Hemagglutination by equine infectious anemia virus

Area of Science:

• Virology
• Immunology

Background:

• Equine infectious anemia (EIA) is a significant viral disease affecting horses.
• Understanding the properties of EIA virus is crucial for diagnosis and control.

Purpose of the Study:

• To characterize the hemagglutinating (HA) properties of Equine infectious anemia virus.
• To investigate the association of hemagglutinin with virus particles and its stability.

Main Methods:

• Propagation of EIA virus on equine dermal cell line.
• Hemagglutination assays with guinea pig erythrocytes.
• Cesium chloride density gradient centrifugation.
• Stability testing across various temperatures, pH, and enzyme treatments.

Main Results:

• EIA virus demonstrated hemagglutination of guinea pig erythrocytes.
• Hemagglutinin was inseparable from virus particles via density gradient centrifugation.
• HA activity was stable over a wide pH range and temperature (4°C), but not at 56°C.
• Lipid solvents destroyed HA activity, while proteolytic enzymes moderately affected it.
• Neuraminidase slightly enhanced HA, and Phospholipase C inactivated infectivity without affecting HA titer.
• Erythrocyte receptors were sensitive to proteases and formaldehyde, but not neuraminidase or detergents.

Conclusions:

• The hemagglutinin of EIA virus is closely associated with virus particles.
• HA activity depends on viral lipids and proteins.
• Hemagglutination can be inhibited by EIA virus-infected horse sera, suggesting diagnostic potential.
• Erythrocyte receptor properties offer insights into the interaction mechanism.