Dataset Information

Conjunctival Microbiome-Host Responses Are Associated With Impaired Epithelial Cell Health in Both Early and Late Stages of Trachoma.

ABSTRACT: Background: Trachoma, a neglected tropical disease, is the leading infectious cause of blindness and visual impairment worldwide. Host responses to ocular chlamydial infection resulting in chronic inflammation and expansion of non-chlamydial bacteria are hypothesized risk factors for development of active trachoma and conjunctival scarring. Methods: Ocular swabs from trachoma endemic populations in The Gambia were selected from archived samples for 16S sequencing and host conjunctival gene expression. We recruited children with active trachoma and adults with conjunctival scarring, alongside corresponding matched controls. Findings: In children, active trachoma was not associated with significant changes in the ocular microbiome. Haemophilus enrichment was associated with antimicrobial responses but not linked to active trachoma. Adults with scarring trachoma had a reduced ocular bacterial diversity compared to controls, with increased relative abundance of Corynebacterium. Increased abundance of Corynebacterium in scarring disease was associated with innate immune responses to the microbiota, dominated by altered mucin expression and increased matrix adhesion. Interpretation: In the absence of current Chlamydia trachomatis infection, changes in the ocular microbiome associate with differential expression of antimicrobial and inflammatory genes that impair epithelial cell health. In scarring trachoma, expansion of non-pathogenic bacteria such as Corynebacterium and innate responses are coincident, warranting further investigation of this relationship. Comparisons between active and scarring trachoma supported the relative absence of type-2 interferon responses in scarring, whilst highlighting a common suppression of re-epithelialization with altered epithelial and bacterial adhesion, likely contributing to development of scarring pathology.

SUBMITTER: Pickering H

PROVIDER: S-EPMC6736612 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Conjunctival Microbiome-Host Responses Are Associated With Impaired Epithelial Cell Health in Both Early and Late Stages of Trachoma.

Pickering Harry H Palmer Christine D CD Houghton Joanna J Makalo Pateh P Joof Hassan H Derrick Tamsyn T Goncalves Adriana A Mabey David C W DCW Bailey Robin L RL Burton Matthew J MJ Roberts Chrissy H CH Burr Sarah E SE Holland Martin J MJ

Frontiers in cellular and infection microbiology 20190821

<b>Background:</b> Trachoma, a neglected tropical disease, is the leading infectious cause of blindness and visual impairment worldwide. Host responses to ocular chlamydial infection resulting in chronic inflammation and expansion of non-chlamydial bacteria are hypothesized risk factors for development of active trachoma and conjunctival scarring. <b>Methods:</b> Ocular swabs from trachoma endemic populations in The Gambia were selected from archived samples for 16S sequencing and host conjuncti ...[more]

PMID: 31552195

Similar Datasets

Project description:Trachoma is a poorly understood immuno-fibrogenic disease process, initiated by Chlamydia trachomatis (Ct). Differences in conjunctival gene expression profiles between Ethiopians with trachomatous trichiasis (with (TTI) and without (TT) inflammation) and controls (NC) were investigated to identify relevant host responses. Tarsal conjunctival swab samples were collected for RNA isolation and Ct PCR. Transcriptome-wide microarray experiments were conducted on 42 samples (TTI 13, TT 15, NC14). Specific results were confirmed using multiplex quantitative RT-PCR for 16 mRNA targets in an independent collection of case-control samples: 386 case-control pairs (TTI 244, TT 142, NC 386). The gene expression profiles of cases were consistent with: squamous metaplasia (Keratins, SPRR), pro-inflammatory cytokine production (IL-1β, CXCL5, S100A7) and tissue remodelling (MMP7, MMP9, MMP12, HAS3). There was no difference in the level of IFNG between cases and controls. However, cases had increased INDO, NOS2A, and IL13RA2 and reduced IL13. Ct was detected in 1/772. Cases show evidence of ongoing inflammation and tissue remodelling, which were more marked where clinical inflammation was also present. Significantly, these processes appear to be active in the absence of current Ct infection. There was limited evidence of a TH1 response (INDO, NOS2A) and no association between a TH2 response and cases. The epithelium appears actively involved in late cicatricial stages of trachoma through production of pro-inflammatory factors (IL-1β, CXCL5, S100A7). Longitudinal studies are needed to investigate which aetiological factors and pathways are associated with progressive scarring and whether simply controlling chlamydial infection will halt progression in people with established cicatricial disease. Case - control study. Conjunctival swab samples were collected from people with trachomatous trichiasis with (TTI) and without (TT) clinically visable inflammation compared to normal controls (C). Total RNA extracted and analysed on the Illumina WG-6 platrom. Additional extensive qRT-PCR work done on a large set of case-control pairs.

Project description:Establishing and maintaining beneficial interactions between the host and associated gut microbiota are pivotal requirements for host health. Autophagy is an important catabolic recycling pathway that degrades long-lived proteins and some organelles by lysosome to maintain cellular homeostasis. Although impaired autophagy is thought to be closely correlated with Crohn's disease (CD), the functional role of autophagy in the maintenance of gut microbiota is poorly understood. As autophagy-related 5 (Atg5) is a key gene associated with the extension of the phagophoric membrane in autophagic vesicles, we established a gut-specific Atg5 knockout mouse model, and we found that the disruption of autophagic flux in the intenstinal epithelium cells dramatically altered the composition of the gut microbiota and reduced alpha diversity. Microbial function prediction indicated that the pathway allocated for infectious diseases was enriched in Atg5-/- mice. "Candidatus Arthromitus" and the Pasteurellaceae family were increased in Atg5-/- mice, whereas Akkermansia muciniphila and the Lachnospiraceae family were reduced. Transcriptome analysis revealed that two key inflammatory bowel disease (IBD)-related transcription factors, RORC and TBX21, of host cells were upregulated in Atg5-/- mice, thus elevating the Muc2-related immunological response. The findings suggest that intestinal autophagy plays a vital role in modulating the diversity and composition of gut microbiota.IMPORTANCE The homeostasis of host-microbiota interactions is of great importance to host health. Previous studies demonstrated that disruption of autophagy was linked to inflammatory bowel disease. However, the interaction mechanism of gut microbiota regulated by autophagy was obscure. In an intestinal epithelium-specific autophagy-related 5 (Atg5) knockout mouse model, we observed a significant alteration and decreased diversity in the gut microbiota of Atg5-deficient mice compared with that of wild-type mice. Although the numbers of some organisms (e.g., Akkermansia muciniphila and members of the Lachnospiraceae family) associated with the control of inflammation decreased, those of proinflammationory bacteria (e.g., "Candidatus Arthromitus") and potential pathogens (the Pasteurellaceae family) increased in Atg5-/- mice. Differential gene expression analysis revealed that two key genes, RORC and TBX21, involved in inflammatory bowel disease were upregulated in Atg5-/- mice. Our study suggests that Atg5 deficiency results in an imbalance of the host-microbe interaction and deterioration of the gut microenvironment.

Project description:Ocular infection with Chlamydia trachomatis (trachoma) is the leading cause of blindness that results from infection. Chronic inflammation is believed to drive the scarring process and the progressive blinding disease, however the mechanisms by which this occurs are not completely understood. We hypothesized that Micro RNA (miRNA), as key regulators of genes in inflammatory pathways, are involved in the immunopathogenesis and tissue remodeling observed in trachoma. Conjunctival swabs were collected from a total of 63 individuals resident in trachoma endemic communities in The Gambia, West Africa. MiRNA was extracted from the conjunctival swabs of 23 healthy controls (N), 18 cases with trachomatous scarring (TS) and 22 cases with trachomatous scarring in the presence of clinically significant inflammation (TSI) using Qiagen Allprep DNA/RNA/protein kits. Following reverse transcription and pre-amplification, quantitative RT-PCR was performed using TaqMan Array Human MicroRNA genecards (Av2.0 and Bv3.0) on a 7900HT thermal cycler (Life Technologies, Inc). A total of 754 of the most well characterised unique human miRNA from miRBase (www.mirbase.org/) were screened. Data from each array were uploaded and analysed using the high throughput qPCR package in bioconductor R. Samples with a global miRNA median cycle threshold of 40 were filtered out. A and B cards were analysed separately due to differences in performance of samples on each card. In the A card group 40 samples were normalized and tested: 8 TSI, 16 TS and 16 N. In the B card group 29 samples were normalized and tested: 6 TSI, 13 TS and 10 N. Results were normalized by rank invariant normalization as it reduced the coefficient of variation and increased sample distribution homology more than any other normalization procedure tested. Data in each group were tested for differential expression by Limma. 63 total Samples. In the A card group 40 samples were normalized and tested: 8 TSI, 16 TS and 16 N. In the B card group 29 samples were normalized and tested: 6 TSI, 13 TS and 10 N. Results were normalized by rank invariant normalization as it reduced the coefficient of variation and increased sample distribution homology more than any other normalization procedure tested.

Dataset Information

Conjunctival Microbiome-Host Responses Are Associated With Impaired Epithelial Cell Health in Both Early and Late Stages of Trachoma.

Publications

Conjunctival Microbiome-Host Responses Are Associated With Impaired Epithelial Cell Health in Both Early and Late Stages of Trachoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets