Host Tissue Destruction Research Articles

Microbial diagnostics in periodontal diseases.

Microbial analytical methods have been instrumental in elucidating the complex microbial etiology of periodontal diseases, by shaping our understanding of subgingival community dynamics. Certain pathobionts can orchestrate the establishment of dysbiotic communities that can subvert the host immune system, triggering inflammation and tissue destruction. Yet, diagnosis and management of periodontal conditions still rely on clinical and radiographic examinations, overlooking the well-established microbial etiology. This review summarizes the chronological emergence of periodontal etiological models and the co-evolution with technological advances in microbial detection. We additionally review the microbial analytical approaches currently accessible to clinicians, highlighting their value in broadening the periodontal assessment. The epidemiological importance of obtaining culture-based antimicrobial susceptibility profiles of periodontal taxa for antibiotic resistance surveillance is also underscored, together with clinically relevant analytical approaches to guide antibiotherapy choices, when necessary. Furthermore, the importance of 16S-based community and shotgun metagenomic profiling is discussed in outlining dysbiotic microbial signatures. Because dysbiosis precedes periodontal damage, biomarker identification offers early diagnostic possibilities to forestall disease relapses during maintenance. Altogether, this review highlights the underutilized potential of clinical microbiology in periodontology, spotlighting the clinical areas most conductive to its diagnostic implementation for enhancing prevention, treatment predictability, and addressing global antibiotic resistance.

Effects of Everolimus in Modulating the Host Immune Responses against Mycobacterium tuberculosis Infection.

The phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (P13K/AKT/mTOR) pathway plays a key role in tuberculosis (TB) pathogenesis and infection. While the activity levels of this pathway during active infection are still debated, manipulating this pathway shows potential benefit for host-directed therapies. Some studies indicate that pathway inhibitors may have potential for TB treatment through upregulation of autophagy, while other studies do not encourage the use of these inhibitors due to possible host tissue destruction by Mycobacterium tuberculosis (M. tb) and increased infection risk. Investigating further clinical trials and their use of pathway inhibitors is necessary in order to ascertain their potential for TB treatment. This paper is particularly focused on the drug everolimus, an mTOR inhibitor. One of the first clinical trials sponsored by the Aurum Institute showed potential benefit in using everolimus as an adjunctive therapy for tuberculosis. Infection with tuberculosis is associated with a metabolic shift from oxidative phosphorylation towards glycolysis. The everolimus arm in the clinical trial showed further reduction than the control for both maximal and peak glycolytic activity. Compared with control, those receiving everolimus demonstrated increased lung function through forced expiratory volume in 1 s (FEV1) measurements, suggesting that everolimus may mitigate inflammation contributing to lung damage.

The intricate relationship between autoimmunity disease and neutrophils death patterns: a love-hate story.

Autoimmune diseases are pathological conditions that result from the misidentification of self-antigens in immune system, leading to host tissue damage and destruction. These diseases can affect different organs and systems, including the blood, joints, skin, and muscles. Despite the significant progress made in comprehending the underlying pathogenesis, the complete mechanism of autoimmune disease is still not entirely understood. In autoimmune diseases, the innate immunocytes are not functioning properly: they are either abnormally activated or physically disabled. As a vital member of innate immunocyte, neutrophils and their modes of death are influenced by the microenvironment of different autoimmune diseases due to their short lifespan and diverse death modes. Related to neutrophil death pathways, apoptosis is the most frequent cell death form of neutrophil non-lytic morphology, delayed or aberrant apoptosis may contribute to the development anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). In addition, NETosis, necroptosis and pyroptosis which are parts of lytic morphology exacerbate disease progression through various mechanisms in autoimmune diseases. This review aims to summarize recent advancements in understanding neutrophil death modes in various autoimmune diseases and provide insights into the development of novel therapeutic approaches for autoimmune diseases.

Composition of subgingival microbiota associated with periodontitis and diagnosis of malignancy-a cross-sectional study.

Periodontitis is one of the world's most prevalent infectious conditions, affecting between 25 and 40% of the adult population. It is a consequence of the complex interactions between periodontal pathogens and their products, which trigger the host inflammatory response, chronic inflammation, and tissue destruction. Chronic systemic low-grade inflammation is involved in numerous diseases, and it is also known that long-lasting inflammation and chronic infections predispose one to cancer. Here, we characterized and compared the subgingival microbiota associated with periodontitis and diagnosis of malignancy in a longitudinal 10-year follow-up study. The study was conducted on 50 patients with periodontitis and 40 periodontally healthy individuals. The recorded clinical oral health parameters were periodontal attachment loss (AL), bleeding on probing (BOP), gingival index (GI), probing depth (PD), and plaque index (PI). Subgingival plaque was collected from each participant, from which DNA was extracted, and 16S rRNA gene amplicon sequencing performed. Cancer diagnoses data were collected between the years 2008-2018 from the Swedish Cancer Registry. The participants were categorized based on having cancer at the time of sample collection (CSC), having developed cancer later (DCL), and controls without any cancer. The most abundant phyla across all 90 samples were Actinobacteria, Proteobacteria, Firmicutes, Bacteroidetes, and Fusobacteria. At the genus level, Treponema, Fretibacterium, and Prevotella were significantly more abundant in samples of periodontitis patients compared to non-periodontitis individuals. With regard to samples of cancer patients, Corynebacterium and Streptococcus were more abundant in the CSC group; Prevotella were more abundant in the DCL group; and Rothia, Neisseria, and Capnocytophaga were more abundant in the control group. In the CSC group, we also found that the presence of periodontal inflammation, in terms of BOP, GI, and PLI, significantly correlated with species belonging to the genera Prevotella, Treponema, and Mycoplasma. Our results revealed that several subgingival genera were differentially enriched among the studied groups. These findings underscore the need for further research to fully understand the role that oral pathogens may play in the development of cancer.

Inflammatory stimulation of osteoblasts and keratinocytes from a SAPHO patient for implant risk evaluation

The present report exemplifies a translational method, which could assist the clinical pre-evaluation of patients at risk before surgical interventions. In this study, a presurgical implant decision in a case of SAPHO (synovitis, acne, palmoplantar pustulosis, hyperostosis, osteitis) is described. Since the etiology of this syndrome is likely to involve genetic, infectious and immunological components, lipopolysaccharides (LPS) may conceptually trigger cytokine production leading to a specific chronic inflammation and immunological host response. This may hamper proper healing or accentuate the destruction of periodontal host tissues. In our approach, we examined the ex vivo cell viability and immune responses of primary osteoblasts and keratinocytes under sterile inflammation induced by P. gingivalis LPS. Keratinocytes and osteoblasts were obtained from biopsies of the keratinized gingiva and alveolar bone tissues of a SAPHO human subject. Enzymatically dissociated cells were thus cultured and incubated to LPS at different concentrations (50ng/ml, 200ng/ml, 500ng/ml and 1µg/ml) for 24 h in order to test inflammatory cytokine response (quantitative real time PCR) and toxicity (cell viability). Healthy primary keratinocytes and osteoblasts were used as control cells. The highest concentration of LPS (1µg/ml) significantly reduced cell viability (p < 0.05). Meanwhile, all tested LPS concentrations similarly enhanced the mRNA expressions of selected inflammatory cytokines (TNFalpha, IL-6, IL-8, IL-1beta and IL-1alpha) up to =~3.5-fold, when compared to the healthy cell controls (p < 0.05). This study demonstrated a valuable inflammatory risk evaluation before implant placement, which was successfully performed based on the presented laboratory diagnostic/prognostic approach.
 Accepted for publication: December 12, 2022
 Published online: January, 2022

A method for reducing the concentrations of Fusarium graminearum trichothecenes in durum wheat grain with the use of Debaryomyces hansenii

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is one of the most dangerous diseases of durum wheat. This hemibiotrophic pathogen transitions from the biotrophic phase, during which it penetrates host tissues and secretes trichothecenes, to the necrotrophic phase which leads to the destruction of host tissues. Yeasts applied to spikes often reduce mycotoxin concentrations, but the underlying mechanisms have not been fully elucidated. Therefore, the aim of this study was to analyze the concentrations trichothecenes in durum wheat grain and changes in the F. graminearum transcriptome under the influence the Debaryomyces hansenii antagonistic yeast strain. Debaryomyces hansenii cells adhered to and formed cell aggregates/biofilm on the surface of spikes and pathogenic hyphae. Biological control suppressed the spread of F. graminearum by 90 % and decreased the content of deoxynivalenol (DON) in spikes by 31.2 %. Yeasts significantly reduced the expression of pathogen's genes encoding the rpaI subunit of RNA polymerase I and the activator of Hsp90 ATPase, but they had no effect on mRNA transcript levels of genes encoding the enzymes involved in the biosynthesis of trichothecenes. The yeast treatment reduced the number of F. graminearum operational taxonomic units (OTUs) nearly five-fold and increased the number of D. hansenii OTUs more than six-fold in the spike mycobiome. The mechanisms that suppress infections should be explored to develop effective biological methods for reducing the concentrations mycotoxins in wheat grain.

Virulence Factors of the Periodontal Pathogens: Tools to Evade the Host Immune Response and Promote Carcinogenesis.

Periodontitis is the most common chronic, inflammatory oral disease that affects more than half of the population in the United States. The disease leads to destruction of the tooth-supporting tissue called periodontium, which ultimately results in tooth loss if uncured. The interaction between the periodontal microbiota and the host immune cells result in the induction of a non-protective host immune response that triggers host tissue destruction. Certain pathogens have been implicated periodontal disease formation that is triggered by a plethora of virulence factors. There is a collective evidence on the impact of periodontal disease progression on systemic health. Of particular interest, the role of the virulence factors of the periodontal pathogens in facilitating the evasion of the host immune cells and promotion of carcinogenesis has been the focus of many researchers. The aim of this review is to examine the influence of the periodontal pathogens Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P. gingivalis), and Fusobacterium nucleatum (F. nucleatum) in the modulation of the intracellular signaling pathways of the host cells in order to evade the host immune response and interfere with normal host cell death and the role of their virulence factors in this regard.

An apical protein, Pcr2, is required for persistent movement by the human parasite Toxoplasma gondii.

The phylum Apicomplexa includes thousands of species of unicellular parasites that cause a wide range of human and animal diseases such as malaria and toxoplasmosis. To infect, the parasite must first initiate active movement to disseminate through tissue and invade into a host cell, and then cease moving once inside. The parasite moves by gliding on a surface, propelled by an internal cortical actomyosin-based motility apparatus. One of the most effective invaders in Apicomplexa is Toxoplasma gondii, which can infect any nucleated cell and any warm-blooded animal. During invasion, the parasite first makes contact with the host cell "head-on" with the apical complex, which features an elaborate cytoskeletal apparatus and associated structures. Here we report the identification and characterization of a new component of the apical complex, Preconoidal region protein 2 (Pcr2). Pcr2 knockout parasites replicate normally, but they are severely diminished in their capacity for host tissue destruction due to significantly impaired invasion and egress, two vital steps in the lytic cycle. When stimulated for calcium-induced egress, Pcr2 knockout parasites become active, and secrete effectors to lyse the host cell. Calcium-induced secretion of the major adhesin, MIC2, also appears to be normal. However, the movement of the Pcr2 knockout parasite is spasmodic, which drastically compromises egress. In addition to faulty motility, the ability of the Pcr2 knockout parasite to assemble the moving junction is impaired. Both defects likely contribute to the poor efficiency of invasion. Interestingly, actomyosin activity, as indicated by the motion of mEmerald tagged actin chromobody, appears to be largely unperturbed by the loss of Pcr2, raising the possibility that Pcr2 may act downstream of or in parallel with the actomyosin machinery.

Locally Delivered 1.2% Simvastatin Gel and 1% Metformin Gel in Chronic Periodontitis Patients

Background: This study was carried out to investigate the effectiveness of 1.2% Simvastatin gel and 1% Metformin gel in chronic periodontitis pockets. The rationale behind using Statins is that this class of drugs has a potential anti-inflammatory effect on oral epithelial cells, blocking the intermediate metabolites of the mevalonate pathway. Statins also modulate bone formation by increasing the expression of bone morphogenetic protein-2 providing a new direction in the field of periodontal therapy. Statin administration decreases GCF levels of pro-inflammatory mediators which are responsible for much of the host tissue destruction seen in periodontitis. Metformin acts at molecular level via both AMPK (5’adenosine monophosphate activated protein kinase) dependent & AMPK independent pathways. It shows effects on Nuclear Factor-κB (NF-κB), differentiation of monocytes into macrophages as well as suppressing IL-2, interferon (IFN)-γ and TNF-α from these macrophages which thereby improved the periodontal clinical parameters. There is no evidence of literature till now comparing the clinical efficacy of 1.2% Simvastatin gel with 1% Metformin gel in patients with chronic periodontitis. Method: The study population consisted of 48 sites from chronic periodontitis patients, divided into 3 groups which received sub gingival irrigation with Scaling and root planning alone, SRP with 1.2% Simvastatin gel and SRP with1% Metformin gel. Results: 1.2% Simvastatin gel and 1% Metformin gel improve the periodontal health with statistically significant improvement in the PPD, RAL, RGML values as compared to SRP alone. Conclusion: LDD systems using gel formulations are advantageous because of their sustainability, prolonged release, stability in the pockets, clinical effect of 1.2% Simvastatin gel and 1% Metformin gel improves the periodontal health compared to SRP alone.

Biomarkers in Ocular Graft-Versus-Host Disease: Implications for the Involvement of B Cells

Graft-versus-host disease (GVHD) is an immune-mediated inflammatory disease resulting from destruction of host tissue by donor immunoreactive cells and occurs in 30% to 70% of post-hematopoietic stem cell transplantation (HSCT) patients. Ocular involvement occurs in up to 60% to 90% of patients with chronic GVHD. T cells have long been recognized as a key driver of alloreactivity in chronic ocular GVHD (oGVHD). However, the role of B-cells has not been elucidated. To further explore the involvement of B-cells in the immune mechanism of chronic oGVHD and to uncover more sensitive biomarker indicators, we conducted this study on the tear cytokine analysis of chronic oGVHD. The study enrolled 18 patients (27 eyes) diagnosed with chronic oGVHD and 11 patients (22 eyes) diagnosed with dry eye disease (DED) as a control group. The microsphere-based immunoassay was used to determine 29 tear cytokines in both groups. Spearman's test was used to analyze the correlation between cytokine levels and different ophthalmic indexes (National Institutes of Health eye score, fluorescein tear film break-up time, corneal fluorescein staining, and Schirmer's test). Receiver operating characteristic curves were used to assess the predictive potential of the identified cytokines for chronic oGVHD. Twenty tear cytokine levels were elevated in patients with chronic oGVHD compared to those with DED (P < .05). Proliferation-inducing ligand (APRIL) and epidermal growth factor showed lower levels in patients with chronic oGVHD. Ultimately, IL-2, 6, and 8, ICAM-1 (CD54), E-selectin (CD62E), neuropilin-1, and B-cell activation factor (BAFF) levels had a strong correlation with ophthalmic indexes and an area under the curve (AUC) > 0.85. BAFF/APRIL exhibited superior diagnostic capabilities (AUC = 0.995; 95% confidence interval, 0.983-1.000). Our study identified IL-2, 6, 8, ICAM-1, CD62E, E-selectin, neuropilin-1, and BAFF as promising tear biomarkers that can indicate the severity of chronic oGVHD. Notably, APRIL/BAFF shows superior diagnostic capabilities, revealing that B cells may play an important role as immune substrates in chronic oGVHD. © 2023 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Genomic characterization and pathogenicity analysis of the Vibrio mimicus Y4 causing red body disease in Macrobrachium nipponense

Vibrio mimicus distributes widely in the aquatic ecosystem and causes vibriosis in various aquatic animals. For the past few years, Macrobrachium nipponense has been suffering from red body disease with significant economic loss in Jiangsu, and V. mimicus is recognized to be the etiological agent of the disease. In this study we investigated the pathogenicity and antibiotic resistance of V. mimicus Y4 which caused red body disease in M. nipponense in the genomic level. In addition, the high pathogenicity of V. mimicus Y4 was further verified by survival analysis and lesions of hepatopancreas and gill tissues of M. nipponense. The complete genome sequence analysis showed that its genome contained two circular chromosomes and one plasmid with a total size of 4,347,065 bp, which harbored 4084 coding genes. Among these genes, 387 genes were predicted as virulence related genes which could be classified as type IV pilus, flagella, hemolysin, heme receptors, type VI secretion system, and so on, which are involved in the colonization, invasion and destruction of host tissues; 129 genes were predicted as antibiotic resistance genes, including aminoglycoside resistant, macrolide resistant, beta-lactam resistant, and polymyxin resistant genes, which agree with the antibiotic resistance results, which indicated V. mimicus Y4 to be a multidrug-resistant bacterium. The LD50 of the strain Y4 to M. nipponense was 3.28 × 105 CFU/mL at 96 h post-infection. Histopathological analysis exhibited obvious severe lesions of hepatopancreas and gill tissues of diseased M. nipponense, such as the basal laminae of the hepatopancreatic tubules were rupture, vacuolation were decreased, and gill filament cells were broken in diseased prawns. This study provides a theoretical basis for better understanding of the pathogenicity and antibiotic resistance, which might contribute to the prevention of V. mimicus in the future.

The Basics of Infectious Diseases

Infectious Diseases result from exposure and contact between a host (human being) and an (uninvited) guest (micro-organism). Given the fact that billions of micro-organisms are in and around us at any time, overall, infectious diseases are comparatively rare; of the millions of different microbial species, only about 300 are known to cause human diseases. Besides exposure and contact, factors on the side of the host (genetic background, environment, underlying diseases and their therapy) and on the side of the micro-organisms (pathogenicity / virulence factors) are necessary to result in an infectious disease. “Colonization” means that a micro-organism can attach on skin or mucous membrane for some time or even indefinitely but does not invade host tissue and does not cause any symptoms. Colonizers may even induce an immune response. “Infection” is defined as a micro-organism invading through skin or mucous membranes the tissue of a host, leading to no disease (“asymptomatic infection”); or symptomatic disease. It is followed by health, disability, or death. Following the infection, microorganisms may persist in the body for a long time or even for life without causing any symptoms, which is called “latent infection”. Infectious diseases may not only be due to pathogenicity factors of a micro-organism, but may also result from (i.) direct destruction of host tissues (e.g., from viral replication); (ii.) the acute host (immune-) response; and from late immune responses resulting in immune-mediated “post-infectious diseases”. Some infections may cause an immune response that is directed against host-tissue, resulting in an “autoimmune-disease”. Given the increasing number of microbes, the increasing number of exposures, and the increasing number and fraction of susceptible/predisposed humans, it is obvious that infectious diseases will increase in the future. Vaccines and vaccination may help solve this problem.

Not-so-opposite ends of the spectrum: CD8+ T cell dysfunction across chronic infection, cancer and autoimmunity.

CD8+ T cells are critical mediators of cytotoxic effector function in infection, cancer and autoimmunity. In cancer and chronic viral infection, CD8+ T cells undergo a progressive loss of cytokine production and cytotoxicity, a state termed T cell exhaustion. In autoimmunity, autoreactive CD8+ T cells retain the capacity to effectively mediate the destruction of host tissues. Although the clinical outcome differs in each context, CD8+ T cells are chronically exposed to antigen in all three. These chronically stimulated CD8+ T cells share some common phenotypic features, as well as transcriptional and epigenetic programming, across disease contexts. A better understanding of these CD8+ T cell states may reveal novel strategies to augment clearance of chronic viral infection and cancer and to mitigate self-reactivity leading to tissue damage in autoimmunity.

DOES TOLL LIKE RECEPTORS HAVE DOUBLE EDGE? : A REVIEW

Vertebral immunity can be broadly classified into adaptive and innate immunity .Innate immunity is the first line of defense. Adaptive immunity are regulated by clonally distributed B and T lymphocytes and are characterized by specificity and memory .Innate immunity works through toll-like receptors (TLRs), which recognize the molecular patterns on virulent bacteria known as pathogen-associated molecular patterns(PAMP). The periodontium is constantly exposed to microorganisms which inturn stimulates the innate immune sytem. The toll like receptors present on gingival epithelial cells are continuously stimulated, resulting in production of cytokines and defensins that help to maintain oral health. If the epithelial barrier is breached, allowing invasion of bacteria into the underlying connective tissue, the TLRs on other resident and non-resident cells of the periodontium become activated. This leads to an exaggerated release of pro-inflammatory cytokines and other biological mediators, which may cause host tissue destruction. The present review examines the role of TLRs and their signaling in periodontal health and disease

Neutrophils in the Pathogenesis of Rheumatoid Arthritis and Systemic Lupus Erythematosus: Same Foe Different M.O.

Dysregulated neutrophil activation contributes to the pathogenesis of autoimmune diseases including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Neutrophil-derived reactive oxygen species (ROS) and granule proteases are implicated in damage to and destruction of host tissues in both conditions (cartilage in RA, vascular tissue in SLE) and also in the pathogenic post-translational modification of DNA and proteins. Neutrophil-derived cytokines and chemokines regulate both the innate and adaptive immune responses in RA and SLE, and neutrophil extracellular traps (NETs) expose nuclear neoepitopes (citrullinated proteins in RA, double-stranded DNA and nuclear proteins in SLE) to the immune system, initiating the production of auto-antibodies (ACPA in RA, anti-dsDNA and anti-acetylated/methylated histones in SLE). Neutrophil apoptosis is dysregulated in both conditions: in RA, delayed apoptosis within synovial joints contributes to chronic inflammation, immune cell recruitment and prolonged release of proteolytic enzymes, whereas in SLE enhanced apoptosis leads to increased apoptotic burden associated with development of anti-nuclear auto-antibodies. An unbalanced energy metabolism in SLE and RA neutrophils contributes to the pathology of both diseases; increased hypoxia and glycolysis in RA drives neutrophil activation and NET production, whereas decreased redox capacity increases ROS-mediated damage in SLE. Neutrophil low-density granulocytes (LDGs), present in high numbers in the blood of both RA and SLE patients, have opposing phenotypes contributing to clinical manifestations of each disease. In this review we will describe the complex and contrasting phenotype of neutrophils and LDGs in RA and SLE and discuss their discrete roles in the pathogenesis of each condition. We will also review our current understanding of transcriptomic and metabolomic regulation of neutrophil phenotype in RA and SLE and discuss opportunities for therapeutic targeting of neutrophil activation in inflammatory auto-immune disease.

Automated Quantitative Analysis of Airway Epithelial Cell Detachment Upon Fungal Challenge.

Host-pathogen interactions involve a complex interplay between host and pathogen factors, resulting in either host protective immunity or establishment of disease. One of the hallmarks for disease progression is host tissue destruction. The first host surface to interact with the opportunistic respiratory fungal pathogen, Aspergillus fumigatus, is the airway epithelium. Unravelling the mechanisms involved in airway epithelial cell damage by A. fumigatus is essential to understanding the establishment and progression of infection in the host. Although host cell damage can be measured in vitro by indirect cell lysis assays, here, we describe an automated, simple, and low-cost assay to directly visualize and quantify epithelial cell line damage after challenge with A. fumigatus. We employ the previously characterized tissue noninvasive A. fumigatus ΔpacC mutant to demonstrate the quantitative difference in cell damage relative to its parental tissue invasive strain. This assay is easily scaled up for high-throughput screening of multiple Aspergillus mutants and can be adapted to suit diverse host cell lines, different time points of infection, challenge with other microbes, and drugs or novel compounds.

Phagocytosis and neutrophil extracellular traps.

Neutrophils are recruited rapidly to sites of infection in response to host- and/or microbe-derived proinflammatory molecules. At such sites, neutrophils phagocytose microbes and are activated to produce superoxide and other reactive oxygen species (ROS). In addition, neutrophils contain stores of antimicrobial peptides and enzymes that work in concert with ROS to kill ingested microbes. Neutrophils can also release chromosomal DNA bound with antimicrobial peptides and enzymes to form web-like structures known as extracellular traps. Neutrophil extracellular traps (NETs) have been reported to ensnare and kill microbes and are commonly considered to be an important component of innate host defense. Notably, the formation of NETs is most often reported as a cytolytic process. Whereas intraphagosomal killing of microbes sequesters cytotoxic antimicrobial molecules that would otherwise damage host tissues, the formation of NETs and associated extracellular release of these molecules can contribute to host tissue destruction and disease. Here we compare and contrast phagocytosis and NETs in host defense, with emphasis on recent studies of NETs that ultimately underscore the importance of phagocytosis as the primary means by which neutrophils eliminate microbes.

Assessment of disease suppressing ability of some fungicides and Neem oil on for management of Alternaria blight disease linseed (Linum usitatissimum L.)

Alternaria lini and Alternaria linicola is known to cause destruction of host tissue through the reduction of photosynthetic potential by inciting spots and blights of the crops including linseed (Linum usitatissimum L.) Altrnaria blight of Linseed also reduces the oil content and quality of fiber of linseed. The present investigation was aimed to evaluate the efficacy of various fungicides and neem oil for management of this important disease. Three sprays of fungicides namely carbendazim 0.2%, mancozeb @ 0.2%, hexaconazole @ 0.1%, propiconazole @ 0.1%, tubaconazole 0.1%, kresoxin- methyl 0.1% and trichyclazole+mancozeb 0.1% and neem oil was done after the first appearance of the symptoms of Alternaria leaf blight. Minimum disease severity with maximum seed yield was recorded with three sprays of Mancozeb @ 0.2% followed by Propiconazole @ 0.1% and Hexaconazole @ 0.1%, respectively. Maximum seed yield (1443.75 kg./ha) was obtained with the spraying of Mancozeb @ 0.2% followed by Hexaconazole @ 0.1%. Good control was also obtained by the spray of carbendazim @ 0.2%, propiconazole @ 0.1% and hexaconazole @ 0.1%. Neem oil and @ 2% was found good for control of Altenaria blight pathogens and these could be used as substitute of chemical fungicides for ecofriendly management of Alternaria leaf spot.

The Dual Role of Antimicrobial Peptides in Autoimmunity.

Autoimmune diseases (AiDs) are characterized by the destruction of host tissues by the host immune system. The etiology of AiDs is complex, with the implication of multiple genetic defects and various environmental factors (pathogens, antibiotic use, pollutants, stress, and diet). The interaction between these two compartments results in the rupture of tolerance against self-antigens and the unwanted activation of the immune system. Thanks to animal models, the immunopathology of many AiDs is well described, with the implication of both the innate and adaptive immune systems. This progress toward the understanding of AiDs led to several therapies tested in patients. However, the results from these clinical trials have not been satisfactory, from reversing the course of AiDs to preventing them. The need for a cure has prompted many investigators to explore alternative aspects in the immunopathology of these diseases. Among these new aspects, the role of antimicrobial host defense peptides (AMPs) is growing. Indeed, beyond their antimicrobial activity, AMPs are potent immunomodulatory molecules and consequently are implicated in the development of numerous AiDs. Importantly, according to the disease considered, AMPs appear to play a dual role in autoimmunity with either anti- or pro-inflammatory abilities. Here, we aimed to summarize the current knowledge about the role of AMPs in the development of AiDs and attempt to provide some hypotheses explaining their dual role. Definitely, a complete understanding of this aspect is mandatory before the design of AMP-based therapies against AiDs.

The role of sodium thiocyanate supplementation during dextran sodium sulphate-stimulated experimental colitis

Ulcerative colitis is a condition characterised by the infiltration of leukocytes into the gastrointestinal wall. Leukocyte-MPO catalyses hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN) formation from chloride (Cl−) and thiocyanous (SCN−) anions, respectively. While HOCl indiscriminately oxidises biomolecules, HOSCN primarily targets low-molecular weight protein thiols. Oxidative damage mediated by HOSCN may be reversible, potentially decreasing MPO-associated host tissue destruction. This study investigated the effect of SCN− supplementation in a model of acute colitis. Female mice were supplemented dextran sodium sulphate (DSS, 3% w/v) in the presence of 10 mM Cl− or SCN− in drinking water ad libitum, or with salts (NaCl and NaSCN only) or water only (controls). Behavioural studies showed mice tolerated NaSCN and NaCl-treated water with water-seeking frequency. Ion-exchange chromatography showed increased fecal and plasma SCN− levels in thiocyanate supplemented mice; plasma SCN− reached similar fold-increase for smokers. Overall there was no difference in weight loss and clinical score, mucin levels, crypt integrity and extent of cellular infiltration between DSS/SCN− and DSS/Cl− groups. Neutrophil recruitment remained unchanged in DSS-treated mice, as assessed by fecal calprotectin levels. Total thiol and tyrosine phosphatase activity remained unchanged between DSS/Cl− and DSS/SCN− groups, however, colonic tissue showed a trend in decreased 3-chlorotyrosine (1.5-fold reduction, p < 0.051) and marked increase in colonic GCLC, the rate-limiting enzyme in glutathione synthesis. These data suggest that SCN− administration can modulate MPO activity towards a HOSCN-specific pathway, however, this does not alter the development of colitis within a DSS murine model.