Adipose tissue is a target for Ebola virus, having systemic implications in metabolism and stress during acute and prolonged infection

The geographical range of Ebola virus (EBOV) outbreaks overlaps with the habitat of diverse ecosystems that are home to many potential reservoir species. Although researchers have discovered EBOV viral RNA and serological evidence in different rodents and bats, live virus has not been isolated from any species. Identifying the host reservoir is only the first of many challenges; predicting and preventing spillover events requires research on population distribution, ecology, host metabolism and immunology. The EBOV field is clearly missing critical knowledge about where the virus hides, either from being overlooked during sampling, being rarely encountered and/or specific conditions are required that regulate viral expression. To this end, we investigated EBOV infection in cryptic tissues in vitro and in vivo and found that adipose tissue (AT), plays a significant role in both acute and prolonged infections. AT is a dynamic endocrine organ that helps regulate homeostasis, and coordinating energy metabolism, as well as neuroendocrine and immune functions; however, its role in infectious disease has been less thoroughly studied. To assess the role of AT during EBOV infection, we used immortalized and primary brown adipose cultures in vitro as well as developed in vivo reservoir models using Golden Syrian hamsters (Mesocricetus auratus) and Deer mice (Peromyscus maniculatus). Wild type EBOV infected rodents showed no clinical signs of disease nor detectable virus in commonly sampled tissues and swabs. However, EBOV RNA and viral antigen was detected in AT up to 56 days post infection. Furthermore, we tested numerous metabolic agents and found that administration of epinephrine significantly increased viral replication in adipose depots and spillover into the blood. These results show the importance of AT in long-term infection and how the metabolism of this tissue may play a role in viral transmission between reservoir species and/or zoonotic spillover events. Addition