Sensitivity of macrophages from different species to African swine fever (ASF) virus

Area of Science:

• Veterinary Virology
• Cell Biology
• Immunology

Background:

• African swine fever (ASF) virus is a significant threat to swine populations globally.
• Understanding the cellular targets and interactions of ASF virus is crucial for disease control.
• Swine monocytes differentiated into macrophages are identified as sensitive cells.

Purpose of the Study:

• To characterize swine macrophages susceptible to ASF virus.
• To investigate the effect of ASF virus on macrophages from various species.
• To determine the cytopathic effects and viral replication in infected macrophages.

Main Methods:

• In vitro differentiation of swine monocytes into macrophages.
• Characterization of macrophage morphology, phagocytic capacity, and receptor presence.
• Infection of macrophages from swine, humans, rabbits, guinea pigs, hamsters, rats, and chickens with ASF virus.
• Adaptation of ASF virus to VERO cells for infection studies.

Main Results:

• Swine macrophages exhibit characteristic morphology, phagocytic capacity, and swine IgG receptors.
• ASF virus infection did not affect macrophages from humans, rabbits, guinea pigs, hamsters, or rats.
• Chicken macrophages showed enhanced DNA synthesis and cytopathic effects upon ASF virus infection.
• ASF virus adapted to VERO cells induced strong cytopathic effects and destruction in human macrophages, without infectious virus or DNA synthesis.

Conclusions:

• Swine monocytes differentiated into macrophages are the primary susceptible white blood cells for ASF virus.
• ASF virus exhibits differential effects on macrophages across species, with notable impact on chicken and human cells.
• The cytopathic effect in human macrophages infected with adapted ASF virus is independent of viral replication or DNA synthesis.