Expression in CD169 Macrophages is Important for Strong Immune Response after Vaccination with VSV-EBOV.

Ebola virus epidemics can be effectively limited by the VSV-EBOV vaccine (Ervebo) due to its rapid protection abilities; however, side effects prevent the broad use of VSV-EBOV as vaccine. Mechanisms explaining the efficient immune activation after single injection with the VSV-EBOV vaccine remain mainly unknown. Here, using the clinically available VSV-EBOV vaccine (Ervebo), we show that the cell-intrinsic expression of the interferon-inhibitor in CD169 macrophages is one important factor modulating the anti-Ebola virus immune response. The absence of in CD169 macrophages led to the reduced local replication of VSV-EBOV followed by a diminished innate as well as adaptive immune response. In line, -Cre x mice showed reduced innate and adaptive immune responses against the VSV wildtype strain and died quickly after infection, suggesting that a lack of makes mice more susceptible to the side effects of the VSV vector. In conclusion, our study shows that expression in CD169 macrophages is one important surrogate marker for effective vaccination against VSV-EBOV, and probably other VSV-based vaccines also.