- Signaling Crosstalk Mechanisms That May Fine-Tune Pathogen-Responsive NFκB. [Review]
- FIFront Immunol 2019; 10:433
- Precise control of inflammatory gene expression is critical for effective host defense without excessive tissue damage. The principal regulator of inflammatory gene expression is nuclear factor kappa…
Precise control of inflammatory gene expression is critical for effective host defense without excessive tissue damage. The principal regulator of inflammatory gene expression is nuclear factor kappa B (NFκB), a transcription factor. Nuclear NFκB activity is controlled by IκB proteins, whose stimulus-responsive degradation and re-synthesis provide for transient or dynamic regulation. The IκB-NFκB signaling module receives input signals from a variety of pathogen sensors, such as toll-like receptors (TLRs). The molecular components and mechanisms of NFκB signaling are well-understood and have been reviewed elsewhere in detail. Here we review the molecular mechanisms that mediate cross-regulation of TLR-IκB-NFκB signal transduction by signaling pathways that do not activate NFκB themselves, such as interferon signaling pathways. We distinguish between potential regulatory crosstalk mechanisms that (i) occur proximal to TLRs and thus may have stimulus-specific effects, (ii) affect the core IκB-NFκB signaling module to modulate NFκB activation in response to several stimuli. We review some well-documented examples of molecular crosstalk mechanisms and indicate other potential mechanisms whose physiological roles require further study.
- Differential expression of toll-like receptor 13 and ribosomal protein L29 in inflammatory lung and brain. [Journal Article]
- JBJ Biol Regul Homeost Agents 2019 07 16; 33(4)
- Viral dsRNA acts as the paramount pathogen-associated molecular pattern on infection and orchestrates inflammation or immune cascades of the host's tissues. The comparative effects or mechanisms of i…
Viral dsRNA acts as the paramount pathogen-associated molecular pattern on infection and orchestrates inflammation or immune cascades of the host's tissues. The comparative effects or mechanisms of inflammation or immunity in different organs on viral infections are critical in immunology or virology. To outline the organ-based molecular mechanisms of inflammation or immunity on viral infection, we challenged mice with the viral mimic poly(I:C) and quantified inflammatory cytokines Il-1b and TNF-α in the brain and lung tissues. As cytokines showed differential expression, transcriptome screenings of mouse lung and brain tissues were analyzed. We identified 629 differentially expressed genes (DEGs) in lung and 137 DEGs in brain tissues with a few overlapping genes. Most of those DEGs were interferon-stimulated genes (ISGs) that are involved in the anti-viral defense mechanisms. The expression patterns of viral dsRNA stimulated genes, and consequently, their association with different molecular mechanisms of inflammation and immunity were specific to the organs. The effects of viral mimic were higher in the lung than in the brain in terms of the number of DEGs and ISGs. Interestingly ribosomal protein L29 (Rpl29), a cell surface heparin-binding protein, was upregulated in the brain and downregulated in the lung. The contrasting expression of Rpl29 gene might be responsible for tissue-specific inflammatory responses in lung and brain tissue on virus infection. In addition, the upregulation of Tlr13, a dsRNA and bacterial 23s rRNA receptor, in the poly(I:C)-stimulated mouse lungs suggests its important role in lung inflammatory responses. It is likely that the combined effects of these genes orchestrate the organ-specific inflammatory or immune responses. Our findings would be beneficial to explore new insights in inflammation and immunity against many critical viral diseases.
- Induction of IL-22 protein and IL-22-producing cells in rainbow trout Oncorhynchus mykiss. [Journal Article]
- DCDev Comp Immunol 2019 Jul 12; :103449
- IL-22 is a critical cytokine which is involved in modulating tissue responses during inflammation, and is produced mainly by T cells and innate leucocytes. In mammals, IL-22 is a key component in muc…
IL-22 is a critical cytokine which is involved in modulating tissue responses during inflammation, and is produced mainly by T cells and innate leucocytes. In mammals, IL-22 is a key component in mucosal defences, tissue repair, epithelial cell survival and proliferation. In teleosts, IL-22 has been cloned and studied in several species, and the transcript is highly expressed in mucosal tissues and induced by pathogen associated molecular patterns (PAMPs), suggesting IL-22 also functions as an important component of the innate immune response in fish. To investigate these immune responses further, we have validated and characterised two monoclonal antibodies (mAbs) which were raised against two different peptide immunogens of salmonid IL-22. Our results show that both mAbs specifically react to their own peptide immunogens and recombinant IL-22, and are able to detect the induction of native protein expression after stimulation. In flow cytometry, an increase in IL-22 positive cells was detected after stimulation in vitro with cytokines and PAMPs and in vivo after bacterial challenge. The immunohistochemistry results showed that IL-22 is highly upregulated in the gills after challenge, both in cells within the gill filaments and in the interbranchial lymphoid tissue. Such results suggest IL-22 may have a role in triggering local antimicrobial defences in fish that may facilitate efficient microbial clearance. Hence monitoring IL-22 producing cells/protein secretion may provide an alternative mean to assess the effectiveness of mucosal vaccines.
- Multimodal surveillance of healthcare associated infections in an intensive care unit of a large teaching hospital. [Journal Article]
- AIAnn Ig 2019 Sep-Oct; 31(5):399-413
- CONCLUSIONS: By integrating information gathered from active surveillance, environmental microbiological surveillance, surveillance of bacterial isolates and behavioral surveillance of healthcare personnel, the multimodal infection surveillance system returned a precise and detailed view of the infectious risk and microbial ecology of the ICU.
- CD14: Biology and role in the pathogenesis of disease. [Review]
- CGCytokine Growth Factor Rev 2019 Jul 03
- Human monocyte differentiation antigen CD14 is a pattern recognition receptor (PRR) that enhances innate immune responses. CD14 was first identified as a marker of monocytes to signal intracellular r…
Human monocyte differentiation antigen CD14 is a pattern recognition receptor (PRR) that enhances innate immune responses. CD14 was first identified as a marker of monocytes to signal intracellular responses upon bacterial encounters. Given the absence of an intracellular tail, CD14 was doubted to have the signaling capacities. Later CD14 was confirmed as the TLR co-receptor for the detection of pathogen-associated molecular patterns. However, CD14 has been revealed as a multi-talented receptor. In last decade, CD14 was identified to activate NFAT to regulate the life cycle of myeloid cells in a TLR4-independent manner and to transport inflammatory lipids to induce phagocyte hyperactivation. And its influences on multiple related diseases have been further considered. In this review, we summarize advancements in the basic biology of the CD14 including its structure, binding ligands, signaling pathways, and its roles in the pathogenesis of inflammation, atherosclerosis, tumor and metabolic diseases. We also discuss the therapeutic potential of targeting the CD14 in related diseases.
- A single-CRD C-type lectin (CgCLec-3) with novel DIN motif exhibits versatile immune functions in Crassostrea gigas. [Journal Article]
- FSFish Shellfish Immunol 2019 Jul 03; 92:772-781
- C-type lectins (CTLs), as important pattern recognition receptors (PRRs), are a superfamily of Ca2+-dependent carbohydrate-recognition proteins which participate in nonself-recognition and eliminatin…
C-type lectins (CTLs), as important pattern recognition receptors (PRRs), are a superfamily of Ca2+-dependent carbohydrate-recognition proteins which participate in nonself-recognition and eliminating pathogens. In the present study, a novel CTL (designated as CgCLec-3) was identified from the Pacific oyster Crassostrea gigas. There was only one carbohydrate-recognition domain (CRD) of 151 amino acid residues within the deduced amino acid sequence of CgCLec-3. The deduced amino acid sequence of CgCLec-3 CRD shared low homology with the CRDs of other CTLs in oyster with the identities ranging from 12% to 22%. A novel DIN motif was found in Ca2+-binding site 2 of CgCLec-3. The relative expression level of CgCLec-3 in hemocytes was up-regulated significantly after the stimulations of bacteria and Pathogen Associated Molecular Patterns (PAMPs). Immunohistochemistry assay showed that CgCLec-3 protein was mainly distributed in gill and mantle, less in gonad, and could not be detected in adductor muscle and hepatopancreas. The recombinant protein (rCgCLec-3) could bind lipopolysaccharide (LPS), mannose (MAN) and peptidoglycan (PGN), but not poly (I:C). rCgCLec-3 exihibited strong binding ability to Vibrio anguillarum and V. splendidus, moderate binding activities to Escherichia coli, Pichia pastoris and Yarrowia lipolytica, weak binding affinity to Staphylococcus aureus and Micrococcus luteus. rCgCLec-3 could agglutinate microorganisms, in a Ca2+-dependent manner and its activity to agglutinate V. splendidus was remarkably higher than that to agglutinate E. coli, S. aureus and P. pastoris. The phagocytic activity of oyster hemocytes was significantly enhanced after incubation with rCgCLec-3. rCgCLec-3 also exhibited antibacterial activity against E. coli and S. aureus. The results clearly suggested that CgCLec-3 in Pacific oyster C. gigas not only served as a PRR involved in the PAMPs recognition and microbes binding, but also functioned as an immune effector participating in the clearance of invaders.
- Broad-spectrum capture of clinical pathogens using engineered Fc-mannose-binding lectin enhanced by antibiotic treatment. [Journal Article]
- FF1000Res 2019; 8:108
- CONCLUSIONS: The efficiency of pathogen detection and variation between binding of different strains of the same species could be improved by treating the bacteria with antibiotics, or mechanical disruption using a bead mill, prior to FcMBL capture to reveal previously concealed binding sites within the bacterial cell wall. As FcMBL can bind to pathogens and PAMPs in urine as well as blood, its broad-binding capability could be leveraged to develop a variety of clinically relevant technologies, including infectious disease diagnostics, therapeutics, and vaccines.
- Developmental and Immune Role of a Novel Multiple Cysteine Cluster TLR From Eisenia andrei Earthworms. [Journal Article]
- FIFront Immunol 2019; 10:1277
- Earthworms are not endowed with adaptive immunity and they are rely on the tools of innate immunity. Cells of the innate immune system utilize pattern recognition receptors, such as Toll-like recepto…
Earthworms are not endowed with adaptive immunity and they are rely on the tools of innate immunity. Cells of the innate immune system utilize pattern recognition receptors, such as Toll-like receptors, to detect the pathogen-associated molecular patterns (PAMPs). The first earthworm TLR was isolated from Eisenia andrei earthworms (EaTLR), which belongs to the single cysteine cluster TLR (sccTLR). Here, we identified a new multiple cysteine cluster TLR (mccTLR) in E. andrei earthworms. Phylogenetic DNA analysis revealed that it has no variability within one earthworm as well as in the population. By screening of the tissue expression profile, the TLR was expressed primarily in earthworm seminal vesicles and receptacles suggesting a connection to sperm cells. Seminal vesicles are often heavily infected by gregarine parasites. As a sign of immune response, a strong melanization reaction is visible around parasites. Stimulation experiments with profilin from related parasite Toxoplasma gondii, led to the upregulation of mccEaTLR in the earthworm seminal vesicles. Also, profilin activated prophenoloxidase cascade, the efficient mechanism of innate immunity. However, its involvement in the NF-κB signaling was not proven. Further, we provide evidence that the antibiotics metronidazole and griseofulvin destroyed the developing spermatocytes. The observed decrease in the mccEaTLR mRNA levels after the antibiotic treatment of parasites is caused by the decline of sperm cells numbers rather than by diminution of the parasites. Since earthworms with extensively reduced parasite load had a similar amount of mccEaTLR mRNA, presumably, earthworm sperm cells have a certain level of mccEaTLR expressed as a standard, which can be augmented by particular antigenic stimulation. Also, mccEaTLR was expressed mainly in the early stages of earthworm development and presumably is primarily involved in early embryonic development. Expression of mccEaTLR in seminal vesicles correlates with the expression of endothelial monocyte-activation polypeptide II. High-throughput sequencing of gregarine DNA from seminal vesicles of individual earthworms resulted in great diversity of the observed genotypes. Phylogenetically, all observed OTUs belong to the clade of earthworm gregarines suggesting host specificity. Overall, mccEaTLR is supposed to play a function role in early embryonic development and potentially it participates in immune response against parasites.
- Overexpression of BSK5 in Arabidopsis thaliana Provides Enhanced Disease Resistance. [Journal Article]
- PSPlant Signal Behav 2019 Jul 02; :1-3
- Plant surface-localized pattern recognition receptors (PRRs) recognize pathogen- or damage-associated molecular patterns (PAMP/DAMPs) and activate pattern-triggered immunity (PTI). PRRs recruit recep…
Plant surface-localized pattern recognition receptors (PRRs) recognize pathogen- or damage-associated molecular patterns (PAMP/DAMPs) and activate pattern-triggered immunity (PTI). PRRs recruit receptor-like cytoplasmic kinases (RLCKs) to transduce the perceived signal to downstream signaling components. Brassinosteroid-signaling kinase 5 (BSK5) is a member of the RLCK XII subfamily and mutational analysis revealed its involvement in plant immunity. Here, we provide evidence that overexpression of BSK5 in transgenic Arabidopsis plants enhanced disease resistance to the bacterial pathogen Pseudomonas syringae and to the fungus Botrytis cinerea. Remarkably, upon treatment with the flg22, elf18 and pep1 PAMP/DAMPs, BSK5-overexpressing plants displayed higher levels of immune responses, including production of reactive oxygen species, callose deposition at the cell wall, and PATHOGENESIS-RELATED1 (PR1) gene expression. Together, these findings further substantiate the role of BSK5 in plant immunity and illustrate its potential use for improving plant disease resistance.
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- Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination and diagnostics. [Journal Article]
- MIMicrobes Infect 2019 Jun 25
- Plague is a vector-borne disease caused by Yersinia pestis. Transmitted by fleas from rodent reservoirs, Y. pestis emerged less than 6000 years ago from an enteric bacterial ancestor through events o…
Plague is a vector-borne disease caused by Yersinia pestis. Transmitted by fleas from rodent reservoirs, Y. pestis emerged less than 6000 years ago from an enteric bacterial ancestor through events of gene gain and genome reduction. It is a highly remarkable model for the understanding of pathogenic bacteria evolution, and a major concern for public health as highlighted by recent human outbreaks. A complex set of virulence determinants, including the Yersinia outer membrane proteins (Yops), the broad range protease Pla, pathogen-associated molecular patterns (PAMPs) and iron capture systems play critical roles in the molecular strategies that Y. pestis employs to subvert the human immune system, allowing unrestricted bacterial replication in lymph nodes (bubonic plague) and in lungs (pneumonic plague). Some of these immunogenic proteins as well as the capsular antigen F1 are exploited for diagnostic purposes, which are critical in the context of the rapid onset of death in the absence of antibiotic treatment (less than a week for bubonic plague and less than 48 h for pneumonic plague). In here, we review recent research advances on Y. pestis evolution, virulence factors function, bacterial strategies to subvert mammalian innate immune responses, vaccination and problems associated to pneumonic plague diagnosis.