In vitro host range of equine infectious anemia virus.

This research explores the host range of the equine infectious anemia virus (EIAV), demonstrating that it can infect not only equine cells but also canine and feline cell cultures, therefore extending its in vitro host range.

Research Methodology and Scope

• The researchers began by inoculating the EIAV onto cell cultures of canine and feline origin, this led to chronic infections in these cell cultures. Infection of equine cell cultures was also performed for comparative purposes.
• The nature of the virus produced in the heterologous as well as the equine cells was determined using multiple techniques.

Virus Determination

• SDS-PAGE (Sodium dodecyl sulfate–polyacrylamide gel electrophoresis), a technique used to separate proteins based on their electrophoretic mobility, was used to purify the virus from different cell lines. The protein composition was found to be very similar across different cell lines.
• Immunological identity was confirmed by gel diffusion tests using an antiserum to the major core protein (p24) of equine-derived EIAV. This test demonstrated that antigenic characteristics were maintained across species.
• Competitive radioimmunoassays, where radioactively labelled antigens compete with unlabelled antigens for a fixed quantity of antibody binding sites, were used to compare antigenicity across the viruses derived from different cells.
• A strong similarity between the viruses was further established by hybridizing or combining viral RNAs with EIAV complementary DNA. This showed a high degree of relatedness between the viruses.

Conclusions

• Based on these findings, the study concludes that EIAV has an amphotropic cell culture host range. This means that the virus has the ability to infect both equine and non-equine cells in vitro, demonstrating a broader host range than previously thought.
• The viruses derived from different permissive cell lines were similar in protein composition, immunological identity, antigenicity, and relatedness at the nucleic acid level. This further supports the assertion that the EIAV has an amphotropic cell culture host range.