Untersuchungen zur Immunpathogenese der Afrikanischen Schweinepest im Edelschwein

• Forschungsstelle: BLV
• Projektnummer: 1.19.02

Schlüsselwörter (Deutsch)

Asfarviridae, Asfivirus, Afrikanische Schweinepest, ASP, Schein, Wildschwein, Schweizer Edelschwein, Markrophag

Schlüsselwörter (Englisch)

Asfarviridae, Asfivirus, African swine fever, ASF, pig, wild boar, Swiss Large White, macrophage

Kurzbeschreibung (Deutsch)

Seit 2007 breitet sich die Afrikanische Schweinepest (ASP) in Ost-Europa aus. Ausbrüche in der Tschechei und in Ungarn, in Regionen die nicht direkt den endemischen Gebieten anliegen zeigen, dass das ASP Virus (ASPV) über grössere Distanzen verschleppt werden kann. Demzufolge muss die ASPV-Forschung am IVI dringend intensiviert werden um die Diagnostik und die Veterinärbehörden mit praktischer wissenschaftlicher Expertise zu unterstützen. Mit diesem Projekt sollen die Eigenschaften aktueller ASPV Isolate im Schweizer Edelschwein untersucht werden. Insbesondere soll die Rolle der Antikörper in der Immunpathogenese und im Schutz gegen die Krankheit genauer definiert werden. Ein weiteres Ziel ist es, mittels genetischen Methoden permanente Zelllinien für die Isolierung des Virus zu erzeugen, als Ersatz von primären Makrophagen Kulturen. Nicht zuletzt werden die Infektionsversuche im Schwein auch Trainingsgelegenheiten für Kliniker und Veterinärbehörden bieten und die Validierung von Desinfektionsprotokollen unter simulierten Feldbedingungen ermöglichen.

Kurzbeschreibung (Englisch)

After the successful eradication of African swine fever (ASF) from Europe except Sardinia in the mid-90s, a virulent ASF virus (ASFV) re-emerged in the Caucasus region in 2007. Since then, ASFV progressed westward, reaching the Baltic States and Poland in 2014 and causing important losses in wild boar and domestic pigs. The most recent outbreaks in the Czech Republic and Hungary in regions that are not directly adjacent to endemic areas show that the virus can be transported over large distances. Accordingly, it is essential to raise preparedness by reinforcing the IVI research program on ASFV in order to support the diagnostic laboratories and official veterinary authorities with solid scientific expertise in the field. To this end, the present project aims to investigate the specificities of recent ASFV isolates from Eastern Europe in Swiss Large White pigs with respect to disease manifestation, virus persistence and immunological responses, considering a potential influence of co-infections with opportunistic pathogens such as porcine circovirus type 2, mycoplasma and bacteria. Experiments will address in particular the role of antibodies in ASF immunopathogenesis and in protection against infection, a major gap in the field. An additional objective is to identify key cellular factors that restrict the tropism of ASFV to differentiated porcine macrophages by applying high throughput genetic approaches. This will allow knowledge-based genetic engineering of permanent ASFV-permissive porcine cell lines to replace primary macrophage cultures for reliable ASFV isolation. Finally, the studies in vivo will provide training opportunities for clinicians and veterinarians and allow validation of disinfection procedures under simulated field conditions.

Projektziele (Englisch)

In order to be prepared in case of ASFV emergence in Switzerland and effectively contribute to the local and regional efforts to control the disease, it is essential for the IVI to reinforce its research program on ASFV and dedicate technical and scientific expertise in the field. To this end, and to address the selected gaps outlined above, important goals are to understand the specificities of recent genotype II ASF isolates as opposed to endemic genotype I strains with respect to disease manifestation, virus persistence, disease immunopathogenesis, and virus-host interaction. The development of cell culture platforms for rapid and reliable isolation of ASFV from field material is also of high priority. Finally, the experiments planned will also permit the acquisition of practical experience with clinical and pathological cases and the investigation and validation of disinfection procedures. Therefore, the specific aims of this study are:

1) to characterize the phenotype of selected recent genotype II ASF isolates from Eastern Europe in comparison with a prototype genotype I isolate in Swiss Large White pigs of different hygiene status, i.e. in conventional versus SPF pigs.

2) to study the targets, functions and type of antibody responses in the immunopathogenesis of ASF and in protection against infection versus persistence.

3) to identify the cellular factors that restrict the replication of ASFV to porcine macrophages.

Expertenbericht/Kurzevaluation (Deutsch)

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Zugehörige Dokumente

• 1 19 02 ASF summary [PDF] 121 kB

Publikationen / Ergebnisse (Englisch)

Labroussaa, F.; Mehinagic, K., Cippa, V.; Liniger, M.; Akarsu, H.; Ruggli, N.; Jores, J. (2021) In-yeast reconstruction of the African swine fever virus genome isolated from clinical samples. STAR Protoc 2(3):100803.

Radulovic, E.; Mehinagic, K.; Wüthrich, T.; Hilty, M.; Posthaus, H.; Summerfield, A; Ruggli, N.; Benarafa, C. (2022a) The baseline immunological and hygienic status of pigs impact disease severity of African swine fever. PLoS Pathog 18(8): e1010522.

Zugehörige Dokumente

• In-Yeast reconstruction of the African swinge fever virus genome [PDF] 2'921 kB
• Publikation 1.19.02 [PDF] 2'847 kB
• Labroussaa 2021 [PDF] 2'921 kB
• Radulovic2022 [PDF] 3'739 kB