Feline leukemia virus envelope protein (FeLV Env)

The Feline leukemia virus envelope protein (FeLV Env) is a glycoprotein complex embedded in the viral lipid envelope, composed of surface (SU/gp70) and transmembrane (TM/p15E) subunits generated by proteolytic cleavage. The SU subunit mediates binding to host cell surface receptors (primarily phosphate transporter Pit1 for most subgroups, sometimes Pit2 or SLC35F2 for some rare variants), determining host specificity, cell entry, and subgroup phenotype. The TM subunit is responsible for the fusion of the viral and host cell membranes, allowing the viral core to enter the cytoplasm. The envelope is the principal viral determinant for host range, cell and tissue tropism, and is a major target for neutralizing antibodies and vaccine design. Mutational variation in Env underlies emergence of new viral strains, escape from immune surveillance, and changes in virulence or host specificity. The envelope protein is essential for productive infection and is directly implicated in the oncogenic and immunosuppressive potential seen in FeLV-associated disease in cats.

Other names

FeLV EnvSurface glycoprotein (SU)Transmembrane protein (TM)Viral envelope glycoprotein gp70 (SU/gp70) and p15E (TM/p15E)

Neutralizing antibodies block SU/receptor interaction - Fusion inhibitors prevent membrane merger - Receptor antagonists/decoys inhibit viral entry - Vaccines elicit immune response against Env