Molecular cloning and expression in Escherichia coli of equine type I interferons.

The research article pertains to a study where genes for various types of interferons are isolated from an equine genomic library and expressed in E. coli, and their antiviral activities on both equine and human cells were examined.

Isolation of Interferon Genes

• The research commenced with using human interferon-alpha 2 (IFN-alpha 2) and interferon-beta (IFN-beta) DNA to probe an equine genomic library.
• Through this probing, the team was able to successfully isolate recombinant phages containing the genes for equine interferon-alpha (EqIFN-alpha), interferon-beta (EqIFN-beta), and interferon-omega (EqIFN-omega).

Analysis and Discovery

• The subsequent sequence and hybridization analyses of these genes revealed that the equine genome comprises gene families of each of these three type I interferon classes.
• This finding indicates that these types of interferon genes are not exclusive to humans and are present in the genomes of other organisms like horses.

Mature Proteins and Homology

• The research found that the mature proteins of EqIFN-alpha are 71-77% homologous to human IFN-alpha polypeptides. Homology indicates the similarity of the structures in two entities, in this case, the similarity in the structure of proteins. Therefore, the closer the percentage of homology, the more similar the structures or characteristics.
• The researchers also found that EqIFN-beta is only 59% homologous to its human counterpart, indicating less similarity in terms of structure and characteristics between these two types of interferon-beta.

Expression and Antiviral Activity

• The isolated equine interferon genes were expressed in E.coli for further examination. After expressing in E.coli, the antiviral activity of these interferons was tested on both equine and human cells.
• The researchers discovered that EqIFN-alpha possesses antiviral activity on both equine and human cells, while EqIFN-beta showed activity only on equine cells.

Conclusion

• The research provides significant insights into the presence and properties of various types of interferons in horses. This could potentially be of great impact in understanding and improving the treatment of viral infections in horses and perhaps, even in human beings.