Structure of African Swine Fever Virus and Associated Molecular Mechanisms Underlying Infection and Immunosuppression: A Review.

Yue Wang,Jing Zhang,Wenping Yang,Dan Li,Weifang Kang,Haixue Zheng

doi:10.3389/fimmu.2021.715582

Abstract

African swine fever (ASF) is an acute, highly contagious, and deadly infectious disease. The mortality rate of the most acute and acute ASF infection is almost 100%. The World Organization for Animal Health [Office International des épizooties (OIE)] lists it as a legally reported animal disease and China lists it as class I animal epidemic. Since the first diagnosed ASF case in China on August 3, 2018, it has caused huge economic losses to animal husbandry. ASF is caused by the African swine fever virus (ASFV), which is the only member of Asfarviridae family. ASFV is and the only insect-borne DNA virus belonging to the Nucleocytoplasmic Large DNA Viruses (NCLDV) family with an icosahedral structure and an envelope. Till date, there are still no effective vaccines or antiviral drugs for the prevention or treatment of ASF. The complex viral genome and its sophisticated ability to regulate the host immune response may be the reason for the difficulty in developing an effective vaccine. This review summarizes the recent findings on ASFV structure, the molecular mechanism of ASFV infection and immunosuppression, and ASFV-encoded proteins to provide comprehensive proteomic information for basic research on ASFV. In addition, it also analyzes the results of previous studies and speculations on the molecular mechanism of ASFV infection, which aids the study of the mechanism of clinical pathological phenomena, and provides a possible direction for an intensive study of ASFV infection mechanism. By summarizing the findings on molecular mechanism of ASFV- regulated host cell immune response, this review provides orientations and ideas for fundamental research on ASFV and provides a theoretical basis for the development of protective vaccines against ASFV.

Highlights

African swine fever virus (ASFV) is a 200 nm diameter icosahedral DNA virus comprising envelope, capsid, inner capsule membrane, core shell, and inner core
The high conservation of key residues indicates that the recognition characteristics of PNP868RMT cap are similar to those of the host cell and virus particles (12). Another in vitro study has reported that Ba71V D250R encodes a decapping protein (ASFVDP), which interacts with ribosomal protein L23a and the mRNA cap structure located on the endoplasmic reticulum (ER) and interacts with poly(A) RNA through the N-terminal structure resulting in a decrease in the number of transcripts of the virus and host cells to shut off the cell and regulate the time of viral gene expression (41)
The detailed process of ASFV infected cells has been described in previous studies, the involved proteins of cells and viral are still unknown

Summary

Introduction

African swine fever virus (ASFV) is a 200 nm diameter icosahedral DNA virus comprising envelope, capsid, inner capsule membrane, core shell, and inner core. P12 promotes the adsorption of virus particles on host cells as an outer envelope protein by binding to specific receptors on the host cell membrane to mediate ASFV entry. The intermediate and late genes which encode virus particle structure related proteins start expression at 8-16 hpi.

Results

Conclusion