scholarly journals Giardia duodenalis extracellular vesicles regulate the proinflammatory immune response in mouse macrophages in vitro via the MAPK, AKT and NF-κB pathways

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Panpan Zhao ◽  
Lili Cao ◽  
Xiaocen Wang ◽  
Jianhua Li ◽  
Jingquan Dong ◽  
...  
Keyword(s):  
Immune Response ◽  
Inflammatory Response ◽  
Signaling Pathways ◽  
Innate Immune Response ◽  
Proinflammatory Cytokines ◽  
Giardia Duodenalis ◽  
Innate Immune ◽  
Tnf Α ◽  
Mouse Macrophages

Abstract Background Giardia duodenalis is an extracellular protozoan parasite that causes giardiasis in mammals. The presentation of giardiasis ranges from asymptomatic to severe diarrhea, and the World Health Organization lists it in the Neglected Diseases Initiative. Extracellular vesicles (EVs) are a key mediator of intracellular communication. Although previous studies have shown that G. intestinalis can regulate a host’s innate immune response, the role of G. intestinalis EVs (GEVs) in triggering a G. intestinalis-induced innate immune response remains to be further explored. Methods In this study, GEVs, G. intestinalis and GEVs + G. intestinalis were inoculated into macrophages, respectively. The transcription and secretion levels of proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor alpha (TNF-α), were measured using real-time quantitative PCR (qPCR) and enzyme-linked immunosorbent assays (ELISAs). The phosphorylation levels of the MAPK, AKT and NF-κB signaling pathways in GEV-stimulated mouse macrophages were examined using western blotting and immunofluorescence methods. The roles of activated pathways in the GEV-triggered inflammatory response were determined using inhibition assays, western blotting and ELISAs. Results The results showed that pretreatment with GEVs enhanced with G. intestinalis (GEVs + G. intestinalis) induced IL-1β, IL-6 and TNF-α transcription and secretion from mouse macrophages compared to stimulation with either GEVs or G. intestinalis alone. Inoculation of mouse macrophages with GEVs upregulated the phosphorylation levels of the p38 MAPK, p44/42 MAPK (Erk1/2), AKT and NF-κB signaling pathways and led to the nuclear translocation of NF-κB p65. Blocking the activated p38, Erk and NF-κB signaling pathways significantly downregulated the secretion of proinflammatory cytokines, and blocking the activated AKT signaling pathway demonstrated reverse effects. Conclusions The results of this study reveal that GEVs can enhance G. intestinalis-induced inflammatory response levels in mouse macrophages through activation of the p38, ERK and NF-κB signaling pathways. The role of GEVs in regulating host cell immune responses may provide insights into exploring the underlying mechanisms in G. intestinalis–host interactions. Graphical abstract

scholarly journals Giardia duodenalis Induces Proinflammatory Cytokine Production in Mouse Macrophages via TLR9-Mediated p38 and ERK Signaling Pathways

2021 ◽  
Vol 9 ◽  
Author(s):  
Xudong Pu ◽  
Xin Li ◽  
Lili Cao ◽  
Kaiming Yue ◽  
Panpan Zhao ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Signaling Pathways ◽  
Proinflammatory Cytokines ◽  
Giardia Duodenalis ◽  
Erk Signaling ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Mouse Macrophages ◽  
Host Inflammatory Response

Giardia duodenalis, also known as Giardia lamblia or Giardia intestinalis, is an important opportunistic, pathogenic, zoonotic, protozoan parasite that infects the small intestines of humans and animals, causing giardiasis. Several studies have demonstrated that innate immunity-associated Toll-like receptors (TLRs) are critical for the elimination of G. duodenalis; however, whether TLR9 has a role in innate immune responses against Giardia infection remains unknown. In the present study, various methods, including reverse transcriptase–quantitative polymerase chain reaction, Western blot, enzyme-linked immunosorbent assay, immunofluorescence, inhibitor assays, and small-interfering RNA interference, were utilized to probe the role of TLR9 in mouse macrophage-mediated defenses against G. lamblia virus (GLV)–free or GLV-containing Giardia trophozoites. The results revealed that in G. duodenalis–stimulated mouse macrophages, the secretion of proinflammatory cytokines, including interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and IL-12 p40, was enhanced, concomitant with the significant activation of TLR9, whereas silencing TLR9 attenuated the host inflammatory response. Notably, the presence of GLV exacerbated the secretion of host proinflammatory cytokines. Moreover, G. duodenalis stimulation activated multiple signaling pathways, including the nuclear factor κB p65 (NF-κB p65), p38, ERK, and AKT pathways, the latter three in a TLR9-dependent manner. Additionally, inhibiting the p38 or ERK pathway downregulated the G. duodenalis–induced inflammatory response, whereas AKT inhibition aggravated this process. Taken together, these results indicated that G. duodenalis may induce the secretion of proinflammatory cytokines by activating the p38 and ERK signaling pathways in a TLR9-dependent manner in mouse macrophages. Our in vitro findings on the mechanism underlying the TLR9-mediated host inflammatory response may help establish the foundation for an in-depth investigation of the role of TLR9 in the pathogenicity of G. duodenalis.

scholarly journals Angiotensin II AT1 blockade reduces the lipopolysaccharide-induced innate immune response in rat spleen

2009 ◽  
Vol 296 (5) ◽  
pp. R1376-R1384 ◽  
Author(s):  
Enrique Sánchez-Lemus ◽  
Julius Benicky ◽  
Jaroslav Pavel ◽  
Ignacio M. Larrayoz ◽  
Jin Zhou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Inflammatory Response ◽  
Protein Expression ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Bacterial Endotoxin ◽  
Ang Ii ◽  
Tnf Α ◽  
Mrna And Protein Expression

ANG II AT1 receptor blockade reduces inflammation in hypertension. To determine whether ANG II AT1 receptor blockers (ARBs) influence the innate immune inflammatory response in normotensive rats, we studied rat plasma and spleen after a 3-day subcutaneous pretreatment with the ARB candesartan followed by a single dose of the bacterial endotoxin LPS (50 μg/kg ip). Peripheral administration of LPS to rodents produced a generalized inflammatory response with increased release of TNF-α, IL-1β, and IL-6 into the circulation. Candesartan pretreatment reduced the LPS-induced release of TNF-α, IL-1β, and IL-6 into the circulation. The red pulp of rat spleen expressed large numbers of AT1 receptors and the LPS receptors Toll-like receptor 4 and CD14. Candesartan administration significantly blocked AT1 receptors. The ARB reduced the LPS-induced upregulation of CD14 gene expression; expression of TNF-α and IL-6 mRNA and protein; expression of IL-1β and IκB-α mRNA; COX-2 mRNA and protein expression and PGE2 concentration; inducible nitric oxide synthase (iNOS) gene and protein expression and iNOS activity; and Nox2 gene expression and 8-isoprostane levels. In addition, candesartan reduced the CD14 protein expression in saline- and LPS-treated rats. Our results suggest that AT1 receptors are essential for the development of the full innate immune response to bacterial endotoxin. The ARB decreased the general peripheral inflammatory reaction to LPS and partially decreased the inflammatory response in the spleen. An unrestricted innate immune response to the bacterial endotoxin may have deleterious effects for the organism and may lead to development of chronic inflammatory disease. We postulate that ARBs may have therapeutic effects on inflammatory conditions.

scholarly journals Innate Immunity in the Middle Ear Mucosa

2021 ◽  
Vol 11 ◽  
Author(s):  
Helen M. Massa ◽  
Kirsten M. Spann ◽  
Allan W. Cripps
Keyword(s):  
Immune Response ◽  
Inflammatory Response ◽  
Innate Immune Response ◽  
Middle Ear ◽  
Treatment Options ◽  
Respiratory Viruses ◽  
Innate Immune ◽  
Clinical Presentations ◽  
Host Innate Immune Response

Otitis media (OM) encompasses a spectrum of clinical presentations ranging from the readily identifiable Acute OM (AOM), which is characterised by otalgia and fever, to chronic otitis media with effusion (COME) where impaired hearing due to middle ear effusion may be the only clinical symptom. Chronic suppurative OM (CSOM) presents as a more severe form of OM, involving perforation of the tympanic membrane. The pathogenesis of OM in these varied clinical presentations is unclear but activation of the innate inflammatory responses to viral and/or bacterial infection of the upper respiratory tract performs an integral role. This localised inflammatory response can persist even after pathogens are cleared from the middle ear, eustachian tubes and, in the case of respiratory viruses, even the nasal compartment. Children prone to OM may experience an over exuberant inflammatory response that underlies the development of chronic forms of OM and their sequelae, including hearing impairment. Treatments for chronic effusive forms of OM are limited, with current therapeutic guidelines recommending a “watch and wait” strategy rather than active treatment with antibiotics, corticosteroids or other anti-inflammatory drugs. Overall, there is a clear need for more targeted and effective treatments that either prevent or reduce the hyper-inflammatory response associated with chronic forms of OM. Improved treatment options rely upon an in-depth understanding of OM pathogenesis, particularly the role of the host innate immune response during acute OM. In this paper, we review the current literature regarding the innate immune response within the middle ear to bacterial and viral otopathogens alone, and as co-infections. This is an important consideration, as the role of respiratory viruses as primary pathogens in OM is not yet fully understood. Furthermore, increased reporting from PCR-based diagnostics, indicates that viral/bacterial co-infections in the middle ear are more common than bacterial infections alone. Increasingly, the mechanisms by which viral/bacterial co-infections may drive or maintain complex innate immune responses and inflammation during OM as a chronic response require investigation. Improved understanding of the pathogenesis of chronic OM, including host innate immune response within the middle ear is vital for development of improved diagnostic and treatment options for our children.

scholarly journals Possible Role of Pineal and Extra-Pineal Melatonin in Surveillance, Immunity, and First-Line Defense

2021 ◽  
Vol 22 (22) ◽  
pp. 12143
Author(s):  
Regina P. Markus ◽  
Kassiano S. Sousa ◽  
Sanseray da Silveira Cruz-Machado ◽  
Pedro A. Fernandes ◽  
Zulma S. Ferreira
Keyword(s):  
Immune Response ◽  
Inflammatory Response ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Whole Body ◽  
Pineal Melatonin ◽  
Inflammatory Phase ◽  
Cellular Debris ◽  
Anti Inflammatory

Melatonin is a highly conserved molecule found in prokaryotes and eukaryotes that acts as the darkness hormone, translating environmental lighting to the whole body, and as a moderator of innate and acquired defense, migration, and cell proliferation processes. This review evaluates the importance of pineal activity in monitoring PAMPs and DAMPs and in mounting an inflammatory response or innate immune response. Activation of the immune–pineal axis, which coordinates the pro-and anti-inflammatory phases of an innate immune response, is described. PAMPs and DAMPs promote the immediate suppression of melatonin production by the pineal gland, which allows leukocyte migration. Monocyte-derived macrophages, important phagocytes of microbes, and cellular debris produce melatonin locally and thereby initiate the anti-inflammatory phase of the acute inflammatory response. The role of locally produced melatonin in organs that directly contact the external environment, such as the skin and the gastrointestinal and respiratory tracts, is also discussed. In this context, as resident macrophages are self-renewing cells, we explore evidence indicating that, besides avoiding overreaction of the immune system, extra-pineal melatonin has a fundamental role in the homeostasis of organs and tissues.

scholarly journals The role of beneficial bacteria wall elasticity in regulating innate immune response

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Viktoria V. Мokrozub ◽  
Liudmyla M. Lazarenko ◽  
Liubov M. Sichel ◽  
Lidia P. Babenko ◽  
Petro M. Lytvyn ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Beneficial Bacteria

scholarly journals Tumour viruses and innate immunity

2017 ◽  
Vol 372 (1732) ◽  
pp. 20160267 ◽  
Author(s):  
Sharon E. Hopcraft ◽  
Blossom Damania
Keyword(s):  
Immune Response ◽  
Inflammatory Response ◽  
Viral Infection ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Host Cells ◽  
Oncogenic Viruses ◽  
Barr Virus ◽  
Human T Cell ◽  
Epstein Barr

Host cells sense viral infection through pattern recognition receptors (PRRs), which detect pathogen-associated molecular patterns (PAMPs) and stimulate an innate immune response. PRRs are localized to several different cellular compartments and are stimulated by viral proteins and nucleic acids. PRR activation initiates signal transduction events that ultimately result in an inflammatory response. Human tumour viruses, which include Kaposi's sarcoma-associated herpesvirus, Epstein–Barr virus, human papillomavirus, hepatitis C virus, hepatitis B virus, human T-cell lymphotropic virus type 1 and Merkel cell polyomavirus, are detected by several different PRRs. These viruses engage in a variety of mechanisms to evade the innate immune response, including downregulating PRRs, inhibiting PRR signalling, and disrupting the activation of transcription factors critical for mediating the inflammatory response, among others. This review will describe tumour virus PAMPs and the PRRs responsible for detecting viral infection, PRR signalling pathways, and the mechanisms by which tumour viruses evade the host innate immune system. This article is part of the themed issue ‘Human oncogenic viruses’.

scholarly journals Mitochondrial UPR negatively regulates wounding-induced innate immune response in C. elegans epidermis

2021 ◽  
Author(s):  
Jianzhi Zhao ◽  
Hongying Fu ◽  
Hengda Zhou ◽  
Xuecong Ren ◽  
Yuanyuan Wang ◽  
...  
Keyword(s):  
Immune Response ◽  
Signaling Pathways ◽  
Innate Immune Response ◽  
Tissue Damage ◽  
P38 Map Kinase ◽  
Innate Immune ◽  
Loss Of Function ◽  
C Elegans ◽  
Unfolded Protein ◽  
Protein Response

Tissue damage elicits a rapid innate immune response that is essential for efficient wound healing and survival of metazoans. It is well known that p38 MAPK kinase, TGF-β, and hemidesmosome signaling pathways have been involved in wounding-induced innate immunity in C. elegans. Here, we find that loss of function of ATFS-1 increased innate immune response while an elevated level of mitochondrial unfolded protein response (mitoUPR) inhibits the innate immune response upon epidermal wounding. Epidermal wounding triggers the nucleus export of ATFS-1 and inhibits themitoUPR in C. elegans epidermis. Moreover, genetic analysis suggests that ATFS-1 functions upstream of the p38 MAP kinase, TGF-β, and DAF-16 signaling pathways in regulating AMPs induction. Thus, our results suggest that the mitoUPR function as an intracellular signal required to fine-tune innate immune response after tissue damage.

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