Herpes simplex virus type 1 infection of endothelium reduces collagen and fibronectin synthesis

Protein synthesis was assessed in virus-infected and -uninfected cultures of bovine aorta endothelial cells by following the incorporation of [14C]proline into nondialyzable protein and by use of an ELISA assay. Monolayers were infected at confluency by incubating with herpes simplex virus type I at a multiplicity of infection (ratio of virus to cells) of 1.0, 1 hour prior to the introduction of the [14C]proline. Samples were taken from infected and uninfected cultures at various time points postinfection from both medium and cell layer fractions and analyzed for total 14C-labeled protein, 14C-labeled collagen, and 14C-labeled fibronectin. Medium proteins were analyzed by polyacrylamide gel electrophoresis, gel filtration, and electroimmunoblotting. No change was detected in total [14C] incorporation into nondialyzable protein in infected compared with uninfected endothelial cells; however, there was a significant decrease in the synthesis of collagen and fibronectin in infected cultures. The hydroxy[14C]proline content of fractionated medium proteins showed no significant differences between infected and uninfected cultures; therefore, the decrease in collagen synthesis cannot be explained by increased collagen degradation. These data suggest that infection of bovine endothelial cells causes a reduction in the synthesis of collagen and fibronectin.