scholarly journals TLR3 and TLR7 RNA Sensor Activation during SARS-COV-2 Infection

2021 ◽  
Vol 9 (9) ◽  
pp. 1820
Author(s):  
Daria Bortolotti ◽  
Valentina Gentili ◽  
Sabrina Rizzo ◽  
Giovanna Schiuma ◽  
Silvia Beltrami ◽  
...  
Keyword(s):  
Post Infection ◽  
Clinical Strain ◽  
Multicellular Spheroids ◽  
Innate And Adaptive Immunity ◽  
Rna Sensors ◽  
Ifn Γ ◽  
Sensor Activation ◽  
Molecular Patterns

(1) Background: Acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent for the coronavirus disease (COVID-19) that has led to a pandemic that began in March 2020. The role of the SARS-CoV-2 components on innate and adaptive immunity is still unknown. We investigated the possible implication of pathogen-associated molecular patterns (PAMPs)–pattern recognition receptors (PRRs) interaction. (2) Methods: We infected Calu-3/MRC-5 multicellular spheroids (MTCSs) with a SARS-CoV-2 clinical strain and evaluated the activation of RNA sensors, transcription factors, and cytokines/interferons (IFN) secretion, by quantitative real-time PCR, immunofluorescence, and ELISA. (3) Results: Our results showed that the SARS-CoV-2 infection of Calu-3/MRC-5 multicellular spheroids induced the activation of the TLR3 and TLR7 RNA sensor pathways. In particular, TLR3 might act via IRF3, producing interleukin (IL)-1α, IL-1β, IL-4, IL-6, and IFN-α and IFN-β, during the first 24 h post-infection. Then, TLR3 activates the NFκB transduction pathway, leading to pro-inflammatory cytokine secretion. Conversely, TLR7 seems to mainly act via NFκB, inducing type 1 IFN, IFN-γ, and IFN-λ3, starting from the 48 h post-infection. (4) Conclusion: We showed that both TLR3 and TLR7 are involved in the control of innate immunity during lung SARS-CoV-2 infection. The activation of TLRs induced pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-4, and IL-6, as well as interferons. TLRs could be a potential target in controlling the infection in the early stages of the disease.

scholarly journals Viruses Seen by Our Cells: The Role of Viral RNA Sensors

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Elias A. Said ◽  
Nicolas Tremblay ◽  
Mohammed S. Al-Balushi ◽  
Ali A. Al-Jabri ◽  
Daniel Lamarre
Keyword(s):  
Rna Viruses ◽  
Innate Immune ◽  
Rna Helicases ◽  
Antiviral Responses ◽  
Cytokines And Chemokines ◽  
Rna Sensors ◽  
Molecular Patterns ◽  
Type 1 Interferons

The role of the innate immune response in detecting RNA viruses is crucial for the establishment of proper inflammatory and antiviral responses. Different receptors, known as pattern recognition receptors (PRRs), are present in the cytoplasm, endosomes, and on the cellular surface. These receptors have the capacity to sense the presence of viral nucleic acids as pathogen-associated molecular patterns (PAMPs). This recognition leads to the induction of type 1 interferons (IFNs) as well as inflammatory cytokines and chemokines. In this review, we provide an overview of the significant involvement of cellular RNA helicases and Toll-like receptors (TLRs) 3, 7, and 8 in antiviral immune defenses.

scholarly journals MBD2 acts as a repressor to maintain the homeostasis of the Th1 program in type 1 diabetes by regulating the STAT1-IFN-γ axis

2021 ◽  
Author(s):  
Tiantian Yue ◽  
Fei Sun ◽  
Faxi Wang ◽  
Chunliang Yang ◽  
Jiahui Luo ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Type 1 Diabetes ◽  
Adoptive Transfer ◽  
Nod Mice ◽  
Transcriptional Level ◽  
Clinical Settings ◽  
Cpg Dna ◽  
Ifn Γ

AbstractThe methyl-CpG-binding domain 2 (MBD2) interprets DNA methylome-encoded information through binding to the methylated CpG DNA, by which it regulates target gene expression at the transcriptional level. Although derailed DNA methylation has long been recognized to trigger or promote autoimmune responses in type 1 diabetes (T1D), the exact role of MBD2 in T1D pathogenesis, however, remains poorly defined. Herein, we generated an Mbd2 knockout model in the NOD background and found that Mbd2 deficiency exacerbated the development of spontaneous T1D in NOD mice. Adoptive transfer of Mbd2−/− CD4 T cells into NOD.scid mice further confirmed the observation. Mechanistically, Th1 stimulation rendered the Stat1 promoter to undergo a DNA methylation turnover featured by the changes of DNA methylation levels or patterns along with the induction of MBD2 expression, which then bound to the methylated CpG DNA within the Stat1 promoter, by which MBD2 maintains the homeostasis of Th1 program to prevent autoimmunity. As a result, ectopic MBD2 expression alleviated CD4 T cell diabetogenicity following their adoptive transfer into NOD.scid mice. Collectively, our data suggest that MBD2 could be a viable target to develop epigenetic-based therapeutics against T1D in clinical settings.

IL-36R ligands are potent regulators of dendritic and T cells

Blood ◽  
2011 ◽  
Vol 118 (22) ◽  
pp. 5813-5823 ◽  
Author(s):  
Solenne Vigne ◽  
Gaby Palmer ◽  
Céline Lamacchia ◽  
Praxedis Martin ◽  
Dominique Talabot-Ayer ◽  
...  
Keyword(s):  
T Cells ◽  
Mhc Class Ii ◽  
Critical Role ◽  
T Helper ◽  
Innate And Adaptive Immunity ◽  
Murine Bone Marrow ◽  
Intracellular Signals ◽  
Tnf Α ◽  
Ifn Γ

Abstract IL-36α (IL-1F6), IL-36β (IL-1F8), and IL-36γ (IL-1F9) are members of the IL-1 family of cytokines. These cytokines bind to IL-36R (IL-1Rrp2) and IL-1RAcP, activating similar intracellular signals as IL-1, whereas IL-36Ra (IL-1F5) acts as an IL-36R antagonist (IL-36Ra). In this study, we show that both murine bone marrow-derived dendritic cells (BMDCs) and CD4+ T lymphocytes constitutively express IL-36R and respond to IL-36α, IL-36β, and IL-36γ. IL-36 induced the production of proinflammatory cytokines, including IL-12, IL-1β, IL-6, TNF-α, and IL-23 by BMDCs with a more potent stimulatory effect than that of other IL-1 cytokines. In addition, IL-36β enhanced the expression of CD80, CD86, and MHC class II by BMDCs. IL-36 also induced the production of IFN-γ, IL-4, and IL-17 by CD4+ T cells and cultured splenocytes. These stimulatory effects were antagonized by IL-36Ra when used in 100- to 1000-fold molar excess. The immunization of mice with IL-36β significantly and specifically promoted Th1 responses. Our data thus indicate a critical role of IL-36R ligands in the interface between innate and adaptive immunity, leading to the stimulation of T helper responses.

Effect of prolonged exercise and carbohydrate ingestion on type 1 and type 2 T lymphocyte distribution and intracellular cytokine production in humans

2005 ◽  
Vol 98 (2) ◽  
pp. 565-571 ◽  
Author(s):  
G. I. Lancaster ◽  
Q. Khan ◽  
P. T. Drysdale ◽  
F. Wallace ◽  
A. E. Jeukendrup ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
T Lymphocyte ◽  
Cytokine Production ◽  
Stress Hormone ◽  
Induced Stress ◽  
Ifn Γ ◽  
Exercise Induced

The present study was undertaken to examine the role of the exercise-induced stress hormone response on the regulation of type 1 and type 2 T lymphocyte intracellular cytokine production. Subjects performed 2.5 h of cycling exercise at 65% maximal O2 uptake while ingesting a 6.4% carbohydrate (CHO) solution, 12.8% CHO solution, or a placebo. Peripheral whole blood samples were stimulated and stained for T lymphocyte surface antigens (CD4 and CD8). Cells were then permeabilized, stained for intracellular cytokines, and analyzed using flow cytometry. Exercise resulted in a decrease ( P < 0.05) in the number and percentage of IFN-γ positive CD4+ and CD8+ T lymphocytes. These stimulated cells produced less IFN-γ immediately postexercise ( P < 0.05) and 2-h postexercise ( P < 0.05) compared with preexercise. However, CHO ingestion, which attenuated the exercise-induced stress hormone response compared with placebo ( P < 0.05), prevented both the decrease in the number and percentage of IFN-γ-positive CD4+ and CD8+ T lymphocytes and the suppression of IFN-γ production from stimulated CD4+ and CD8+ T lymphocytes. There was no effect of exercise on the number of, or cytokine production from, IL-4-positive CD4+ or CD8+ T lymphocytes. These data provide support for the role of exercise-induced elevations in stress hormones in the regulation of type 1 T lymphocyte cytokine production and distribution.

scholarly journals Interleukin-35 Prevents Development of Autoimmune Diabetes Possibly by Maintaining the Phenotype of Regulatory B Cells

2021 ◽  
Vol 22 (23) ◽  
pp. 12988
Author(s):  
Zhengkang Luo ◽  
Sara Lundin ◽  
Mariela Mejia-Cordova ◽  
Imane Hassani ◽  
Martin Blixt ◽  
...  
Keyword(s):  
B Cells ◽  
Low Dose ◽  
Autoimmune Diabetes ◽  
Healthy Controls ◽  
Regulatory B Cells ◽  
Experimental Autoimmune Uveitis ◽  
Ifn Γ ◽  
Experimental Autoimmune

The anti-inflammatory role of regulatory B cells (Breg cells) has been associated with IL-35 based on studies of experimental autoimmune uveitis and encephalitis. The role of Breg cells and IL-35+ Breg cells for type 1 diabetes (T1D) remains to be investigated. We studied PBMCs from T1D subjects and healthy controls (HC) and found lowered proportions of Breg cells and IL-35+ Breg cells in T1D. To elucidate the role of Breg cells, the lymphoid organs of two mouse models of T1D were examined. Lower proportions of Breg cells and IL-35+ Breg cells were found in the animal models of T1D compared with control mice. In addition, the systemic administration of recombinant mouse IL-35 prevented hyperglycemia after multiple low dose streptozotocin (MLDSTZ) injections and increased the proportions of Breg cells and IL-35+ Breg cells. A higher proportion of IFN-γ+ cells among Breg cells were found in the PBMCs of the T1D subjects. In the MLDSTZ mice, IL-35 administration decreased the proportions of IFN-γ+ cells among the Breg cells. Our data illustrate that Breg cells may play an important role in the development of T1D and that IL-35 treatment prevents the development of hyperglycemia by maintaining the phenotype of the Breg cells under an experimental T1D condition.

Innate immune receptors in type 1 diabetes: the relationship to cell death-associated inflammation

2020 ◽  
Vol 48 (3) ◽  
pp. 1213-1225 ◽  
Author(s):  
Tae Kang Kim ◽  
Myung-Shik Lee
Keyword(s):  
Innate Immunity ◽  
Type 1 Diabetes ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Innate Immune ◽  
Therapeutic Modalities ◽  
Immune Receptors ◽  
Molecular Patterns

The importance of innate immunity in host defense and inflammatory responses has been clearly demonstrated after the discovery of innate immune receptors such as Toll-like receptors (TLRs) or Nucleotide-binding oligomerization domain-containing protein (Nod)-like receptors (NLRs). Innate immunity also plays a critical role in diverse pathological conditions including autoimmune diseases such as type 1 diabetes (T1D). In particular, the role of a variety of innate immune receptors in T1D has been demonstrated using mice with targeted disruption of such innate immune receptors. Here, we discuss recent findings showing the role of innate immunity in T1D that were obtained mostly from studies of genetic mouse models of innate immune receptors. In addition, the role of innate immune receptors involved in the pathogenesis of T1D in sensing death-associated molecular patterns (DAMPs) released from dead cells or pathogen-associated molecular patterns (PAMPs) will also be covered. Elucidation of the role of innate immune receptors in T1D and the nature of DAMPs sensed by such receptors may lead to the development of new therapeutic modalities against T1D.

Type 2 immune response associated with silicosis is not instrumental in the development of the disease

2007 ◽  
Vol 292 (1) ◽  
pp. L107-L113 ◽  
Author(s):  
Pierre Misson ◽  
Frank Brombacher ◽  
Monique Delos ◽  
Dominique Lison ◽  
Francois Huaux
Keyword(s):  
Immune Response ◽  
Lung Fibrosis ◽  
Receptor Expression ◽  
Fibrotic Disease ◽  
Pulmonary Response ◽  
Type 2 Immune Response ◽  
Ifn Γ

It has been proposed that the development of lung fibrosis is associated with a T helper type 2 response, mainly characterized by IL-4 and IL-13 production. We investigated the potential role of type 2 immune polarization in the silicotic process and examined the pulmonary response to silica particles in mice genetically deficient for IL-4. We found that IL-4−/− mice were not protected against the development of silicosis, suggesting that IL-4 is not essential for the development of this fibrotic disease. By evaluating the intensity of silica-induced lung fibrosis in mice deficient for IL-4 receptor α (IL-4Rα), we showed that the establishment of pulmonary fibrosis was independent of both IL-4 and IL-13. Strong impairment of the type 2 immune response (IgG1) in the lungs of IL-4−/− and IL-4Rα−/− mice did not affect the development of the disease. Measurement of IL-13α2 receptor expression and IgG2a, IL-12p70, and IFN-γ levels in silica-treated IL-4−/− and IL-4Rα−/− animals showed that the development of silicosis was not related to an IL-13 signaling pathway or a switch to a type 1 response in deficient animals. Our data clearly indicate that the type 2 immune response associated with silicosis in mice is not required for the development of this inflammatory and fibrotic disease.

scholarly journals Critical Role of Type 1 Cytokines in Controlling Initial Infection with Burkholderia mallei

2006 ◽  
Vol 74 (9) ◽  
pp. 5333-5340 ◽  
Author(s):  
Caroline A. Rowland ◽  
Ganjana Lertmemongkolchai ◽  
Alison Bancroft ◽  
Ashraful Haque ◽  
M. Stephen Lever ◽  
...  
Keyword(s):  
T Cells ◽  
Critical Role ◽  
Disease Model ◽  
Cell Mediated Immunity ◽  
Burkholderia Mallei ◽  
Monocyte Chemoattractant Protein 1 ◽  
Ifn Γ

ABSTRACT Burkholderia mallei is a gram-negative bacterium which causes the potentially fatal disease glanders in humans; however, there is little information concerning cell-mediated immunity to this pathogen. The role of gamma interferon (IFN-γ) during B. mallei infection was investigated using a disease model in which infected BALB/c mice normally die between 40 and 60 days postinfection. IFN-γ knockout mice infected with B. mallei died within 2 to 3 days after infection, and there was uncontrolled bacterial replication in several organs, demonstrating the essential role of IFN-γ in the innate immune response to this pathogen. Increased levels of IFN-γ, interleukin-6 (IL-6), and monocyte chemoattractant protein 1 were detected in the sera of immunocompetent mice in response to infection, and splenic mRNA expression of IFN-γ, IL-6, IL-12p35, and IL-27 was elevated 24 h postinfection. The effects of IL-18, IL-27, and IL-12 on stimulation of the rapid IFN-γ production were investigated in vitro by analyzing IFN-γ production in the presence of heat-killed B. mallei. IL-12 was essential for IFN-γ production in vitro; IL-18 was also involved in induction of IFN-γ, but IL-27 was not required for IFN-γ production in response to heat-killed B. mallei. The main cellular sources of IFN-γ were identified in vitro as NK cells, CD8+ T cells, and TCRγδ T cells. Our data show that B. mallei is susceptible to cell-mediated immune responses which promote expression of type 1 cytokines. This suggests that development of effective vaccines against glanders should target the production of IFN-γ.

scholarly journals Role of Gamma Interferon and Interleukin-4 in Host Defense against the Human Filarial Parasite Brugia malayi

2000 ◽  
Vol 68 (5) ◽  
pp. 3034-3035 ◽  
Author(s):  
Subash Babu ◽  
Lisa M. Ganley ◽  
Thomas R. Klei ◽  
Leonard D. Shultz ◽  
T. V. Rajan
Keyword(s):  
Host Defense ◽  
Brugia Malayi ◽  
Gamma Interferon ◽  
Interleukin 4 ◽  
Ifn Γ ◽  
Canonical Type ◽  
Time Required

ABSTRACT We have investigated the roles of gamma interferon (IFN-γ) and interleukin-4 (IL-4) in host defense against Brugia malayi. Our data suggest that the lack of either IFN-γ or IL-4 prolongs the time required to achieve sterile immunity, suggesting that both canonical type 1 and type 2 responses are involved in the clearance of infection.

scholarly journals Differential Cytokine Pattern in the Spleens and Livers of BALB/c Mice Infected with Penicillium marneffei: Protective Role of Gamma Interferon

2003 ◽  
Vol 71 (1) ◽  
pp. 465-473 ◽  
Author(s):  
Francesca Sisto ◽  
Annarita Miluzio ◽  
Orazio Leopardi ◽  
Maurizio Mirra ◽  
Johan R. Boelaert ◽  
...  
Keyword(s):  
Immune Response ◽  
Gamma Interferon ◽  
Penicillium Marneffei ◽  
Yeast Cells ◽  
Interleukin 12 ◽  
Type 2 Cytokines ◽  
Ifn Γ

ABSTRACT Penicillium marneffei is an intracellular opportunistic fungus causing invasive mycosis in AIDS patients. T cells and macrophages are important for protection in vivo. However, the role of T-cell cytokines in the immune response against P. marneffei is still unknown. We studied by semiquantitative reverse transcription-PCR and biological assays the patterns of expression of Th1 and Th2 cytokines in the organs of wild-type (wt) and gamma interferon (IFN-γ) knockout (GKO) mice infected intravenously with P. marneffei conidia. At 3 × 105 conidia/mouse, a self-limiting infection developed in wt BALB/c mice, whereas all GKO mice died at day 18 postinoculation. Splenic and hepatic granulomas were present in wt mice, whereas disorganized masses of macrophages and yeast cells were detected in GKO mice. The infection resolved faster in the spleens than in the livers of wt mice and was associated with the local expression of type 1 cytokines (high levels of interleukin-12 [IL-12] and IFN-γ) but not type 2 cytokines (low levels of IL-4 and IL-10). Conversely, both type 1 and type 2 cytokines were detected in the livers of wt animals. Disregulation of the cytokine profile was seen in the spleens but not in the livers of GKO mice. The inducible nitric oxide synthase mRNA level was low and the TNF-α level was high in both spleens and livers of GKO mice compared to wt mice. These data suggest that the polarization of a protective type 1 immune response against P. marneffei is regulated at the level of individual organs and that the absence of IFN-γ is crucial for the activation of fungicidal macrophages and the development of granulomas.

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