Project description:Bats are the natural reservoir host for a number of zoonotic viruses, including Hendra virus (HeV) which causes severe clinical disease in humans and other susceptible hosts. Our understanding of the ability of bats to avoid clinical disease following infection with viruses such as HeV has come predominantly from in vitro studies focusing on innate immunity. Information on the early host response to infection in vivo is lacking and there is no comparative data on responses in bats compared with animals that succumb to disease. In this study, we examined the sites of HeV replication and the immune response of infected Australian black flying foxes and ferrets at 12, 36 and 60 hours post exposure (hpe). Viral antigen was detected at 60 hpe in bats and was confined to the lungs whereas in ferrets there was evidence of widespread viral RNA and antigen by 60 hpe. The mRNA expression of IFNs revealed antagonism of type I and III IFNs and a significant increase in the chemokine, CXCL10, in bat lung and spleen following infection. In ferrets, there was an increase in the transcription of IFN in the spleen following infection. Liquid chromatography tandem mass spectrometry (LC-MS/MS) on lung tissue from bats and ferrets was performed at 0 and 60 hpe to obtain a global overview of viral and host protein expression. Gene Ontology (GO) enrichment analysis of immune pathways revealed that six pathways, including a number involved in cell mediated immunity were more likely to be upregulated in bat lung compared to ferrets. GO analysis also revealed enrichment of the type I IFN signaling pathway in bats and ferrets. This study contributes important comparative data on differences in the dissemination of HeV and the first to provide comparative data on the activation of immune pathways in bats and ferrets in vivo following infection.
Project description:To examine the fundamental immunity in bats, particularly the status of their innate immune system in the basal healthy state, we profile Pteropus alecto bat tissue with Deep NGS coverage. This is coupled to a paired experiment where bats were stimulated in vivo with various PRR ligands to activate immune pathways.
Project description:To examine the fundamental immunity in bats, particularly the status of their innate immune system in the basal healthy state, we profile Eonycteris spelaea bat tissue with Deep NGS coverage. This is coupled to a paired experiment where bats were stimulated in vivo with various PRR ligands to activate immune pathways.
Project description:Ulcerative colitis is a chronic inflammatory disorder for which a definitive cure is still missing. This is characterized by an overwhelming inflammatory milieu in the colonic tract where a composite set of immune and non-immune cells orchestrate its pathogenesis. Over the last years, a growing body of evidence has been pinpointing gut virome dysbiosis as underlying its progression. Nonetheless, its role during the early phases of chronic inflammation is far from being fully defined. Here we show the gut virome-associated Hepatitis B virus protein X, most likely acquired after an event of zoonotic spillover, to be associated with the early stages of ulcerative colitis and to induce colonic inflammation in mice. It acts as a transcriptional regulator in epithelial cells, provoking barrier leakage and altering mucosal immunity at the level of both innate and adaptive immunity. This study paves the way to the comprehension of the aetiopathogenesis of intestinal inflammation and encourages further investigations of the virome as a trigger also in other scenarios. Moreover, it provides a brand-new standpoint that looks at the virome as a target for tailored treatments, blocking the early phases of chronic inflammation and possibly leading to better disease management.
Project description:Bats harbour various viruses without severe symptoms and act as natural reservoirs. This tolerance of bats toward viral infections is assumed to be originated from the uniqueness of their immune system. However, how the innate immune response varies between primates and bats remains unclear. To illuminate differences in innate immune responses among animal species, we performed a comparative single-cell RNA-sequencing analysis on peripheral blood mononuclear cells (PBMCs) from four species including Egyptian fruit bats inoculated with various infectious stimuli.
Project description:Hearing mediates many behaviors critical for survival in echolocating bats, including foraging and navigation. Although most mammals are susceptible to progressive age-related hearing loss, the evolution of biosonar, which requires the ability to hear low-intensity echoes from outgoing sonar signals, may have selected against the development of hearing deficits in bats. Many echolocating bats exhibit exceptional longevity and rely on acoustic behaviors for survival to old age; however relatively little is known about the aging bat auditory system. In this study, we used DNA methylation to estimate the ages of wild-caught big brown bats (Eptesicus fuscus) and measured hearing sensitivity in young and aging bats using auditory brainstem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs). We found no evidence for hearing deficits in bats up to 12.5 years of age, demonstrated by comparable thresholds and similar ABR and DPOAE amplitudes across age groups. We additionally found no significant histological evidence for cochlear aging, with similar hair cell counts, afferent, and efferent innervation patterns in young and aging bats. Here we demonstrate that big brown bats show minimal evidence for age-related hearing loss and therefore represent informative models for investigating mechanisms that may preserve hearing function over a long lifetime.