Feline leukemia virus envelope glycoprotein gp70 (gp70)

The Feline leukemia virus envelope glycoprotein gp70, also known as the surface (SU) subunit, is a critical viral protein responsible for the initial stages of infection in domestic cats [3, 11]. It is derived from the proteolytic cleavage of the gp85 precursor and resides on the outer surface of the viral envelope, where it mediates attachment to specific host cell receptors such as the thiamine transporter (THTR1) or neutral amino acid transporters (SLC1A4/SLC1A5) [3, 14]. This binding event is a prerequisite for the subsequent membrane fusion process facilitated by the transmembrane protein p15E, allowing the viral genome to enter the host cell [1, 13]. Because of its exposed position and essential role in entry, gp70 is the primary target for neutralizing antibodies and serves as the central component in most feline leukemia virus (FeLV) vaccines, including recombinant and subunit formulations [2, 9, 11]. In clinical practice, gp70 is also utilized as a diagnostic marker to assess the immune status of cats or to detect the presence of the virus through specialized assays [7, 11]. Research into small molecule inhibitors and monoclonal antibodies targeting gp70 continues to be a focus for developing more effective antiviral therapies to combat FeLV-associated diseases like lymphoma and severe anemia [1, 6, 13]. The protein's high degree of variability in certain domains allows the virus to evade the host immune system, presenting a significant challenge for long-term therapeutic efficacy [3, 4]. Understanding the structural and functional properties of gp70 is therefore vital for the advancement of both preventative and curative strategies against this widespread feline pathogen [1, 13].

Other names

Surface glycoprotein (SU) [3, 11]gp70 [1, 7]FeLV SU [3, 11]Envelope glycoprotein gp70 [1, 13]

Neutralization of viral entry by blocking the interaction between the gp70 surface protein and host cell receptors [3, 13]; induction of a protective humoral immune response through the production of gp70-specific neutralizing antibodies [4, 11].