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Published on: November 1, 2011
Replication of African swine fever virus in cell cultures
Abstract:
Infection-specific, nonstructural, African swine fever virus antigens, as visualized by the immunofluorescence technique, appeared as fine stipplings, evenly distributed in the cytoplasm and nucleus of Vero cells and in monocytes by postinoculation hour (PIH) 3. Cytoplasmic inclusion bodies (IB) appeared at PIH 4 and continued to increase in size up to PIH 8. The viral DNA was solely synthesized within the IB of infected monocytes, as evidenced by an autoradiographic chase experiment; maximum synthesis occurred at PIH 5. The 2,300-S and 2,500-S (sedimentation coefficient) structural viral antigens were visualized in the IB at PIH 5 and 6, respectively. The infective new progeny of African swine fever virus were formed between PIH 7 and 8, and the cell surface viral antigens were produced between PIH 8 and 9. Free virus was released between PIH 10 and 11. Infected cells detached from the glass surface from PIH 13. The 5-iodo-2'-deoxyuridine interfered with the formation of infective virus, but not interfere with the production of viral antigens.
Insights
African swine fever virus (ASFV) infection in Vero cells and monocytes shows viral antigens appearing by 3 hours postinoculation. Viral DNA synthesis peaks at 5 hours, with new infectious virus forming by 7-8 hours.
Area of Science:
- Veterinary Virology
- Cell Biology
- Molecular Virology
Background:
- African swine fever virus (ASFV) is a highly contagious pathogen causing significant economic losses in swine populations worldwide.
- Understanding the early stages of ASFV infection is crucial for developing effective control strategies.
Purpose of the Study:
- To characterize the temporal dynamics of ASFV replication in host cells.
- To identify the sites of viral DNA synthesis and antigen production during infection.
Main Methods:
- Immunofluorescence microscopy was used to visualize viral antigens in infected Vero cells and monocytes.
- Autoradiographic chase experiments were employed to track viral DNA synthesis.
- Sedimentation analysis was performed to characterize structural viral antigens.
Main Results:
- Nonstructural ASFV antigens were detected as early as 3 hours postinoculation (PIH) in the cytoplasm and nucleus.
- Cytoplasmic inclusion bodies (IB) formed by PIH 4, with viral DNA synthesis peaking at PIH 5 within these IB.
- Infectious progeny virus was produced between PIH 7-8, and free virus was released by PIH 10-11.
Conclusions:
- The study elucidates the precise timeline of ASFV replication, from initial antigen appearance to virus release.
- Inclusion bodies are identified as the primary sites for ASFV DNA replication and structural antigen assembly.
- Interference with infective virus formation by 5-iodo-2'-deoxyuridine suggests potential therapeutic targets.
