Project description:Bats can harbor many pathogens without showing disease. However, the mechanisms by which bats resolve these infections or limit pathology remain unclear. To illuminate the bat immune response to coronaviruses, viruses with high public health significance, we will use serum proteomics to assess broad differences in immune proteins of uninfected and infected vampire bats (Desmodus rotundus). In contrast to global profiling techniques of blood such as transcriptomics, proteomics provides a unique perspective into immunology, as the serum proteome includes proteins from not only blood but also those secreted from proximal tissues. Here, we expand our recent work on the serum proteome of wild vampire bats (Desmodus rotundus) to better understand CoV pathogenesis. Across 19 bats sampled in 2019 in northern Belize with available sera, we detected CoVs in oral or rectal swabs from four individuals. We used data independent acquisition-based mass spectrometry to profile and compare the undepleted serum proteome of these 19 bats. These results will provide much needed insight into changes in the bat serum proteome in response to coronavirus infection.
Project description:It is well established that the pathogenicity and pathology of rabies virus (RABV) varies according to the variant, but the exact mechanism for this is still not completely known. In this study, the gene expression profile in brains of mice infected with virus isolated from a human case of dog rabies (V2) or vampire bat-acquired rabies (V3) were analyzed in experimental condition. In total, 138 array probes associated with 120 genes were differentially expressed between mice inoculated with V2 and the control mice at day 10 post-inoculation. A single probe corresponding to an unannotated gene was identified in V3 versus control mice. Gene ontology (GO) analysis revealed that all of the genes up-regulated in mice inoculated with V2 were involved in the biological process of immune defense against pathogens. Although both variants being considered pathogenic, inoculation in exactly same condition generated particular results regarding gene expression, more likely to differences in pathogenesis between dog and bat-related variants, already considered in other studies. This study was the first to demonstrate the global gene expression in experimental rabies infection due to V3 wild-type rabies virus, which reservoir is the vampire bat Desmodus rotundus, an important transmitter of rabies for humans and production animals in Latin America.
Project description:Bats are increasingly studied as model systems for longevity and as natural hosts to some virulent viruses. Yet our ability to characterize immune mechanisms of viral tolerance and to quantify infection dynamics in wild bats is often limited by small sample volumes and few species-specific reagents. To address this, we demonstrate how proteomics can overcome these limitations by using data-independent acquisition-based shotgun proteomics (i.e., bottom-up proteomics) to survey the serum proteome of 17 vampire bats (Desmodus rotundus) from Belize. We focused this work on vampire bats, a species that has an obligate diet of blood and feeds on prey as diverse as sea lions, tapirs, livestock, and even humans, providing numerous opportunities for transmission of viruses (e.g., rabies virus, adenovirus, herpesvirus) to and from these recipient hosts. Using just 2 μL of sample and relatively short separations of undepleted serum digests, we identified 361 proteins across five orders of magnitude. We also used known bat virus proteomes to identify Rh186 from Macacine herpesvirus 3 and ORF1a from Middle East respiratory syndrome-related coronavirus, indicating that mass spectrometry-based techniques show promise for pathogen detection. Our results demonstrate the feasibility and capabilities of serum proteomic analyses in wild bats, including possibilities to simultaneously detect host immunological components and viral infection as well as to establish preliminary ranges of vampire bat proteins for comparison with other mammalian blood proteomes. Overall, these results can be used to design targeted mass-spectrometry assays to quantify immunological markers and detect pathogens. More broadly, our findings also highlight the application of proteomics in advancing wildlife immunology and pathogen surveillance.