Different but Not Unique: Deciphering the Immunity of the Jamaican Fruit Bat by Studying Its Viriome

Abstract

A specialized and fine-tuned immune response of bats upon infection with viruses is believed to provide the basis for a "friendly" coexistence with these pathogens, which are often lethal for humans and other mammals. First insights into the immunity of bats suggest that bats have evolved to possess their own strategies to cope with viral infections. Yet, the molecular details for this innocuous coexistence remain poorly described and bat infection models are the key to unveiling these secrets. In Jamaican fruit bats (Artibeus jamaicensis), a New World bat species, infection experiments with its (putative) natural viral pathogens Tacaribe virus (TCRV), rabies virus (RABV), and the bat influenza A virus (IAV) H18N11, have contributed to an accurate, though still incomplete, representation of the bat-imposed immunity. Surprisingly, though many aspects of their innate and adaptive immune responses differ from that of the human immune response, such as a contraction of the IFN locus and reduction in the number of immunoglobulin subclasses, variations could also be observed between Jamaican fruit bats and other bat species.

Keywords: Artibeus jamaicensis; Tacaribe virus (TCRV); bat immunity; bat infection studies; bat influenza A virus (IAV) H18N11; bat viruses; rabies virus (RABV).

Figure 1

IFN genes in humans, mice and bats. (A) Schematic representation of the type I IFN gene loci in humans, mice, R. aegyptiacus, P. alecto, and A. jamaicensis. Although R. aegyptiacus exhibits an expansion of the type I IFN genes, both P. alecto and A. jamaicensis demonstrate a contraction compared to humans and mice. Genes encoding IFN-α are shown in orange, IFN-β in purple, IFN-δ in yellow, IFN-ε in green, IFN-ζ in grey, IFN-κ in red, and IFN-ω in blue. (B) Number of the different type I IFN members found in humans, mice, R. aegyptiacus, P. alecto, P. vampyrus, M. lucifugus, and A. jamaicensis. (C) Comparison of the number of genes coding for functional type I, type II, and type III IFN genes for each of the indicated species. Notably, genes encoding IFN-λ have not yet been identified in A. jamaicensis.