<abstract xmlns="http://www.w3.org/1999/xhtml"><sec id="j_jvetres-2020-0039_s_005_w2aab3b7c80b1b6b1aab1c16b1Aa"><h3>Introduction</h3><p>African swine fever (ASF) is a pressing economic problem in a number of Eastern European countries. It has also depleted the Chinese sow population by 50%. Managing the disease relies on culling infected pigs or hunting wild boars as sanitary zone creation. The constraints on the development of an efficient vaccine are mainly the virus’ mechanisms of host immune response evasion. The study aimed to adapt a field ASFV strain to established cell lines and to construct recombinant African swine fever virus (ASFV) strain.</p></sec><sec id="j_jvetres-2020-0039_s_006_w2aab3b7c80b1b6b1aab1c16b2Aa"><h3>Material and Methods</h3><p>The host immune response modulation genes <italic>A238L</italic>, <italic>EP402R</italic>, and <italic>9GL</italic> were deleted using the clustered regularly interspaced short palindromic repeats/caspase 9 (CRISPR/Cas9) mutagenesis system. A representative virus isolate (Pol18/28298/Out111) from Poland was isolated in porcine primary pulmonary alveolar macrophage (PPAM) cells. Adaptation of the virus to a few established cell lines was attempted. The plasmids encoding CRISPR/Cas9 genes along with gRNA complementary to the target sequences were designed, synthesised, and transfected into ASFV-infected PPAM cells.</p></sec><sec id="j_jvetres-2020-0039_s_007_w2aab3b7c80b1b6b1aab1c16b3Aa"><h3>Results</h3><p>The reconstituted virus showed similar kinetics of replication in comparison to the parent virus isolate.</p></sec><sec id="j_jvetres-2020-0039_s_008_w2aab3b7c80b1b6b1aab1c16b4Aa"><h3>Conclusion</h3><p>Taking into account the usefulness of the developed CRISPR/Cas9 system it has been shown that modification of the <italic>A238L</italic>, <italic>EP402R</italic>, and <italic>9GL</italic> genes might occur with low frequency, resulting in difficulties in separation of various virus populations.</p></sec></abstract>

IntroductionAfrican swine fever (ASF) is a pressing economic problem in a number of Eastern European countries. It has also depleted the Chinese sow population by 50%. Managing the disease relies on culling infected pigs or hunting wild boars as sanitary zone creation. The constraints on the development of an efficient vaccine are mainly the virus’ mechanisms of host immune response evasion. The study aimed to adapt a field ASFV strain to established cell lines and to construct recombinant African swine fever virus (ASFV) strain.Material and MethodsThe host immune response modulation genes A238L, EP402R, and 9GL were deleted using the clustered regularly interspaced short palindromic repeats/caspase 9 (CRISPR/Cas9) mutagenesis system. A representative virus isolate (Pol18/28298/Out111) from Poland was isolated in porcine primary pulmonary alveolar macrophage (PPAM) cells. Adaptation of the virus to a few established cell lines was attempted. The plasmids encoding CRISPR/Cas9 genes along with gRNA complementary to the target sequences were designed, synthesised, and transfected into ASFV-infected PPAM cells.ResultsThe reconstituted virus showed similar kinetics of replication in comparison to the parent virus isolate.ConclusionTaking into account the usefulness of the developed CRISPR/Cas9 system it has been shown that modification of the A238L, EP402R, and 9GL genes might occur with low frequency, resulting in difficulties in separation of various virus populations.

Attempts at the development of a recombinant African swine fever virus strain with abrogated <italic>EP402R, 9GL</italic>, and <italic>A238L</italic> gene structure using the CRISPR/Cas9 system

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Attempts at the development of a recombinant African swine fever virus strain with abrogated , and  gene structure using the CRISPR/Cas9 system

IntroductionAfrican swine fever (ASF) is a pressing economic problem in a number of Eastern European countries. It has also depleted the Chinese sow population...

Attempts at the development of a recombinant African swine fever virus strain with abrogated EP402R, 9GL, and A238L gene structure using the CRISPR/Cas9 system

Published Online: Jun 03, 2020

Page range: 197 - 205

Received: Oct 04, 2019

Accepted: May 25, 2020

DOI: https://doi.org/10.2478/jvetres-2020-0039

Keywords
African swine fever, CRISPR/Cas9,

© 2020 G. Woźniakowski et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Attempts at the development of a recombinant African swine fever virus strain with abrogated EP402R, 9GL, and A238L gene structure using the CRISPR/Cas9 system

Published Online: Jun 03, 2020

Page range: 197 - 205

Received: Oct 04, 2019

Accepted: May 25, 2020

DOI: https://doi.org/10.2478/jvetres-2020-0039

KeywordsAfrican swine fever, CRISPR/Cas9,

© 2020 G. Woźniakowski et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
African swine fever, CRISPR/Cas9,