Surveying the Vampire Bat (Desmodus rotundus) Serum Proteome: A Resource for Identifying Immunological Proteins and Detecting Pathogens

Abstract

Bats are increasingly studied as model systems for longevity and as natural hosts for some virulent viruses. Yet the 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. Here, we demonstrate how proteomics can overcome these limitations by using data-independent acquisition-based shotgun proteomics to survey the serum proteome of 17 vampire bats (Desmodus rotundus) from Belize. Using just 2 μL of sample and relatively short separations of undepleted serum digests, we identified 361 proteins across 5 orders of magnitude. Levels of immunological proteins in vampire bat serum were then compared to human plasma via published databases. Of particular interest were antiviral and antibacterial components, circulating 20S proteasome complex and proteins involved in redox activity. Lastly, we used known virus proteomes to putatively 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. 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.

Gene losses in the common vampire bat illuminate molecular adaptations to blood feeding

“…In addition to enhanced excretion, a previous study found that vampire bats limit gastrointestinal iron absorption by increased expression of hepcidin, a factor that inhibits intestinal iron absorption 47 . Furthermore, iron-storing ferritin genes are expanded in the common vampire bat genome 21 and these bats have high levels of iron-binding RFESD in the serum proteome 54 . Thus, limited iron absorption (mediated by increased hepcidin expression), a higher capacity for iron storage (mediated by ferritin and RFESD), and enhanced iron excretion (mediated by inactivating the inhibitory factor REP15) help vampire bats to cope with their iron-rich diet.…”

Gene losses in the common vampire bat illuminate molecular adaptations to blood feeding

“…In addition to enhanced excretion, a previous study found that vampire bats limit gastrointestinal iron absorption by increased expression of hepcidin, a factor that inhibits intestinal iron absorption ( 28 ). Furthermore, iron-storing ferritin genes are expanded in the common vampire bat genome ( 17 ), and these bats have high levels of iron-binding RFESD (Rieske Fe-S domain containing) in the serum proteome ( 34 ). Thus, limited iron absorption (mediated by increased hepcidin expression), a higher capacity for iron storage (mediated by ferritin and RFESD), and enhanced iron excretion (mediated by inactivating the inhibitory factor REP15 ) help vampire bats cope with their iron-rich diet.…”

Host gene expression in wildlife disease: making sense of species‐level responses

“…Looking beyond gene regulation as the primary molecular process of interest, genomic (Blanchong et al, 2016;Longo et al, 2014), epigenomic (Bandyopadhaya et al, 2016;Garcia et al, 2019), proteomic (Heck & Neely, 2020;Horvatić et al, 2016;Neely et al, 2021), and metabolomic methods are also highly relevant to the study of host-pathogen interactions and wildlife disease outcome. For example, genomic methods commonly used to parse organismal adaptation to environmental stressors, such as genome-wide association mapping and selection scans (Brennan et al, 2018;Elbers et al, 2018;Reid et al, 2016), can identify loci that are under selection due to pathogen pressure (Alves et al, 2019;Auteri & Knowles, 2020;Gignoux-Wolfsohn et al, 2021;Gupta et al, 2020;Schwensow et al, 2020).…”