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: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.
Project description:Campylobacter jejuni infection often results in bloody, inflammatory diarrhea, indicating bacterial disruption and invasion of the intestinal epithelium. Whilst C. jejuni infection can be reproduced in vitro using intestinal epithelial cell (IEC) lines, low numbers of bacteria invading IECs do not reflect these clinical symptoms. Performing in vitro assays under atmospheric oxygen conditions is neither optimal for microaerophilic C. jejuni nor reflects the low oxygen environment of the intestinal lumen. A Vertical Diffusion Chamber (VDC) model system creates microaerobic conditions at the apical surface and aerobic conditions at the baso-lateral surface of cultured IECs producing an in vitro system that closely mimics in vivo conditions in the human intestine. Nine-fold increases in interacting and eighty-fold increases in intracellular C. jejuni 11168H wild-type strain bacteria were observed after 24 hours co-culture with Caco-2 IECs in VDCs with microaerobic conditions at the apical surface compared to aerobic conditions. Increased bacterial interaction was matched by an enhanced and directional host innate immune response, particularly an increased baso-lateral secretion of the pro-inflammatory chemokine IL-8. Analysis of the invasive ability of a non-motile C. jejuni 11168H rpoN mutant in the VDC model system indicates that motility is an important factor in the early stages of bacterial invasion. The first report of the use of a VDC model system for studying the interactions of an invasive bacterial pathogen with IECs demonstrates the importance of performing such experiments under conditions that represent the in vivo situation and will allow novel insights into C. jejuni pathogenic mechanisms. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-125]
