Hemagglutination with equine arteritis virus.

The research studied the hemagglutination capabilities of Equine arteritis virus (EAV) with erythrocytes derived from different animal species at varying temperatures. They found that the virus could cause hemagglutination with mouse and chicken erythrocytes, but not with other animals tested. Hemagglutination activity could be enhanced by specific treatments, and the reaction was inhibited by specific antiserum.

Background and Methodology

• The study was conducted using Equine arteritis virus (EAV), a virus that primarily affects horses but can infect other species as well. The virus was grown on RK13 cell cultures for testing.
• The researchers tested the ability of EAV to cause hemagglutination, which is the clumping together of red blood cells/erythrocytes. This was carried out at a range of temperatures: 4 degrees Celsius, room temperature, and 37 degrees Celsius.
• Erythrocytes from a variety of species were used in this study, including mouse, chicken, cattle, horse, rabbit, guinea pig, mongolian gerbil, goose, and chick embryo.

Findings

• They observed that EAV could cause hemagglutination with erythrocytes from mice and chickens, regardless of the temperature. However, it could not cause hemagglutination with erythrocytes of the other species tested in the study.
• When it came to chickens, there was individual variation in agglutinability or the ability of their erythrocytes to be clumped by the virus. This necessitated the selection of specific birds to obtain erythrocytes that demonstrated hemagglutination.
• The researchers were able to boost the hemagglutination activity of the virus by treating it with a substance called Tween 80, followed by ether.

Inhibiting Hemagglutination and Antibody Correlation

• The hemagglutination reaction could be inhibited using a specific antiserum, indicating the potential for protective or preventative measures against the virus.
• Higher hemagglutination-inhibiting (HI) antibody titers were obtained by incubating a mixture of serum and hemagglutination antigen at 4 degrees Celsius for 24 hours. An antibody titer is a test that determines the presence and amount of antibodies in the blood.
• There was a significant positive correlation between the HI antibody titers and neutralizing antibody titers in individual horse sera. Neutralizing antibodies are antibodies that neutralize the biological effects of the virus. This suggests that individuals with higher levels of neutralizing antibodies may have a more effective inhibition of hemagglutination caused by the virus.