Expression of CXCR4 in the brain of feline immunodeficiency virus infected cat

Advances in understanding the mechanisms of human immunodeficiency virus (HIV)-1 entry have revealed that the cell surface CD4 expression alone is insufficient and needs an additional molecule on its surface for the viral entry. These are G-protein coupled seven transmembrane (7-TM) family molecules (chemokine receptor) and amongst them one is CXCR4. Feline homologue of CXCR4 acting as a co-receptor for feline immunodeficiency virus (FIV) entry is already reported for the Crandle feline kidney cells strain (CrFK) of FIV. An experiment was carried out to search the expression of CXCR4 retrospectively in FIV (CrFK) infected cat brain tissues using immunohistochemically in the formalin fixed paraffin sections against 12G5, a mouse monoclonal antibody to CXCR4. We observed the expression of this receptor in feline neurons, astrocytes and in some vascular endothelial cells. The study of expression of CXCR4 in the brain, which is one of the many chemokine receptors in the central nervous system, may provide further insight into the interactions between brain cells, pathogens, and the immune system, and help understand the pathogenesis of HIV dementia.