Efficacy assessment of antiretroviral drugs against equine infectious anemia virus in vitro

Equine infectious anemia virus (EIAV) is an equine lentivirus related to human immunodeficiency virus type 1 (HIV-1). Both viruses are related among the Retroviridae family, but their clinical manifestations are different as EIAV causes a long persistent infection with no progressive immune dysfunction in most cases. Today, no treatment is approved against EIAV, contrary to HIV-1, manageable through antiretroviral therapy, known as HAART (highly active antiretroviral therapy) or cART (combination antiretroviral therapy). No information about the efficacy of antiretroviral drugs against EIAV is available in the literature. This study evaluates the in vitro antiviral effect of eighteen FDA-approved antiretroviral compounds from different drug families, in an equine cells in vitro infection model with EIAV reference strain. Equine dermal cells, as well as equine peripheral blood mononuclear cells were treated with non-cytotoxic drug concentrations and infected with EIAV. Relative virus release in culture supernatants was assessed through relative quantification of viral RNA via RTqPCR and viral DNA comprising proviral integration in the cell genome was assessed through qPCR of infected cells, both after nucleic acid extractions. Out of eighteen tested drugs, thirteen showed a significant antiviral effect against EIAV in vitro, an interesting discovery showing the similarities between HIV-1 and EIAV and opening a possibility to treat equine infectious anemia to avoid the disease spread.