Human Cytomegalovirus (HCMV)
Human cytomegalovirus (HCMV) is a species of the Cytomegalovirus genus of viruses, which in turn is a member of the viral family known as Herpesviridae or herpesviruses. Infection with CMV is very common, with estimates suggesting that 50-80% of the population in the UK have been infected at some point with CMV. Most cases of CMV infection are asymptomatic, but it can cause illness with symptoms similar to that of Flu or glandular fever.
A significant problem associated with CMV infection results from infection of a pregnant woman, who may then pass the virus on to her newborn child, leading to congenital CMV. A child with CMV infection may experience learning difficulties, and deafness.
CMV glycoprotein B (gB)
CMV glycoprotein B is an important envelope protein of HCMV, acting as a receptor for entry of the virus into fibroblasts. This protein has been the target of vaccines designed to prevent HCMV infection by preventing entry into host cells. However, the HCMV pentameric complex also acts as a receptor for host-cell entry into epithelial and endothelial cells, and vaccine results using gB alone have only shown partial success.
This CMV glycoprotein B is derived from the sequence of the BE/14/2011 strain, and is fused with the Fc region of human IgG1 at the C-terminus via a glycine-serine linker. The total calculated MW is 104kDa. The furin cleavage site at AA457-460 has been mutated to prevent proteolytic processing during expression. The cytomegalovirus glycoprotein B protein is expressed in HEK293 cells, and DTT-reduced protein migrates as a band of 140-150kDa.