scholarly journals Modulatory upregulation of an insulin peptide gene by different pathogens in C. elegans

2017 ◽  
Author(s):  
Song-Hua Lee ◽  
Shizue Omi ◽  
Nishant Thakur ◽  
Clara Taffoni ◽  
Jérôme Belougne ◽  
...  

ABSTRACTWhen an animal is infected, its innate immune response needs to be tightly regulated across tissues and coordinated with other aspects of organismal physiology. Previous studies with Caenorhabditis elegans have demonstrated that insulin-like peptide genes are differentially expressed in response to different pathogens. They represent prime candidates for conveying signals between tissues upon infection. Here, we focused on one such gene, ins-11 and its potential role in mediating cross-tissue regulation of innate immune genes. While diverse bacterial intestinal infections can trigger the up-regulation of ins-11 in the intestine, we show that epidermal infection with the fungus Drechmeria coniospora triggers an upregulation of ins-11 in the epidermis. Using the Shigella virulence factor OpsF, a MAP kinase inhibitor, we found that in both cases, ins-11 expression is controlled cell autonomously by p38 MAPK, but via distinct transcription factors, STA-2/STAT in the epidermis and HLH-30/TFEB in the intestine. We established that ins-11, and the insulin signaling pathway more generally, are not involved in the regulation of antimicrobial peptide gene expression in the epidermis. The up-regulation of ins-11 in the epidermis does, however, affect intestinal gene expression in a complex manner, and has a deleterious effect on longevity. These results support a model in which insulin signaling, via ins-11, contributes to the coordination of the organismal response to infection, influencing the allocation of resources in an infected animal.


2018 ◽  
Author(s):  
Michael R Evans ◽  
Claire D James ◽  
Molly L Bristol ◽  
Tara J Nulton ◽  
Xu Wang ◽  
...  

AbstractHuman papillomaviruses (HPV) are causative agents in ano-genital and oropharyngeal cancers. The virus must reprogram host gene expression to promote infection, and E6 and E7 contribute to this via targeting of cellular transcription factors including p53 and pRb, respectively. The HPV16 E2 protein regulates host gene expression in U2OS cells and in this study we extend these observations into TERT immortalized oral keratinocytes (NOKs) that are capable of supporting late stages of the HPV16 life cycle. We observed repression of innate immune genes by E2 that are also repressed by the intact HPV16 genome in NOKs. RNA-seq data identified 167 up and 395 downregulated genes by E2; there was a highly significant overlap of the E2 regulated genes with those regulated by the intact HPV16 genome in the same cell type. siRNA targeting of E2 reversed repression of E2 targeted genes. The ability of E2 to repress innate immune genes was confirmed in an ano-genital immortalized keratinocyte cell line, N/Tert-1. We present analysis of data from The Cancer Genome Atlas (TCGA) for HPV16 positive and negative head and neck cancers (HNC) suggesting that E2 plays a role in regulation of the host genome in cancers. Patients with HPV16 positive HNC with a loss of E2 expression exhibit a worse clinical outcome and we discuss how this could, at least partially, be related to the loss of E2 host gene regulation.ImportanceHPV16 positive tumors that retain expression of E2 have a better clinical outcome than those that have lost E2 expression. It has been suggested that this is due to a loss of E2 repression of E6 and E7 expression but this is not supported by data from tumors where there is not more E6 and E7 expression in the absence of E2. Here we report that E2 regulates host gene expression and place this regulation in context of the HPV16 life cycle and HPV16 positive head and neck cancers (the majority of which retain E2 expression). We propose that this E2 function may play an important part in the increased response of HPV16 positive cancers to radiation therapy. Therefore, host gene regulation by E2 may be important for promotion of the HPV16 life cycle, and also for the response of HPV16 positive tumors to radiation therapy.



2020 ◽  
Author(s):  
KO West ◽  
AR Wagner ◽  
HM Scott ◽  
KJ Vail ◽  
K Carter ◽  
...  

ABSTRACTWhile the signaling cascades and transcription factors that activate gene expression in macrophages following pattern recognition receptor engagement are well known, the role of post-transcriptional RNA processing in modulating innate immune gene expression remains understudied. Recent phosphoproteomics analyses revealed that members of the SR and hnRNP families of splicing regulatory proteins undergo dynamic post-translational modification in infected macrophages. To begin to test if these splicing factors play a privileged role in controlling the innate immune transcriptome, we analyzed steady state gene expression and alternatively spliced isoform production in ten SR/hnRNP knockdown RAW 264.7 macrophage cell lines following infection with the bacterial pathogen Salmonella enterica serovar Typhimurium (Salmonella). We observed that thousands of genes were up or downregulated in SR/hnRNP knockdown cells and differentially expressed genes (DEGs) varied significantly depending on the SR/hnRNP examined. We discovered that a subset of critical innate immune genes (Nos2, Mx1, Il1a) rely heavily on SR/hnRNPs for proper induction and/or repression, while others (Tnf, Il1b) are generally unaffected by splicing factor knockdown. We also discovered that many key immune sensors and signaling molecules are subject to regulation by alternative splicing. While our data does not provide evidence for positive correlation between a transcripts’ reliance of SR/hnRNPs for proper expression and the gene’s induction level, length, or intron/exon architecture, we found that many rapidly induced primary response genes are repressed by SR/hnRNPs. Consistent with SR/hnRNP proteins contributing to innate immune outcomes, knockdown of hnRNP K and U significantly enhanced the ability of RAW 264.7 macrophages to control viral replication. Based on these collective findings, we conclude that many innate immune genes have evolved to rely on one or more splicing regulatory factors to ensure the proper timing and magnitude of their induction, supporting a model wherein pre-splicing is a critical regulatory node in the innate immune response.



2018 ◽  
Vol 93 (4) ◽  
Author(s):  
Michael R. Evans ◽  
Claire D. James ◽  
Molly L. Bristol ◽  
Tara J. Nulton ◽  
Xu Wang ◽  
...  

ABSTRACTHuman papillomaviruses (HPVs) are causative agents in ano-genital and oropharyngeal cancers. The virus must reprogram host gene expression to promote infection, and E6 and E7 contribute to this via the targeting of cellular transcription factors, including p53 and pRb, respectively. The HPV16 E2 protein regulates host gene expression in U2OS cells, and in this study, we extend these observations into telomerase reverse transcriptase (TERT) immortalized oral keratinocytes (NOKs) that are capable of supporting late stages of the HPV16 life cycle. We observed repression of innate immune genes by E2 that are also repressed by the intact HPV16 genome in NOKs. Transcriptome sequencing (RNA-seq) data identified 167 up- and 395 downregulated genes by E2; there was a highly significant overlap of the E2-regulated genes with those regulated by the intact HPV16 genome in the same cell type. Small interfering RNA (siRNA) targeting of E2 reversed the repression of E2-targeted genes. The ability of E2 to repress innate immune genes was confirmed in an ano-genital immortalized keratinocyte cell line, N/Tert-1. We present the analysis of data from The Cancer Genome Atlas (TCGA) for HPV16-positive and -negative head and neck cancers (HNC) suggesting that E2 plays a role in the regulation of the host genome in cancers. Patients with HPV16-positive HNC with a loss of E2 expression exhibited a worse clinical outcome, and we discuss how this could, at least partially, be related to the loss of E2 host gene regulation.IMPORTANCEHuman papillomavirus 16 (HPV16)-positive tumors that retain expression of E2 have a better clinical outcome than those that have lost E2 expression. It has been suggested that this is due to a loss of E2 repression of E6 and E7 expression, but this is not supported by data from tumors where there is not more E6 and E7 expression in the absence of E2. Here we report that E2 regulates host gene expression and place this regulation in the context of the HPV16 life cycle and HPV16-positive head and neck cancers (the majority of which retain E2 expression). We propose that this E2 function may play an important part in the increased response of HPV16-positive cancers to radiation therapy. Therefore, host gene regulation by E2 may be important for promotion of the HPV16 life cycle and also for the response of HPV16-positive tumors to radiation therapy.



2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 518-518
Author(s):  
G. T. Cousillas ◽  
W. J. Weber ◽  
B. Walcheck ◽  
D. E. Kerr ◽  
T. H. Elsasser ◽  
...  


Author(s):  
Wanhai Qin ◽  
Xanthe Brands ◽  
Cornelis Veer ◽  
Alex F. Vos ◽  
Brendon P. Scicluna ◽  
...  


Genetics ◽  
2021 ◽  
Author(s):  
Xiaofen Wu ◽  
Kongyan Niu ◽  
Xiaofan Wang ◽  
Jing Zhao ◽  
Han Wang ◽  
...  

Abstract Inflammaging refers to low-grade, chronically activated innate immunity that has deleterious effects on healthy lifespan. However, little is known about the intrinsic signaling pathway that elicits innate immune genes during aging. Here using Drosophila melanogaster, we profile the microRNA targetomes in young and aged animals, and reveal Dawdle (Daw), an activin-like ligand of the TGF-β pathway, as a physiological target of microRNA-252 (miR-252). We show that miR-252 cooperates with Forkhead box O (FoxO), a conserved transcriptional factor implicated in aging, to repress Daw. Unopposed Daw triggers hyper activation of innate immune genes coupled with a decline in organismal survival. Using adult muscle tissues, single-cell sequencing analysis describes that Daw and its downstream innate immune genes are expressed in distinct cell types, suggesting a cell non-autonomous mode of regulation. We further determine the genetic cascade by which Daw signaling leads to increased Kenny/IKKγ protein, which in turn activates Relish/NF-κB protein and consequentially innate immune genes. Finally, transgenic increase of miR-252 and FoxO pathway factors in wild-type Drosophila extends lifespan and mitigates the induction of innate immune genes in aging. Together, we propose that miR-252 and FoxO promote healthy longevity by cooperative inhibition on Daw mediated inflammaging.



2021 ◽  
Author(s):  
Phillip Wibisono ◽  
Shawndra Wibisono ◽  
Jan Watteyne ◽  
Chia-Hui Chen ◽  
Durai Sellegounder ◽  
...  

A key question in current immunology is how the innate immune system generates high levels of specificity. Like most invertebrates, Caenorhabditis elegans does not have an adaptive immune system and relies solely on innate immunity to defend itself against pathogen attacks, yet it can still differentiate different pathogens and launch distinct innate immune responses. Here, we have found that functional loss of NMUR-1, a neuronal GPCR homologous to mammalian receptors for the neuropeptide neuromedin U, has diverse effects on C. elegans survival against various bacterial pathogens. Transcriptomic analyses and functional assays revealed that NMUR-1 modulates C. elegans transcription activity by regulating the expression of transcription factors, which, in turn, controls the expression of distinct immune genes in response to different pathogens. Our study has uncovered a molecular basis for the specificity of C. elegans innate immunity that could provide mechanistic insights into understanding the specificity of vertebrate innate immunity.



2003 ◽  
Vol 23 (22) ◽  
pp. 8272-8281 ◽  
Author(s):  
Hanna Uvell ◽  
Ylva Engström

ABSTRACT Innate immune reactions are crucial processes of metazoans to protect the organism against overgrowth of faster replicating microorganisms. Drosophila melanogaster is a precious model for genetic and molecular studies of the innate immune system. In response to infection, the concerted action of a battery of antimicrobial peptides ensures efficient killing of the microbes. The induced gene expression relies on translocation of the Drosophila Rel transcription factors Relish, Dif, and Dorsal to the nucleus where they bind to κB-like motifs in the promoters of the inducible genes. We have identified another putative promoter element, called region 1 (R1), in a number of antimicrobial peptide genes. Site-directed mutagenesis of the R1 site diminished Cecropin A1 (CecA1) expression in transgenic Drosophila larvae and flies. Infection of flies induced a nuclear R1-binding activity that was unrelated to the κB-binding activity in the same extracts. Although the R1 motif was required for Rel protein-mediated CecA1 expression in cotransfection experiments, our data argue against it being a direct target for the Drosophila Rel proteins. We propose that the R1 and κB motifs are targets for distinct regulatory complexes that act in concert to promote high levels of antimicrobial peptide gene expression in response to infection.



Author(s):  
Katja Koeppen ◽  
Amanda B Nymon ◽  
Roxanna Barnaby ◽  
Zhongyou Li ◽  
Thomas H Hampton ◽  
...  

Mutations in CFTR alter macrophage responses, for example, by reducing their ability to phagocytose and kill bacteria. Altered macrophage responses may facilitate bacterial infection and inflammation in the lungs, contributing to morbidity and mortality in cystic fibrosis (CF). Extracellular vesicles (EVs) are secreted by multiple cell types in the lungs and participate in the host immune response to bacterial infection, but the effect of EVs secreted by CF airway epithelial cells (AEC) on CF macrophages is unknown. This report examines the effect of EVs secreted by primary AEC on monocyte derived macrophages (MDM) and contrasts responses of CF and WT MDM. We found that EVs generally increase pro-inflammatory cytokine secretion and expression of innate immune genes in MDM, especially when EVs are derived from AEC exposed to Pseudomonas aeruginosa, and that this effect is attenuated in CF MDM. Specifically, EVs secreted by P. aeruginosa exposed AEC induced immune response genes and increased secretion of pro-inflammatory cytokines, chemoattractants and chemokines involved in tissue repair by WT MDM, but these effects were less robust in CF MDM. We attribute attenuated responses by CF MDM to differences between CF and WT macrophages because EVs secreted by CF AEC or WT AEC elicited similar responses in CF MDM. Our findings demonstrate the importance of AEC EVs in macrophage responses and show that the Phe508del mutation in CFTR attenuates the innate immune response of MDM to EVs.



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