The Vampire Bat Virome: Evolutionary Implications in an Immunological Context

• Applicant: Professor Alex Greenwood, Ph.D.
• Subject Area: Evolution, Anthropology ; Virology
• Term: from 2014 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258361275

Surveillance of wildlife is an important strategy for detecting viruses with zoonotic potential that represent a health risk both for humans and for other animals. Several viruses have been recently characterized in different bat species and many of these have medical importance, such as SARS. However, viral surveillance studies have been carried out only in insectivorous or fruit eating bats and have been mainly restricted on describing absence or presence of viruses. Little is known about the viral epidemiology and diversity among the common vampire bat, Desmodus rotundus. The vampire bat feeding behavior involves close body contact with its food source, which could provide a direct route of pathogen transmission via exchanged body fluids; therefore, it represents a novel and important study model. Molecular and phylogenetic analysis suggests host virus co evolution and frequent cross species transmission events. It is known that interaction between epidemiological and evolutionary processes may drive a pathogens spatiotemporal incidence within a host or population. Reversely, historical pathogen interactions that have led to co adaptation in a host may be detected by molecular signatures that have contributed in the shaping of the structural and genetic diversity of immune receptors. In mammalian species, viruses are first sensed by the innate immune system by pattern recognition receptors, PRRs, such as Toll like receptors, TLRs. TLRs phylogenies reflect the natural history of a species, but may also define immune sub populations. A correlation between SNPs and sites evolving under selective pressure in TLRs and specific infections in wildlife has been detected, showning that genetic variation at TLRs is largely influenced by pathogen interactions. Thus, TLRs are an excellent model for viral host phylodynamic studies. We hypothesize that vampire bats carry a repertoire of non canonical viral strains with zoonotic potential. Moreover, molecular signatures will be detected both in viral taxa and in the viral sensing innate immune TLRs, revealing specific viral host interaction co evolutionary patterns. Therefore, the aims of this study are to uncover the virome of a sample population of free ranging vampire bats from Mexico and to characterize the vampire bat TLRs involved in viral sensing. Further, we will integrate the data in a phylodynamic context, by using molecular evolutionary approaches. The proposed project intends to make innovating contributions to the fields of emerging zoonotic diseases and wildlife surveillance using state of the art technology. This work will be of direct benefit both to Germany and to our collaborating country Mexico, as it involves bidirectional scientific exchange and the knowledge gained could be of significance to public and veterinary health as well as conservation biology research both in Latin America and in Europe.

• DFG Programme: Research Grants