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. Dendritic cells were isolated from rat spleens, and RNA extracted immediately (input samples) or after 24 hours of treatment as indicated.