Biomimetic phosphorus dendrimer multi-epitope nanovaccine enhances humoral and cellular immune response against African swine fever virus.

Using nanoparticles (NPs) as a platform for multivalent antigen display is an effective strategy to increase the immunogenicity of subunit vaccines, which can induce high levels of humoral and cellular immunity. In addition, antigens that target antigen-presenting cells (APCs) can further increase their immunogenicity. To date, there are no commercially available ASFV vaccines available worldwide.

METTL3 regulates PRRSV replication by suppressing interferon beta through autophagy-mediated IKKε degradation.

Methyltransferase-like-3 (METTL3)-mediated N6-methyladenosine (mA) modification of messenger RNAs plays a pivotal role in regulating innate immune responses, either promoting or combating virus replication. However, the biological function of METTL3 during porcine reproductive and respiratory syndrome virus (PRRSV) infection remains unclear. In this study, we found that PRRSV infection reprograms mA modifications in cellular transcripts, enhances METTL3 expression, and alters its subcellular distribution.

Identification of a linear B-cell epitope in B117L-213 protein of ASFV using monoclonal antibodies.

African Swine Fever (ASF) is a highly infectious, acute, hemorrhagic Swine disease caused by the African Swine Fever Virus (ASFV). It is lethal to both domestic pigs and wild boars, and has caused significant economic losses to the global pig industry. Vaccines represent the most significant means of preventing and treating viral diseases.

Cholesterol-dependent Nsp5-endosomes co-trafficking to lysosomes facilitates porcine reproductive and respiratory syndrome virus replication by activating autophagy.

Our previous studies showed that intracellular endosomal vesicles participated in PRRS virions trafficking in the early stage of viral infection, and cholesterol retention in endosomal vesicles disturbed viral replication via blocking PRRSV-endosomal vesicles membrane fusion. However, whether endosomal vesicles were associated with PRRSV protein(s) trafficking and the role of cholesterol in this process was still unclarity. In this study, we sought to elucidate the mechanism of cholesterol in endosomal vesicles-mediated viral protein transportation.

Epitope mapping targeting the K205R protein of African swine fever virus using nanobody as a novel tool.

African swine fever (ASF) is a highly infectious and lethal swine disease, leading to enormous losses in the pig industry. K205R, a non-structural protein of ASF virus (ASFV), is abundantly expressed at the early stages of viral infection and induces a strong immune response. In our previous study, five strains of K205R-specific nanobodies (Nbs) were screened through phage display technology, among which Nb1, Nb14, Nb35, and Nb82 exhibited good affinity.

Modification of African classical swine fever p30 protein with magnetic nanoparticles and establishment of a novel rapid detection method.

African swine fever has caused huge losses to the global pig industry. In the absence of effective vaccines, reliable detection methods are crucial. The p30 protein of ASFV is often used as a target for detection due to its high antigenicity in the early stage of virus replication.

Tripartite motif 25 inhibits protein aggregate degradation during PRRSV infection by suppressing p62-mediated autophagy.

Viral infection causes endoplasmic reticulum stress and protein metabolism disorder, influencing protein aggregates formation or degradation that originate from misfolded proteins. The mechanism by which host proteins are involved in the above process remains largely unknown. The present study found that porcine reproductive and respiratory syndrome virus (PRRSV) infection promoted the degradation of intracellular ubiquitinated protein aggregates via activating autophagy.

Preparation and epitope analysis of monoclonal antibodies against African swine fever virus DP96R protein.

Background: Many proteins of African swine fever virus (ASFV, such as p72, p54, p30, CD2v, K205R) have been successfully expressed and characterized. However, there are few reports on the DP96R protein of ASFV, which is the virulence protein of ASFV and plays an important role in the process of host infection and invasion of ASFV.

Results: Firstly, the prokaryotic expression vector of DP96R gene was constructed, the prokaryotic system was used to induce the expression of DP96R protein, and monoclonal antibody was prepared by immunizing mice.

Identification of a novel linear B-cell epitope on the p30 protein of African swine fever virus using monoclonal antibodies.

The outbreak of African Swine Fever (ASF) has caused huge economic losses to the pig industry. There are no safe and effective vaccines or diagnostics available. The p30 protein serves as a key target for the detection of ASFV antibodies and is an essential antigenic protein for early serological diagnosis.

A nanobody inhibiting porcine reproductive and respiratory syndrome virus replication via blocking self-interaction of viral nucleocapsid protein.

Porcine reproductive and respiratory syndrome (PRRS) is a serious global pig industry disease. Understanding the mechanism of viral replication and developing efficient antiviral strategies are necessary for combating with PRRS virus (PRRSV) infection. Recently, nanobody is considered to be a promising antiviral drug, especially for respiratory viruses.

Establishment and characterization of a novel indirect ELISA method based on ASFV antigenic epitope-associated recombinant protein.

African Swine Fever (ASF) is an acute and highly lethal disease in pigs caused by African Swine Fever Virus (ASFV). Viral proteins have been commonly used as antigenic targets for the development of ASF diagnostic methods. However, the prokaryotic expression of viral proteins has deficiencies such as instability, insolubility, and high cost in eukaryotic situations.

Establishment of a Dual-Antigen Indirect ELISA Based on p30 and pB602L to Detect Antibodies against African Swine Fever Virus.

African swine fever (ASF) is an acute, virulent, and highly fatal infectious disease caused by the African swine fever virus (ASFV). There is no effective vaccine or diagnostic method to prevent and control this disease currently, which highlights the significance of ASF early detection. In this study, we chose an early antigen and a late-expressed antigen to co-detect the target antibody, which not only helps in early detection but also improves accuracy and sensitivity.

An Intracellular Epitope of ASFV CD2v Protein Elicits Humoral and Cellular Immune Responses.

The African swine fever virus (ASFV) causes high mortality in domestic pigs. ASFV encodes an important protein target for subunit vaccine development, CD2v, but its most effective immunological regions are not known. Herein, we generated a monoclonal antibody (mAb) named IF3 by immunizing mice against the intracellular region of the CD2v protein (CD2v-IR).

Identification of a Linear B Cell Epitope on p54 of African Swine Fever Virus Using Nanobodies as a Novel Tool.

African swine fever (ASF) has received great attention from the swine industry due to the pandemic and the lack of vaccines or effective treatments. In the present study, 13 African swine fever virus (ASFV) p54-specific nanobodies (Nbs) were successfully screened based on Bactrian camel immunization of p54 protein and phage display technology, and their reactivity with the p54 C-terminal domain (p54-CTD) was determined; however, only Nb8-horseradish peroxidase (Nb8-HRP) exhibited the best reactivity. Immunoperoxidase monolayer assay (IPMA) and immunofluorescence assay (IFA) results indicated that Nb8-HRP specifically reacted with ASFV-infected cells.

A Novel Linear B-Cell Epitope on the P54 Protein of African Swine Fever Virus Identified Using Monoclonal Antibodies.

The African swine fever virus (ASFV) is a highly infectious viral pathogen that presents a major threat to the global pig industry. No effective vaccine is available for the virus. The p54 protein, a major structural component of ASFV, is involved in virus adsorption and entry to target cells and also plays a key role in ASFV vaccine development and disease prevention.

TAT Nanobody Exerts Antiviral Effect against PRRSV In Vitro by Targeting Viral Nucleocapsid Protein.

Porcine reproductive and respiratory syndrome (PRRS) is caused by the PRRS virus (PRRSV), which has brought huge economic losses to the pork industry worldwide since its first discovery in the late 1980s in North America. To date, there are no effective commercial vaccines or therapeutic drugs available for controlling the spread of PRRSV. Due to their unique advantages of high affinity and high specificity, nanobodies (Nbs) have received increasing attention in the process of disease diagnosis and treatment.

Identification of a linear B-cell epitope on the African swine fever virus CD2v protein.

African swine fever virus (ASFV) poses a serious threat to domestic pigs and wild boars, which is responsible for substantial production and economic losses. A dominant ASFV specific linear B cell epitope that reacted with the convalescent serum was explored and identified with the help of immune informatics techniques. It is essential in understanding the host immunity and in developing diagnostic technical guidelines and vaccine design.

Splenic-targeting biomimetic nanovaccine for elevating protective immunity against virus infection.

Background: The prevalence of viral infectious diseases has become a serious threat to public safety, economic and social development. Vaccines have been served as the most effective platform to prevent virus transmission via the activation of host immune responses, while the low immunogenicity or safety, the high cost of production, storage, transport limit their effective clinical application. Therefore, there is a need to develop a promising strategy to improve the immunogenicity and safety of vaccines.

African Swine Fever Virus MGF110-7L Induces Host Cell Translation Suppression and Stress Granule Formation by Activating the PERK/PKR-eIF2α Pathway.

African swine fever (ASF) is a highly contagious and often lethal disease of pigs caused by ASF virus (ASFV) and recognized as the biggest killer in global swine industry. Despite exhibiting incredible self-sufficiency, ASFV remains unconditionally dependent on the host translation machinery for its mRNA translation. However, less is yet known regarding how ASFV-encoded proteins regulate host translation machinery in infected cells.

K205R specific nanobody-horseradish peroxidase fusions as reagents of competitive ELISA to detect African swine fever virus serum antibodies.

Background: African swine fever virus (ASFV) is a highly contagious hemorrhagic disease and often lethal, which has significant economic consequences for the swine industry. Due to lacking of commercial vaccine, the prevention and control of ASF largely depend on early large-scale detection and screening. So far, the commercial ELISA kits have a long operation time and are expensive, making it difficult to achieve large-scale clinical applications.

Porcine reproductive and respiratory syndrome virus non-structural protein 4 cleaves guanylate-binding protein 1 via its cysteine proteinase activity to antagonize GBP1 antiviral effect.

Porcine reproductive and respiratory syndrome (PRRS) is a highly infectious disease caused by PRRS virus (PRRSV) that causes great economic losses to the swine industry worldwide. PRRSV has been recognized to modulate the host antiviral interferon (IFN) response and downstream interferon-stimulated gene expression to intercept the antiviral effect of host cells. Guanylate-binding proteins (GBPs) are IFN-inducible GTPases that exert broad antiviral activity against several DNA and RNA viruses, of which GBP1 is considered to play a pivotal role.

A synthetic toll-like receptor 7 agonist inhibits porcine reproductive and respiratory syndrome virus replication in piglets.

Toll-like receptor 7 (TLR7) agonists have been shown to exert therapeutic effects against several viruses. However, antiviral potential of TLR7 agonist in inhibiting porcine reproductive and respiratory syndrome virus (PRRSV) infection has not been assessed in vivo. In our previous study, a synthetic TLR7 agonist, SZU101, was confirmed to inhibit PRRSV infection of porcine alveolar macrophages (PAMs).