Immune Defense Genes Research Articles

Comparative Genomics Screens Identify a Novel Small Secretory Peptide, SlSolP12, which Activates Both Local and Systemic Immune Response in Tomatoes and Exhibits Broad-Spectrum Activity.

Small secreted peptides (SSPs) are essential for defense mechanisms in plant-microbe interactions, acting as danger-associated molecular patterns (DAMPs). Despite the first discovery of SSPs over three decades ago, only a limited number of SSP families, particularly within Solanaceae plants, have been identified due to inefficient approaches. This study employed comparative genomics screens with Solanaceae proteomes (tomato, tobacco, and pepper) to discover a novel SSP family, SolP. Bioinformatics analysis suggests that SolP may serve as an endogenous signal initiating the plant PTI response. Interestingly, SolP family members from tomato, tobacco, and pepper share an identical sequence (VTSNALALVNRFAD), named SlSolP12 (also referred to as NtSolP15 or CaSolP1). Biochemical and phenotypic analyses revealed that synthetic SlSolP12 peptide triggers multiple defense responses: ROS burst, MAPK activation, callose deposition, stomatal closure, and expression of immune defense genes. Furthermore, SlSolP12 enhances systemic resistance against Botrytis cinerea infection in tomato plants and interferes with classical peptides, flg22 and Systemin, which modulate the immune response. Remarkably, SolP12 activates ROS in diverse plant species, such as Arabidopsis thaliana, soybean, and rice, showing a broad spectrum of biological activities. This study provides valuable approaches for identifying endogenous SSPs and highlights SlSolP12 as a novel DAMP that could serve as a useful target for crop protection.

Expression of genes related to ileal barrier function in heritage and modern broiler chickens

ABSTRACT 1. An experiment was conducted to determine differences in the expression of genes encoding intestinal barrier proteins between fast, medium and slow-growing chickens. Chicken breeds Athens Canadian Random Bred (ACRB), Longenecker’s Heritage (LHR), RedBro, Hubbard H1 (HH1), Cobb500 and Ross708 were raised from hatch for 35 d. 2. Ileal samples were collected at embryonic day E19 (−2 days post-hatch), hatch and d 7, 14, 21, 28 and 35 post-hatch to assess the expression of genes encoding tight junction proteins (claudins, CLDN; occludin, OCLN; zonula occludens, ZO; and junctional adhesion molecules, JAM), mucin (Muc2), immunoglobulin A (IgA), polymeric immunoglobulin receptor (pIgR) and fatty acid binding protein (FABP2). 3. Expression of CLDN-1 was increased (p < 0.0001) in LHR compared to Cobb500 while CLDN-5 was increased (p < 0.0001) in ACRB, HH1, RedBro and Ross708 compared to LHR as well as in ACRB compared to Cob500. Occludin was upregulated (p = 0.01) in ACRB and LHR compared to Ross708 at d 14 post-hatch. Expression of ZO-1 was upregulated (p = 0.001) in LHR compared to Ross708, HH1 and Cobb500. Tight junction genes, except CLDN-4, JAM-2 and JAM-3 were downregulated (p < 0.0001) at hatch and d 7 post-hatch. Expression of Muc2 was increased (p < 0.0001) in LHR compared to RedBro and from −2 d to d 7 post-hatch. 4. Immunoglobulin A was increased (p = 0.001) in LHR compared to Ross708 and HH1 at −2 d post-hatch and in LHR compared to ACRB, Cobb500 and Ross708 at hatch. In addition, IgA expression was increased in all breeds at d 14 post-hatch while pIgR was upregulated (p = 0.02) in Cobb500 and Ross708 compared to ACRB, HH1, LHR and RedBro at hatch. 5. The gene expression patterns suggest that selection for growth may have not induced changes in junctional complexes and immune defence genes. However, the results confirmed that the expression of these genes is age dependent.

УРОВЕНЬ ЭКСПРЕССИИ ГЕНОВ ИММУННОГО СТАТУСА В КРОВИ У ПОРОСЯТ-ГИПОТРОФИКОВ

The article presents data on the level of expression of immune defense genes in normotrophic and hypotrophic piglets. 20 sows of 3–4 farrows and the offspring obtained from them were selected for the experiment. The piglets underwent clinical examination and weighing. Not reaching 800 g animals were counted as piglets-hypotrophic, animals over 800 g – respectively normotrophic. In the blood of normotrophic and hypotrophic piglets, the gene expression levels of IL-1β, TGF-β and TNF-α have minor changes: an increase in hypotrophic piglets by 1.2 and 1.1 times. However, the level of expression of the IFN-α gene in hypotrophic piglets was 4.2 times higher than in normotrophic piglets, which may be due to the immune response against the background of malnutrition, namely possible pyrogenicity.

NLRs derepress MED10b- and MED7-mediated repression of jasmonate-dependent transcription to activate immunity

Plant intracellular nucleotide-binding domain, leucine-rich repeat-containing receptors (NLRs) activate a robust immune response upon detection of pathogen effectors. How NLRs induce downstream immune defense genes remains poorly understood. The Mediator complex plays a central role in transducing signals from gene-specific transcription factors to the transcription machinery for gene transcription/activation. In this study, we demonstrate that MED10b and MED7 of the Mediator complex mediate jasmonate-dependent transcription repression, and coiled-coil NLRs (CNLs) in Solanaceae modulate MED10b/MED7 to activate immunity. Using the tomato CNL Sw-5b, which confers resistance to tospovirus, as a model, we found that the CC domain of Sw-5b directly interacts with MED10b. Knockout/down of MED10b and other subunits including MED7 of the middle module of Mediator activates plant defense against tospovirus. MED10b was found to directly interact with MED7, and MED7 directly interacts with JAZ proteins, which function as transcriptional repressors of jasmonic acid (JA) signaling. MED10b-MED7-JAZ together can strongly repress the expression of JA-responsive genes. The activated Sw-5b CC interferes with the interaction between MED10b and MED7, leading to the activation of JA-dependent defense signaling against tospovirus. Furthermore, we found that CC domains of various other CNLs including helper NLR NRCs from Solanaceae modulate MED10b/MED7 to activate defense against different pathogens. Together, our findings reveal that MED10b/MED7 serve as a previously unknown repressor of jasmonate-dependent transcription repression and are modulated by diverse CNLs in Solanaceae to activate the JA-specific defense pathways.

Rejection of Lepeophtheirus salmonis driven in part by chitin sensing is not impacted by seawater acclimitization in Coho salmon (Oncorhynchus kisutch)

There is tremendous variation in life-history strategies among anadromous salmonids. Species that enter the ocean environment at small sizes (< 20 g) are likely under more physiological pressure from pathogens; however, little data is available on responses at these early stages. With this in mind, we performed salmon louse challenges with Coho salmon either immediately after seawater entry (SW; ca. 10 g) or after 30 days in SW (ca. 20 g). Irrespective of size or time in SW, parasites were rapidly rejected by the host, with > 90% of all parasites lost by 16 days post-infection (dpi). Rejection was concomitant with host epithelial granulomatous infiltrations that initially targeted the embedded frontal filament (4 dpi) and the entire parasite by 10 dpi. Illumina sequencing, followed by functional enrichment analysis, revealed a concerted defense response in the fin within 1 dpi that included multiple innate and adaptive immunity components. Strikingly, early indications of an allergic-type inflammatory response were associated with chitin sensing pathways orchestrated by early overexpression of the IgE-receptor, fcer1g. Additionally, there was profound overexpression of several classes of c-type lectin receptors, including dectin-2, mincle, and dc-sign at 1 dpi onward. These profiles and upregulation of cellular effector markers were corroborated by histopathological evaluation, revealing the simultaneous presence of mast cell/eosinophilic granular cells, sacciform cells, macrophages/histiocytes, and granulocytes in fin. At 10 dpi and concurrent with parasite expulsion, there was evidence of immunoregulation in addition to tissue remodelling pathways. At 16 dpi, the response was effectively abrogated. Simultaneous profiling of the parasite transcriptome revealed early induction of chitin metabolism and immunomodulation, toxin production and ECM degradation; however, after 7 dpi, these were replaced with overexpression of stress and immune defense genes. These data present the first evidence for Coho salmon demonstrating chitin- and sugar moiety-sensing as key drivers of salmon louse rejection.

Studies of Streptococcus anginosus Virulence in Dictyostelium discoideum and Galleria mellonella Models.

For many years, Streptococcus anginosus has been considered a commensal colonizing the oral cavity, as well as the gastrointestinal and genitourinary tracts. However, recent epidemiological and clinical data designate this bacterium as an emerging opportunistic pathogen. Despite the reported pathogenicity of S. anginosus, the molecular mechanism underpinning its virulence is poorly described. Therefore, our goal was to develop and optimize efficient and simple infection models that can be applied to examine the virulence of S. anginosus and to study host-pathogen interactions. Using 23 S. anginosus isolates collected from different infections, including severe and superficial infections, as well as an attenuated strain devoid of CppA, we demonstrate for the first time that Dictyostelium discoideum is a suitable model for initial, fast, and large-scale screening of virulence. Furthermore, we found that another nonvertebrate animal model, Galleria mellonella, can be used to study the pathogenesis of S. anginosus infection, with an emphasis on the interactions between the pathogen and host innate immunity. Examining the profile of immune defense genes, including antimicrobial peptides, opsonins, regulators of nodulation, and inhibitors of proteases, by quantitative PCR (qPCR) we identified different immune response profiles depending on the S. anginosus strain. Using these models, we show that S. anginosus is resistant to the bactericidal activity of phagocytes, a phenomenon confirmed using human neutrophils. Notably, since we found that the data from these models corresponded to the clinical severity of infection, we propose their further application to studies of the virulence of S. anginosus.

Exosomes Released by Influenza-Virus-Infected Cells Carry Factors Capable of Suppressing Immune Defense Genes in Naïve Cells.

Background: Exosomes are involved in intercellular communication and can transfer regulatory molecules between cells. Consequently, they can participate in host immune response regulation. For the influenza A virus (IAV), there is very limited information on changes in exosome composition during cell infection shedding light on the potential role of these extracellular membrane vesicles. Thus, the aim of our work was to study changes in exosomal composition following IAV infection of cells, as well as to evaluate their effect on uninfected cells. Methods: To characterize changes in the composition of cellular miRNAs and mRNAs of exosomes during IAV infection of A549 cells, NGS was used, as well as PCR to identify viral genes. Naïve A549 cells were stimulated with infected-cell-secreted exosomes for studying their activity. Changes in the expression of genes associated with the cell's immune response were shown using PCR. The effect of exosomes on IAV replication was shown in MDCK cells using In-Cell ELISA and PCR of the supernatants. Results: A change in the miRNA composition (miR-21-3p, miR-26a-5p, miR-23a-5p, miR-548c-5p) and mRNA composition (RPL13A, MKNK2, TRIB3) of exosomes under the influence of the IAV was shown. Many RNAs were involved in the regulation of the immune response of the cell, mainly by suppressing it. After exosome stimulation of naïve cells, a significant decrease in the expression of genes involved in the immune response was shown (RIG1, IFIT1, MDA5, COX2, NFκB, AnxA1, PKR, IL6, IL18). When infecting MDCK cells, a significant decrease in nucleoprotein levels was observed in the presence of exosomes secreted by mock-infected cells. Viral levels in supernatants also decreased. Conclusions: Exosomes secreted by IAV-infected cells could reduce the immune response of neighboring intact cells, leading to more effective IAV replication. This may be associated both with regulatory functions of cellular miRNAs and mRNAs carried by exosomes, or with the presence of viral mRNAs encoding proteins with an immunosuppressive function.

Bromodomain-containing factor GTE4 regulates Arabidopsis immune response

BackgroundPlants are continuously challenged with biotic stress from environmental pathogens, and precise regulation of defense responses is critical for plant survival. Defense systems require considerable amounts of energy and resources, impairing plant growth, and plant hormones controlling transcriptional regulation play essential roles in establishing the appropriate balance between defense response to pathogens and growth. Chromatin regulators modulating gene transcription are broadly involved in regulating stress-responsive genes. However, which chromatin factors are involved in coordinating hormone signaling and immune responses in plants, and their functional mechanisms, remains unclear. Here, we identified a role of bromodomain-containing protein GTE4 in negatively regulating defense responses in Arabidopsis thaliana.ResultsGTE4 mainly functions as activator of gene expression upon infection with Pseudomonas syringe. Genome-wide profiling of GTE4 occupancy shows that GTE4 tends to bind to active genes, including ribosome biogenesis related genes and maintains their high expression levels during pathogen infection. However, GTE4 is also able to repress gene expression. GTE4 binds to and represses jasmonate biosynthesis gene OPR3. Disruption of GTE4 results in overaccumulation of jasmonic acid (JA) and enhanced JA-responsive gene expression. Unexpectedly, over-accumulated JA content in gte4 mutant is coupled with downregulation of JA-mediated immune defense genes and upregulation of salicylic acid (SA)-mediated immune defense genes, and enhanced resistance to Pseudomonas, likely through a noncanonical pathway.ConclusionsOverall, we identified a new role of the chromatin factor GTE4 as negative regulator of plant immune response through inhibition of JA biosynthesis, which in turn noncanonically activates the defense system against Pseudomonas. These findings provide new knowledge of chromatic regulation of plant hormone signaling during defense responses.

Expression of immune response genes in human corneal epithelial cells interacting with Aspergillus flavus conidia

BackgroundAspergillus flavus, one of the causative agents of human fungal keratitis, can be phagocytosed by human corneal epithelial (HCE) cells and the conidia containing phagosomes mature into phagolysosomes. But the immunological responses of human corneal epithelial cells interacting with A. flavus are not clear. In this study, we report the expression of immune response related genes of HCE cells exposed to A. flavus spores using targeted transcriptomics.MethodsHuman corneal epithelial cell line and primary cultures were grown in a six-well plate and used for coculture experiments. Internalization of the conidia was confirmed by immunofluorescence microscopy of the colocalized endosomal markers CD71 and LAMP1. Total RNA was isolated, and the quantity and quality of the isolated RNA were assessed using Qubit and Bioanalyzer. NanoString nCounter platform was used for the analysis of mRNA abundance using the Human Immunology panel. R-package and nSolver software were used for data analysis. KEGG and FunRich 3.1.3 tools were used to analyze the differentially expressed genes.ResultsDifferent morphotypes of conidia were observed after 6 h of coculture with human corneal epithelial cells and found to be internalized by epithelial cells. NanoString profiling showed more than 20 differentially expressed genes in immortalized human corneal epithelial cell line and more than ten differentially expressed genes in primary corneal epithelial cells. Distinct set of genes were altered in their expression in cell line and primary corneal epithelial cells. KEGG pathway analysis revealed that genes associated with TNF signaling, NF-KB signaling, and Th17 signaling were up-regulated, and genes associated with chemokine signaling and B cell receptor signaling were down regulated. FunRich pathway analysis showed that pathways such as CDC42 signaling, PI3K signaling, and Arf6 trafficking events were activated by the clinical isolates CI1123 and CI1698 in both type of cells.ConclusionsCombining the transcript analysis data from cell lines and primary cultures, we showed the up regulation of immune defense genes in A. flavus infected cells. At the same time, chemokine signaling and B cell signaling pathways are downregulated. The variability in the expression levels in the immortalized cell line and the primary cultures is likely due to the variable epigenetic reprogramming in the immortalized cells and primary cultures in the absence of any changes in the genome. It highlights the importance of using both cell types in host-pathogen interaction studies.

Characterization and expression analysis of differentially expressed genes in the red swamp crayfish Procambarus clarkii in response to Vibrio cholerae challenge

Procambarus clarkii is an important freshwater aquaculture species. One of the most serious diseases in P. clarkii is rotten shell disease. However, there is few report about the immune response of P. clarkii hepatopancreas to Vibrio cholerae. Using transcriptome analysis, this research investigated the immunological response of P. clarkii to V. cholerae at the gene expression level. It was found that 44,043,166 cleaning readings were present in the treatment group. A total of 34,237 unigenes were discovered, with a mean length of 1507. Moreover, 360 unigenes were found to have significantly altered expression, with 102 of them being considerably up-regulated. According to further annotation and analysis, it was found that DEGs are rich in Glutathione metabolism, Lysosome, Phagosome, Apoptosis, Adherens junction, and Leukocyte transient migration. These pathways are mostly associated with antioxidants, phagocytosis, and pathogen clearance. Furthermore, quantitative real time-PCR (qRT-PCR) confirmed the up-regulation of immune defense genes of DEGs, which supported the RNA-seq data. This study may serve as a foundation for future research on the immunological response of P. clarkii, as well as provide recommendations for P. clarkii against V. cholerae infection.

Light spectra influence the reproductive performance and expression of immune and anti-oxidative defense genes in endangered golden mahseer (Tor putitora) female brooders

Present study was aimed to assess the effects of different light spectra on reproductive performance and mRNA expression of some immune and anti-oxidant defense genes in endangered golden mahseer. The relative fecundity of brooders and fertilization rate of eggs did not change due to different light spectra. Whereas there was significantly higher rate of hatching (%) of eggs and survival (%) of fry obtained from brooders reared in white and green light compared to blue light. No significant effect of light spectra was observed on the expression levels of il1β, il10, tlr5, and inos. There was a linear increase in the relative expression of serum amyloid A (saa) (Y = 1.980x – 0.118, R2 = 0.972) and igl (Y = 1.077x + 0.093, R2 = 0.998) from white light to green light with maximum values found under green light. The mhc1 level was higher in white and green lights compared to blue spectra. A positive linear correlation was noticed between mRNA expression of crfb4 and hatching percentage (Y = 13.95x + 69.07, R2 = 0.920) of the eggs as well as survival percentage of fry (Y = 0.054x – 3.520, R2 = 0.985) obtained from brooders under different light spectra. The expression levels of all three anti-oxidative defense genes were significantly and similarly affected by light spectra. The maximum expression of anti-oxidative genes was registered in white light, and the minimum was observed in blue light. Overall, the results suggested a higher reproductive performance and immune status of golden mahseer female brooders reared under green light. Hence, green lights could be a better option for broodstock management of golden mahseer in captive conditions.

Host-specific gene expression as a tool for introduction success in Naupactus parthenogenetic weevils.

Food resource access can mediate establishment success in invasive species, and generalist herbivorous insects are thought to rely on mechanisms of transcriptional plasticity to respond to dietary variation. While asexually reproducing invasives typically have low genetic variation, the twofold reproductive capacity of asexual organisms is a marked advantage for colonization. We studied host-related transcriptional acclimation in parthenogenetic, invasive, and polyphagous weevils: Naupactus cervinus and N. leucoloma. We analyzed patterns of gene expression in three gene categories that can mediate weevil-host plant interactions through identification of suitable host plants, short-term acclimation to host plant defenses, and long-term adaptation to host plant defenses and their pathogens. This approach employed comparative transcriptomic methods to investigate differentially expressed host detection, detoxification, immune defense genes, and pathway-level gene set enrichment. Our results show that weevil gene expression responses can be host plant-specific, and that elements of that response can be maintained in the offspring. Some host plant groups, such as legumes, appear to be more taxing as they elicit a complex gene expression response which is both strong in intensity and specific in identity. However, the weevil response to taxing host plants shares many differentially expressed genes with other stressful situations, such as host plant cultivation conditions and transition to novel host, suggesting that there is an evolutionarily favorable shared gene expression regime for responding to different types of stressful situations. Modulating gene expression in the absence of other avenues for phenotypic adaptation may be an important mechanism of successful colonization for these introduced insects.

Antimicrobial peptide and sequence variation along a latitudinal gradient in two anurans

BackgroundWhile there is evidence of both purifying and balancing selection in immune defense genes, large-scale genetic diversity in antimicrobial peptides (AMPs), an important part of the innate immune system released from dermal glands in the skin, has remained uninvestigated. Here we describe genetic diversity at three AMP loci (Temporin, Brevinin and Palustrin) in two ranid frogs (Rana arvalis and R. temporaria) along a 2000 km latitudinal gradient. We amplified and sequenced part of the Acidic Propiece domain and the hypervariable Mature Peptide domain (~ 150-200 bp) in the three genes using Illumina Miseq and expected to find decreased AMP genetic variation towards the northern distribution limit of the species similarly to studies on MHC genetic patterns.ResultsWe found multiple loci for each AMP and relatively high gene diversity, but no clear pattern of geographic genetic structure along the latitudinal gradient. We found evidence of trans-specific polymorphism in the two species, indicating a common evolutionary origin of the alleles. Temporin and Brevinin did not form monophyletic clades suggesting that they belong to the same gene family. By implementing codon evolution models we found evidence of strong positive selection acting on the Mature Peptide. We also found evidence of diversifying selection as indicated by divergent allele frequencies among populations and high Theta k values.ConclusionOur results suggest that AMPs are an important source of adaptive diversity, minimizing the chance of microorganisms developing resistance to individual peptides.

New insight into the molecular basis of Fe (III) stress responses of Procambarus clarkii by transcriptome analysis

Iron in excess can have toxic effects on living organisms. In China, the freshwater crayfish Procambarus clarkii is a source of aquatic food with high-quality protein and has significant commercial value. P. clarkii shows oxidative stress on exposure to heavy metals, and antioxidant enzymes, such as ubiquitination enzymes and proteasomes, play important roles in oxidative stress. To understand the antioxidant defense system of P. clarkii, we analyzed the hepatopancreas transcriptomes of P. clarkii after stimulation with FeCl3. In total, 5199 differentially expressed genes (DEGs) were identified (2747 upregulated and 2452 downregulated). GO analysis revealed that these DEGs belonged to 16 cellular component, 16 molecular function, and 19 biological process subcategories. A total of 1069 DEGs were classified into 25 categories by using COG. Some antioxidant defense pathways, such as “Ubiquitin mediated proteolysis” and “Glutathione metabolism,” were identified using KEGG. In addition, quantitative real time-PCR (qRT-PCR) substantiated the up-regulation of a random selection of DEGs including antioxidant and immune defense genes. We obtained information for P. clarkii transcriptome databases and new insights into the responses of P. clarkii hepatopancreas to heavy metals.

The fatty acid oleate is required for innate immune activation and pathogen defense in Caenorhabditis elegans.

Fatty acids affect a number of physiological processes, in addition to forming the building blocks of membranes and body fat stores. In this study, we uncover a role for the monounsaturated fatty acid oleate in the innate immune response of the nematode Caenorhabditis elegans. From an RNAi screen for regulators of innate immune defense genes, we identified the two stearoyl-coenzyme A desaturases that synthesize oleate in C. elegans. We show that the synthesis of oleate is necessary for the pathogen-mediated induction of immune defense genes. Accordingly, C. elegans deficient in oleate production are hypersusceptible to infection with diverse human pathogens, which can be rescued by the addition of exogenous oleate. However, oleate is not sufficient to drive protective immune activation. Together, these data add to the known health-promoting effects of monounsaturated fatty acids, and suggest an ancient link between nutrient stores, metabolism, and host susceptibility to bacterial infection.

Effects of fluticasone propionate and budesonide on the expression of immune defense genes in bronchial epithelial cells

BackgroundCOPD patients have increased risk of pneumonia when treated with fluticasone propionate (FP), whereas this is generally not the case with budesonide (BUD) treatment. We hypothesized that BUD and FP differentially affect the expression of immune defense genes. MethodsHuman bronchial epithelial 16HBE cells and air-liquid interface (ALI)-cultured primary bronchial epithelial cells (PBECs) were pre-treated with clinically equipotent concentrations of BUD or FP (0.16–16 nM BUD and 0.1–10 nM FP), and the expression of immune defense genes was studied at baseline and after exposure to rhinovirus (RV16). ResultsUsing microfluidic cards, we observed that both BUD and FP significantly suppressed CXCL8, IFNB1 and S100A8 mRNA expression in unstimulated 16HBE cells. Interestingly, BUD, but not FP, significantly increased lactotransferrin (LTF) expression. The difference between the effect of BUD and FP on LTF expression was statistically significant and confirmed by qPCR and at the protein level by western blotting. RV16 infection of ALI-cultured PBECs significantly increased the expression of CCL20, IFNB1 and S100A8, but not of LTF or CAMP/LL-37. In these RV16-exposed cells, LTF expression was again significantly higher upon pre-treatment with BUD than with FP. The same was observed for S100A8, but not for CCL20, IFNB1 or CAMP/LL-37 expression. ConclusionsTreatment of human bronchial epithelial cells with BUD results in significantly higher expression of specific immune defense genes than treatment with FP. The differential regulation of these immune defense genes may help to explain the clinical observation that BUD and FP treatment differ with respect to the risk of developing pneumonia in COPD.

Expression of innate immune defence genes in healthy and onychomycotic nail and stratum corneum

Onychomycosis, a fungal infection of the nail, is predominantly caused by dermatophytes1. Our understanding of the pathogenic response to these fungi and their ability to establish chronic infection and evade immune clearance remains limited2. Evidence suggests an association between onychomycosis and immunosuppression3 but the nail plate represents a site of infection with negligible adaptive immune cell presence; the host response here led largely by components of the innate immune system4 including antimicrobial peptides (AMP). AMP are a cornerstone of innate host defence4, but their role in onychomycosis, is poorly understood. This study is the first detailed investigation of associations between innate immune defence gene expression and onychomycosis. This article is protected by copyright. All rights reserved.

TLR ligands, but not modulators of histone modifiers, can induce the complex immune response pattern of endotoxin tolerance in mammary epithelial cells.

Excessive stimulation of the TLR4 axis through LPS reduces the expression of some cytokine genes in immune cells, while stimulating the expression of immune defense genes during a subsequent bacterial infection. This endotoxin tolerance (ET) is mediated via epigenetic mechanisms. Priming the udder of cows with LPS was shown to induce ET in mammary epithelial cells (MEC), thereby protecting the udder against reinfection for some time. Seeking alternatives to LPS priming we tried to elicit ET by priming MEC with either lipopeptide (Pam2CSK4) via the TLR2/6 axis or inhibitors of histone-modifying enzymes. Pre-incubation of MEC with Pam2CSK4 enhanced baseline and induced expression of bactericidal (β-defensin; SLPI) and membrane protecting factors (SAA3, TGM3), while reducing the expression of cytokine- and chemokine-encoding genes (TNF, IL1β) after a subsequent pathogen challenge, the latter, however, not as efficiently as after LPS priming. Pre-treating MEC with various inhibitors of histone H3 modifiers (for demethylation, acetylation or deacetylation) all failed to induce any of the protective factors and only resulted in some dampening of cytokine gene expression after the re-challenge. Hence, triggering immune functions via the TLR axis, but not through those histone modifiers, induced the beneficial phenomenon of ET in MEC.

Annotation of the Asian Citrus Psyllid Genome Reveals a Reduced Innate Immune System

Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as Huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Hemipterans characterized to date lack a number of insect immune genes, including those associated with the Imd pathway targeting Gram-negative bacteria. The D. citri draft genome was used to characterize the immune defense genes present in D. citri. Predicted mRNAs identified by screening the published D. citri annotated draft genome were manually searched using a custom database of immune genes from previously annotated insect genomes. Toll and JAK/STAT pathways, general defense genes Dual oxidase, Nitric oxide synthase, prophenoloxidase, and cellular immune defense genes were present in D. citri. In contrast, D. citri lacked genes for the Imd pathway, most antimicrobial peptides, 1,3-β-glucan recognition proteins (GNBPs), and complete peptidoglycan recognition proteins. These data suggest that D. citri has a reduced immune capability similar to that observed in A. pisum, P. humanus, and R. prolixus. The absence of immune system genes from the D. citri genome may facilitate CLas infections, and is possibly compensated for by their relationship with their microbial endosymbionts.

Impact of CTLA4 Genotype and Other Immune Response Gene Polymorphisms on Outcomes after Umbilical Cord Blood Transplantation - a Eurocord, CBC-Ctiwb-EBMT, Netcord and FMRP-USP Study

Introduction: Donor and recipient polymorphisms of immune defense and inflammatory cytokine genes have been associated with outcomes after bone marrow or peripheral blood stem cell transplantation (SCT), but have not been described in the setting of umbilical cord blood transplantation (CBT).Material and Methods: We evaluated the impact of genetic polymorphisms of recipients and CBU units on survival and other CBT outcomes using the following candidate genes related to immune response: NACHT-leucine-rich repeat with a pyrin domain at N-terminus (NLRP1-rs5862, NLRP2-rs043684, NLRP3-rs10754558), Toll-interleukin-1 receptor domain containing adaptor protein (TIRAP/Mal-rs8177374), interleukin-10 (IL10-rs1800872), V-rel reticuloendotheliosis viral oncogene homolog (REL-rs13031237), tumor necrosis factor receptor superfamily - member 1B (TNFRSF1B-rs1061622) and associated protein 4 of cytotoxic T lymphocyte (CTLA4-rs3087243). Seven Netcord banks provided pre-transplant DNA samples from 851 CBU units and 173 recipients. All patients underwent CBT at EBMT centers. Malignant (n=696) and non-malignant (n=155) diseases were analyzed separately.Results: Among the 851 recipients, 57% were male and 61% adults. Degree of HLA matching between CBU unit and recipient (HLA-A, -B at antigen level and -DRB1 at allele level) was 6/6 in 12%, 5/6 in 40%, and ≤4/6 in 48% of transplants. Myeloablative conditioning was used in 77% of cases and anti-thymocyte globulin or monoclonal antibodies in 82% of cases. Median infused total nucleated cells (TNC) and CD34+ cells were 3.7x107/kg and 1.6x105/kg, respectively. In the cohort with malignant diseases, multivariable analysis adjusted for patient-, donor- and disease-related variables showed that recipients of CBU with GG CTLA4 genotype had a poorer neutrophil engraftment (HR 1.24; 95% CI 1.09-1.40; p=0.03), increased NRM (HR 1.52; 95% CI 1.35-1.72%; p<0.01) and inferior disease-free survival (DFS) (HR 1.41; 95% CI 1.06-1.88; p=0.02), whereas the AA CTLA4 genotype was associated with lower relapse rate (HR 0.64; 95% CI 0.57-0.72; p=0.02). Recipients of GG TNFRSF1B CBU had lower platelet recovery (HR 1.94; 95% CI 1.71-2.19; p=0.02). With the aim to confirm these results in a more homogenous cohort of recipients, we analyzed recipients with acute leukemias, receiving myeloablative conditioning and with available high resolution typing of HLA-A,-B,-C and-DRB1 (n=305). In this subset analysis, recipients of GG CTLA4 CBU had increased NRM (HR 1.72; 95% CI 1.10-2.70%; p=0.02), but no impact on DFS and relapse was observed. In the cohort of patients with non-malignant diseases (n=155), there was no statistical association between the selected candidate genes and outcomes. Similarly, all recipient gene polymorphisms tested (n=173) were not associated with CBT outcomes.Conclusion: In this retrospective analysis, CBU gene polymorphisms CTLA4 and TNFSF1B impacted CBT outcomes. Importantly, CTLA4 GG genotype was associated with inferior survival and the AA genotype with lower relapse rate in patients with malignant disorders. The possible biological explanation of the impact of CTLA4 is that GG genotype is associated with decreased production of soluble CTLA4 (whose primarily functions is to inhibit T-cell activation) which contributes to decrease suppression of T-cell alloimune responses post CBT If these findings are confirmed in further studies, CTLA4 gene polymorphisms can be used among other factors to select CBU with the aim to improve survival after CBT. DisclosuresNo relevant conflicts of interest to declare.