Studying Immune Response to Two Infectious Diseases

Results:

Researchers Determine Global Prevalence of FIV Viruses and Examine Susceptibility

Feline immunodeficiency virus (FIV) and feline coronavirus (FCoV) are two serious infectious diseases that significantly affect the health of cats worldwide. Mitochondrial genomics has determined that variations in mitochondrial DNA (mitochondria are the energy-producing factories within cells) are associated with differences in disease progression in people with human immunodeficiency virus (HIV). Because FIV is similar to HIV, researchers from the National Cancer Institute hypothesized that specific variations in mitochondrial DNA sequences may be associated with susceptibility to FIV. They collected tissue samples from wild and feral cats around the world and screened these samples for FIV. About 7 percent of the samples tested positive for FIV, and most of these FIV-positive samples were subtype A (one of five FIV subtypes). Researchers are confident that their findings reflect the global prevalence of this particular subtype. The researchers also sequenced the FIV genome from blood samples of domestic cats and their close relatives from around the world. The genome sequence will be a valuable new tool in studying how different species-specific FIV strains evolve within each cat species. Finally, researchers generated whole mitochondrial sequences from 143 domestic cats worldwide.  They discovered several functional differences in mitochondrial DNA sequences, suggesting that differences in cats’ mitochondrial efficiency may explain why some are more susceptible to FIV infection.  This study is the first of its kind to apply advanced mitochondrial genomic analysis to companion animals in an effort to provide information on the immune response to feline viruses and develop better diagnostic tools and therapies for FIV and FCoV.

D08FE-052
Dr. Jill Pecon-Slattery, National Cancer Institute