The expression profile of sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1) in feline tissues.

SAMHD1 restricts lentiviruses by limiting availability of deoxynucleoside triphosphates for reverse transcription. HIV-2 and SIV have virion-associated proteins to counteract SAMHD1. Cats have an ortholog to human SAMHD1 and the FIV is restricted by human SAMHD1, but expression of feline SAMHD1 is unknown. Using a whole-body tissue microarray consisting of 24 tissues for immunohistochemistry, SAMHD1 expression was identified in a wide range of cat tissues. SAMHD1 was most strongly expressed in skin and mucosal epithelium, and in hemolymphatic and spermatogenic tissues. Both nuclear and cytoplasmic expression was detected. Feline cell lines susceptible to FIV infection also highly expressed SAMHD1. Preferential expression of SAMHD1 at sites of viral entry and replication supports a role for feline SAMHD1 in restricting FIV.