Characterization of ferret Pit1 as a receptor of feline leukemia virus subgroup B

Feline leukemia virus (FeLV) is a retrovirus that causes immune suppression and immunodeficiency, leading to opportunistic infections and leukemia/lymphoma in cats. Today, a variety of domestic mammals are kept in houses, and it is important to evaluate the possibility of interspecies transmission of FeLV. In this study, we assessed the infectivity of FeLV-B in ferrets that belong to Mustelidae. By pseudotype virus infection assay, we revealed that a ferret cell line, Mpf cells, is resistant to FeLV-B infection. The mRNA expression level of the FeLV-B receptor, Pit-1, was approximately half that of cat FEA cells in ferret Mpf cells. There was no significant difference in receptor usage between ferret’s and cat’s Pit1. These data may indicate the presence of the post-transcriptional modification and/or the restriction factor(s) against the FeLV-B infection in ferrets.