The Response of Tissue Mast Cells to TLR3 Ligand Poly(I:C) Treatment

Mast cells (MCs) are found mainly at the anatomical sites exposed to the external environment; thus, they are localized close to blood vessels, lymphatic vessels, and a multitude of immune cells. Moreover, those cells can recognize invading pathogens through a range of surface molecules known as pathogen recognition receptors (PRRs), mainly Toll-like receptors (TLRs). MCs are extensively engaged in the control and clearance of bacterial infections, but much less is known about their contribution to antiviral host response as well as pathomechanisms of virus-induced diseases. In the study, we employed in vivo differentiated mature tissue mast cells freshly isolated from rat peritoneal cavity. Here, we demonstrated that rat peritoneal mast cells (rPMCs) express viral dsRNA-specific TLR3 molecule (intracellularly and on the cell surface) as well as other proteins associated with cellular antiviral response: IRF3, type I and II IFN receptors, and MHC I. We found that exposure of rPMCs to viral dsRNA mimic, i.e., poly(I:C), induced transient upregulation of surface TLR3 (while temporarily decreased TLR3 intracellular expression), type II IFN receptor, and MHC I. TLR3 ligand-stimulated rPMCs did not degranulate but generated and/or released type I IFNs (IFN-α and IFNβ) as well as proinflammatory lipid mediators (cysLTs), cytokines (TNF, IL-1β), and chemokines (CCL3, CXCL8). We documented that rPMC priming with poly(I:C) did not affect FcεRI-dependent degranulation. However, their costimulation with TLR3 agonist and anti-IgE led to a significant increase in cysLT and TNF secretion. Our findings confirm that MCs may serve as active participants in the antiviral immune response. Presented data on modulated FcεRI-mediated MC secretion of mediators upon poly(I:C) treatment suggests that dsRNA-type virus infection could influence the severity of allergic reactions.

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SARS-CoV-2 Nucleocapsid Protein Targets RIG-I-Like Receptor Pathways to Inhibit the Induction of Interferon Response

Cells ◽

10.3390/cells10030530 ◽

2021 ◽

Vol 10 (3) ◽

pp. 530

Author(s):

Soo Jin Oh ◽

Ok Sarah Shin

Keyword(s):

Nucleocapsid Protein ◽

Nuclear Translocation ◽

Nonstructural Protein ◽

Poly I:C ◽

Interferon Response ◽

Type I ◽

Antiviral Immune Response ◽

N Protein ◽

Nonstructural Protein 1 ◽

Polycytidylic Acid

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.

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Abstract 124: Parthenogenetic Stem Cell-derived Cardiomyocytes Express Major Histocompatibility Complex-I only after Inflammatory Stimulation

Circulation Research ◽

10.1161/res.115.suppl_1.124 ◽

2014 ◽

Vol 115 (suppl_1) ◽

Author(s):

Satish Galla ◽

Michael Didie ◽

Vijayakumar Muppala ◽

Ralf Dressel ◽

Wolfram Hubertus Zimmermann

Keyword(s):

Major Histocompatibility Complex ◽

Heart Muscle ◽

Immunological Response ◽

Type I ◽

Major Histocompatibility ◽

Adrenergic Stimulation ◽

Mhc I ◽

Histocompatibility Complex

Background: Pluripotent parthenogenetic stem cells (PSCs) can be directed towards a cardiac fate and utilized in tissue engineered heart repair. In vivo applications of tissue engineered allografts are compromised by expression of mismatching major histocompatibility complex proteins (MHC; encoded in the murine H2 locus). Here we investigated whether PSC-derived cardiomyocytes (CM) express MHC-I. Methods: Mouse PSCs (A3-line from B6D2F1 strain with haploidentical H2K d -locus) expressing a CM-specific neomycin-resistance and GFP were differentiated and purified for CM by addition of G418 (85% purity by FACS for actinin). To simulate heart muscle biology in vitro, we made use of engineered heart muscle (EHM) constructed from PSC-derived CM (75%), growth-inhibited murine embryonic fibroblasts (MEF (25%); NMRI mice), and collagen type I. MHC class-I H2K d (MHC-I) expression was assessed on CM and Non myocytes before EHM assembly and from enzymatically digested EHMs (cultured for 10 days) by FACS. Interferon gamma (IFNγ) was added for 48 h to stimulate MHC-I expression. As a reference, we investigated MHC-I expression in CM from neonatal mice and adult mouse hearts by FACS and by immunofluorescence staining. Results: EHM showed a positive ionotropic response to beta-adrenergic stimulation which could be reduced by muscarinergic stimulation. A3-CM, in contrast to Non myocytes, showed negligible expression of MHC-I (1±0.5% vs. 60±10% positive cells; n=3). EHM culture did not change MHC-I expression in CM. IFNγ treatment resulted in a marked increase of MHC-I-expression in CM monolayer culture (40±6%; n=3) and in EHM (30±8%; n=3). For comparison, 30% (n=2) neonatal CM expressed MHC-I while MHC-I was not detectable in adult CM. Conclusion: PSC-derived CM show a similarly low expression of MHC-I as adult CM and respond with MHC-I upregulation to IFNγ stimulation. This suggests a mature immunological response in PSC-CM with important implications for in vivo applications, i.e., MHC-I matching will likely be a prerequisite for successful allografting of PSC-EHM.

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Enhancing innate antiviral immune responses in rainbow trout by double stranded RNA delivered with cationic phytoglycogen nanoparticles

Scientific Reports ◽

10.1038/s41598-019-49931-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Tamiru N. Alkie ◽

Jondavid de Jong ◽

Kristof Jenik ◽

Karl M. Klinger ◽

Stephanie J. DeWitte-Orr

Keyword(s):

Rainbow Trout ◽

Immune Responses ◽

Cell Line ◽

Culture Conditions ◽

Type I Interferons ◽

Poly I:C ◽

Synthetic Analogue ◽

Type I ◽

Viral Dsrna

Abstract Innate immunity is induced when pathogen-associated molecular patterns (PAMPs) bind host pattern recognition receptors (PRRs). Polyinosinic:polycytidylic acid [poly(I:C)] is a synthetic analogue of viral dsRNA that acts as a PAMP, inducing type I interferons (IFNs) in vertebrates. In the present study, the immunostimulatory effects of high molecular weight (HMW) poly(I:C) in rainbow trout cells were measured when bound to a cationic phytoglycogen nanoparticle (Nano-HMW). The physical characteristics of the nanoparticle itself, when bound to different lengths of dsRNA and when cell associated was evaluated. Optimal concentration and timing for innate immune stimulation was measured using the RTG-P1 reporter cell line. The immunostimulatory effects of HMW poly (I:C) was compared to Nano-HMW in vitro using the RTgutGC cell line cultured in a conventional monolayer or a transwell culture system. The ability of an activated intestinal epithelium to transmit an antiviral signal to macrophages was evaluated using a co-culture of RTgutGC cells and RTSll (a monocyte/macrophage cell). In all culture conditions, Nano-HMW was a more effective inducer of IFN-related antiviral immune responses compared to HMW poly (I:C) alone. This study introduces the use of cationic phytoglycogen nanoparticles as a novel delivery system for immunomodulatory molecules to enhance immune responses in aquatic vertebrates.

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Integrity of the Antiviral STING-mediated DNA Sensing in Tumor Cells Is Required to Sustain the Immunotherapeutic Efficacy of Herpes Simplex Oncolytic Virus

Cancers ◽

10.3390/cancers12113407 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3407 ◽

Cited By ~ 1

Author(s):

Guendalina Froechlich ◽

Carmen Caiazza ◽

Chiara Gentile ◽

Anna Morena D’Alise ◽

Maria De Lucia ◽

...

Keyword(s):

Immune Checkpoint Blockade ◽

Oncolytic Viruses ◽

Type I ◽

Dna Sensing ◽

Antiviral Immune Response ◽

Viral Spread ◽

Immunosuppressive Tumor Microenvironment ◽

Tumor Immunogenicity

The dichotomic contribution of cancer cell lysis and tumor immunogenicity is considered essential for effective oncovirotherapy, suggesting that the innate antiviral immune response is a hurdle for efficacy of oncolytic viruses. However, emerging evidence is resizing this view. By sensing cytosolic DNA, the cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) axis can both counteract viral spread and contribute to the elicitation of adaptive immunity via type I interferon responses. In this paper, we analyzed the tumor-resident function of Sting-mediated DNA sensing in a combined approach of oncovirotherapy and PD-1 immune checkpoint blockade, in an immunocompetent murine model. While supporting increased lytic potential by oncolytic HER2-retargeted HSV-1 in vitro and in vivo, Sting-knockout tumors showed molecular signatures of an immunosuppressive tumor microenvironment. These signatures were correspondingly associated with ineffectiveness of the combination therapy in a model of established tumors. Results suggest that the impairment in antiviral response of Sting-knockout tumors, while favoring viral replication, is not able to elicit an adequate immunotherapeutic effect, due to lack of immunogenic cell death and the inability of Sting-knockout cancer cells to promote anti-tumor adaptive immune responses. Accordingly, we propose that antiviral, tumor-resident Sting provides fundamental contributions to immunotherapeutic efficacy of oncolytic viruses.

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Regulation of anaphylactic responses by phosphatidylinositol phosphate kinase type I α

Journal of Experimental Medicine ◽

10.1084/jem.20041891 ◽

2005 ◽

Vol 201 (6) ◽

pp. 859-870 ◽

Cited By ~ 45

Author(s):

Junko Sasaki ◽

Takehiko Sasaki ◽

Masakazu Yamazaki ◽

Kunie Matsuoka ◽

Choji Taya ◽

...

Keyword(s):

Mast Cells ◽

Actin Polymerization ◽

Negative Regulator ◽

Type I ◽

Filamentous Actin ◽

Critical Signal ◽

Cell Functions ◽

Phosphatidylinositol Phosphate

The membrane phospholipid phosphatidylinositol 4, 5-bisphosphate [PI(4,5)P2] is a critical signal transducer in eukaryotic cells. However, the physiological roles of the type I phosphatidylinositol phosphate kinases (PIPKIs) that synthesize PI(4,5)P2 are largely unknown. Here, we show that the α isozyme of PIPKI (PIPKIα) negatively regulates mast cell functions and anaphylactic responses. In vitro, PIPKIα-deficient mast cells exhibited increased degranulation and cytokine production after Fcε receptor-I cross-linking. In vivo, PIPKIα−/− mice displayed enhanced passive cutaneous and systemic anaphylaxis. Filamentous actin was diminished in PIPKIα−/− mast cells, and enhanced degranulation observed in the absence of PIPKIα was also seen in wild-type mast cells treated with latrunculin, a pharmacological inhibitor of actin polymerization. Moreover, the association of FcεRI with lipid rafts and FcεRI-mediated activation of signaling proteins was augmented in PIPKIα−/− mast cells. Thus, PIPKIα is a negative regulator of FcεRI-mediated cellular responses and anaphylaxis, which functions by controlling the actin cytoskeleton and dynamics of FcεRI signaling. Our results indicate that the different PIPKI isoforms might be functionally specialized.

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Counter-regulation in the IKK family

Biochemical Journal ◽

10.1042/bj20102168 ◽

2011 ◽

Vol 434 (1) ◽

pp. e1-e2 ◽

Cited By ~ 2

Author(s):

Luke A. J. O'Neill

Keyword(s):

Inflammatory Diseases ◽

Interleukin 1 ◽

Nuclear Factor Κb ◽

Type I Interferons ◽

Poly I:C ◽

Type I ◽

Control Mechanisms ◽

Biochemical Journal ◽

Regulatory Feedback Loop

The human IKK [IκB (inhibitor of NF-κB) kinase] family has four members; they are the central kinases of innate immunity. Two members, IKKα and IKKβ, the so-called canonical members, phosphoryate IκBα, leading to activation of the transcription factor NF-κB (nuclear factor κB), which controls the expression of many immune and inflammatory genes. The IKK-related proteins TBK-1 (TANK-binding kinase 1) and IKKϵ have a different substrate – IRF3 (interferon regulatory factor 3) – which regulates a different set of genes, the products of which include Type I interferons. Toll-like receptors (TLRs) such as the lipopolysaccharide receptor TLR4 or the poly(I:C) receptor TLR3 activate each of the IKKs, but the pro-inflammatory cytokine IL-1 (interleukin 1), which signals in a broadly similar way to the TLRs, has so far been shown to activate only the canonical IKKs. In this issue of the Biochemical Journal, Clark et al. bring new insights into the regulation of IKKs. They demonstrate that IL-1 is in fact able to activate IKKϵ/TBK-1, which occurs via IKKα/IKKβ. The consequence of this is not IRF3 activation, but a negative feedback effect on IKKα/IKKβ. This provides us with yet another regulatory feedback loop in a system already replete with control mechanisms. It attests yet again to the importance of keeping these innate immune pathways in check, since if they proceed uncontrolled, inflammatory diseases can occur. Importantly, this study utilized new and specific inhibitors of these kinases, suggesting that the interpretation of any effects the compound might have in vivo may be complex, since for example the inhibition of IKKϵ/TBK-1 might actually have a pro-inflammatory effect.

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Morin inhibits Fyn kinase in mast cells and IgE-mediated type I hypersensitivity response in vivo

Biochemical Pharmacology ◽

10.1016/j.bcp.2009.01.019 ◽

2009 ◽

Vol 77 (9) ◽

pp. 1506-1512 ◽

Cited By ~ 50

Author(s):

Jie Wan Kim ◽

Jun Ho Lee ◽

Bang Yeon Hwang ◽

Se Hwan Mun ◽

Na Young Ko ◽

...

Keyword(s):

Mast Cells ◽

Type I ◽

Hypersensitivity Response ◽

Fyn Kinase ◽

Ige Mediated ◽

Type I Hypersensitivity

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Brain Mast Cells Act as an Immune Gate to the Hypothalamic-Pituitary-Adrenal Axis in Dogs

Journal of Experimental Medicine ◽

10.1084/jem.194.1.71 ◽

2001 ◽

Vol 194 (1) ◽

pp. 71-78 ◽

Cited By ~ 61

Author(s):

Itsuro Matsumoto ◽

Yasuhisa Inoue ◽

Toshio Shimada ◽

Tadaomi Aikawa

Keyword(s):

Mast Cells ◽

Host Defense ◽

Bacterial Infections ◽

Immunoglobulin E ◽

Intravenous Route ◽

Pars Tuberalis ◽

Type I ◽

Cortisol Secretion ◽

Hypothalamic Pituitary Adrenal ◽

H2 Blocker

Mast cells perform a significant role in the host defense against parasitic and some bacterial infections. Here we show that in the dog, degranulation of brain mast cells evokes hypothalamic-pituitary-adrenal responses via histamine release. A large number of mast cells were found in a circumscribed ventral region of the hypothalamus, including the pars tuberalis and median eminence. When these intracranial mast cells were passively sensitized with immunoglobulin E via either the intracerebroventricular or intravenous route, there was a marked increase in the adrenal cortisol secretion elicited by a subsequent antigenic challenge (whether this was delivered via the central or peripheral route). Comp.48/80, a mast cell secretagogue, also increased cortisol secretion when administered intracerebroventricularly. Pretreatment (intracerebroventricularly) with anti-corticotropin–releasing factor antibodies or a histamine H1 blocker, but not an H2 blocker, attenuated the evoked increases in cortisol. These data show that in the dog, degranulation of brain mast cells evokes hypothalamic-pituitary-adrenal responses via centrally released histamine and corticotrophin-releasing factor. On the basis of these data, we suggest that intracranial mast cells may act as an allergen sensor, and that the activated adrenocortical response may represent a life-saving host defense reaction to a type I allergy.

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The Expression of ephrinA1/ephA2 Receptor Increases in Chronic Rhinosinusitis and ephrinA1/ephA2 Signaling Affects Rhinovirus-Induced Innate Immunity in Human Sinonasal Epithelial Cells

Frontiers in Immunology ◽

10.3389/fimmu.2021.793517 ◽

2021 ◽

Vol 12 ◽

Author(s):

Sang Hag Lee ◽

Sung Hoon Kang ◽

Mun Soo Han ◽

Ji Won Kwak ◽

Hyeon Geun Kim ◽

...

Keyword(s):

Immune Response ◽

Epithelial Cells ◽

Chronic Rhinosinusitis ◽

Cultured Cells ◽

Normal Mucosa ◽

Poly I:C ◽

Type I ◽

Antiviral Immune Response ◽

Immune Mediators ◽

Sinonasal Mucosa

EphA2 receptor and its ephrin ligands are involved in virus infection, epithelial permeability, and chemokine secretion. We hypothesized that ephrinA1/ephA2 signaling participates in rhinovirus (RV)-induced antiviral immune response in sinonasal mucosa of patients with chronic rhinosinusitis (CRS). Therefore, we investigated the expression of ephrinA1/ephA2 in normal and inflamed sinonasal mucosa and evaluated whether they regulate chemokine secretion and the production of antiviral immune mediators including interferons (IFNs) in RV-infected human primary sinonasal epithelial cells. For this purpose, the expression and distribution of ephrinA1/ephA2 in sinonasal mucosa were evaluated with RT-qPCR, immunofluorescence, and western blot. Their roles in chemokine secretion and the production of antiviral immune mediators such as type I and III IFNs, and interferon stimulated genes were evaluated by stimulating ephA2 with ephrinA1 and inactivating ephA2 with ephA2 siRNA or inhibitor in cells exposed to RV and poly(I:C). We found that ephrinA1/ephA2 were expressed in normal mucosa and their levels increased in inflamed sinonasal mucosa of CRS patients. RV infection or poly(I:C) treatment induced chemokine secretion which were attenuated by blocking the action of ephA2 with ephA2 siRNA or inhibitor. The production of antiviral immune mediators enhanced by rhinovirus or poly (I:C) is increased by blocking ephA2 compared with that of cells stimulated by either rhinovirus or poly(I:C) alone. In addition, blocking ephA2 attenuated RV replication in cultured cells. Taken together, these results describe a novel role of ephrinA1/ephA2 signaling in antiviral innate immune response in sinonasal epithelium, suggesting their participation in RV-induced development and exacerbations of CRS.

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Alterations in the HLA-B*57:01 Immunopeptidome by Flucloxacillin and Immunogenicity of Drug-Haptenated Peptides

Frontiers in Immunology ◽

10.3389/fimmu.2020.629399 ◽

2021 ◽

Vol 11 ◽

Author(s):

Montserrat Puig ◽

Suryatheja Ananthula ◽

Ramesh Venna ◽

Swamy Kumar Polumuri ◽

Elliot Mattson ◽

...

Keyword(s):

T Cell ◽

Bacterial Infections ◽

Cell Function ◽

Human Leukocyte ◽

Drug Induced ◽

Mhc I ◽

Anchor Residue ◽

Drug Molecules

Neoantigen formation due to the interaction of drug molecules with human leukocyte antigen (HLA)-peptide complexes can lead to severe hypersensitivity reactions. Flucloxacillin (FLX), a β-lactam antibiotic for narrow-spectrum gram-positive bacterial infections, has been associated with severe immune-mediated drug-induced liver injury caused by an influx of T-lymphocytes targeting liver cells potentially recognizing drug-haptenated peptides in the context of HLA-B*57:01. To identify immunopeptidome changes that could lead to drug-driven immunogenicity, we used mass spectrometry to characterize the proteome and immunopeptidome of B-lymphoblastoid cells solely expressing HLA-B*57:01 as MHC-I molecules. Selected drug-conjugated peptides identified in these cells were synthesized and tested for their immunogenicity in HLA-B*57:01-transgenic mice. T cell responses were evaluated in vitro by immune assays. The immunopeptidome of FLX-treated cells was more diverse than that of untreated cells, enriched with peptides containing carboxy-terminal tryptophan and FLX-haptenated lysine residues on peptides. Selected FLX-modified peptides with drug on P4 and P6 induced drug-specific CD8+ T cells in vivo. FLX was also found directly linked to the HLA K146 that could interfere with KIR-3DL or peptide interactions. These studies identify a novel effect of antibiotics to alter anchor residue frequencies in HLA-presented peptides which may impact drug-induced inflammation. Covalent FLX-modified lysines on peptides mapped drug-specific immunogenicity primarily at P4 and P6 suggesting these peptide sites as drivers of off-target adverse reactions mediated by FLX. FLX modifications on HLA-B*57:01-exposed lysines may also impact interactions with KIR or TCR and subsequent NK and T cell function.

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