers clues about viral evolution.


Assuntos
Herpesvirus Suídeo 1 , Pseudorraiva , Proteínas do Envelope Viral , Tropismo Viral , Animais , Camundongos , Genômica , Herpesvirus Suídeo 1/genética , Mutagênese , Mutação , Pseudorraiva/genética , Suínos , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo
15.
J Virol ; 97(10): e0082423, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37724880

RESUMO

IMPORTANCE: African swine fever (ASF) is an acute, hemorrhagic, and severe porcine infectious disease caused by African swine fever virus (ASFV). ASF outbreaks severely threaten the global pig industries and result in serious economic losses. No safe and efficacious commercial vaccine is currently available except in Vietnam. To date, large gaps in the knowledge concerning viral biological characteristics and immunoevasion strategies have hindered the ASF vaccine design. In this study, we demonstrate that pD129L negatively regulates the type I interferon (IFN) signaling pathway by interfering with the interaction of the transcriptional coactivator p300 and IRF3, thereby inhibiting the induction of type I IFNs. This study reveals a novel immunoevasion strategy employed by ASFV, shedding new light on the intricate mechanisms for ASFV to evade the host immune responses.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Proteína p300 Associada a E1A , Fator Regulador 3 de Interferon , Interferon Tipo I , Animais , Febre Suína Africana/virologia , Interferon Tipo I/metabolismo , Interferon beta/metabolismo , Suínos , Fatores de Transcrição/metabolismo , Vacinas/metabolismo , Proteína p300 Associada a E1A/metabolismo , Fator Regulador 3 de Interferon/metabolismo , Evasão da Resposta Imune
16.
mBio ; 14(5): e0164523, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37772878

RESUMO

IMPORTANCE: Sliding clamp is a highly conserved protein in the evolution of prokaryotic and eukaryotic cells. The sliding clamp is required for genomic replication as a critical co-factor of DNA polymerases. However, the sliding clamp analogs in viruses remain largely unknown. We found that the ASFV E301R protein (pE301R) exhibited a sliding clamp-like structure and similar functions during ASFV replication. Interestingly, pE301R is assembled into a unique ring-shaped homotetramer distinct from sliding clamps or proliferating cell nuclear antigens (PCNAs) from other species. Notably, the E301R gene is required for viral life cycle, but the pE301R function can be partially restored by the porcine PCNA. This study not only highlights the functional role of the ASFV pE301R as a viral sliding clamp analog, but also facilitates the dissection of the complex replication mechanism of ASFV, which provides novel clues for developing antivirals against ASF.


Assuntos
Vírus da Febre Suína Africana , Suínos , Animais , Vírus da Febre Suína Africana/genética , Replicação Viral , DNA Polimerase Dirigida por DNA , Células Eucarióticas
17.
J Virol ; 97(9): e0056923, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37607059

RESUMO

Proinflammatory factors play important roles in the pathogenesis of African swine fever virus (ASFV), which is the causative agent of African swine fever (ASF), a highly contagious and severe hemorrhagic disease. Efforts in the prevention and treatment of ASF have been severely hindered by knowledge gaps in viral proteins responsible for modulating host antiviral responses. In this study, we identified the I10L protein (pI10L) of ASFV as a potential inhibitor of the TNF-α- and IL-1ß-triggered NF-κB signaling pathway, the most canonical and important part of host inflammatory responses. The ectopically expressed pI10L remarkably suppressed the activation of NF-κB signaling in HEK293T and PK-15 cells. The ASFV mutant lacking the I10L gene (ASFVΔI10L) induced higher levels of proinflammatory cytokines production in primary porcine alveolar macrophages (PAMs) compared with its parental ASFV HLJ/2018 strain (ASFVWT). Mechanistic studies suggest that pI10L inhibits IKKß phosphorylation by reducing the K63-linked ubiquitination of NEMO, which is necessary for the activation of IKKß. Morever, pI10L interacts with the kinase domain of IKKß through its N-terminus, and consequently blocks the association of IKKß with its substrates IκBα and p65, leading to reduced phosphorylation. In addition, the nuclear translocation efficiency of p65 was also altered by pI10L. Further biochemical evidence supported that the amino acids 1-102 on pI10L were essential for the pI10L-mediated suppression of the NF-κB signaling pathway. The present study clarifies the immunosuppressive activity of pI10L, and provides novel insights into the understanding of ASFV pathobiology and the development of vaccines against ASF. IMPORTANCE African swine fever (ASF), caused by the African swine fever virus (ASFV), is now widespread in many countries and severely affects the commercial rearing of swine. To date, few safe and effective vaccines or antiviral strategies have been marketed due to large gaps in knowledge regarding ASFV pathobiology and immune evasion mechanisms. In this study, we deciphered the important role of the ASFV-encoded I10L protein in the TNF-α-/IL-1ß-triggered NF-κB signaling pathway. This study provides novel insights into the pathogenesis of ASFV and thus contributes to the development of vaccines against ASF.

18.
PLoS Pathog ; 19(8): e1011580, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37566637

RESUMO

The multigene family genes (MGFs) in the left variable region (LVR) of the African swine fever virus (ASFV) genome have been reported to be involved in viral replication in primary porcine alveolar macrophages (PAMs) and virulence in pigs. However, the exact functions of key MGFs in the LVR that regulate the replication and virulence of ASFV remain unclear. In this study, we identified the MGF300-2R gene to be critical for viral replication in PAMs by deleting different sets of MGFs in the LVR from the highly virulent strain ASFV HLJ/18 (ASFV-WT). The ASFV mutant lacking the MGF300-2R gene (Del2R) showed a 1-log reduction in viral titer, and induced higher IL-1ß and TNF-α production in PAMs than did ASFV-WT. Mechanistically, the MGF300-2R protein was found to interact with and degrade IKKα and IKKß via the selective autophagy pathway. Furthermore, we showed that MGF300-2R promoted the K27-linked polyubiquitination of IKKα and IKKß, which subsequently served as a recognition signal for the cargo receptor TOLLIP-mediated selective autophagic degradation. Importantly, Del2R exhibited a significant reduction in both replication and virulence compared with ASFV-WT in pigs, likely due to the increased IL-1ß and TNF-α, indicating that MGF300-2R is a virulence determinant. These findings reveal that MGF300-2R suppresses host innate immune responses by mediating the degradation of IKKα and IKKß, which provides clues to paving the way for the rational design of live attenuated vaccines to control ASF.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Suínos , Animais , Vírus da Febre Suína Africana/genética , Virulência , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Macrófagos , Proteínas Serina-Treonina Quinases/metabolismo , Autofagia
19.
Front Immunol ; 14: 1228811, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37559723

RESUMO

Cellular metabolism plays a central role in the regulation of both innate and adaptive immunity. Immune cells utilize metabolic pathways to modulate the cellular differentiation or death. The intricate interplay between metabolism and immune response is critical for maintaining homeostasis and effective antiviral activities. In recent years, immunometabolism induced by viral infections has been extensively investigated, and accumulating evidence has indicated that cellular metabolism can be hijacked to facilitate viral replication. Generally, virus-induced changes in cellular metabolism lead to the reprogramming of metabolites and metabolic enzymes in different pathways (glucose, lipid, and amino acid metabolism). Metabolic reprogramming affects the function of immune cells, regulates the expression of immune molecules and determines cell fate. Therefore, it is important to explore the effector molecules with immunomodulatory properties, including metabolites, metabolic enzymes, and other immunometabolism-related molecules as the antivirals. This review summarizes the relevant advances in the field of metabolic reprogramming induced by viral infections, providing novel insights for the development of antivirals.


Assuntos
Viroses , Vírus , Humanos , Antivirais/farmacologia , Redes e Vias Metabólicas , Imunidade
20.
Front Immunol ; 14: 1204730, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37334362

RESUMO

Viruses are simple yet highly pathogenic microorganisms that parasitize within cells and pose serious threats to the health, economic development, and social stability of both humans and animals. Therefore, it is crucial to understand the dynamic mechanism of virus infection in hosts. One effective way to achieve this is through virus tracking technology, which utilizes fluorescence imaging to track the life processes of virus particles in living cells in real-time, providing a comprehensively and detailed spatiotemporal dynamic process and mechanism of virus infection. This paper provides a broad overview of virus tracking technology, including the selection of fluorescent labels and virus labeling components, the development of imaging microscopes, and its applications in various virus studies. Additionally, we discuss the possibilities and challenges of its future development, offering theoretical guidance and technical support for effective prevention and control of the viral disease outbreaks and epidemics.


Assuntos
Viroses , Vírus , Animais , Humanos , Vírion , Tecnologia , Estágios do Ciclo de Vida
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