Project description:Small RNAs are emerging as important molecules for cross-species communication. Thanks to available and affordable sequencing technologies it is now possible to sequence small RNAs (sRNA-Seq) present in samples of interacting organisms. A first step when analyzing sRNA-Seq of two interacting species is to determine which sequences are being produced by which organism. Due to their small size (18-30), small RNAs could easily map to both host and parasite genomes. Here we produced data for Mus musculus intestinal epithelial cells treated with Extracellular Vesicles (EV) produced by the parasitic nematode Heligmosomoides bakeri.
Project description:Inflammatory injury to the intestine triggers a reprogramming of the intestinal epithelium to a fetal-like state, facilitating rapid restoration of the epithelial barrier. Although the intestinal microbiota is a key modulator of inflammation, its role in driving epithelial fetal-like reversion and promoting restitution remains unclear. Using irradiation (IR) injury as a model for small intestinal epithelium restitution, we found that the intestinal microbiota accelerated epithelial restitution by amplifying a repair-associated inflammatory response that promoted the emergence of fetal-like intestinal epithelial cells (IECs), marked by Ly6a and Clu. NOD2, the strongest genetic link to the development of Crohn’s disease, was expressed in fetal-like IECs following injury. Notably, stimulation of NOD2 by its peptidoglycan ligand in an ileal organoid model potentiated an inflammatory gene signature characterized by interferon (IFN) signaling, coinciding with enterocyte recovery. NOD2 deficiency exacerbated epithelial apoptosis following IR injury, while epithelial-specific NOD2 signaling promoted the emergence of fetal-like IECs and enhanced epithelial proliferation. Together, these results identify a critical role for microbiota and microbial sensing by NOD2 in controlling the fate of fetal-like IECs following injury, thereby contributing to the protective effect of this microbial sensor during intestinal inflammation.
Project description:MARTX toxins are large single polypeptide bacterial toxins that translocate multiple cytotoxic and functionally independent effector domains into the cytosol of a target eukaryotic cell. Pandemic Vibrio cholerae El Tor O1 strains secrete a MARTX toxin with three effector domains — the actin crosslinking domain (ACD), the Rho inactivation domain (RID), and the alpha/beta-hydrolase domain (ABH) — to regulate innate immunity and enhance colonization. The goal of this study was to compare changes in the transcriptome of human intestinal epithelial cells (IECs) treated with V. cholerae modified to secret a toxin with only one effector domain to the transcriptome of cells treated with V. cholerae secreting the wild type MARTX toxin that delivers all three effector domains simultaneously. We demonstrate that when all three effectors are delivered there is no change in transcriptional response of IECs compared to untreated cells. However, when only ACD is delivered, transcriptional profiling revealed a significant proinflammatory response is activated. These data suggests that V. cholerae may utilize co-delivery of RID and/or ABH to silence the intestinal immune response to ACD activity. These data provide insight into how the V. cholerae MARTX toxin effector domains function together to alter the innate immune response of IECs during bacterial infection.
