Cysteinyl Leukotriene Receptor-1 Antagonists as Modulators of Innate Immune Cell Function

Cysteinyl leukotrienes (cysLTs) are produced predominantly by cells of the innate immune system, especially basophils, eosinophils, mast cells, and monocytes/macrophages. Notwithstanding potent bronchoconstrictor activity, cysLTs are also proinflammatory consequent to their autocrine and paracrine interactions with G-protein-coupled receptors expressed not only on the aforementioned cell types, but also on Th2 lymphocytes, as well as structural cells, and to a lesser extent neutrophils and CD8+cells. Recognition of the involvement of cysLTs in the immunopathogenesis of various types of acute and chronic inflammatory disorders, especially bronchial asthma, prompted the development of selective cysLT receptor-1 (cysLTR1) antagonists, specifically montelukast, pranlukast, and zafirlukast. More recently these agents have also been reported to possess secondary anti-inflammatory activities, distinct from cysLTR1 antagonism, which appear to be particularly effective in targeting neutrophils and monocytes/macrophages. Underlying mechanisms include interference with cyclic nucleotide phosphodiesterases, 5′-lipoxygenase, and the proinflammatory transcription factor, nuclear factor kappa B. These and other secondary anti-inflammatory mechanisms of the commonly used cysLTR1 antagonists are the major focus of the current review, which also includes a comparison of the anti-inflammatory effects of montelukast, pranlukast, and zafirlukast on human neutrophilsin vitro, as well as an overview of both the current clinical applications of these agents and potential future applications based on preclinical and early clinical studies.

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Administration of cardiac mesenchymal cells modulates innate immunity in the acute phase of myocardial infarction in mice

Scientific Reports ◽

10.1038/s41598-020-71580-z ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Yi Kang ◽

Marjan Nasr ◽

Yiru Guo ◽

Shizuka Uchida ◽

Tyler Weirick ◽

...

Keyword(s):

Myocardial Infarction ◽

Innate Immunity ◽

Mechanism Of Action ◽

Cell Activation ◽

Cell Function ◽

Immune Cell ◽

Mesenchymal Cell ◽

Cell Types

Abstract Although cardiac mesenchymal cell (CMC) therapy mitigates post-infarct cardiac dysfunction, the underlying mechanisms remain unidentified. It is acknowledged that donor cells are neither appreciably retained nor meaningfully contribute to tissue regeneration—suggesting a paracrine-mediated mechanism of action. As the immune system is inextricably linked to wound healing/remodeling in the ischemically injured heart, the reparative actions of CMCs may be attributed to their immunoregulatory properties. The current study evaluated the consequences of CMC administration on post myocardial infarction (MI) immune responses in vivo and paracrine-mediated immune cell function in vitro. CMC administration preferentially elicited the recruitment of cell types associated with innate immunity (e.g., monocytes/macrophages and neutrophils). CMC paracrine signaling assays revealed enhancement in innate immune cell chemoattraction, survival, and phagocytosis, and diminished pro-inflammatory immune cell activation; data that identifies and catalogues fundamental immunomodulatory properties of CMCs, which have broad implications regarding the mechanism of action of CMCs in cardiac repair.

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Anti-Inflammatory and Antibacterial Activity Constituents from the Stem of Cinnamomum validinerve

Molecules ◽

10.3390/molecules25153382 ◽

2020 ◽

Vol 25 (15) ◽

pp. 3382 ◽

Cited By ~ 1

Author(s):

Chi-Lung Yang ◽

Ho-Cheng Wu ◽

Tsong-Long Hwang ◽

Chu-Hung Lin ◽

Yin-Hua Cheng ◽

...

Keyword(s):

Bacterial Infections ◽

Immune Cell ◽

Intraperitoneal Administration ◽

In Vitro Study ◽

Human Neutrophils ◽

Infection Model ◽

Ic50 Values ◽

Anti Inflammatory

One new dibenzocycloheptene, validinol (1), and one butanolide firstly isolated from the natural source, validinolide (2), together with 17 known compounds were isolated from the stem of Cinnamomum validinerve. Among the isolates, lincomolide A (3), secosubamolide (7), and cinnamtannin B1 (19) exhibited potent inhibition on both superoxide anion generation (IC50 values of 2.98 ± 0.3 µM, 4.37 ± 0.38 µM, and 2.20 ± 0.3 µM, respectively) and elastase release (IC50 values of 3.96 ± 0.31 µM, 3.04 ± 0.23 µM, and 4.64 ± 0.71 µM, respectively) by human neutrophils. In addition, isophilippinolide A (6), secosubamolide (7), and cinnamtannin B1 (19) showed bacteriostatic effects against Propionibacterium acnes in in vitro study, with minimal inhibitory concentration (MIC) values at 16 μg/mL, 16 μg/mL, and 500 μg/mL, respectively. Further investigations using the in vivo ear P. acnes infection model showed that the intraperitoneal administration of the major component cinnamtannin B1 (19) reduced immune cell infiltration and pro-inflammatory cytokines TNF-α and IL-6 at the infection sites. The results demonstrated the potential of cinnamtannin B1 (19) for acne therapy. In summary, these results demonstrated the anti-inflammatory potentials of Formosan C. validinerve during bacterial infections.

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Vitamin D Modulation of the Innate Immune Response to Paediatric Respiratory Pathogens Associated with Acute Lower Respiratory Infections

Nutrients ◽

10.3390/nu13010276 ◽

2021 ◽

Vol 13 (1) ◽

pp. 276

Author(s):

Amy S. Bleakley ◽

Paul V. Licciardi ◽

Michael J. Binks

Keyword(s):

Vitamin D ◽

Immune Responses ◽

Immune Cell ◽

Respiratory Infections ◽

Cell Types ◽

Innate Immune ◽

Respiratory Pathogens ◽

Acute Lower Respiratory Infections ◽

Syncytial Virus

Vitamin D is an essential component of immune function and childhood deficiency is associated with an increased risk of acute lower respiratory infections (ALRIs). Globally, the leading childhood respiratory pathogens are Streptococcus pneumoniae, respiratory syncytial virus and the influenza virus. There is a growing body of evidence describing the innate immunomodulatory properties of vitamin D during challenge with respiratory pathogens, but recent systematic and unbiased synthesis of data is lacking, and future research directions are unclear. We therefore conducted a systematic PubMed literature search using the terms “vitamin D” and “Streptococcus pneumoniae” or “Respiratory Syncytial Virus” or “Influenza”. A priori inclusion criteria restricted the review to in vitro studies investigating the effect of vitamin D metabolites on human innate immune cells (primary, differentiated or immortalised) in response to stimulation with the specified respiratory pathogens. Eleven studies met our criteria. Despite some heterogeneity across pathogens and innate cell types, vitamin D modulated pathogen recognition receptor (PRRs: Toll-like receptor 2 (TLR2), TLR4, TLR7 and nucleotide-binding oligomerisation domain-containing protein 2 (NOD2)) expression; increased antimicrobial peptide expression (LL-37, human neutrophil peptide (HNP) 1-3 and β-defensin); modulated autophagosome production reducing apoptosis; and modulated production of inflammatory cytokines (Interleukin (IL) -1β, tumour necrosis factor-α (TNF-α), interferon-ɣ (IFN-ɣ), IL-12p70, IFN-β, Regulated on Activation, Normal T cell Expressed (RANTES), IL-10) and chemokines (IL-8 and C-X-C motif chemokine ligand 10 (CXCL10)). Differential modulation of PRRs and IL-1β was reported across immune cell types; however, this may be due to the experimental design. None of the studies specifically focused on immune responses in cells derived from children. In summary, vitamin D promotes a balanced immune response, potentially enhancing pathogen sensing and clearance and restricting pathogen induced inflammatory dysregulation. This is likely to be important in controlling both ALRIs and the immunopathology associated with poorer outcomes and progression to chronic lung diseases. Many unknowns remain and further investigation is required to clarify the nuances in vitamin D mediated immune responses by pathogen and immune cell type and to determine whether these in vitro findings translate into enhanced immunity and reduced ALRI in the paediatric clinical setting.

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Staphylococcus aureus secreted lipases do not inhibit innate immune killing mechanisms

Wellcome Open Research ◽

10.12688/wellcomeopenres.16194.2 ◽

2021 ◽

Vol 5 ◽

pp. 286

Author(s):

Fiona Sargison ◽

Mariya I Goncheva ◽

Joana Alves ◽

Amy Pickering ◽

J Ross Fitzgerald

Keyword(s):

Staphylococcus Aureus ◽

Whole Blood ◽

Immune Cell ◽

Innate Immune ◽

Human Neutrophils ◽

Bacterial Killing ◽

Isogenic Mutant ◽

Extracellular Milieu ◽

The Impact

Background: Staphylococcus aureus causes an array of diseases in both humans and livestock. Pathogenesis is mediated by a plethora of proteins secreted by S. aureus, many of which remain incompletely characterised. For example, S. aureus abundantly secretes two isoforms of the enzyme lipase into the extracellular milieu, where they scavenge upon polymeric triglycerides. It has previously been suggested that lipases may interfere with the function of innate immune cells, such as macrophages and neutrophils, but the impact of lipases on phagocytic killing mechanisms remains unknown. Methods: We employed the epidemic S. aureus clone USA300 strain LAC and its lipase deficient isogenic mutant, along with recombinant lipase proteins, in in vitro experimental infection assays. To determine if lipases can inhibit innate immune killing mechanisms, the bactericidal activity of whole blood, human neutrophils, and macrophages was analysed. In addition, gentamycin protection assays were carried out to examine the influence of lipases on S. aureus innate immune cell escape. Results: There were no differences in the survival of S. aureus USA300 LAC wild type and its lipase-deficient isogenic mutant after incubation with human whole blood or neutrophils. Furthermore, there was no detectable lipase-dependent effect on phagocytosis, intracellular survival, or escape from both human primary and immortalised cell line macrophages, even upon supplementation with exogenous recombinant lipases. Conclusions: S. aureus lipases do not inhibit bacterial killing mechanisms of human macrophages, neutrophils, or whole blood. These findings broaden our understanding of the interaction of S. aureus with the innate immune system.

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Neuroinflammation Modulation via a7 Nicotinic Acetylcholine Receptor and Its Chaperone, RIC-3

Molecules ◽

10.3390/molecules26206139 ◽

2021 ◽

Vol 26 (20) ◽

pp. 6139

Author(s):

Tehila Mizrachi ◽

Adi Vaknin-Dembinsky ◽

Talma Brenner ◽

Millet Treinin

Keyword(s):

Neurodegenerative Diseases ◽

Nicotinic Acetylcholine Receptors ◽

Cell Function ◽

Immune Cell ◽

Cell Types ◽

Nicotinic Acetylcholine ◽

Inflammatory Pathway ◽

Therapeutic Implications ◽

Α7 Nachr ◽

Anti Inflammatory

Nicotinic acetylcholine receptors (nAChRs) are widely expressed in or on various cell types and have diverse functions. In immune cells nAChRs regulate proliferation, differentiation and cytokine release. Specifically, activation of the α7 nAChR reduces inflammation as part of the cholinergic anti-inflammatory pathway. Here we review numerous effects of α7 nAChR activation on immune cell function and differentiation. Further, we also describe evidence implicating this receptor and its chaperone RIC-3 in diseases of the central nervous system and in neuroinflammation, focusing on multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Deregulated neuroinflammation due to dysfunction of α7 nAChR provides one explanation for involvement of this receptor and of RIC-3 in neurodegenerative diseases. In this review, we also provide evidence implicating α7 nAChRs and RIC-3 in neurodegenerative diseases such as Alzheimer’s disease (AD) and Parkinson’s disease (PD) involving neuroinflammation. Besides, we will describe the therapeutic implications of activating the cholinergic anti-inflammatory pathway for diseases involving neuroinflammation.

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PPARγand the Innate Immune System Mediate the Resolution of Inflammation

PPAR Research ◽

10.1155/2015/549691 ◽

2015 ◽

Vol 2015 ◽

pp. 1-20 ◽

Cited By ~ 98

Author(s):

Amanda Croasdell ◽

Parker F. Duffney ◽

Nina Kim ◽

Shannon H. Lacy ◽

Patricia J. Sime ◽

...

Keyword(s):

Immune System ◽

Innate Immune System ◽

Cell Function ◽

Immune Cell ◽

Therapeutic Potential ◽

Adaptive Immune Response ◽

Innate Immune ◽

M2 Macrophage ◽

Resolution Of Inflammation ◽

Anti Inflammatory

The resolution of inflammation is an active and dynamic process, mediated in large part by the innate immune system. Resolution represents not only an increase in anti-inflammatory actions, but also a paradigm shift in immune cell function to restore homeostasis. PPARγ, a ligand activated transcription factor, has long been studied for its anti-inflammatory actions, but an emerging body of literature is investigating the role of PPARγand its ligands (including thiazolidinediones, prostaglandins, and oleanolic acids) in all phases of resolution. PPARγcan shift production from pro- to anti-inflammatory mediators by neutrophils, platelets, and macrophages. PPARγand its ligands further modulate platelet and neutrophil function, decreasing trafficking, promoting neutrophil apoptosis, and preventing platelet-leukocyte interactions. PPARγalters macrophage trafficking, increases efferocytosis and phagocytosis, and promotes alternative M2 macrophage activation. There are also roles for this receptor in the adaptive immune response, particularly regarding B cells. These effects contribute towards the attenuation of multiple disease states, including COPD, colitis, Alzheimer’s disease, and obesity in animal models. Finally, novel specialized proresolving mediators—eicosanoids with critical roles in resolution—may act through PPARγmodulation to promote resolution, providing another exciting area of therapeutic potential for this receptor.

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Staphylococcus aureus secreted lipases do not inhibit innate immune killing mechanisms

Wellcome Open Research ◽

10.12688/wellcomeopenres.16194.1 ◽

2020 ◽

Vol 5 ◽

pp. 286

Author(s):

Fiona Sargison ◽

Joana Alves ◽

Amy Pickering ◽

J Ross Fitzgerald

Keyword(s):

Staphylococcus Aureus ◽

Whole Blood ◽

Immune Cell ◽

Innate Immune ◽

Human Neutrophils ◽

Bacterial Killing ◽

Isogenic Mutant ◽

Extracellular Milieu ◽

The Impact

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In vitro evidence for the involvement of H2S pathway in the effect of clodronate during inflammatory response

Scientific Reports ◽

10.1038/s41598-021-94228-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Rosangela Montanaro ◽

Alessio D’Addona ◽

Andrea Izzo ◽

Carlo Ruosi ◽

Vincenzo Brancaleone

Keyword(s):

Inflammatory Markers ◽

In Vitro Study ◽

Inos Expression ◽

Beneficial Effects ◽

Tnf Α ◽

Inflammatory State ◽

Anti Inflammatory ◽

Underlying Mechanisms ◽

Inflammatory Effect

AbstractClodronate is a bisphosphonate agent commonly used as anti-osteoporotic drug. Throughout its use, additional anti-inflammatory and analgesic properties have been reported, although the benefits described in the literature could not solely relate to their inhibition of bone resorption. Thus, the purpose of our in vitro study is to investigate whether there are underlying mechanisms explaining the anti-inflammatory effect of clodronate and possibly involving hydrogen sulphide (H2S). Immortalised fibroblast-like synoviocyte cells (K4IM) were cultured and treated with clodronate in presence of TNF-α. Clodronate significantly modulated iNOS expression elicited by TNF-α. Inflammatory markers induced by TNF-α, including IL-1, IL-6, MCP-1 and RANTES, were also suppressed following administration of clodronate. Furthermore, the reduction in enzymatic biosynthesis of CSE-derived H2S, together with the reduction in CSE expression associated with TNF-α treatment, was reverted by clodronate, thus rescuing endogenous H2S pathway activity. Clodronate displays antinflammatory properties through the modulation of H2S pathway and cytokines levels, thus assuring the control of the inflammatory state. Although further investigation is needed to stress out how clodronate exerts its control on H2S pathway, here we showed for the first the involvement of H2S in the additive beneficial effects observed following clodronate therapy.

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The Transcriptional Regulator CpsY Is Important for Innate Immune Evasion in Streptococcus pyogenes

Infection and Immunity ◽

10.1128/iai.00925-16 ◽

2016 ◽

Vol 85 (3) ◽

Cited By ~ 2

Author(s):

Luis A. Vega ◽

Kayla M. Valdes ◽

Ganesh S. Sundar ◽

Ashton T. Belew ◽

Emrul Islam ◽

...

Keyword(s):

Streptococcus Pyogenes ◽

Immune Evasion ◽

Immune Cell ◽

Group A Streptococcus ◽

Transcriptional Regulator ◽

Innate Immune ◽

Content Type ◽

Human Host

ABSTRACTAs an exclusively human pathogen,Streptococcus pyogenes(the group A streptococcus [GAS]) has specifically adapted to evade host innate immunity and survive in multiple tissue niches, including blood. GAS can overcome the metabolic constraints of the blood environment and expresses various immunomodulatory factors necessary for survival and immune cell resistance. Here we present our investigation of one such factor, the predicted LysR family transcriptional regulator CpsY. The encoding gene,cpsY, was initially identified as being required for GAS survival in a transposon-site hybridization (TraSH) screen in whole human blood. CpsY is homologous with transcriptional regulators ofStreptococcus mutans(MetR),Streptococcus iniae(CpsY), andStreptococcus agalactiae(MtaR) that regulate methionine transport, amino acid metabolism, resistance to neutrophil-mediated killing, and survivalin vivo. Our investigation indicated that CpsY is involved in GAS resistance to innate immune cells of its human host. However, GAS CpsY does not manifest thein vitrophenotypes of its homologs in other streptococcal species. GAS CpsY appears to regulate a small set of genes that is markedly different from the regulons of its homologs. The differential expression of these genes depends on the growth medium, and CpsY modestly influences their expression. The GAS CpsY regulon includes known virulence factors (mntE,speB,spd,nga[spn],prtS[SpyCEP], andsse) and cell surface-associated factors of GAS (emm1,mur1.2,sibA[cdhA], andM5005_Spy0500). Intriguingly, the loss of CpsY in GAS does not result in virulence defects in murine models of infection, suggesting that CpsY function in immune evasion is specific to the human host.

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