A DUAL ROLE FOR ENDOTHELIAL-CELLS IN CYTOMEGALOVIRUS-INFECTION - A STUDY OF CYTOMEGALOVIRUS-INFECTION IN A SERIES OF RAT ENDOTHELIAL-CELL LINES

Several clinical findings point to the involvement of microvascular en dothelial cells in cytomegalovirus-related pathology. In this study th e interactions of cytomegalovirus (CMV) with microvascular endothelial cells was investigated in an in vitro rat model. A series of rat endo thelial cell lines, considered representative for the heterogeneity of heart microvascular endothelium in vivo, were infected with rat CMV ( RCMV). The course of infection and production of infectious virus were examined using immunofluorescence staining and plaque titration assay s, and was compared with infection of fully permissive rat fibroblasts . These endothelial cell lines diplayed differences in susceptibility to CMV infection. Two endothelial cell lines (RHEC 50 and 191) were pr actically non-permissive, while four endothelial cell lines (RHEC 3, 1 0, 11 and 116) were partly permissive for CMV infection. In contrast t o CMV infection in fibroblasts, only limited infection of the permissi ve endotheliaI cell lines was observed without spreading of CMV infect ion through the monolayer, although infectious virus was produced. Det achment of infected endotheliaI cells and recovery of the monolayer wi th time was observed. The detached endothelial cells were able to tran smit CMV infection to fibroblast monolayers, but not to endothelial mo nolayers, Our in vitro results demonstrate differences in permissivene ss for RCMV between the series of rat endothelial cell lines, which is suggestive for endothelial heterogeneity to CMV infection in vivo. Ou r findings indicate that endotheliaI cells are relatively resistant to CMV infection and that, upon infection, the endothelial monolayer may dispose of the virus via detachment of the infected cells. This point s to a dual role for the endothelium in CMV infection in vivo: a barri er for CMV infection (by the endothelial monolayer) on the one hand an d spreading of CMV infection (by detached infected cells) on the other hand. Copyright (C) 1996 Elsevier Science B.V.