Mapping the viral genetic determinants of endothelial cell tropism in human cytomegalovirus.
Endothelial cells are natural sites of infection for human cytomegalovirus (HCMV) and are increasingly recognized to play an important role in viral dissemination, as well as provide access to underlying tissues and organs. However, the viral factors required for endothelial cell tropism are poorly defined. The goals of the project were to develop a system to study endothelial cell infectivity factors in HCMV, and map the viral genetic determinants required for these tropism functions. HCMV infection of primary aortic endothelial cells (AEC) was studied as a means to evaluate aspects relevant to both pathogenesis of acute infection and chronic vascular diseases. A series of HCMV virus strains was screened for endothelial tropism by comparing replication efficiencies on AEC. A virus strain that was efficient for replication (AD169varATCC), and a virus strain that was restricted for replication (Toledo), were selected for further analysis and characterization. We present evidence for a novel HCMV endothelial tropism factor that functioned following viral internalization across the endothelial cell plasma membrane and prior to nuclear entry. This factor may be involved in intracellular transport of the virion capsid-tegument structure. Complementation approaches using pseudotype virus infection of AEC demonstrated that the tropism defective strain could be rescued in trans. This supported the existence of a viral encoded tropism determinant. Using a gain of function approach, endothelial cell infectivity of the non-tropic HCMV strain Toledo was rescued with AD169 cosmid sequences. Tropism-specific viral genetic determinant(s) may be mapped to a region of the AD169 viral DNA encompassing UL48-56.
D001011:Aorta; D002467:Cell Nucleus / Q000821:virology; D002478:Cells, Cultured; D003360:Cosmids / Q000235:genetics; D003587:Cytomegalovirus / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D003586:Cytomegalovirus Infections / Q000821:virology*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000821:virology*; D005347:Fibroblasts; D005816:Genetic Complementation Test; D006801:Humans; D018613:Microscopy, Confocal; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication
D014764:Viral Proteins