scholarly journals Penaeus monodon Interferon Regulatory Factor (PmIRF) Activates IFNs and Antimicrobial Peptide Expression via a STING-Dependent DNA Sensing Pathway

2022 ◽  
Vol 12 ◽  
Author(s):  
Suthinee Soponpong ◽  
Piti Amparyup ◽  
Taro Kawai ◽  
Anchalee Tassanakajon

Interferon regulatory factors (IRFs) are transcription factors found in both vertebrates and invertebrates that were recently identified and found to play an important role in antiviral immunity in black tiger shrimp Penaeus monodon. In this study, we investigated the mechanism by which P. monodon IRF (PmIRF) regulates the immune-related genes downstream of the cytosolic DNA sensing pathway. Depletion of PmIRF by double-stranded RNA-mediated gene silencing significantly reduced the mRNA expression levels of the IFN-like factors PmVago1, PmVago4, and PmVago5 and antilipopolysaccharide factor 6 (ALFPm6) in shrimp. In human embryonic kidney (HEK293T) cells transfected with PmIRF or co-transfected with DEAD-box polypeptide (PmDDX41) and simulator of IFN genes (PmSTING) expression plasmids, the promoter activity of IFN-β, nuclear factor (NF-κB), and ALFPm6 was synergistically enhanced following stimulation with the nucleic acid mimics deoxyadenylic–deoxythymidylic acid sodium salt [poly(dA:dT)] and high molecular weight (HMW) polyinosinic–polycytidylic acid [poly(I:C)]. Both nucleic acid mimics also significantly induced PmSTING, PmIRF, and ALFPm6 gene expression. Co-immunoprecipitation experiments showed that PmIRF interacted with PmSTING in cells stimulated with poly(dA:dT). PmSTING, PmIRF, and PmDDX41 were localized in the cytoplasm of unstimulated HEK293T cells and PmIRF and PmDDX41 were translocated to the nucleus upon stimulation with the nucleic acid mimics while PmSTING remained in the cytoplasm. These results indicate that PmIRF transduces the pathogen signal via the PmDDX41–PmSTING DNA sensing pathway to induce downstream production of interferon-like molecules and antimicrobial peptides.

2019 ◽  
Author(s):  
Jerry Z. Xu ◽  
Ramesh Kumar ◽  
Haoli Gong ◽  
Luyao Liu ◽  
Nicole Ramos-Solis ◽  
...  

ABSTRACTReproductive tract pathology caused byChlamydia trachomatisinfection is an important global cause of human infertility. To better understand the mechanisms associated withChlamydia-induced genital tract pathogenesis in humans, we used CRISPR genome editing to disrupt TLR3 function in the human oviduct epithelial (hOE) cell-line OE-E6/E7, in order to investigate the possible role(s) of TLR3 signaling in the immune response toChlamydia. Disruption of TLR3 function in these cells significantly diminished theChlamydia-induced synthesis of several inflammation biomarkers including IFN-β, IL-6, IL-6Ra, sIL-6Rβ (gp130), IL-8, IL-20, IL-26, IL-34, sTNF-R1, TNFSF13B, MMP-1, MMP-2, and MMP-3. In contrast, theChlamydia-induced synthesis of CCL-5, IL-29 (IFNλ1) and IL-28A (IFNλ2) were significantlyincreasedin the TLR3-deficient hOE cells when compared to their wild-type counterparts. Our results propose a role for TLR3 signaling in limiting the genital tract fibrosis, scarring, and chronic inflammation often associated with human chlamydial disease. Interestingly, we saw thatChlamydiainfection induced the production of biomarkers associated with persistence, tumor metastasis, and autoimmunity such as soluble CD163 (sCD163), chitinase-3-like protein 1, osteopontin, and pentraxin-3 in the hOE cells; however, their expression levels were significantly dysregulated in the TLR3-deficient hOE cells. Finally, we demonstrate using the hOE cells that TLR3 deficiency resulted in an increased amount of chlamydial LPS within theChlamydiainclusion, which is suggestive that TLR3 deficiency leads to enhanced chlamydial replication and possibly increased genital tract pathogenesis during human infection.AbbreviationshOE, human OE-E6/E7 cells; TLR3 KO, TLR3 knockout cell line; poly (I:C), Polyinosinic–polycytidylic acid sodium salt.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 530
Author(s):  
Soo Jin Oh ◽  
Ok Sarah Shin

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease 2019 (COVID-19) that has resulted in the current pandemic. The lack of highly efficacious antiviral drugs that can manage this ongoing global emergency gives urgency to establishing a comprehensive understanding of the molecular pathogenesis of SARS-CoV-2. We characterized the role of the nucleocapsid protein (N) of SARS-CoV-2 in modulating antiviral immunity. Overexpression of SARS-CoV-2 N resulted in the attenuation of retinoic acid inducible gene-I (RIG-I)-like receptor-mediated interferon (IFN) production and IFN-induced gene expression. Similar to the SARS-CoV-1 N protein, SARS-CoV-2 N suppressed the interaction between tripartate motif protein 25 (TRIM25) and RIG-I. Furthermore, SARS-CoV-2 N inhibited polyinosinic: polycytidylic acid [poly(I:C)]-mediated IFN signaling at the level of Tank-binding kinase 1 (TBK1) and interfered with the association between TBK1 and interferon regulatory factor 3 (IRF3), subsequently preventing the nuclear translocation of IRF3. We further found that both type I and III IFN production induced by either the influenza virus lacking the nonstructural protein 1 or the Zika virus were suppressed by the SARS-CoV-2 N protein. Our findings provide insights into the molecular function of the SARS-CoV-2 N protein with respect to counteracting the host antiviral immune response.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yang Chen ◽  
Zhengyang Huang ◽  
Bin Wang ◽  
Qinming Yu ◽  
Ran Liu ◽  
...  

Retinoic acid-inducible gene I- (RIG-I-) like receptors (RLRs) have recently been identified as cytoplasmic sensors for viral RNA. RIG-I, a member of RLRs family, plays an important role in innate immunity. Although previous investigations have proved that RIG-I is absent in chickens, it remains largely unknown whether the chicken can respond to RIG-I ligand. In this study, the eukaryotic expression vectors encoding duRIG-I full length (duck RIG-I, containing all domains), duRIG-I N-terminal (containing the two caspase activation and recruitment domain, CARDs), and duRIG-I C-terminal (containing helicase and regulatory domains) labeled with 6*His tags were constructed successfully and detected by western blotting. Luciferase reporter assay and enzyme-linked immunosorbent assay (ELISA) detected the duRIG-I significantly activated NF-κB and induced the expression of IFN-βwhen polyinosinic-polycytidylic acid (poly[I:C], synthetic double-stranded RNA) challenges chicken embryonic fibroblasts cells (DF1 cells), while the duRIG-I was inactive in the absence of poly[I:C]. Further analysis revealed that the CARDs (duRIG-I-N) induced IFN-βproduction regardless of the presence of poly[I:C], while the CARD-lacking duRIG-I (duRIG-I-C) was not capable of activating downstream signals. These results indicate that duRIG-I CARD domain plays an important role in the induction of IFN-βand provide a basis for further studying the function of RIG-I in avian innate immunity.


2009 ◽  
Vol 87 (3) ◽  
pp. 211-220 ◽  
Author(s):  
Nicola Hopwood ◽  
Tlangelani Maswanganyi ◽  
Lois M. Harden

Although it has been established that some acute phase responses present differently depending on whether a virus or bacteria activates the innate immune system, it has not yet been established whether fever and sickness behaviors, such as anorexia and lethargy, present differently. We therefore investigated the effects of administering lipopolysaccharide (LPS) and polyinosinic : polycytidylic acid (poly I:C) on body temperature, food intake, body mass, and activity (cage activity and wheel running). Male Sprague–Dawley rats were randomly assigned to receive an intraperitoneal injection of one of LPS (75 µg/kg or 250 µg/kg), poly I:C (3000 µg/kg or 4000 µg/kg), or saline. Administration of LPS or poly I:C induced fever, anorexia, and lethargy. Although voluntary wheel running and cage activity were both significantly reduced after administration of LPS or poly I:C, they were not affected equally. Indeed voluntary wheel running was decreased on average by approximately 30% more than cage activity regardless of the dose or type of mimetic administered. Our results indicate that poly I:C is less effective at inducing anorexia, lethargy, and fever in rats than is LPS, and that avoidance of exercise in animals and humans during infection is likely to be a more prominent feature of illness than is avoidance of routine daily activity.


2014 ◽  
Vol 82 (3) ◽  
pp. 1335-1342 ◽  
Author(s):  
Yi-Tsung Lin ◽  
Kai-Yu Tseng ◽  
Yi-Chen Yeh ◽  
Fu-Chen Yang ◽  
Chang-Phone Fung ◽  
...  

ABSTRACTKlebsiella pneumoniaeliver abscess (KPLA) is prevalent in East Asia. Liver abscess can develop after translocation ofK. pneumoniaefrom a patient's bowel into the liver via the portal circulation. TREM-1 (triggeringreceptorexpressed onmyeloid cells1) amplifies inflammatory signaling during infection, but its role in KPLA is poorly understood. We used an animal study to characterize the role of TREM-1 in KPLA. We compared survival rates, bacterial burdens in tissues, inflammatory cytokine levels, and histology findings between wild-type andTrem-1knockout (KO) mice after oral inoculation of capsular type K1K. pneumoniae. Translocation ofK. pneumoniaeto mesenteric lymph nodes and liver was examined, and intestinal permeability, antimicrobial peptide expression, and the clearance ofK. pneumoniaein the small intestine were determined. In the absence of TREM-1, KPLA model mice showed increasedK. pneumoniaedissemination, enhanced liver and systemic inflammation, and reduced survival. Impaired bacterial clearance in the small intestine causes enhancedK. pneumoniaetranslocation, which rendersTrem-1KO mice more susceptible toK. pneumoniaeoral infection. In conclusion, TREM-1-mediated bacterial clearance in the small intestine is an important immune response againstK. pneumoniae. TREM-1 deficiency enhancesK. pneumoniaetranslocation in the small intestine and increases mortality rates in mice with KPLA.


2021 ◽  
Author(s):  
Audrey Baylet ◽  
Raoul Vyumvuhore ◽  
Marine Laclaverie ◽  
Laëtitia Marchand ◽  
Carine Mainzer ◽  
...  

SummaryBackgroundCurrently, several biologics are used for the treatment of cutaneous pathologies such as atopic dermatitis (AD), psoriasis (PSO) or skin cancers. The main administration routes are subcutaneous and intravenous injections. However, little is known about antibody penetration through the skin.ObjectivesThe aim was to study the transcutaneous penetration of a reduced-size antibody as a single-chain variable fragment (scFv) compared to a whole antibody (Ab) and to determine its capacity to neutralize an inflammatory cytokine involved in AD such as human interleukin-4 (hIL-4).MethodsTranscutaneous penetration was evaluated by ex vivo studies on tape-stripped pig ear skin. Antibody visualization through the skin was measured by Raman microspectroscopy. In addition, hIL-4 neutralization was studied using two 2D models. First, embryonic alkaline phosphatase (SEAP) secretion by HEK-Blue™ IL-4/IL-13 cells, proportional to hIL-4 cells stimulation, was quantified by OD 620 nm measurement in presence or absence of an anti-hIL4 scFv or Ab. Then, normal human keratinocytes (NHKs) were stimulated with polyinosinic-polycytidylic acid (poly I:C) +/− hIL-4 and treated with anti-hIL4 scFv. Human Interleukin-8 (hIL-8) concentrations were determined in culture supernatants by ELISA.ResultsAfter 24h of application, analysis by Raman microspectroscopy showed that scFv penetrated into the upper dermis while Ab remained on the stratum corneum. In addition, the anti-hIL4 scFv showed better efficiency compared to Ab, with a neutralization percentage at 200 nM of 68% and 47%, respectively, in the HEK-Blue™ IL-4/IL-13 model. hIL-8 dosage in stimulated NHKs supernatants revealed that addition of scFv induced a dose-dependent hIL-4 neutralization.ConclusionsscFv penetrates through to the upper papillary dermis while Ab remains on the surface. The anti-hIL4 scFv neutralizes its target effectively in two 2D models suggesting its potential use as topical therapy for AD.


2005 ◽  
Vol 73 (8) ◽  
pp. 5241-5244 ◽  
Author(s):  
Barbara E. Menzies ◽  
Aimee Kenoyer

ABSTRACT Keratinocytes upregulate expression of endogenous antimicrobial peptides in response to inflammatory stimuli. We show that both viable and heat-inactivated Staphylococcus aureus and lipoteichoic acid differentially alter expression of these peptides upon contact with human keratinocytes. The findings indicate a diversity of staphylococcal factors involved in upregulation of antimicrobial peptide expression in cutaneous epithelia.


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