Chemical modifications on siRNAs avoid Toll-like-receptor-mediated activation of the hepatic immune system in vivo and in vitro

Restrictions on the use of antibiotics in the poultry industry stimulate the development of alternative nutritional solutions to maintain or improve poultry health. This requires more insight in the modulatory effects of feed additives on the immune system and microbiota composition. Compounds known to influence the innate immune system and microbiota composition were selected and screened in vitro, in ovo, and in vivo. Among all compounds, 57 enhanced NK cell activation, 56 increased phagocytosis, and 22 increased NO production of the macrophage cell line HD11 in vitro. Based on these results, availability and regulatory status, six compounds were selected for further analysis. None of these compounds showed negative effects on growth, hatchability, and feed conversion in in ovo and in vivo studies. Based on the most interesting numerical results and highest future potential feasibility, two compounds were analyzed further. Administration of glucose oligosaccharide and long-chain glucomannan in vivo both enhanced activation of intraepithelial NK cells and led to increased relative abundance of lactic acid bacteria (LAB) amongst ileum and ceca microbiota after seven days of supplementation. Positive correlations between NK cell subsets and activation, and relative abundance of LAB suggest the involvement of microbiota in the modulation of the function of intraepithelial NK cells. This study identifies glucose oligosaccharide and long-chain glucomannan supplementation as effective nutritional strategies to modulate the intestinal microbiota composition and strengthen the intraepithelial innate immune system.

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Biofilm formation in the lung contributes to virulence and drug tolerance of Mycobacterium tuberculosis

Nature Communications ◽

10.1038/s41467-021-21748-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Poushali Chakraborty ◽

Sapna Bajeli ◽

Deepak Kaushal ◽

Bishan Dass Radotra ◽

Ashwani Kumar

Keyword(s):

Mycobacterium Tuberculosis ◽

Immune System ◽

Biofilm Formation ◽

Antimycobacterial Activity ◽

Drug Tolerance ◽

Host Immune System ◽

Tissue Sections ◽

Slow Growing

AbstractTuberculosis is a chronic disease that displays several features commonly associated with biofilm-associated infections: immune system evasion, antibiotic treatment failures, and recurrence of infection. However, although Mycobacterium tuberculosis (Mtb) can form cellulose-containing biofilms in vitro, it remains unclear whether biofilms are formed during infection in vivo. Here, we demonstrate the formation of Mtb biofilms in animal models of infection and in patients, and that biofilm formation can contribute to drug tolerance. First, we show that cellulose is also a structural component of the extracellular matrix of in vitro biofilms of fast and slow-growing nontuberculous mycobacteria. Then, we use cellulose as a biomarker to detect Mtb biofilms in the lungs of experimentally infected mice and non-human primates, as well as in lung tissue sections obtained from patients with tuberculosis. Mtb strains defective in biofilm formation are attenuated for survival in mice, suggesting that biofilms protect bacilli from the host immune system. Furthermore, the administration of nebulized cellulase enhances the antimycobacterial activity of isoniazid and rifampicin in infected mice, supporting a role for biofilms in phenotypic drug tolerance. Our findings thus indicate that Mtb biofilms are relevant to human tuberculosis.

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Targeting Toll-Like Receptor 2: Polarization of Porcine Macrophages by a Mycoplasma-Derived Pam2cys Lipopeptide

Vaccines ◽

10.3390/vaccines9070692 ◽

2021 ◽

Vol 9 (7) ◽

pp. 692

Author(s):

Giulia Franzoni ◽

Antonio Anfossi ◽

Chiara Grazia De Ciucis ◽

Samanta Mecocci ◽

Tania Carta ◽

...

Keyword(s):

Mhc Class Ii ◽

Macrophage Polarization ◽

Surface Protein ◽

Antimicrobial Activities ◽

Toll Like Receptor ◽

Activation Markers ◽

Class I Mhc ◽

Toll Like Receptor 2

Toll-like receptor 2 (TLR2) ligands are attracting increasing attention as prophylactic and immunotherapeutic agents against pathogens and tumors. We previously observed that a synthetic diacylated lipopeptide based on a surface protein of Mycoplasma agalactiae (Mag-Pam2Cys) strongly activated innate immune cells, including porcine monocyte-derived macrophages (moMΦ). In this study, we utilized confocal microscopy, flow cytometry, multiplex cytokine ELISA, and RT-qPCR to conduct a comprehensive analysis of the effects of scalar doses of Mag-Pam2Cys on porcine moMΦ. We observed enhanced expression of activation markers (MHC class I, MHC class II DR, CD25), increased phagocytotic activity, and release of IL-12 and proinflammatory cytokines. Mag-Pam2Cys also upregulated the gene expression of several IFN-α subtypes, p65, NOS2, and molecules with antimicrobial activities (CD14, beta defensin 1). Overall, our data showed that Mag-Pam2Cys polarized porcine macrophages towards a proinflammatory antimicrobial phenotype. However, Mag-Pam2Cys downregulated the expression of IFN-α3, six TLRs (TLR3, -4, -5, -7, -8, -9), and did not interfere with macrophage polarization induced by the immunosuppressive IL-10, suggesting that the inflammatory activity evoked by Mag-Pam2Cys could be regulated to avoid potentially harmful consequences. We hope that our in vitro results will lay the foundation for the further evaluation of this diacylated lipopeptide as an immunopotentiator in vivo.

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An integrated framework for quantifying immune-tumour interactions in a 3D co-culture model

Communications Biology ◽

10.1038/s42003-021-02296-7 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Gheed Al-Hity ◽

FengWei Yang ◽

Eduard Campillo-Funollet ◽

Andrew E. Greenstein ◽

Hazel Hunt ◽

...

Keyword(s):

Immune System ◽

Immune Cell ◽

In Vitro Models ◽

Proof Of Concept ◽

Culture Model ◽

Spheroid Growth ◽

Confocal Images ◽

Cancer Spheroids

AbstractInvestigational in vitro models that reflect the complexity of the interaction between the immune system and tumours are limited and difficult to establish. Herein, we present a platform to study the tumour-immune interaction using a co-culture between cancer spheroids and activated immune cells. An algorithm was developed for analysis of confocal images of the co-culture to evaluate the following quantitatively; immune cell infiltration, spheroid roundness and spheroid growth. As a proof of concept, the effect of the glucocorticoid stress hormone, cortisol was tested on 66CL4 co-culture model. Results were comparable to 66CL4 syngeneic in vivo mouse model undergoing psychological stress. Furthermore, administration of glucocorticoid receptor antagonists demonstrated the use of this model to determine the effect of treatments on the immune-tumour interplay. In conclusion, we provide a method of quantifying the interaction between the immune system and cancer, which can become a screening tool in immunotherapy design.

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Serum Amyloid A1/Toll-Like Receptor-4 Axis, an Important Link between Inflammation and Outcome of TBI Patients

Biomedicines ◽

10.3390/biomedicines9060599 ◽

2021 ◽

Vol 9 (6) ◽

pp. 599

Author(s):

Víctor Farré-Alins ◽

Alejandra Palomino-Antolín ◽

Paloma Narros-Fernández ◽

Ana Belen Lopez-Rodriguez ◽

Céline Decouty-Perez ◽

...

Keyword(s):

Injury Severity ◽

White Blood Cells ◽

Serum Amyloid ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Important Link ◽

Tlr4 Mrna ◽

Serum Amyloid A1

Traumatic brain injury (TBI) is one of the leading causes of mortality and disability worldwide without any validated biomarker or set of biomarkers to help the diagnosis and evaluation of the evolution/prognosis of TBI patients. To achieve this aim, a deeper knowledge of the biochemical and pathophysiological processes triggered after the trauma is essential. Here, we identified the serum amyloid A1 protein-Toll-like receptor 4 (SAA1-TLR4) axis as an important link between inflammation and the outcome of TBI patients. Using serum and mRNA from white blood cells (WBC) of TBI patients, we found a positive correlation between serum SAA1 levels and injury severity, as well as with the 6-month outcome of TBI patients. SAA1 levels also correlate with the presence of TLR4 mRNA in WBC. In vitro, we found that SAA1 contributes to inflammation via TLR4 activation that releases inflammatory cytokines, which in turn increases SAA1 levels, establishing a positive proinflammatory loop. In vivo, post-TBI treatment with the TLR4-antagonist TAK242 reduces SAA1 levels, improves neurobehavioral outcome, and prevents blood–brain barrier disruption. Our data support further evaluation of (i) post-TBI treatment in the presence of TLR4 inhibition for limiting TBI-induced damage and (ii) SAA1-TLR4 as a biomarker of injury progression in TBI patients.

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Toll-like receptor-9 stimulated plasmacytoid dendritic cell precursors suppress autoimmune neuroinflammation in a murine model of multiple sclerosis

Scientific Reports ◽

10.1038/s41598-021-84023-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hélène Letscher ◽

Viviane A. Agbogan ◽

Sarantis Korniotis ◽

Pauline Gastineau ◽

Emmanuel Tejerina ◽

...

Keyword(s):

Dendritic Cell ◽

Plasmacytoid Dendritic Cell ◽

Toll Like Receptor ◽

Hematopoietic Progenitors ◽

Autoimmune Encephalomyelitis ◽

Hematopoietic Precursor ◽

Therapeutic Properties ◽

Experimental Autoimmune

AbstractEarly innate education of hematopoietic progenitors within the bone marrow (BM) stably primes them for either trained immunity or instead immunoregulatory functions. We herein demonstrate that in vivo or in vitro activation within the BM via Toll-like receptor-9 generates a population of plasmacytoid dendritic cell (pDC) precursors (CpG-pre-pDCs) that, unlike pDC precursors isolated from PBS-incubated BM (PBS-pre-pDCs), are endowed with the capacity to halt progression of ongoing experimental autoimmune encephalomyelitis. CpG activation enhances the selective migration of pDC precursors to the inflamed spinal cord, induces their immediate production of TGF-β, and after migration, of enhanced levels of IL-27. CpG-pre-pDC derived TGF-β and IL-27 ensure protection at early and late phases of the disease, respectively. Spinal cords of CpG-pre-pDC-protected recipient mice display enhanced percentages of host-derived pDCs expressing TGF-β as well as an accumulation of IL-10 producing B cells and of CD11c+ CD11b+ dendritic cells. These results reveal that pDC precursors are conferred stable therapeutic properties by early innate activation within the BM. They further extend to the pDC lineage promising perspectives for cell therapy of autoimmune diseases with innate activated hematopoietic precursor cells.

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The Scaffold Protein Cybr Is Required for Cytokine-Modulated Trafficking of Leukocytes In Vivo

Molecular and Cellular Biology ◽

10.1128/mcb.02473-05 ◽

2006 ◽

Vol 26 (14) ◽

pp. 5249-5258 ◽

Cited By ~ 15

Author(s):

Vincenzo Coppola ◽

Colleen A. Barrick ◽

Sara Bobisse ◽

Maria Cecilia Rodriguez-Galan ◽

Michela Pivetta ◽

...

Keyword(s):

Immune System ◽

Cytotoxic T Lymphocyte ◽

Leukemia Virus ◽

Physiological Role ◽

Scaffold Protein ◽

Nucleotide Exchange ◽

Lymphocyte Migration ◽

And Migration

ABSTRACT Trafficking and cell adhesion are key properties of cells of the immune system. However, the molecular pathways that control these cellular behaviors are still poorly understood. Cybr is a scaffold protein highly expressed in the hematopoietic/immune system whose physiological role is still unknown. In vitro studies have shown it regulates LFA-1, a crucial molecule in lymphocyte attachment and migration. Cybr also binds cytohesin-1, a guanine nucleotide exchange factor for the ARF GTPases, which affects actin cytoskeleton remodeling during cell migration. Here we show that expression of Cybr in vivo is differentially modulated by type 1 cytokines during lymphocyte maturation. In mice, Cybr deficiency negatively affects leukocytes circulating in blood and lymphocytes present in the lymph nodes. Moreover, in a Th1-polarized mouse model, lymphocyte trafficking is impaired by loss of Cybr, and Cybr-deficient mice with aseptic peritonitis have fewer cells than controls present in the peritoneal cavity, as well as fewer leukocytes leaving the bloodstream. Mutant mice injected with Moloney murine sarcoma/leukemia virus develop significantly larger tumors than wild-type mice and have reduced lymph node enlargement, suggesting reduced cytotoxic T-lymphocyte migration. Taken together, these data support a role for Cybr in leukocyte trafficking, especially in response to proinflammatory cytokines in stress conditions.

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Immunity to pathogenic free-living amoebae: role of cell-mediated immunity

Infection and Immunity ◽

10.1128/iai.29.2.408-410.1980 ◽

1980 ◽

Vol 29 (2) ◽

pp. 408-410

Author(s):

R T Cursons ◽

T J Brown ◽

E A Keys ◽

K M Moriarty ◽

D Till

Keyword(s):

Immune System ◽

Inhibition Test ◽

Delayed Hypersensitivity ◽

Cell Mediated Immunity ◽

Pathogenic Species ◽

Free Living

The role of cell-mediated immunity in defense against pathogenic free-living amoebae was examined. Both the in vitro macrophage inhibition test and the in vivo delayed hypersensitivity test showed responses to both heterologous and homologous antigens, although homologous systems were the most efficient. It is suggested that exposure to nonpathogenic species of free-living amoebae can stimulate the immune system to be effective against pathogenic species. The significance of cell-mediated immunity as a defense against invasion by pathogenic free-living amoebae is discussed.

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CD47 prevents the elimination of diseased fibroblasts in scleroderma

10.1101/2020.06.06.138222 ◽

2020 ◽

Author(s):

Tristan Lerbs ◽

Lu Cui ◽

Megan E. King ◽

Tim Chai ◽

Claire Muscat ◽

...

Keyword(s):

Clinical Trials ◽

Immune System ◽

Autoimmune Disease ◽

Skin Fibrosis ◽

Transfer Model ◽

Self Renewal ◽

Syngeneic Mouse ◽

Fibrotic Tissue

AbstractScleroderma is a devastating fibrotic autoimmune disease. Current treatments are partly effective in preventing disease progression, but do not remove fibrotic tissue. Here, we evaluated whether scleroderma fibroblasts take advantage of the “don’t-eat-me-signal” CD47 and whether blocking CD47 enables the body’s immune system to get rid of diseased fibroblasts. To test this approach, we used a Jun-inducible scleroderma model. We first demonstrated in patient samples that scleroderma upregulated JUN and increased promotor accessibilities of both JUN and the CD47. Next, we established our scleroderma model demonstrating that Jun mediated skin fibrosis through the hedgehog-dependent expansion of CD26+Sca1-fibroblasts in mice. In a niche-independent adaptive transfer model, JUN steered graft survival and conferred increased self-renewal to fibroblasts. In vivo, JUN enhanced the expression of CD47, and inhibiting CD47 eliminated an ectopic fibroblast graft and increased in vitro phagocytosis. In the syngeneic mouse, depleting macrophages ameliorated skin fibrosis. Therapeutically, combined CD47 and IL6 blockade reversed skin fibrosis in mice and led to the rapid elimination of ectopically transplanted scleroderma cells. Altogether, our study is the first to demonstrate the efficiency of combining different immunotherapies in treating scleroderma and provide a rationale for combining CD47 and IL6 inhibition in clinical trials.

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Resolvins as Regulators of the Immune System

The Scientific World JOURNAL ◽

10.1100/tsw.2010.72 ◽

2010 ◽

Vol 10 ◽

pp. 818-831 ◽

Cited By ~ 20

Author(s):

Hiroyuki Seki ◽

Takaharu Sasaki ◽

Tomomi Ueda ◽

Makoto Arita

Keyword(s):

Immune System ◽

Acute Inflammation ◽

Immune Cell ◽

Inflammatory Responses ◽

Bioactive Metabolites ◽

Cell Functions ◽

First Response ◽

Beneficial Impact

Inflammation is the first response of the immune system to infection or injury, but excessive or inappropriate inflammatory responses contribute to a range of acute and chronic human diseases. Clinical assessment of dietary supplementation of ω-3 polyunsaturated fatty acids (i.e., eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) indicate that they have beneficial impact on these diseases, although the mechanisms are poorly understood at the molecular level. In this decade, it has been revealed that EPA and DHA are enzymatically converted to bioactive metabolites in the course of acute inflammation and resolution. These metabolites were shown to regulate immune cell functions and to display potent anti-inflammatory actions bothin vitroandin vivo. Because of their ability to resolve an acute inflammatory response, they are referred to as proresolving mediators, or resolvins. In this review, we provide an overview of the formation and actions of these lipid mediators.

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