HCMV

The human cytomegalovirus (HCMV) is a widespread pathogen responsible for generally asymptomatic and persistent infections in healthy people. HCMV is a member of the betaherpesvirinae subfamily, whose virion structure, kinetics of viral gene expression and persistence for the lifetime of their host are typical of other herpesviruses. However, its strict species specificity, salivary gland tropism, and slow growth in cell cultures differentiate it as the prototype betaherpesvirus.

The virion of HCMV consists of a 100-nm diameter icosahedral nucleocapsid containing a 230-kb, double-stranded linear DNA genome surrounded by a proteinaceous layer defined as the tegument or matrix, which, in turn, is enclosed by a lipid bilayer containing a large number of viral glycoproteins. The mature virion particle is 150–200 nm in diameter.

The HCMV genome is the largest of all herpesviruses and has a high G+C content. Like that of herpes simplex virus-1, it contains an arrangement of unique long, unique short, and repeat regions. Since each long and short region can be oriented in either direction, four genome isomers are produced in viral progeny (Class E structure).

The HCMV causes disease and death in immunocompromised patients including organ transplant recipients, individuals with cancer and HIV-infected patients.