Project description:Influenza A virus (IAV) pandemics result from interspecies transmission events within the avian reservoir and further into mammals including humans. Investigating the molecular basis for virus–host interactions enabling this process is vital to understand zoonotic IAV spread. Receptor incompatibility has been suggested to limit zoonotic IAV transmission from the wild bird reservoir as well as between different bird species. Using glycoproteomics, we have studied the repertoires of expressed glycan structures with focus on putative receptors for IAV in mallards, chickens and tufted ducks; three bird species with different roles in the zoonotic ecology of IAV. The methodology used could not only pinpoint specific glycan structures to the specific glycosylation sites of identified glycoproteins but could also be used to successfully discriminate α2,3- from α2,6-linked terminal sialic acids by careful analysis of oxonium ions released from glycopeptides during MS/MS (MS2), and MS/MS/MS (MS3). Our analysis clearly demonstrated that all three bird species can produce complex α2,3 and α2,6-linked Neu5Ac N-glycans including α2,3-linked sialyl Lewis structures, as well as both N- and O- glycans terminated with both α2,3 and α2,6-linked Neu5Ac. Furthermore, we reveal many similarities in the repertoires of expressed receptors both between the bird species investigated and to previously published data from pigs and humans. Our findings of sialylated glycan structures previously anticipated to be mammalian specific in all three bird species have major implications for our understanding of the role of receptor incompatibility in interspecies transmission of IAV.
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.
2023-02-20 | GSE204665 | GEO
Project description:Fecal virome of Bradypus crinitus