Proteomic comparison of Marburg and Kasokero virus infection in natural host Egyptian rousette bat reveals distinct antiviral pathways

Bats serve as reservoir hosts for various zoonotic viruses, yet the molecular mechanisms allowing viral persistence without causing noticeable illness are not fully understood. The Egyptian rousette bat (ERB) is the only known natural reservoir of Marburg virus (MARV) and a crucial host in the enzootic cycle of Kasokero virus (KASV).

This study utilized serial cross-sectional serum proteomics in conjunction with tissue-specific viral kinetics to examine systemic host responses to experimental MARV and KASV infections in captive ERBs.

Over 16% of the detected proteins (67 out of 419) were exclusively found in infected animals. However, traditional acute inflammatory markers typically associated with pathology in other susceptible hosts, such as humans and non-human primates, were notably absent. The analysis revealed both shared and virus-specific responses, with MARV infection leading to limited and transient perturbations, while KASV infection triggered a broader and more sustained activation of complement, lectin pathway, and hepatometabolic proteins.

Network-based analysis uncovered coordinated proteasome modules, including circulating immunoproteasome complexes. This suggests that enhanced antigen-processing capacity is a feature of these virus-host dynamics. In summary, these findings shed light on how ERBs mount structured, virus-dependent systemic responses, providing valuable insights into the mechanisms underlying viral infection in natural reservoir hosts.