PKM2 induces mitophagy through the AMPK-mTOR pathway promoting CSFV proliferation.

Viruses exploit the host cell's energy metabolism system to support their replication. Mitochondria, known as the powerhouse of the cell, play a critical role in regulating cell survival and virus replication. Our prior research indicated that the classical swine fever virus (CSFV) alters mitochondrial dynamics and triggers glycolytic metabolic reprogramming. However, the role and mechanism of PKM2, a key regulatory enzyme of glycolytic metabolism, in CSFV replication remain unclear. In this study, we discovered that CSFV enhances PKM2 expression and utilizes PKM2 to inhibit pyruvate production. Using an affinity purification coupled mass spectrometry system, we successfully identified PKM as a novel interaction partner of the CSFV non-structural protein NS4A. Furthermore, we validated the interaction between PKM2 and both CSFV NS4A and NS5A through co-immunoprecipitation and confocal analysis. PKM2 was found to promote the expression of both NS4A and NS5A. Moreover, we observed that PKM2 induces mitophagy by activating the AMPK-mTOR signaling pathway, thereby facilitating CSFV proliferation. In summary, our data reveal a novel mechanism whereby PKM2, a metabolic enzyme, promotes CSFV proliferation by inducing mitophagy. These findings offer a new avenue for developing antiviral strategies. IMPORTANCE: Viruses rely on the host cell's material-energy metabolic system for replication, inducing host metabolic disorders and subsequent immunosuppression-a major contributor to persistent viral infections. Classical swine fever virus (CSFV) is no exception. Classical swine fever is a severe acute infectious disease caused by CSFV, resulting in significant economic losses to the global pig industry. While the role of the metabolic enzyme PKM2 (pyruvate dehydrogenase) in the glycolytic pathway of tumor cells has been extensively studied, its involvement in viral infection remains relatively unknown. Our data unveil a new mechanism by which the metabolic enzyme PKM2 mediates CSFV infection, offering novel avenues for the development of antiviral strategies.

IDO1 promotes CSFV replication by mediating tryptophan metabolism to inhibit NF-κB signaling.

Tryptophan metabolism plays a crucial role in facilitating various cellular processes essential for maintaining normal cellular function. Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzes the conversion of tryptophan (Trp) into kynurenine (Kyn), thereby initiating the degradation of Trp. The resulting Kyn metabolites have been implicated in the modulation of immune responses. Currently, the role of IDO1-mediated tryptophan metabolism in the process of viral infection remains relatively unknown. In this study, we discovered that classical swine fever virus (CSFV) infection of PK-15 cells can induce the expression of IDO1, thereby promoting tryptophan metabolism. IDO1 can negatively regulate the NF-κB signaling by mediating tryptophan metabolism, thereby facilitating CSFV replication. We found that silencing the IDO1 gene enhances the expression of IFN-α, IFN-ß, and IL-6 by activating the NF-κB signaling pathway. Furthermore, our observations indicate that both silencing the IDO1 gene and administering exogenous tryptophan can inhibit CSFV replication by counteracting the cellular autophagy induced by Rapamycin. This study reveals a novel mechanism of IDO1-mediated tryptophan metabolism in CSFV infection, providing new insights and a theoretical basis for the treatment and control of CSFV.IMPORTANCEIt is well known that due to the widespread use of vaccines, the prevalence of classical swine fever (CSF) is shifting towards atypical and invisible infections. CSF can disrupt host metabolism, leading to persistent immune suppression in the host and causing significant harm when co-infected with other diseases. Changes in the host's metabolic profiles, such as increased catabolic metabolism of amino acids and the production of immunoregulatory metabolites and their derivatives, can also influence virus replication. Mammals utilize various pathways to modulate immune responses through amino acid utilization, including increased catabolic metabolism of amino acids and the production of immunoregulatory metabolites and their derivatives, thereby limiting viral replication. Therefore, this study proposes that targeting the modulation of tryptophan metabolism may represent an effective approach to control the progression of CSF.

Role of CIV NS1 Protein in Innate Immunity and Viral Replication.

The innate immune pathway serves as the first line of defense against viral infections and plays a crucial role in the host's immune response in clearing viruses. Prior research has indicated that the influenza A virus has developed various strategies to avoid host immune responses. Nevertheless, the role of the NS1 protein of the canine influenza virus (CIV) in the innate immune pathway remains unclear. In this study, eukaryotic plasmids of NS1, NP, PA, PB1, and PB2 were constructed, and it was found that these proteins interact with melanoma differentiation-associated gene 5 (MDA5) and antagonize the activation of IFN-ß promoters by MDA5. We selected the NS1 protein for further study and found that NS1 does not affect the interaction between the viral ribonucleoprotein (RNP) subunit and MDA5, but that it downregulates the expression of the laboratory of genetics and physiology 2 (LGP2) and retinoic acid-inducible gene-I (RIG-I) receptors in the RIG-I pathway. Additionally, NS1 was found to inhibit the expression of several antiviral proteins and cytokines, including MX dynamin like GTPase 1 (MX1), 2'-5'oligoadenylate synthetase (OAS), Signal Transducers and Activators of Transcription (STAT1), tripartite motif 25 (TRIM25), interleukin-2 (IL-2), IFN, IL-8, and IL-1ß. To further investigate the role of NS1, a recombinant H3N2 virus strain (rH3N2) and an NS1-null virus (rH3N2ΔNS1) were rescued using reverse-genetic technology. The rH3N2ΔNS1 virus exhibited lower viral titers compared to rH3N2, but had a stronger activation effect on the receptors LGP2 and RIG-I. Furthermore, when compared to rH3N2, rH3N2ΔNS1 exhibited a more pronounced activation of antiviral proteins such as MX1, OAS, STAT1, and TRIM25, as well as antiviral cytokines such as IL-6, IFN-ß, and IL-1ß. These findings suggest a new mechanism by which NS1, a nonstructural protein of CIV, facilitates innate immune signaling and provides new avenues for the development of antiviral strategies.

Swine Enteric Coronavirus: Diverse Pathogen-Host Interactions.

Swine enteric coronavirus (SeCoV) causes acute gastroenteritis and high mortality in newborn piglets. Since the last century, porcine transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV) have swept farms all over the world and caused substantial economic losses. In recent years, porcine delta coronavirus (PDCoV) and swine acute diarrhea syndrome coronavirus (SADS-CoV) have been emerging SeCoVs. Some of them even spread across species, which made the epidemic situation of SeCoV more complex and changeable. Recent studies have begun to reveal the complex SeCoV-host interaction mechanism in detail. This review summarizes the current advances in autophagy, apoptosis, and innate immunity induced by SeCoV infection. These complex interactions may be directly involved in viral replication or the alteration of some signal pathways.

Immunogenicity and Immunoprotection of PCV2 Virus-like Particles Incorporating Dominant T and B Cell Antigenic Epitopes Paired with CD154 Molecules in Piglets and Mice.

Porcine circovirus type 2 (PCV2) is capable of causing porcine circovirus-associated disease (PCVAD) and is one of the major threats to the global pig industry. The nucleocapsid protein Cap encoded by the PCV2 ORF2 gene is an ideal antigen for the development of PCV2 subunit vaccines, and its N-terminal nuclear localization sequence (NLS) structural domain is essential for the formation of self-assembling VLPs. In the present study, we systematically expressed and characterized full-length PCV2 Cap proteins fused to dominant T and B cell antigenic epitopes and porcine-derived CD154 molecules using baculovirus and found that the Cap proteins fusing epitopes were still capable of forming virus-like particles (VLPs). Both piglet and mice experiments showed that the Cap proteins fusing epitopes or paired with the molecular adjuvant CD154 were able to induce higher levels of humoral and cellular responses, particularly the secretion of PCV2-specific IFN-γ and IL-4. In addition, vaccination significantly reduced clinical signs and the viral load of PCV2 in the blood and tissues of challenged piglets. The results of the study provide new ideas for the development of a more efficient, safe and broad-spectrum next-generation PCV2 subunit vaccine.

Historical Evolutionary Dynamics and Phylogeography Analysis of Transmissible Gastroenteritis Virus and Porcine Deltacoronavirus: Findings from 59 Suspected Swine Viral Samples from China.

Since the beginning of the 21st century, humans have experienced three coronavirus pandemics, all of which were transmitted to humans via animals. Recent studies have found that porcine deltacoronavirus (PDCoV) can infect humans, so swine enteric coronavirus (SeCoV) may cause harm through cross-species transmission. Transmissible gastroenteritis virus (TGEV) and PDCoV have caused tremendous damage and loss to the pig industry around the world. Therefore, we analyzed the genome sequence data of these two SeCoVs by evolutionary dynamics and phylogeography, revealing the genetic diversity and spatiotemporal distribution characteristics. Maximum likelihood and Bayesian inference analysis showed that TGEV could be divided into two different genotypes, and PDCoV could be divided into four main lineages. Based on the analysis results inferred by phylogeography, we inferred that TGEV might originate from America, PDCoV might originate from Asia, and different migration events had different migration rates. In addition, we also identified positive selection sites of spike protein in TGEV and PDCoV, indicating that the above sites play an essential role in promoting membrane fusion to achieve adaptive evolution. In a word, TGEV and PDCoV are the past and future of SeCoV, and the relatively smooth transmission rate of TGEV and the increasing transmission events of PDCoV are their respective transmission characteristics. Our results provide new insights into the evolutionary characteristics and transmission diversity of these SeCoVs, highlighting the potential for cross-species transmission of SeCoV and the importance of enhanced surveillance and biosecurity measures for SeCoV in the context of the COVID-19 epidemic.

Viruses Hijack ERAD to Regulate Their Replication and Propagation.

Endoplasmic reticulum-associated degradation (ERAD) is highly conserved in yeast. Recent studies have shown that ERAD is also ubiquitous and highly conserved in eukaryotic cells, where it plays an essential role in maintaining endoplasmic reticulum (ER) homeostasis. Misfolded or unfolded proteins undergo ERAD. They are recognized in the ER, retrotranslocated into the cytoplasm, and degraded by proteasomes after polyubiquitin. This may consist of several main steps: recognition of ERAD substrates, retrotranslocation, and proteasome degradation. Replication and transmission of the virus in the host is a process of a "game" with the host. It can be assumed that the virus has evolved various mechanisms to use the host's functions for its replication and transmission, including ERAD. However, until now, it is still unclear how the host uses ERAD to deal with virus infection and how the viruses hijack the function of ERAD to obtain a favorable niche or evade the immune clearance of the host. Recent studies have shown that viruses have also evolved mechanisms to use various processes of ERAD to promote their transmission. This review describes the occurrence of ERAD and how the viruses hijack the function of ERAD to spread by affecting the homeostasis and immune response of the host, and we will focus on the role of E3 ubiquitin ligase.

Viral Infection Modulates Mitochondrial Function.

Mitochondria are important organelles involved in metabolism and programmed cell death in eukaryotic cells. In addition, mitochondria are also closely related to the innate immunity of host cells against viruses. The abnormality of mitochondrial morphology and function might lead to a variety of diseases. A large number of studies have found that a variety of viral infections could change mitochondrial dynamics, mediate mitochondria-induced cell death, and alter the mitochondrial metabolic status and cellular innate immune response to maintain intracellular survival. Meanwhile, mitochondria can also play an antiviral role during viral infection, thereby protecting the host. Therefore, mitochondria play an important role in the interaction between the host and the virus. Herein, we summarize how viral infections affect microbial pathogenesis by altering mitochondrial morphology and function and how viruses escape the host immune response.

The Role of Autophagy and Autophagy Receptor NDP52 in Microbial Infections.

Autophagy is a general protective mechanism for maintaining homeostasis in eukaryotic cells, regulating cellular metabolism, and promoting cell survival by degrading and recycling cellular components under stress conditions. The degradation pathway that is mediated by autophagy receptors is called selective autophagy, also named as xenophagy. Autophagy receptor NDP52 acts as a 'bridge' between autophagy and the ubiquitin-proteasome system, and it also plays an important role in the process of selective autophagy. Pathogenic microbial infections cause various diseases in both humans and animals, posing a great threat to public health. Increasing evidence has revealed that autophagy and autophagy receptors are involved in the life cycle of pathogenic microbial infections. The interaction between autophagy receptor and pathogenic microorganism not only affects the replication of these microorganisms in the host cell, but it also affects the host's immune system. This review aims to discuss the effects of autophagy on pathogenic microbial infection and replication, and summarizes the mechanisms by which autophagy receptors interact with microorganisms. While considering the role of autophagy receptors in microbial infection, NDP52 might be a potential target for developing effective therapies to treat pathogenic microbial infections.

Important roles of C-terminal residues in degradation of capsid protein of classical swine fever virus.

BACKGROUND: Capsid (C) protein plays an important role in the replication of classical swine fever virus (CSFV). The ubiquitin proteasome system (UPS) involves in replication of many viruses via modulation of viral proteins. The relationship of CSFV with UPS is poorly understood and the impact of 26S proteasome on C protein has never been reported before. METHODS: In this study, fused C protein with an EGFP tag is expressed in PK-15 and 3D4/2 cells. MG132 and 3-methyladenine (3-MA) are used to detect the roles of 26S proteasome and autophagolysosome in expression levels of C protein. Truncated and mutant C proteins are used to find the exact residues responsible for the degradation of C protein. Immunoprecipitaion is performed to find whether C protein is ubiquitinated or not. RESULTS: C-EGFP protein expresses in a cleaved form at a low level and is degraded by 26S proteasome which could be partly inhibited by MG132. C-terminal residues play more important roles in the degradation of C protein than N-terminal residues. Residues 260 to 267, especially M260 and L261, are crucial for the degradation. In addition, C-terminal residues 262 to 267 determine cleavage efficiency of C protein. CONCLUSIONS: CSFV C protein is degraded by 26S proteasome in a ubiquitin-independent manner. Last 8 residues at C-terminus of immature C protein play a major role in proteasomal degradation of CSFV C protein and determine the cleavage efficiency of C protein by signal peptide peptidase (SPP). Our findings provide valuable help for fully understanding degradation process of C protein and contribute to fully understanding the role of C protein in CSFV replication.

Correction: Li et al. African Swine Fever Virus: A Review. Life 2022, 12, 1255.

In the original publication [...].

CSFV restricts necroptosis to sustain infection by inducing autophagy/mitophagy-targeted degradation of RIPK3.

IMPORTANCE: CSFV infection in pigs causes persistent high fever, hemorrhagic necrotizing multi-organ inflammation, and high mortality, which seriously threatens the global swine industry. Cell death is an essential immune response of the host against pathogen invasion, and lymphopenia is the most typical clinical feature in the acute phase of CSFV infection, which affects the initial host antiviral immunity. As an "old" virus, CSFV has evolved mechanisms to evade host immune response after a long genetic evolution. Here, we show that necroptosis is a limiting host factor for CSFV infection and that CSFV-induced autophagy can subvert this host defense mechanism to promote its sustained replication. Our findings reveal a complex link between necroptosis and autophagy in the process of cell death, provide evidence supporting the important role for CSFV in counteracting host cell necrosis, and enrich our knowledge of pathogens that may subvert and evade this host defense.

Role of mitochondria in the regulation of ferroptosis and disease.

Ferroptosis is a distinctive form of iron-dependent cell death characterized by significant ultrastructural changes in mitochondria. Given the crucial involvement of mitochondria in various cellular processes such as reactive oxygen species production, energy metabolism, redox status, and iron metabolism, mounting evidence suggests a vital role of mitochondria in the regulation and execution of ferroptosis. Furthermore, there exists a strong correlation between ferroptosis and various diseases. In this review, we aim to summarize the mechanisms underlying the induction and defense of ferroptosis, emphasizing the influence of mitochondria on this intricate process. Additionally, we provide an overview of the role of ferroptosis in disease, particularly cancer, and elucidate the mechanisms by which drugs targeting mitochondria impact ferroptosis. By presenting a theoretical foundation and reference point, this review aims to contribute to both basic cell biology research and the investigation of clinically relevant diseases.

Role of OGDH in Atophagy-IRF3-IFN-ß pathway during classical swine fever virus infection.

Classical swine fever (CSF) is a severe infectious disease caused by the classical swine fever virus (CSFV) that poses significant challenges to the swine industry. α-ketoglutarate dehydrogenase (OGDH), the first rate-limiting enzyme of the tricarboxylic acid (TCA) cycle, catalyzes α-ketoglutarate (α-KG) to succinyl-CoA, playing a crucial role in glycometabolism. Our previous studies showed that CSFV disrupts the TCA cycle, resulting in α-KG accumulation. However, the interplay between CSFV and OGDH remains unclear. In this study, we found that CSFV significantly reduces OGDH protein levels and promotes α-KG secretion through OGDH in PK-15 cells. Furthermore, we observed CSFV C protein interacts with OGDH and revealed that CSFV utilizes NDP52/NBR1 to target OGDH protein degradation in the autophagy-lysosome pathway. We also unveiled that OGDH overexpression inhibits CSFV proliferation, whereas OGDH knockdown increases CSFV proliferation. Further investigation into the mechanisms of OGDH on CSFV replication revealed that OGDH regulates the AMPK-mTOR-autophagy pathway. Additionally, using the autophagy agonist/inhibitor, rapamycin/3-MA, we observed that OGDH modulates autophagy to regulate the IRF3-IFN-ß network and CSFV replication. These findings shed light on the role of OGDH in CSFV infection and host metabolism, promoting the development of innovative strategies for combating CSFV and other viral infections via targeting metabolic pathways.

The regulation of cell homeostasis and antiviral innate immunity by autophagy during classical swine fever virus infection.

CSFV (classical swine fever virus) is currently endemic in developing countries in Asia and has recently re-emerged in Japan. Under the pressure of natural selection pressure, CSFV keeps evolving to maintain its ecological niche in nature. CSFV has evolved mechanisms that induce immune depression, but its pathogenic mechanism is still unclear. In this study, using transcriptomics and metabolomics methods, we found that CSFV infection alters innate host immunity by activating the interferon pathway, inhibiting host inflammation, apoptosis, and remodelling host metabolism in porcine alveolar macrophages. Moreover, we revealed that autophagy could alter innate immunity and metabolism induced by CSFV infection. Enhanced autophagy further inhibited CSFV-induced RIG-I-IRF3 signal transduction axis and JAK-STAT signalling pathway and blocked type I interferon production while reducing autophagy inhibition of the NF-κB signalling pathway and apoptosis in CSFV infection cells. Furthermore, the level of CSFV infection-induced glycolysis and the content of lactate and pyruvate, as well as 3-phosphoglyceraldehyde, a derivative of glycolysis converted to serine, was altered by autophagy. We also found that silencing HK2 (hexokinase 2), the rate-limiting enzyme of glycolytic metabolism, could induce autophagy but reduce the interferon signalling pathway, NF-κB signalling pathway, and inhibition of apoptosis induced by CSFV infection. In addition, inhibited cellular autophagy by silencing ATG5 or using 3-Methyladenine, could backfill the inhibitory effect of silencing HK2 on the cellular interferon signalling pathway, NF-κB signalling pathway, and apoptosis.

Virus-like particle vaccines with epitopes from porcine epidemic virus and transmissible gastroenteritis virus incorporated into self-assembling ADDomer platform provide clinical immune responses in piglets.

Introduction: Porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) are major intestinal coronaviruses that cause vomiting, diarrhea, dehydration, and mortality in piglets. These viruses coexist and lead to significant economic losses in the swine industry. Virus-like particles (VLPs) have emerged as promising alternatives to conventional inactivated vaccines due to their exceptional safety, efficacy, and ability to provide multi-disease protection with a single dose. Methods: Our study focused on specific antigenic epitopes from the PEDV S protein (SS2 and 2C10 regions) and the TGEV S protein (A and D sites) as target candidates. These epitopes were integrated into the ADDomer framework, and we successfully generated recombinant proteins AD, AD-P, AD-T, and AD-PT using the baculovirus expression vector system (BEVS). By meticulously optimizing conditions in High Five cells, we successfully expressed and purified the recombinant proteins. Subsequently, we developed the recombinant ADDomer-VLP vaccine and conducted a comprehensive evaluation of its efficacy in piglets. Results: Following ultrafiltration concentration and sucrose gradient centrifugation purification, the recombinant proteins self-assembled into VLPs as observed by transmission electron microscopy (TEM). Administration of the vaccine did not result in any adverse reactions in the immunized piglets. Additionally, no significant instances of fever were detected in any of the experimental groups, and there were no notable changes in average daily weight gain compared to the control group that received PBS. The recombinant ADDomer-VLP vaccines demonstrated strong immunogenicity, effectively stimulating the production of neutralizing antibodies against both PEDV and TGEV. Moreover, the recombinant ADDomer-VLP vaccine induced elevated levels of IFN-γ, IL-2, and IL-4, and enhanced cytotoxic T lymphocyte (CTL) activity in the peripheral blood of piglets. Discussion: These recombinant VLPs have demonstrated the ability to induce strong cellular and humoral immune responses in piglets, making them an incredibly promising platform for the rapid and simplified development of epitope vaccines.

Evolutionary dynamics and adaptive analysis of Seneca Valley virus.

Over the past 20 years, the Seneca Valley virus (SVV) has emerged in various countries and regions around the world. Infected pigs display symptoms similar to foot-and-mouth disease and other vesicular diseases, causing severe economic losses to affected countries. In recent years, the number of SVV infections has been increasing in Brazil, China, and the United States. In this study, we comprehensively analyzed SVV genomic sequence data from the perspectives of evolutionary dynamics, phylogeography, and codon usage bias. We aimed to gain further insights into SVV's genetic diversity, spatiotemporal distribution patterns, and evolutionary adaptations. Phylogenetic analysis revealed that SVV has evolved into eight distinct lineages. Based on the results of phylogeographic analysis, it is speculated that the United States might have been the source of SVV, from where it subsequently spread to different countries and regions. Moreover, our analysis of positive selection sites in SVV capsid proteins suggests their potential importance in the process of receptor recognition. Finally, codon preference analysis indicates that natural selection has been a primary evolutionary driver influencing SVV codon usage bias. In conclusion, our in-depth investigation into SVV's origin, dissemination, evolution, and adaptation emphasizes the significance of SVV surveillance and control measures.

Crosstalk between mitophagy and innate immunity in viral infection.

Mitochondria are important organelles involved in cell metabolism and programmed cell death in eukaryotic cells and are closely related to the innate immunity of host cells against viruses. Mitophagy is a process in which phagosomes selectively phagocytize damaged or dysfunctional mitochondria to form autophagosomes and is degraded by lysosomes, which control mitochondrial mass and maintain mitochondrial dynamics and cellular homeostasis. Innate immunity is an important part of the immune system and plays a vital role in eliminating viruses. Viral infection causes many physiological and pathological alterations in host cells, including mitophagy and innate immune pathways. Accumulating evidence suggests that some virus promote self-replication through regulating mitophagy-mediated innate immunity. Clarifying the regulatory relationships among mitochondria, mitophagy, innate immunity, and viral infection will shed new insight for pathogenic mechanisms and antiviral strategies. This review systemically summarizes the activation pathways of mitophagy and the relationship between mitochondria and innate immune signaling pathways, and then discusses the mechanisms of viruses on mitophagy and innate immunity and how viruses promote self-replication by regulating mitophagy-mediated innate immunity.

Interaction of SERINC5 and IFITM1/2/3 regulates the autophagy-apoptosis-immune network under CSFV infection.

The host restriction factor serine incorporator 5 (SERINC5) plays a key role in inhibiting viral activity and has been shown to inhibit classical swine fever virus (CSFV) infection. However, the action of SERINC5 in the interaction between host cells and CSFV remains poorly understood. This study found that SERINC5 represses CSFV-induced autophagy through MAPK1/3-mTOR and AKT-mTOR signalling pathways. Further research showed that SERINC5 promotes apoptosis by repressing autophagy. Likewise, it was demonstrated that SERINC5 interacting proteins IFITM1/2/3 inhibit CSFV replication and regulate autophagy in a lysosomal-associated membrane protein LAMP1-dependent manner. In addition, IFITM1/2/3 interference promotes the NF-κB signalling pathway for potential immunoregulation by inhibiting autophagy. Finally, the functional silencing of IFITM1/2/3 genes was demonstrated to enhance the inhibitory effect of SERINC5 on autophagy. Taken together, These data uncover a novel mechanism through SERINC5 and its interacting proteins IFITM1/2/3, which mediates CSFV replication, and provides new avenues for controlling CSFV.

African Swine Fever Virus: A Review.

African swine fever (ASF) is a viral disease with a high fatality rate in both domestic pigs and wild boars. ASF has greatly challenged pig-raising countries and also negatively impacted regional and national trade of pork products. To date, ASF has spread throughout Africa, Europe, and Asia. The development of safe and effective ASF vaccines is urgently required for the control of ASF outbreaks. The ASF virus (ASFV), the causative agent of ASF, has a large genome and a complex structure. The functions of nearly half of its viral genes still remain to be explored. Knowledge on the structure and function of ASFV proteins, the mechanism underlying ASFV infection and immunity, and the identification of major immunogenicity genes will contribute to the development of an ASF vaccine. In this context, this paper reviews the available knowledge on the structure, replication, protein function, virulence genes, immune evasion, inactivation, vaccines, control, and diagnosis of ASFV.