Rat cytomegalovirus efficiently replicates within dendritic cells and affects both surface marker and gene expression
Dendritic cells (DC) play a crucial role in generating and maintaining antiviral immunity. While DC are implicated in the antiviral defense by inducing T cell responses, they can also become infected by Cytomegalovirus (CMV). CMV is not only highly species-specific but also specialized in evading immune protection, and this specialization is in part due to characteristic genes encoded by a given virus. Here, we investigated whether RCMV can infect XCR1+ DC and if infection of DC alters the expression of cell surface markers and migration behavior. We demonstrate that wild-type RCMV and a _vxcl1 mutant virus infect splenic rat DC ex vivo and identify viral assembly compartments. Replication-competent RCMV reduced XCR1 and MHCII surface expression. Further, gene expression of infected DC was analyzed by single cell RNA-sequencing. RCMV infection reverted a state of DC activation that was induced by DC cultivation. On the functional level, we observed impaired chemotactic activity of infected XCR1+ DC compared to mock treated cells. We therefore speculate that as a result of RCMV infection, DC exhibit diminished XCR1 expression and are thereby inhibited from the lymphocyte crosstalk. Overall design: Dendritic cells were isolated from rat spleens, and RNA extracted immediately (input samples) or after 24 hours of treatment as indicated.