Project description:Bats harbor highly virulent viruses that can infect other mammals, including humans, posing questions about their immune tolerance mechanisms. Bat cells employ multiple strategies to limit virus replication and virus-induced immunopathology, but the coexistence of bats and fatal viruses remains poorly understood. Here, we investigated the antiviral RNA interference (RNAi) pathway in bat cells and discovered that they have an enhanced antiviral RNAi response, producing canonical viral small interfering RNAs (vsiRNAs) upon Sindbis virus (SINV) infection that were missing in human cells. Disruption of Dicer function resulted in increased viral load for three different RNA viruses in bat cells, indicating an interferon-independent antiviral pathway. Furthermore, our findings reveal the simultaneous engagement of Dicer and pattern-recognition receptors (PRRs), such as retinoic acid-inducible gene I (RIG-I), with double-stranded RNA, suggesting that Dicer attenuates the interferon response initiation in bat cells. These insights advance our comprehension of the distinctive strategies bats employ to coexist with viruses.
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:Bats harbor high-impact zoonotic viruses in absence of clinical disease, which has been recently associated with unique features of their immune system. They seem to restrict inflammation and possibly limit disease manifestation to a minimum. In-depth characterization of cellular immunity in bats is yet largely missing, and imprinting of age and development on immune cell compartments remains unexplored. We employed single-cell transcriptomics and established immunostaining panels to investigate the immune cell populations peripheral blood for juvenile and adult Egyptian Rousette bats (ERB).
Project description:Bats harbor highly virulent viruses that can infect other mammals, including humans, posing questions about their immune tolerance mechanisms. Bat cells employ multiple strategies to limit virus replication and virus-induced immunopathology, but the coexistence of bats and fatal viruses remains poorly understood. Here, we investigated the antiviral RNA interference (RNAi) pathway in bat cells and discovered that they have an enhanced antiviral RNAi response, producing canonical viral small interfering RNAs (vsiRNAs) upon Sindbis virus (SINV) infection that were missing in human cells. Disruption of Dicer function resulted in increased viral load for three different RNA viruses in bat cells, indicating an interferon-independent antiviral pathway. Furthermore, our findings reveal the simultaneous engagement of Dicer and pattern-recognition receptors (PRRs), such as retinoic acid-inducible gene I (RIG-I), with double-stranded RNA, suggesting that Dicer attenuates the interferon response initiation in bat cells. These insights advance our comprehension of the distinctive strategies bats employ to coexist with viruses.
Project description:SARS-CoV-2 has caused the largest known coronavirus pandemic and is believed to have emerged from insectivorous bats. Little is known about the evolution of these viruses in their reservoir bat species. In this study, we investigated SARS-CoV-2-host interaction using human and bat cells. Bat cells mount a robust and early antiviral response but elicit a dampened pro-inflammatory response upon SARS-CoV-2 infection compared to human cells. Furthermore, an inactivating R685P mutation within the furin cleavage site (FCS) of the SARS-CoV-2 spike protein was naturally selected for in infected bat cells. Taken together, our data demonstrate that insectivorous bat cells have evolved a differential antiviral immune response against SARS-CoV-2 infection, likely to mitigate immunopathology that is observed in humans. Our study sheds light on the evolution of sarbecoviruses in bats and extends molecular evidence to data from field studies that have demonstrated that SARS-CoV-2-related viruses in wild-caught bats lack an intact FCS.
Project description:Bats are a widespread group of mammals thought to host a variety of viruses and other disease agents. Here we performed RNA-sequencing on Artibeus jamaicensis infected with the New World arenavirus, Tacaribe Virus, to generate an extensive bat transcriptome.
Project description:Bats are natural hosts for a wide diversity of viruses. While many of these viruses are highly pathogenic in humans, most do not appear to cause major symptoms in bats. These modern bat-specific characteristics are the result of past virus-host (co)evolution and virus-driven host adaptations. Innate immunity is the first line of defense against viruses in mammals, we aim at characterizing bat innate immunity in response to viruses. Using genome-wide and gene candidate evolutionary analyses, we found that many bat antiviral genes have undergone multiple duplication events in a lineage-specific manner, specifically in the Myotis bat lineage. We focus on Myotis yumanensis as a model in the Myotis lineage. We performed transcriptomic analyses and observed the upregulation of most mammalian genes implicated in the different steps of the innate immune response from sensing to interferon-stimulated genes (ISGs), showing the conservation of the core innate immunity. Our study will contribute to identifying adaptations that shaped bat innate immunity. These adaptations may contribute to the bat-virus specificity and influence viral emergence to another mammalian host
Project description:Bats are natural reservoirs for a large range of emerging viruses that cause lethal diseases in humans and domestic animals, but remain asymptomatic in bats. Understanding the host-pathogen interactions relies on the availability of relevant models including susceptible cells, derived from viral target tissues. To obtain bat cell types pertinent for the study of viral infection, we applied somatic reprogramming approach to Pteropus primary cells as initial substrates. Using the novel combination of three transcription factors: ESRRB, CDX2 and c-MYC, we generated reprogrammed cells exhibiting stem cells features.