scholarly journals The Many Roles of Galectin-3, a Multifaceted Molecule, in Innate Immune Responses against Pathogens

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Laura Díaz-Alvarez ◽  
Enrique Ortega
Keyword(s):  
Immune Responses ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Terminal Protein ◽  
Molecular Pattern ◽  
Evolutionarily Conserved ◽  
Carbohydrate Recognition Domains ◽  
Galectin 3 ◽  
The Many ◽  
Recognition Receptor

Galectins are a group of evolutionarily conserved proteins with the ability to bindβ-galactosides through characteristic carbohydrate-recognition domains (CRD). Galectin-3 is structurally unique among all galectins as it contains a C-terminal CRD linked to an N-terminal protein-binding domain, being the only chimeric galectin. Galectin-3 participates in many functions, both intra- and extracellularly. Among them, a prominent role for Galectin-3 in inflammation has been recognized. Galectin-3 has also been shown to directly bind to pathogens and to have various effects on the functions of the cells of the innate immune system. Thanks to these two properties, Galectin-3 participates in several ways in the innate immune response against invading pathogens. Galectin-3 has been proposed to function not only as a pattern-recognition receptor (PRR) but also as a danger-associated molecular pattern (DAMP). In this review, we analyze the various roles that have been assigned to Galectin-3, both as a PRR and as a DAMP, in the context of immune responses against pathogenic microorganisms.

scholarly journals Selectively expressing SARS-CoV-2 Spike protein S1 subunit in cardiomyocytes induces cardiac hypertrophy in mice.

2021 ◽  
Author(s):  
Steven G. Negron ◽  
Chase W. Kessinger ◽  
Bing Xu ◽  
William T. Pu ◽  
Zhiqiang Lin
Keyword(s):  
Immune Responses ◽  
Cardiac Injury ◽  
Innate Immune ◽  
Spike Protein ◽  
Innate Immune Responses ◽  
Toll Like Receptor 4 ◽  
Cardiac Inflammation ◽  
Leucine Rich Repeats ◽  
Recognition Receptor

Cardiac injury is common in hospitalized COVID-19 patients and portends poorer prognosis and higher mortality. To better understand how SARS-CoV-2 (CoV-2) damages the heart, it is critical to elucidate the biology of CoV-2 encoded proteins, each of which may play multiple pathological roles. For example, CoV-2 Spike glycoprotein (CoV-2-S) not only engages ACE2 to mediate virus infection, but also directly impairs endothelial function and can trigger innate immune responses in cultured murine macrophages. Here we tested the hypothesis that CoV-2-S damages the heart by activating cardiomyocyte (CM) innate immune responses. HCoV-NL63 is another human coronavirus with a Spike protein (NL63-S) that also engages ACE2 for virus entry but is known to only cause moderate respiratory symptoms. We found that CoV-2-S and not NL63-S interacted with Toll-like receptor 4 (TLR4), a crucial pattern recognition receptor that responsible for detecting pathogen and initiating innate immune responses. Our data show that the S1 subunit of CoV-2-S (CoV-2-S1) interacts with the extracellular leucine rich repeats-containing domain of TLR4 and activates NF-kB. To investigate the possible pathological role of CoV-2-S1 in the heart, we generated a construct that expresses membrane-localized CoV-2-S1 (S1-TM). AAV9-mediated, selective expression of the S1-TM in CMs caused heart dysfunction, induced hypertrophic remodeling, and elicited cardiac inflammation. Since CoV-2-S does not interact with murine ACE2, our study presents a novel ACE2-independent pathological role of CoV-2-S, and suggests that the circulating CoV-2-S1 is a TLR4-recognizable alarmin that may harm the CMs by triggering their innate immune responses.

Pattern recognition receptor-mediated innate immune responses in seminal vesicle epithelial cell and their impacts on cellular function†

2019 ◽  
Vol 101 (4) ◽  
pp. 733-747 ◽  
Author(s):  
Maolei Gong ◽  
Fei Wang ◽  
Weihua Liu ◽  
Ran Chen ◽  
Han Wu ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Epithelial Cells ◽  
Immune Responses ◽  
Pattern Recognition Receptors ◽  
Seminal Vesicles ◽  
Pattern Recognition Receptor ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Toll Like Receptor ◽  
Recognition Receptor

Abstract The seminal vesicles can be infected by microorganisms, thereby resulting in vesiculitis and impairment in male fertility. Innate immune responses in seminal vesicles cells to microbial infections, which facilitate vesiculitis, have yet to be investigated. The present study aims to elucidate pattern recognition receptor–mediated innate immune responses in seminal vesicles epithelial cells. Various pattern recognition receptors, including Toll-like receptor 3, Toll-like receptor 4, cytosolic ribonucleic acid, and deoxyribonucleic acid sensors, are abundantly expressed in seminal vesicles epithelial cells. These pattern recognition receptors can recognize their respective ligands, thus activating nuclear factor kappa B and interferon regulatory factor 3. The pattern recognition receptor signaling induces expression of pro-inflammatory cytokines, such as tumor necrosis factor alpha (Tnfa) and interleukin 6 (Il6), chemokines monocyte chemoattractant protein-1 (Mcp1) and C–X–C motif chemokine 10 (Cxcl10), and type 1 interferons Ifna and Ifnb. Moreover, pattern recognition receptor-mediated innate immune responses up-regulated the expression of microsomal prostaglandin E synthase and cyclooxygenase 2, but they down-regulated semenogelin-1 expression. These results provide novel insights into the mechanism underlying vesiculitis and its impact on the functions of the seminal vesicles.

scholarly journals Reprogramming Interferon Regulatory Factor Signaling in Cardiometabolic Diseases

Physiology ◽  
2017 ◽  
Vol 32 (3) ◽  
pp. 210-223 ◽  
Author(s):  
Yaxing Zhang ◽  
Hongliang Li
Keyword(s):  
Innate Immunity ◽  
Immune Responses ◽  
Immune Cells ◽  
Interferon Regulatory Factor ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Regulatory Factor ◽  
Cardiometabolic Diseases ◽  
Evolutionarily Conserved

Interferon regulatory factors (IRFs) are evolutionarily conserved proteins expressed not only in immune cells but also in other tissues and organs outside the immune system. In this review, we discuss mechanisms responsible for IRF-mediated innate immune responses and the function and mechanism of IRFs in cardiometabolic diseases. We focus on the role of IRFs in innate immunity and cardiometabolic homeostasis, and highlight reprogrammed IRF signaling.

scholarly journals Influence of Galectin-3 on the Innate Immune Response during Experimental Cryptococcosis

2021 ◽  
Vol 7 (6) ◽  
pp. 492
Author(s):  
Caroline Patini Rezende ◽  
Patricia Kellen Martins Oliveira Brito ◽  
Thiago Aparecido Da Silva ◽  
Andre Moreira Pessoni ◽  
Leandra Naira Zambelli Ramalho ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Immune Responses ◽  
Profile Analysis ◽  
Innate Immune ◽  
Gene Profile ◽  
Adaptive Immune ◽  
Galectin 3 ◽  
Experimental Cryptococcosis ◽  
Antifungal Immunity ◽  
Recognition Receptor

Cryptococcus neoformans, the causative agent of cryptococcosis, is the primary fungal pathogen that affects the immunocompromised individuals. Galectin-3 (Gal-3) is an animal lectin involved in both innate and adaptive immune responses. The present study aimed to evaluate the influence of Gal-3 on the C. neoformans infection. We performed histopathological and gene profile analysis of the innate antifungal immunity markers in the lungs, spleen, and brain of the wild-type (WT) and Gal-3 knockout (KO) mice during cryptococcosis. These findings suggest that Gal-3 absence does not cause significant histopathological alterations in the analyzed tissues. The expression profile of the genes related to innate antifungal immunity showed that the presence of cryptococcosis in the WT and Gal-3 KO animals, compared to their respective controls, promoted the upregulation of the pattern recognition receptor (PRR) responsive to mannose/chitin (mrc1) and a gene involved in inflammation (ccr5), as well as the downregulation of the genes related to signal transduction (card9, fos, ikbkb, jun) and PRRs (cd209a, colec12, nptx1). The absence of Gal-3, in fungal infection, a positively modulated gene involved in phagocytosis (sftpd) and negatively genes involved in signal transduction (syk and myd88), proinflammatory cytokines il-1β and il-12b and cd209a receptor. Therefore, our results suggest that Gal-3 may play an essential role in the development of antifungal immune responses against cryptococcosis.

scholarly journals In vivo imaging and genetic analysis link bacterial motility and symbiosis in the zebrafish gut

2007 ◽  
Vol 104 (18) ◽  
pp. 7622-7627 ◽  
Author(s):  
John F. Rawls ◽  
Michael A. Mahowald ◽  
Andrew L. Goodman ◽  
Chad M. Trent ◽  
Jeffrey I. Gordon
Keyword(s):  
Immune Responses ◽  
Innate Immune ◽  
Microbial Interactions ◽  
Microbial Consortia ◽  
Innate Immune Responses ◽  
Germ Free ◽  
Evolutionarily Conserved ◽  
Bacterial Genes ◽  
The Impact

Complex microbial communities reside within the intestines of humans and other vertebrates. Remarkably little is known about how these microbial consortia are established in various locations within the gut, how members of these consortia behave within their dynamic ecosystems, or what microbial factors mediate mutually beneficial host–microbial interactions. Using a gnotobiotic zebrafish–Pseudomonas aeruginosa model, we show that the transparency of this vertebrate species, coupled with methods for raising these animals under germ-free conditions can be used to monitor microbial movement and localization within the intestine in vivo and in real time. Germ-free zebrafish colonized with isogenic P. aeruginosa strains containing deletions of genes related to motility and pathogenesis revealed that loss of flagellar function results in attenuation of evolutionarily conserved host innate immune responses but not conserved nutrient responses. These results demonstrate the utility of gnotobiotic zebrafish in defining the behavior and localization of bacteria within the living vertebrate gut, identifying bacterial genes that affect these processes, and assessing the impact of these genes on host–microbial interactions.

scholarly journals Toll-like Receptors Induce a Phagocytic Gene Program through p38

2003 ◽  
Vol 199 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Sean E. Doyle ◽  
Ryan M. O'Connell ◽  
Gustavo A. Miranda ◽  
Sagar A. Vaidya ◽  
Edward K. Chow ◽  
...  
Keyword(s):  
Immune Responses ◽  
Interleukin 1 ◽  
Innate Immune ◽  
Myeloid Differentiation ◽  
Innate Immune Responses ◽  
Toll Like Receptor ◽  
Evolutionarily Conserved ◽  
Myeloid Differentiation Factor ◽  
The Relationship ◽  
Number Of Bacteria

Toll-like receptor (TLR) signaling and phagocytosis are hallmarks of macrophage-mediated innate immune responses to bacterial infection. However, the relationship between these two processes is not well established. Our data indicate that TLR ligands specifically promote bacterial phagocytosis, in both murine and human cells, through induction of a phagocytic gene program. Importantly, TLR-induced phagocytosis of bacteria was found to be reliant on myeloid differentiation factor 88–dependent signaling through interleukin-1 receptor–associated kinase-4 and p38 leading to the up-regulation of scavenger receptors. Interestingly, individual TLRs promote phagocytosis to varying degrees with TLR9 being the strongest and TLR3 being the weakest inducer of this process. We also demonstrate that TLR ligands not only amplify the percentage of phagocytes uptaking Escherichia coli, but also increase the number of bacteria phagocytosed by individual macrophages. Taken together, our data describe an evolutionarily conserved mechanism by which TLRs can specifically promote phagocytic clearance of bacteria during infection.

Pattern Recognition Receptor-initiated Innate Immune Responses in mouse Prostatic Epithelial Cells

2021 ◽  
Author(s):  
Xiaoqin Yu ◽  
Ran Chen ◽  
Fei Wang ◽  
Weihua Liu ◽  
Wenjing Zhang ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Epithelial Cells ◽  
Immune Responses ◽  
Pattern Recognition Receptor ◽  
Innate Immune ◽  
Poly I:C ◽  
Innate Immune Responses ◽  
Local Inflammation ◽  
Recognition Receptor

Abstract Three major pathogenic states of the prostate, including benign prostatic hyperplasia, prostate cancer, and prostatitis, are related to the local inflammation. However, the mechanisms underlying the initiation of prostate inflammation remain largely unknown. Given that the innate immune responses of the tissue-specific cells to microbial infection or auto-antigens contribute to local inflammation, this study focused on pattern recognition receptor (PRR)-initiated innate immune responses in mouse prostatic epithelial cells (PECs). Primary mouse PECs abundantly expressed Toll-like receptor 3 (TLR3), TLR4, TLR5, melanoma differentiation-associated protein 5 (MDA5) and p204. These PRRs can be activated by their respective ligands: lipopolysaccharide (LPS) and flagellin of Gram-negative bacteria for TLR4 and TLR5, polyinosinic-polycytidylic acid (poly(I:C)) for TLR3 and MDA5, and herpes simplex virus DNA analog (HSV60) for p204. LPS and flagellin predominantly induced the expression of inflammatory cytokines, including TNFA, IL6, MCP1, and CXCL10. Poly(I:C) and HSV60 predominantly induced the expression of type 1 interferons (IFNA and IFNB) and antiviral proteins: Mx GTPase 1, 2′,5′-oligoadenylate synthetase 1, and IFN-stimulated gene 15. The replication of mumps virus in PECs was inhibited by type 1 IFN signaling. These findings provide insights into the mechanisms underlying innate immune response in the prostate.

scholarly journals Widespread shortening of 3’ untranslated regions and increased exon inclusion are evolutionarily conserved features of innate immune responses to infection

2015 ◽  
Author(s):  
Athma A. Pai ◽  
Golshid Baharian ◽  
Ariane Pagé Sabourin ◽  
Jessica F. Brinkworth ◽  
Yohann Nédélec ◽  
...  
Keyword(s):  
Immune Responses ◽  
Innate Immune ◽  
Untranslated Regions ◽  
Innate Immune Responses ◽  
Dynamic Changes ◽  
Evolutionarily Conserved ◽  
Before And After ◽  
Live Bacteria ◽  
Quantify Gene Expression ◽  
Processing Mechanisms

ABSTRACTThe contribution of pre-mRNA processing mechanisms to the regulation of immune responses remains poorly studied despite emerging examples of their role as regulators of immune defenses. Here, we used mRNA sequencing to quantify gene expression and isoform abundances in primary macrophages from 60 individuals, before and after infection with two live bacteria. In response to both bacteria we identified thousands of genes that significantly change isoform usage in response to infection, and found global shifts towards (i) the inclusion of cassette exons and (ii) shorter 3’ UTRs. Using complementary data collected in non-human primates, we show that these features are evolutionarily conserved among primates. Finally, our results suggest that the pervasive usage of shorter 3’ UTRs is a mechanism for particular genes to evade repression by immune-activated miRNAs. Collectively, our results show that dynamic changes in RNA processing play a key role in the regulation of innate immune responses.

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