Envelope glycoprotein D (Herpes simplex virus type 2) (gD-2)

Envelope glycoprotein D (gD-2) is a critical structural component of the Herpes Simplex Virus type 2 (HSV-2) envelope, serving as the primary ligand for viral entry into host cells (UniProt P06476). It functions by binding to specific cellular receptors, including Herpesvirus Entry Mediator (HVEM), Nectin-1, and 3-O-sulfated heparan sulfate, which triggers a conformational change that activates the viral fusion machinery (PubMed: 11836371). Because gD-2 is essential for infection and is a major target for the host's neutralizing antibody response, it has been the central focus of prophylactic and therapeutic vaccine development for decades. Notable candidates like the Simplirix vaccine utilized recombinant gD-2 to elicit protective immunity, though clinical trials demonstrated varying levels of success in preventing genital herpes (NIH: NCT00057330). Beyond vaccines, gD-2 is a target for monoclonal antibodies designed to block viral attachment or reduce viral shedding in chronically infected individuals. Understanding the structural biology of gD-2 remains vital for overcoming the challenges of HSV-2's ability to establish lifelong latency in the nervous system.

Other names

Glycoprotein D-2gD2US6Envelope glycoprotein DHSV-2 gD

Vaccines and monoclonal antibodies targeting gD-2 work by inducing or providing neutralizing antibodies that bind to the glycoprotein, thereby sterically hindering its interaction with host cell receptors such as HVEM or Nectin-1 and preventing viral entry and fusion (PubMed: 15709001, PubMed: 22216473).