Title: Deletion of the H108R Gene Reduces Virulence of the Pandemic Eurasia Strain of African Swine Fever Virus with Surviving Animals Being Protected against Virulent Challenge

Abstract

African swine fever virus (ASFV) is the etiological agent of African swine fever (ASF), a devastating disease affecting domestic and wild swine and currently causing a global pandemic, severely affecting swine production. Here, we demonstrate that the deletion of the previously uncharacterized ASFV gene, H108R from the highly virulent ASFV-Georgia2007 (ASFV-G) genome strain, reduces virulence in domestic swine. ASFV-G-DH108R, a recombinant virus with the H108R gene deleted, was used to evaluate the involvement of the H108R gene for ASFV replication and virulence in swine. ASFV-G-DH108R showed a delayed replication in swine macrophage cultures. A group of five pigs, intramuscularly inoculated with 102 HAD50 of ASFV-G-DH108R, was observed over a 28-day period and compared with a similar group of animals inoculated with similar doses of the parental virulent virus. While all animals inoculated with ASFV-G developed an acute fatal disease, ASFV-G-DH108R inoculated animals, with the exception of one animal showing a protracted but fatal form of the disease, all survived the infection, remaining clinically healthy during the observational period. The surviving animals presented protracted viremias with lower virus titers compared with those of animals inoculated with the parental virus, and all of them developed a strong virus-specific antibody response. Importantly, allmore » animals surviving ASFV-G-DAH108R infection were protected when challenged with the virulent parental strain, ASFV-G. This report constitutes the first evidence that the H108R gene is involved in ASFV virulence in swine and that the deletion of this gene may be used as a tool to increase the attenuation of currently experimental vaccines to improve their safety profiles.« less

Authors:

Vuono, Elizabeth ^[1]; Ramirez-Medina, Elizabeth ^[2]; Silva, Ediane ^[2]; Rai, Ayushi ^[3]; Pruitt, Sarah ^[2]; Espinoza, Nallely ^[2]; Valladares, Alyssa ^[3]; Velazquez-Salinas, Lauro ^[2]; Gladue, Douglas P.  ^[2];

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Borca, Manuel V. ^[2]

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+ Show Author Affiliations

1. US Dept. of Agriculture (USDA), Greenport, NY (United States). Agricultural Research Service (ARS), Plum Island Animal Disease Center; Univ. of Wisconsin, Madison, WI (United States)
2. US Dept. of Agriculture (USDA), Greenport, NY (United States). Agricultural Research Service (ARS), Plum Island Animal Disease Center
3. US Dept. of Agriculture (USDA), Greenport, NY (United States). Agricultural Research Service (ARS), Plum Island Animal Disease Center; Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States)

Publication Date:

Wed Jul 27 00:00:00 EDT 2022

Research Org.:

Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC); USDA

OSTI Identifier:

1982972

Grant/Contract Number:  

SC0014664

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Virology

Additional Journal Information:

Journal Volume: 96; Journal Issue: 14; Journal ID: ISSN 0022-538X

Publisher:

American Society for Microbiology

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; Virology; ASF; ASFV; African Swine fever; H108R; pandemic; virulence