scholarly journals The recombinant pseudorabies virus expressing African swine fever virus CD2v protein is safe and effective in mice

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Zhihua Feng ◽  
Jianghua Chen ◽  
Wangwang Liang ◽  
Wenzhi Chen ◽  
Zhaolong Li ◽  
...  
Keyword(s):  
Recombinant Virus ◽  
Recombinant Strain ◽  
Pseudorabies Virus ◽  
Vaccine Candidate ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Vero Cells ◽  
Fever Virus ◽  
Virus Vaccination ◽  
Recombinant Pseudorabies Virus

Abstract Background African swine fever (ASF) leads to high mortality in domestic pigs and wild boar and is caused by the African swine fever virus (ASFV). Currently, no vaccine is commercially available for prevention, and the epidemic is still spreading. Here, we constructed a recombinant pseudorabies virus (PRV) (PRV-ΔgE/ΔgI/ΔTK-(CD2v)) that expresses the CD2v protein of ASFV and evaluated its effectiveness and safety as a vaccine candidate in mice. Methods A homologous recombination fragment containing ASFV CD2v was synthesized and co-transfected into HEK 293 T cells, a knockout vector targeting the PRV TK gene. The transfected cells were infected with PRV-ΔgE/ΔgI, and the recombinant strain (PRV-ΔgE/ΔgI/ΔTK-(CD2v)) was obtained by plaque purification in Vero cells. The expression of ASFV CD2v in the recombinant virus was confirmed by sequencing, Western blotting, and immunofluorescence analysis, and the genetic stability was tested in Vero cells over 20 passages. The virulence, immunogenicity and protective ability of the recombinant virus were further tested in a mouse model. Results The PRV-ΔgE/ΔgI/ΔTK-(CD2v) recombinant strain is stable in Vero cells, and the processing of CD2v does not depend on ASFV infection. The vaccination of PRV-ΔgE/ΔgI/ΔTK-(CD2v) causes neither pruritus, not a systemic infection and inflammation (with the high expression of interleukin-6 (IL6)). Besides, the virus vaccination can produce anti-CD2v specific antibody and activate a specific cellular immune response, and 100% protect mice from the challenge of the virulent strain (PRV-Fa). The detoxification occurs much earlier upon the recombinant virus vaccination and the amount of detoxification is much lower as well. Conclusions The PRV-ΔgE/ΔgI/ΔTK-(CD2v) recombinant strain has strong immunogenicity, is safe and effective, and maybe a potential vaccine candidate for the prevention of ASF and Pseudorabies.

scholarly journals The Role of Interleukine-10 and Interferon-γ as Potential Markers of the Evolution of African Swine Fever Virus Infection in Wild Boar

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 757
Author(s):  
Sandra Barroso-Arévalo ◽  
Jose A. Barasona ◽  
Estefanía Cadenas-Fernández ◽  
José M. Sánchez-Vizcaíno
Keyword(s):  
Wild Boar ◽  
Vaccine Candidate ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Interferon Γ ◽  
Fever Virus ◽  
Control Group ◽  
Challenge Virus ◽  
Ifn Γ

African swine fever virus (ASFv) is one of the most challenging pathogens to affect both domestic and wild pigs. The disease has now spread to Europe and Asia, causing great damage to the pig industry. Although no commercial vaccine with which to control the disease is, as yet, available, some potential vaccine candidates have shown good results in terms of protection. However, little is known about the host immune mechanisms underlying that protection, especially in wild boar, which is the main reservoir of the disease in Europe. Here, we study the role played by two cytokines (IL-10 and IFN-γ) in wild boar orally inoculated with the attenuated vaccine candidate Lv17/WB/Rie1 and challenged with a virulent ASFv genotype II isolate. A group of naïve wild boar challenged with the latter isolate was also established as a control group. Our results showed that both cytokines play a key role in protecting the host against the challenge virus. While high levels of IL-10 in serum may trigger an immune system malfunctioning in challenged animals, the provision of stable levels of this cytokine over time may help to control the disease. This, together with high and timely induction of IFN-γ by the vaccine candidate, could help protect animals from fatal outcomes. Further studies should be conducted in order to support these preliminary results and confirm the role of these two cytokines as potential markers of the evolution of ASFV infection.

Saturable binding sites mediate the entry of African swine fever virus into VERO cells

Virology ◽  
1989 ◽  
Vol 168 (2) ◽  
pp. 393-398 ◽  
Author(s):  
Antonio Alcamí ◽  
Angel L. Carrascosa ◽  
Eladio Viñuela
Keyword(s):  
Binding Sites ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Vero Cells ◽  
Fever Virus ◽  
Saturable Binding

scholarly journals Expression and purification of African Swine Fever virus p72 trimers as subunit vaccine candidate

2020 ◽  
Author(s):  
Kaiwen Meng ◽  
Yueping Zhang ◽  
Wenzhuang Zhu ◽  
Ye Xiang ◽  
Geng Meng
Keyword(s):  
Subunit Vaccine ◽  
Vaccine Candidate ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Expression And Purification ◽  
Technical Approach

The authors have withdrawn this manuscript because the result is invalid. We intend to revise it on our technical approach and interpretation of the results. The authors do not wish for this manuscript to be cited as a reference for this project. Please contact the corresponding author if you have any questions.

scholarly journals Identification of the principal serological immunodeterminants of African swine fever virus by screening a virus cDNA library with antibody

2002 ◽  
Vol 83 (6) ◽  
pp. 1331-1342 ◽  
Author(s):  
S. D. Kollnberger ◽  
B. Gutierrez-Castañeda ◽  
M. Foster-Cuevas ◽  
A. Corteyn ◽  
R. M. E. Parkhouse
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Vero Cells ◽  
Polyclonal Antiserum ◽  
Fever Virus ◽  
Open Reading Frames ◽  
Cdna Expression Library ◽  
Lambda Phage ◽  
Cellular Mechanisms ◽  
Expression Library

Protective immunity to African swine fever virus (ASFV) may involve a combination of both serological and cellular mechanisms. This work is focused on the identification of the possible relevant serological immunodeterminants of immunity. Thus, 14 serological immunodeterminants of ASFV have been characterized by exhaustive screening of a representative lambda phage cDNA expression library of the tissue culture-adapted Ba71V strain of ASFV. The library was constructed using RNA extracted from Vero cells infected for 3, 6, 9 and 12 h. A total of 150 clones was selected arbitrarily by antibody screening of the library with a polyclonal antiserum from a domestic pig surviving infection with the virulent Malta isolate of ASFV. Sequencing of these clones permitted identification of 14 independent viral proteins that stimulated an antibody response. These included six proteins encoded by previously unassigned open reading frames (ORFs) (B602L, C44L, CP312R, E184L, K145R and K205R) as well as some of the more well-studied structural (A104R, p10, p32, p54 and p73) and non-structural proteins (RNA reductase, DNA ligase and thymidine kinase). Immunogenicity of these proteins was confirmed by demonstrating the corresponding antibodies in sera from pigs infected either with the Malta isolate or with the OURT88/3–OURT88/1 isolate combination. Furthermore, the majority of these ORFs were also recognized by immune antiserum from the natural host, the bush pig, following secondary challenge with the virulent Malawi (SINT90/1) isolate of ASFV. Thus, it is possible that some of these determinants may be important in protection against virus infection.

scholarly journals Endosomal proteins NPC1 and NPC2 at African swine fever virus entry/fusion

2021 ◽  
Author(s):  
Covadonga Alonso ◽  
Miguel Ángel Cuesta-Geijo ◽  
Jesús Urquiza ◽  
Ana Del Puerto ◽  
Isabel García-Dorival ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
African Swine Fever Virus ◽  
Direct Interaction ◽  
African Swine Fever ◽  
Vero Cells ◽  
Fever Virus ◽  
Endocytic Pathway ◽  
Viral Fusion ◽  
Transporter Protein ◽  
Niemann Pick

African swine fever virus (ASFV) infectious cycle starts with the viral adsorption and entry into the host cell. The virus is internalized via clathrin/dynamin mediated endocytosis and macropinocytosis. As several other viruses, ASF virion is then internalized and incorporated into the endocytic pathway. Endosomal maturation entails luminal acidification and the lowering of pH acting on the multi-layered virion structure dissolves the outer capsid. Upon decapsidation, the inner viral membrane is exposed to interact with the limiting membrane of the late endosome for fusion. Egress from endosome is related to cholesterol efflux, but it remains an intriguing process albeit essential for infection, specifically for the viral nucleic acid exit to the cytoplasm for replication. ASFV proteins E248R and E199L, with structural homology to the VACV proteins of the fusion complex, seem to have similar functions in ASFV. A direct interaction between these ASFV proteins with the cholesterol transporter protein NPC1 (Niemann-Pick C type 1) was observed, which was also shared by the E248R homologous protein L1R of VACV. Binding occurs between the transmembrane domain of E248R with the loop C of NPC1 at the same domain than EBOV binding site. These interactions suggest that these ASFV proteins are crucial for membrane fusion. CRISPR NPC1 KO Vero cells lacking NPC1 protein that were resistant to EBOV, reduced ASFV infection levels significantly. Reductions on ASFV infectivity and replication in NPC1 KO cells were accompanied by lesser viral factories of smaller size and lacking the typical cohesive morphology between endosomes and viral proteins.  We observed a compensatory effect in NPC1 KO cells, elevating NPC2 levels while silencing NPC2 in Vero cells with shRNA, also reduced ASFV infection. Our findings pave the way to understand the role of these proteins at the membrane viral fusion step for several viruses.

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