Dataset Information

Densovirus crosses the insect midgut by transcytosis and disturbs the epithelial barrier function.

ABSTRACT: Densoviruses are parvoviruses that can be lethal for insects of different orders at larval stages. Although the horizontal transmission mechanisms are poorly known, densoviral pathogenesis usually starts with the ingestion of contaminated food by the host. Depending on the virus, this leads to replication restricted to the midgut or excluding it. In both cases the success of infection depends on the virus capacity to enter the intestinal epithelium. Using the Junonia coenia densovirus (JcDNV) as the prototype virus and the lepidopteran host Spodoptera frugiperda as an interaction model, we focused on the early mechanisms of infection during which JcDNV crosses the intestinal epithelium to reach and replicate in underlying target tissues. We studied the kinetics of interaction of JcDNV with the midgut epithelium and the transport mechanisms involved. Using several approaches, in vivo, ex vivo, and in vitro, at molecular and cellular levels, we show that JcDNV is specifically internalized by endocytosis in absorptive cells and then crosses the epithelium by transcytosis. As a consequence, viral entry disturbs the midgut function. Finally, we showed that four mutations on the capsid of JcDNV affect specific recognition by the epithelial cells but not their binding.

SUBMITTER: Wang Y

PROVIDER: S-EPMC3807927 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Densovirus crosses the insect midgut by transcytosis and disturbs the epithelial barrier function.

Wang Y Y Gosselin Grenet A S AS Castelli I I Cermenati G G Ravallec M M Fiandra L L Debaisieux S S Multeau C C Lautredou N N Dupressoir T T Li Y Y Casartelli M M Ogliastro M M

Journal of virology 20130911 22

Densoviruses are parvoviruses that can be lethal for insects of different orders at larval stages. Although the horizontal transmission mechanisms are poorly known, densoviral pathogenesis usually starts with the ingestion of contaminated food by the host. Depending on the virus, this leads to replication restricted to the midgut or excluding it. In both cases the success of infection depends on the virus capacity to enter the intestinal epithelium. Using the Junonia coenia densovirus (JcDNV) as ...[more]

PMID: 24027326

Similar Datasets

Project description:Introduction Disruption of the epithelial barrier can induce eosinophilic esophagitis (EoE), a TH2-mediated food- and aeroallergen associated chronic inflammatory disease 1, 2. The expression of IL-20 subfamily cytokines, IL-19, IL-20 and IL-24, is increased in TH2-mediated diseases, yet their function in EoE is unknown. Methods Combining RNA-sequencing (RNA-seq) and proteome analysis, we have examined the effects of the IL-20 subfamily on esophageal epithelial cells using patient-derived organoids and an experimental EoE mouse model. Results When stimulated with IL-20 subfamily cytokines patient-derived esophageal organoids showed decreased expression of Filaggrin (FLG) and Filaggrin 2 (FLG2) responsible for epithelial cornification. In agreement, EoE patients with active inflammation showed elevated IL-20 subfamily cytokines and decreased FLG and FLG2 expression. Topical corticosteroid treatment in EoE patients restored filaggrin expression, while reducing IL-20 subfamily cytokines. Abolishment of IL-20 subfamily signalling in Il20R2-/- animals attenuated experimental EoE in an OVA-induced mouse model. In the esophageal keratinocyte cell line, KYSE-180, we identified IL-20 subfamily-induced STAT3 and MAPK (ERK1/2) pathway activation. However, Stat3fl/flKrt5cre mice with an epithelium specific deletion of Stat3 developed exacerbated experimental EoE with a pronounced decrease of Flg2. In line, combined stimulation of patient-derived esophageal organoids with IL-20 subfamily cytokines and pharmacological inhibition of STAT3 resulted in aggravated decrease of FLG and FLG2. In addition, pharmacological STAT3 inhibition resulted in reduced transepithelial electrical resistance (TEER) and increased macromolecular flux in patient-derived air liquid interface (ALI) cultures. Whereas, inhibition of the MAPK (ERK1/2) pathway hampered IL-20 subfamily induced TEER reduction and paracellular flux increment. Finally, MAPK (ERK1/2) inhibitor treatment reduced infiltrating CD45+ immune cells in the esophagus and alleviated experimental EoE in mice. Conclusion We discovered a novel regulatory function of the IL-20 subfamily for epithelial barrier integrity. Aberrant IL-20 subfamily signaling disturbs the epithelial barrier function, while abrogation of IL-20 subfamily and ERK1/2 signaling restores epithelial integrity and attenuates experimental EoE. Therefore, we propose that targeting the IL-20 subfamily pathway could present a novel therapeutic strategy for EoE treatment.

Project description:BackgroundAlteration of commensal bacterial composition is associated with many inflammatory diseases. However, few studies have pinpointed the specific bacterial genes that may suppress host immune responses against microbes and maintain homeostasis in the host intestine.MethodsHigh-throughput screening was performed in Caenorhabditis elegans with a single gene knockout ut screening was performed in Caenorhabditis elegans with a single gene knockout Escherichia coli (E. coli) library and identified the immune suppression gene blc. The coding sequences of blc among different kinds of E. coli strains were aligned to identify the single nucleotide polymorphisms (SNPs). Physiological and biochemical experiments were performed in C. elegans and mice to explore the function of the blc variant.FindingsBy screening 3983 E. coli mutants, we discovered that 9 bacterial genes, when deleted, activate innate immunity in the host C. elegans. Among these 9 genes, the gene encoding blc showed a distinctive SNP in many clinically pathogenic bacteria. We found that bacteria with this SNP, which converts Blc G84 to Blc E84, are highly enriched in the faeces of patients with inflammatory bowel disease (IBD). Exposure to BlcE84-encoding bacteria resulted in epithelial barrier disruption and immune activation in both worms and mice. Detailed analysis indicated that infection with BlcE84-encoding bacteria causes a significant decrease in LPE levels in the intestine and subsequently disrupts gut epithelial integrity in mice. Consistently, the levels of LPE in patients with IBD are significantly lower than those in healthy people. Finally, supplementation with LPE, which activates LPA1/PLCβ/PKC signaling, reversed the defects induced by BlcE84-encoding bacteria.InterpretationOur results identified a novel bacterial gene, blc, in E. coli that regulates host gut integrity and immunity. FUND: The Ministry of Science and Technology of China; the National Natural Science Foundation of China; and the Natural Science Foundation of Jiangsu Province.

Dataset Information

Densovirus crosses the insect midgut by transcytosis and disturbs the epithelial barrier function.

Publications

Densovirus crosses the insect midgut by transcytosis and disturbs the epithelial barrier function.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets