Immune Phagocytes Research Articles

Effect of the organoselenium compound 974zh on the TLR2 and TLR4 gene expression in blood and spleen cells of experimental animals when co-administered with Yersinia pestis EV

One of the important directions for increasing the immunogenic properties of vaccine strains against highly dangerous infections is the search for adjuvants that not only stimulate the immunological effectiveness of vaccination, but can also provide a metabolic correction of the vaccination process. Organoselenium compounds have immunotropic properties and an antioxidant effect, and therefore, the study of the effect of the organoselenium compound 2,6-dipyridinium-9-selenabicyclo[3.3.1]nonane dibromide (974zh) on the activity of the TLR2 and TLR4 gene expression by macroorganism cells of experimental animals immunized with Yersinia pestis EV NIIEG vaccine strain, is a current area of research.The aim of the work. To assess the TLR2 and TLR4 gene expression by cells of the immune phagocyte system of experimental animals immunized with the Y. pestis EV vaccine strain against the background of immunomodulation with the organoselenium compound 974zh.Materials and methods. The study was carried out on 125 certified outbred white mice. Biological material (blood, spleen) was disinfected, and the spleen was homogenized. RNA isolation and reverse transcription were performed using commercial reagent kits. The expression level of the TLR2 and TLR4 genes was determined using real-time polymerase chain reaction with specific primers.Results. When assessing innate immunity using the example of blood and spleen cells of animal models, features of the TLR2 and TLR4 gene expression were revealed in response to the introduction of the Y. pestis EV vaccine strain against the background of immunomodulation with the 974zh. It was found that 974zh induces a statistically significant increase in TLR2 gene expression when co-administered with Y. pestis EV at a dose of both 104 CFU and 103 CFU.Conclusion. Y. pestis EV against the background of immunomodulation with 974zh, stimulates the expression of the TLR2 and TLR4 genes, which may indicate an increase in the immunogenic properties of the Y. pestis EV vaccine strain under the influence of this preparation.

Characterization of Neisseria gonorrhoeae colonization of macrophages under distinct polarization states and nutrients environment.

Neisseria gonorrhoeae (Ng) is a uniquely adapted human pathogen and the etiological agent of gonorrhea, a sexually transmitted disease. Ng has developed numerous mechanisms to avoid and actively suppress innate and adaptive immune responses. Ng successfully colonizes and establishes topologically distinct colonies in human macrophages and avoids phagocytic killing. During colonization, Ng manipulates the actin cytoskeleton to invade and create an intracellular niche supportive of bacterial replication. The cellular reservoir(s) supporting bacterial replication and persistence in gonorrhea infections are poorly defined. The manner in which gonococci colonize macrophages points to this innate immune phagocyte as a strong candidate for a cellular niche during natural infection. Here we investigate whether nutrients availability and immunological polarization alter macrophage colonization by Ng. Differentiation of macrophages in pro-inflammatory (M1-like) and tolerogenic (M2-like) phenotypes prior to infection reveals that Ng can invade macrophages in all activation states, albeit with lower efficiency in M1-like macrophages. These results suggest that during natural infection, bacteria could invade and grow within macrophages regardless of the nutrients availability and the macrophage immune activation status.

DNA hypomethylation promotes the expression of CASPASE-4 which exacerbates inflammation and amyloid-β deposition in Alzheimer’s disease

Alzheimer’s disease (AD) is the sixth leading cause of death in the USA. It is established that neuroinflammation contributes to the synaptic loss, neuronal death, and symptomatic decline of AD patients. Accumulating evidence suggests a critical role for microglia, innate immune phagocytes of the brain. For instance, microglia release pro-inflammatory products such as IL-1β which is highly implicated in AD pathobiology. The mechanisms underlying the transition of microglia to proinflammatory promoters of AD remain largely unknown. To address this gap, we performed reduced representation bisulfite sequencing (RRBS) to profile global DNA methylation changes in human AD brains compared to no disease controls. We identified differential DNA methylation of CASPASE-4 (CASP4), which when expressed promotes the generation of IL-1β and is predominantly expressed in immune cells. DNA upstream of the CASP4 transcription start site was hypomethylated in human AD brains, which was correlated with increased expression of CASP4. Furthermore, microglia from a mouse model of AD (5xFAD) express increased levels of CASP4 compared to wild-type (WT) mice. To study the role of CASP4 in AD, we developed a novel mouse model of AD lacking the mouse ortholog of CASP4 and CASP11, which is encoded by mouse Caspase-4 (5xFAD/Casp4−/−). The expression of CASP11 was associated with increased accumulation of pathologic protein aggregate amyloid-β (Aβ) and increased microglial production of IL-1β in 5xFAD mice. Utilizing RNA-sequencing, we determined that CASP11 promotes unique transcriptomic phenotypes in 5xFAD mouse brains, including alterations of neuroinflammatory and chemokine signaling pathways. Notably, in vitro, CASP11 promoted generation of IL-1β from macrophages in response to cytosolic Aβ through cleavage of downstream effector Gasdermin D (GSDMD). Therefore, here we unravel the role for CASP11 and GSDMD in the generation of IL-1β in response to Aβ and the progression of pathologic inflammation in AD. Overall, our results demonstrate that overexpression of CASP4 due to differential DNA methylation in AD microglia contributes to the progression of AD pathobiology. Thus, we identify CASP4 as a potential target for immunotherapies for the treatment and prevention of AD.

The impact of COVID-19 infection in pediatric and adult patients with primary immunodeficiency: a single center analysis

Background: The global impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been profound, with over 760 million confirmed infections and almost 7 million deaths from coronavirus disease 2019 (COVID-19). The pandemic, officially declared in March 2020, has caused significant and irreversible changes in society. COVID-19 continues to pose a serious threat, ranging from asymptomatic cases to severe outcomes such as acute respiratory distress syndrome and organ failure, putting immense pressure on healthcare systems worldwide. The effects of SARS-CoV-2 infection on individuals with primary immunodeficiency (PID) are not yet fully understood. To date, the available research remains scarce, and the results do not yet provide conclusive evidence of a definitive link between PID and severe SARS-CoV-2 infection. In this study we present the clinical course and outcome of COVID-19 in individuals with PID. Methods: This study is a retrospective analysis involving 65 patients, comprising both pediatric and adult individuals diagnosed with PID, who exhibited symptoms of SARS-CoV-2 infection and tested positive at The Hospital for Sick Children in Toronto, Ontario, Canada. The data was collected from October 2020 to December 2022. Results: Sixty-five patients (36 children and 29 adults) were enrolled in our study. Our patients were diagnosed with primary immunodeficiency, and categorized as combined immunodeficiency, antibody deficiency, immune dysregulation disorder, phagocyte defect, intrinsic and innate immunity, or autoinflammatory disorder. Each of our patients had their COVID-19 infection confirmed through serology, rapid antigen test, and/or PCR. Among the study participants, 24 individuals had pre-existing lung conditions. At the time of contracting the infection, 42 patients had been vaccinated against SARS-CoV-2. The majority of patients in the study experienced mild to moderate symptoms of COVID-19. Conclusion: Our patients with PID exhibited mild to moderate symptoms of COVID-19, and all made a full recovery without any complications. Statement of Novelty: This study sheds light on impact of COVID-19 in individuals with primary immunodeficiency, revealing a noteworthy observation that patients exhibited mild to moderate symptoms, and remarkably, all experienced a complete recovery devoid of complications.

Fungal spore swelling and germination are restricted by the macrophage phagolysosome

Many species of medically important fungi are prolific in the formation of asexual spores. Spores undergo a process of active swelling and cell wall remodelling before a germ tube is formed and filamentous growth ensues. Highly elongated germ tubes are known to be difficult to phagocytose and pose particular challenges for immune phagocytes. However, the significance of the earliest stages of spore germination during immune cell interactions has not been investigated and yet this is likely to be important for defence against sporogenous fungal pathogens. We show here that macrophages restrict the early phases of the spore germination process of Aspergillus fumigatus and Mucor circinelloides including the initial phase of spore swelling, spore germination and early polarised growth. Macrophages are therefore adept at retarding germination as well as subsequent vegetative growth which is likely to be critical for immune surveillance and protection against sporulating fungi.

Mild COVID-19 outcomes in adults with inborn errors of immunity: a single-center experience

Currently, 640 million cases of coronavirus disease 2019 (COVID-19) and 6.6 million deaths have been reported world-wide. Risk factors for severe COVID-19 are known, including those with compromised immunity. Among patients with inborn errors of immunity (IEI), early reports of severe outcomes lead to strict masking and social distancing measures. While this resulted in relatively low infection rates among those with IEI, real-world data describing the clinical course of COVID-19 in this patient population have remained limited. We performed a retrospective study of adult IEI patients followed by our center in which a positive test (rapid antigen or PCR) for COVID-19 was determined between November 2021-November 2022. Medical charts were reviewed, and patient interviews conducted. All patients provided informed consent. Twenty-nine patients were enrolled (22 females, 7 males), aged between 18–69 years (median: 20–29 years). The cohort included those with antibody deficiencies (41.37%), combined immunodeficiencies (34.48%; HIES, CARD11, STAT1-GOF), immune dysregulation disorders (20.69%; LRBA deficiency, AIRE deficiency) and phagocyte defect (3.45%; CGD). The duration of symptoms ranged between 3 days-4 weeks (median: < 1 week). Upper respiratory symptoms (including sore throat, congestion) were reported in 97% while fever was present in 41% of patients. Prior to infection, 14 (48%) patients had underlying asthma or bronchiectasis - 2 subsequently experienced shortness of breath and were treated with inhalers or Sotrovimab, respectively. No treatment was required in 65.5% of cases. The remaining received Paxlovid (10.3%), Sotrovimab (13.79%), or antibiotics (10.3%). Of the 2 patients with STAT1-GOF, one tested positive during a repeat episode of febrile neutropenia which required hospitalization. No other patients were hospitalized or needed ICU admission. No deaths were recorded. In light of these favourable outcomes, patients with IEI can gradually and safely return to normal activities.

Neutrophil Extracellular Traps in Inflammatory and Autoimmune Diseases and Cancer

Neutrophils are innate immune system phagocytes that play a central role in immunity defense. They are equipped with effective antimicrobial that is mainly stored in specialized granules. Considering that, it can also damage host tissue. Neutrophil deployment is heavily regulated through various strategies, including phagocytosis, reactive oxygen species, production degranulation, and the formation of neutrophil extracellular traps (NET). This review article will discuss its role in inflammatory, autoimmune diseases, and cancer and place it as a therapeutic target. It depicts that NET formation includes a suicide program morphologically different from other types of cell death, such as apoptosis and necrosis. Besides, NETs have unique DNA and antimicrobial peptide structures, and antimicrobial activity is among the functions of neutrophils as the first response to inflammation. So, it plays a pivotal role in the pathophysiology of various diseases, especially inflammatory and autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. As a result, it can be effective in the pathogenesis of many diseases, and its pathogenic role can be used as a therapeutic target.

Nanomaterials targeting macrophages in sepsis: A promising approach for sepsis management.

Sepsis is a life-threatening organ dysfunction resulting from dysregulated host responses to infection. Macrophages play significant roles in host against pathogens and the immunopathogenesis of sepsis, such as phagocytosis of pathogens, secretion of cytokines, and phenotype reprogramming. However, the rapid progression of sepsis impairs macrophage function, and conventional antimicrobial and supportive treatment are not sufficient to restore dysregulated macrophages roles. Nanoparticles own unique physicochemical properties, surface functions, localized surface plasmon resonance phenomenon, passive targeting in vivo, good biocompatibility and biodegradability, are accessible for biomedical applications. Once into the body, NPs are recognized by host immune system. Macrophages are phagocytes in innate immunity dedicated to the recognition of foreign substances, including nanoparticles, with which an immune response subsequently occurs. Various design strategies, such as surface functionalization, have been implemented to manipulate the recognition of nanoparticles by monocytes/macrophages, and engulfed by them to regulate their function in sepsis, compensating for the shortcomings of sepsis traditional methods. The review summarizes the mechanism of nanomaterials targeting macrophages and recent advances in nanomedicine targeting macrophages in sepsis, which provides good insight for exploring macrophage-based nano-management in sepsis.

S2182 A Case of Colonic Malakoplakia

Introduction: Malakoplakia is a rare histiocytic inflammatory response that is usually found in the urinary tract. Gastrointestinal involvement is considered the second most common location affected and is a result of dysfunctional macrophages. Histopathology is characterized by granular histiocytes with Micahelis-Gutmann bodies. Although usually an incidental finding, Malakoplakia is associated with immunosuppressive therapy, colorectal carcinoma and infectious diseases. Case Description/Methods: A 54-year-old man with a pmhx of alcohol use disorder was referred to clinic for acute, asymptomatic liver enzyme abnormalities. Laboratory findings were significant for AST of 270 U/L, ALT of 63 U/L, ALP of 65 U/L, and total bilirubin of 0.3 mg/dL. Further workup showed positive hepatitis B surface antigen, reactive hepatitis B core antibody and hepatitis B DNA by PCR was 172K IU/mL. Patient underwent screening colonoscopy which revealed a 2 mm sessile polyp in the cecum (Figure A). Histological examination of the polyp showed von-Hansemann cells containing Michaelis-Gutmann bodies, which is diagnostic for malakoplakia (Figure B). Discussion: The first report of colonic malakoplakia was described by Terner and Lattes in 1965 and usually involves the ascending colon, sigmoid colon and rectum. Clinical manifestations of colonic involvement range from asymptomatic to abdominal pain, fever, diarrhea and rectal bleeding. The lesion is characterized by von-Hansemann cells which are aggregates of histiocytes with eosinophilic cytoplasm and intracytoplasmic Michaelis-Gutmann bodies. Pathogenic mechanisms include a causative organism, altered immune response and phagocyte disfunction. Escherichia coli is the most common isolated pathogen found in 90% of patients with malakoplakia. These chronic bacterial infections are due to suspected abnormal macrophage function resulting in the inability to break down bacteria. The most susceptible include immunosuppressed patients who are post-transplant or have an untreated systemic disease such as chronic hepatitis. Antibiotic therapy, immunotherapy modification and surgical resection are the mainstay of management. While most cases of malakoplakia are diagnosed as incidental findings on screening colonoscopy, there does exist an associate with colorectal adenocarcinoma. Given the potential for significant morbidity if left untreated, malakoplakia diagnosed on incidental screening should prompt a work up for systemic infections, immune compromising diseases and malignancy.Figure 1.: A: Two mm cecum polyp denoted by yellow arrows. Figure B: High-power view of Malakoplakia (60x). Macrophages containing basophilic targetoid structures, known as Michaelis-Gutmann bodies.

Device implant based on poly (lactic acid) with vitamin E for vaccine delivery system in Tilapia: Study for biocompatibility and biodegradation

The use of Poly (lactic acid) (PLA) as a slow-release vehicle for vaccines has attracted the attention of researchers, since its insertion improves the uptake of them, and reduces side effects or by stimulating recruited defense cells, assisting immunity without the need for booster vaccine doses. Seeking to develop new strategies for the administration of drugs and vaccines in aquaculture, we evaluated the biocompatibility and biodegradation of polymeric PLA devices and PLA plus vitamin E devices, implanted through subcutaneous (SC) and intraperitoneal (IP) routes in Nile tilapia. To carry out this study, 84 male tilapia (initial 243.82 ± 56.74 g; final 400.71 ± 100.54 g) were randomly distributed in 3 tanks (n = 28 fish per treatment/tank). The devices were prepared in two formulations: neat PLA (containing 100% PLA) and PLAVE (PLA plus vitamin E) implanted using a commercial AnimalTag® applicator, and non-implanted fish (control). Fish were sampled 15, 30, 60, and 120 days post-implantation (DPI). Blood analysis was used to access blood cells and blood smear for differential leucocytes count. Serum biochemistry to evaluated changes in serum proteins and glycemia. Histopathological investigation using hematoxylin-eosin (H&E) was used to assess polymer-tissue interaction. Histochemistry and immunohistochemistry was used to detection immune cells and phagocytes in capsule, and analyses of melanomacrophage centers (MMCs) to morphometric evaluation and percentage amount of melanin, hemosiderin and lipofucsin pigments. Histopathological study revealed an increase of capsular formation and inflammatory cell infiltration in PLAVE-implanted tilapia through SC route (15 DPI). Tilapia implanted with PLAVE and PLA (SC) presented mast cells and eosinophilic granular cells during 15, 30, and 60 DPI, with a decrease in these cells in the fibrous capsule around the polymer at 120 DPI. PLAVE implanted tilapia SC at 60 DPI showed significantly phagocytosis points than other groups. Phagocytic cells (F4/80+) were observed near to biopolymers in phagocytosis sites. Lipofuscin at 120 DPI in spleen melanomacrophage centers were significantly high in PLAVE implanted tilapias when compared to fish with PLA implants and control. The serum biochemical study of tilapia did not reveal changes in cytotoxicity and liver function in implanted fish. The absence of side effects in hematological and biochemical findings, including the absence of mortality after device implantation, proves its clinical safety. PLA implants in tilapia have demonstrated biocompatibility, biodegradation, clinical safety, and excellent evolution of foreign body inflammatory responses.

Stimulating the autophagic-lysosomal axis enhances host defense against fungal infection in a zebrafish model of invasive Aspergillosis

ABSTRACT The increasing prevalence of antifungal-resistant human pathogenic fungi, particularly azole-resistant Aspergillus fumigatus, is a life-threatening challenge to the immunocompromised population. Autophagy-related processes such as LC3-associated phagocytosis have been shown to be activated in the host response against fungal infection, but their overall effect on host resistance remains uncertain. To analyze the relevance of these processes in vivo, we used a zebrafish animal model of invasive Aspergillosis. To confirm the validity of this model to test potential treatments for this disease, we confirmed that immunosuppressive treatments or neutropenia rendered zebrafish embryos more susceptible to A. fumigatus. We used GFP-Lc3 transgenic zebrafish to visualize the autophagy-related processes in innate immune phagocytes shortly after phagocytosis of A. fumigatus conidia, and found that both wild-type and melanin-deficient conidia elicited Lc3 recruitment. In macrophages, we observed GFP-Lc3 accumulation in puncta after phagocytosis, as well as short, rapid events of GFP-Lc3 decoration of single and multiple conidia-containing vesicles, while neutrophils covered single conidia-containing vesicles with bright and long-lasting GFP-Lc3 signal. Next, using genetic and pharmacological stimulation of three independent autophagy-inducing pathways, we showed that the antifungal autophagy response improves the host survival against A. fumigatus infection, but only in the presence of phagocytes. Therefore, we provide proof-of-concept that stimulating the (auto)phagolysosomal pathways is a promising approach to develop host-directed therapies against invasive Aspergillosis, and should be explored further either as adjunctive or stand-alone therapy for drug-resistant Aspergillus infections.

Disruption of Iron Homeostasis and Mitochondrial Metabolism Are Promising Targets to Inhibit Candida auris.

ABSTRACTFungal infections are a global threat, but treatments are limited due to a paucity in antifungal drug targets and the emergence of drug-resistant fungi such as Candida auris. Metabolic adaptations enable microbial growth in nutrient-scarce host niches, and they further control immune responses to pathogens, thereby offering opportunities for therapeutic targeting. Because it is a relatively new pathogen, little is known about the metabolic requirements for C. auris growth and its adaptations to counter host defenses. Here, we establish that triggering metabolic dysfunction is a promising strategy against C. auris. Treatment with pyrvinium pamoate (PP) induced metabolic reprogramming and mitochondrial dysfunction evident in disrupted mitochondrial morphology and reduced tricarboxylic acid (TCA) cycle enzyme activity. PP also induced changes consistent with disrupted iron homeostasis. Nutrient supplementation experiments support the proposition that PP-induced metabolic dysfunction is driven by disrupted iron homeostasis, which compromises carbon and lipid metabolism and mitochondria. PP inhibited C. auris replication in macrophages, which is a relevant host niche for this yeast pathogen. We propose that PP causes a multipronged metabolic hit to C. auris: it restricts the micronutrient iron to potentiate nutritional immunity imposed by immune cells, and it further causes metabolic dysfunction that compromises the utilization of macronutrients, thereby curbing the metabolic plasticity needed for growth in host environments. Our study offers a new avenue for therapeutic development against drug-resistant C. auris, shows how complex metabolic dysfunction can be caused by a single compound triggering antifungal inhibition, and provides insights into the metabolic needs of C. auris in immune cell environments.IMPORTANCE Over the last decade, Candida auris has emerged as a human pathogen around the world causing life-threatening infections with wide-spread antifungal drug resistance, including pandrug resistance in some cases. In this study, we addressed the mechanism of action of the antiparasitic drug pyrvinium pamoate against C. auris and show how metabolism could be inhibited to curb C. auris proliferation. We show that pyrvinium pamoate triggers sweeping metabolic and mitochondrial changes and disrupts iron homeostasis. PP-induced metabolic dysfunction compromises the utilization of both micro- and macronutrients by C. auris and reduces its growth in vitro and in immune phagocytes. Our findings provide insights into the metabolic requirements for C. auris growth and define the mechanisms of action of pyrvinium pamoate against C. auris, demonstrating how this compound works by inhibiting the metabolic flexibility of the pathogen. As such, our study characterizes credible avenues for new antifungal approaches against C. auris.

Correlation expression Toll-like receptor 4 with multidrugs resistant tuberculosis in diabetes mellitus condition

BackgroundToll-like receptor (TLR) are ligand homologous protein in the APC cell membrane that has functions as a receptor to triger leukocytes and innate immune responses. When there is a Microbacterium tuberculosis (MTB) infection enters from droplets to the lungs, the alveolar macrophages perform a phagocytic function. The interaction between M. tuberculosis and the TLR macrophage receptors produces chemokines which induce migration of monocytes and dendrite cells for destruction. Diabetes militus (DM) has become risk factor for developing tuberculosis. DM condition will reduce immunity and the ability of immune cell phagocytes bactery and triger severe infections. The consequences of more severe infection and metabolic disorders that occur make a person more likely to experience Multidrugs resistant MTB. Not much data that reports on the expression of TLR4 as a ligand that triggers an immune response in conditions of MDR and DM. We try to find out correlation between TLR-4 in MDR MTB, diabetes and level of MTB bacteria in experimental animals. MethodsWe conducted an experimental study on 30 experimental mice weighing 25 grams consisting of negative control grub, infected with MTB, infected with MDR MTB, negative control diabetes, MTB DM, MDR MTB DM. DM animals were induced by streptozosin to experience DM, then in the treatment of infection, intraperitoneal MTB and MDR MTB bacterial injections were given. Termination was carried out on day 14. We count number of bacteria level in the lungs and perform evaluation TLR4 from blood sampel. ResultsThe negative control group had mean TLR value of 1.47 (± 0.46) while the MTB group showed an increase in TLR 9.22 (± 0.39) followed by MDR MTB 9.50 (± 0.29), DM negative control 9, 21 (± 0.24) and more increasing in conditions of DM MTB 13.36 (± 0.32) and DM MDR MTB 13.35 (± 0.34). ANOVA analysis showed a significant difference (P = 0.00). pearson correlation analysis find strong correlation TLR4 in MTB and MDR MTB with diabetes. Conclusionthere were a significant difference level TLR4 between MTB and MDR TB infection with diabetes. higher TLR4 level higher in DM MTB, DM MDR MTB. TLR 4 strong correlates with an increase in the number of MTB bacteria.

Implementation of Early Next-Generation Sequencing for Inborn Errors of Immunity: A Prospective Observational Cohort Study of Diagnostic Yield and Clinical Implications in Dutch Genome Diagnostic Centers.

ObjectiveInborn errors of immunity (IEI) are a heterogeneous group of disorders, affecting different components of the immune system. Over 450 IEI related genes have been identified, with new genes continually being recognized. This makes the early application of next-generation sequencing (NGS) as a diagnostic method in the evaluation of IEI a promising development. We aimed to provide an overview of the diagnostic yield and time to diagnosis in a cohort of patients suspected of IEI and evaluated by an NGS based IEI panel early in the diagnostic trajectory in a multicenter setting in the Netherlands.Study DesignWe performed a prospective observational cohort study. We collected data of 165 patients with a clinical suspicion of IEI without prior NGS based panel evaluation that were referred for early NGS using a uniform IEI gene panel. The diagnostic yield was assessed in terms of definitive genetic diagnoses, inconclusive diagnoses and patients without abnormalities in the IEI gene panel. We also assessed time to diagnosis and clinical implications.ResultsFor children, the median time from first consultation to diagnosis was 119 days versus 124 days for adult patients (U=2323; p=0.644). The median turn-around time (TAT) of genetic testing was 56 days in pediatric patients and 60 days in adult patients (U=1892; p=0.191). A definitive molecular diagnosis was made in 25/65 (24.6%) of pediatric patients and 9/100 (9%) of adults. Most diagnosed disorders were identified in the categories of immune dysregulation (n=10/25; 40%), antibody deficiencies (n=5/25; 20%), and phagocyte diseases (n=5/25; 20%). Inconclusive outcomes were found in 76/165 (46.1%) patients. Within the patient group with a genetic diagnosis, a change in disease management occurred in 76% of patients.ConclusionIn this cohort, the highest yields of NGS based evaluation for IEI early in the diagnostic trajectory were found in pediatric patients, and in the disease categories immune dysregulation and phagocyte diseases. In cases where a definitive diagnosis was made, this led to important disease management implications in a large majority of patients. More research is needed to establish a uniform diagnostic pathway for cases with inconclusive diagnoses, including variants of unknown significance.

An Update on the Pathogenic Role of Neutrophils in Systemic Juvenile Idiopathic Arthritis and Adult-Onset Still's Disease.

Neutrophils are innate immune phagocytes that play a key role in immune defense against invading pathogens. The main offensive mechanisms of neutrophils are the phagocytosis of pathogens, release of granules, and production of cytokines. The formation of neutrophil extracellular traps (NETs) has been described as a novel defense mechanism in the literature. NETs are a network of fibers assembled from chromatin deoxyribonucleic acid, histones, and neutrophil granule proteins that have the ability to kill pathogens, while they can also cause toxic effects in hosts. Activated neutrophils with NET formation stimulate autoimmune responses related to a wide range of inflammatory autoimmune diseases by exposing autoantigens in susceptible individuals. The association between increased NET formation and autoimmunity was first reported in antineutrophil cytoplasmic antibody-related vasculitis, and the role of NETs in various diseases, including systemic lupus erythematosus, rheumatoid arthritis, and psoriasis, has since been elucidated in research. Herein, we discuss the mechanistic role of neutrophils, including NETs, in the pathogenesis of systemic juvenile idiopathic arthritis (SJIA) and adult-onset Still’s disease (AOSD), and provide their clinical values as biomarkers for monitoring and prognosis.

Histamine triggers microglial responses indirectly via astrocytes and purinergic signaling.

Histamine is a monoaminergic neurotransmitter which is released within the entire brain from ascending axons originating in the tuberomammillary nucleus in a sleep state-dependent fashion. Besides the modulation of neuronal firing patterns, brain histamine levels are also thought to modulate functions of glial cells. Microglia are the innate immune cells and professional phagocytes of the central nervous system, and histamine was previously shown to have multiple effects on microglial functions in health and disease. Isolated microglia respond only to agonists of the Hrh2 subtype of histamine receptors (Hrh), and the expression of that isoform is confirmed by a metadata analysis of microglia transcriptomes. When we studied the effect of the histamine receptor isoforms in cortical and thalamic microglia by in situ live cell Ca2+ imaging using a novel, microglia-specific indicator mouse line, microglial cells respond to external histamine application mainly in a Hrh1-, and to a lower extent also in a Hrh2-dependent manner. The Hrh1 response was sensitive to blockers of purinergic P2ry12 receptors, and since Hrh1 expression was predominantly found in astrocytes, we suggest that the Hrh1 response in microglia is mediated by astrocyte ATP release and activation of P2ry12 receptors in microglia. Histamine also stimulates microglial phagocytic activity via Hrh1- and P2ry12-mediated signaling. Taken together, we provide evidence that histamine acts indirectly on microglial Ca2+ levels and phagocytic activity via astrocyte histamine receptor-controlled purinergic signaling.

Macrophage production of matrix metalloproteases in the setting of chorioamnionitis

Maternal responses to bacterial chorioamnionitis (CAM) include production of matrix metalloproteases (MMPs), extracellular membrane-degrading enzymes thought to play a central role in the weakening of fetal membranes during CAM leading to preterm prelabor rupture of membranes (PPROM). Macrophages, the primary innate immune phagocyte of fetal membranes, secrete MMPs when provoked by microbes such as Group B Streptococcus (GBS). The objective of this project is to determine whether maternal cytotrophoblasts (CTBs) decrease macrophage expression of tissue-remodeling MMPs in the setting of GBS infection.

Precisely and Efficiently Enzyme Response Microspheres with Immune Removal Escape Loaded with MCC950 Ameliorate Cardiac Dysfunction in Acute Myocardial Infarction.

Although the percutaneous coronary intervention (PCI)treatment can improve the survival rate of acute myocardial infarction (AMI) patients, the early granulocytes response within 6 hours can induce second injuries during the reperfusion process. The new drug delivery system MMP9 hydrolytic microspheres (NMM) with negatively charged surface was designed out and MCC950 (MCC) was loaded into NMM (NMM-M), MCC is the inhibitor of nucleotide binding oligomerization domain (NOD)-like receptor, pyrin containing domain 3 (NLRP3)-inflammasome which is the key promoter of granulocytes-induced injury. NMM-M could effectively escape the phagocytosis of immune phagocytes in the blood, and target the ischemic region based on the electrostatic attraction and the attraction of enzyme to substrate, and sudden release the loaded MCC within 2 hours. The released MCC can inhibit the NLRP3-inflammasome activity, and then further inhibit the secretion of inflammatory factors in granulocytes which are the main factors of early inflammatory damage, and improving cardiac function, realizing the goal of pre-treatment. Therefore, NMM may be a new delivery system, which can provide the accurately, sufficient and rapidly drug deliver, and MCC may be a novel candidate drug in AMI treatment, which may be hopeful in the future.

Palmitate induces apoptotic cell death and inflammasome activation in human placental macrophages

IntroductionThere is an increasing prevalence of non-communicable diseases worldwide. Metabolic diseases such as obesity and gestational diabetes mellitus (GDM) increasingly affect women during pregnancy, which can harm pregnancy outcomes and the long-term health and wellbeing of exposed offspring. Both obesity and GDM have been associated with proinflammatory effects within the placenta, the critical organ governing fetal development. MethodsThe purpose of these studies was to model, in vitro, the effects of metabolic stress (high levels of glucose, insulin and saturated lipids) on placental macrophage biology, since these cells are the primary innate immune phagocyte within the placenta with roles in governing maternofetal immune tolerance and antimicrobial host defense. Macrophages were isolated from the villous core of term, human placentae delivered through nonlaboring, elective Cesarean sections and exposed to combinations of elevated glucose (30 mM), insulin (10 nM) and the saturated lipid palmitic acid (palmitate, 0.4 mM). ResultsWe found that palmitate alone induced the activation of the nucleotide-binding oligomerization domain-like receptor (NLR) Family Pyrin Domain Containing 3 (NLRP3) inflammasome in placental macrophages, which was associated with increased interleukin 1 beta release and an increase in apoptotic cell death. Glucose and insulin neither provoked these effects nor augmented the impact of palmitate itself. DiscussionOur findings confirm an impact of saturated fat on placental macrophage immune activation and could be relevant to the impact of metabolic stress in vivo.

Emerging Roles for Microglial Phagocytic Signaling in Epilepsy.

Microglia are the resident immune cells and professional phagocytes of the central nervous system. However, little is known about the contribution of their phagocytic signaling to the neuropathology and pathophysiology of epilepsy. Here, we summarize and discuss the implications of recent evidence supporting that aberrant microglia phagocytic activity and alterations in phagocytosis signaling molecules occur in association with microglia–neuronal contacts, neuronal/synaptic loss, and spontaneous recurrent seizures in human and preclinical models of epilepsy. This body of evidence provides strong support that the microglial contribution to epileptogenic networks goes beyond inflammation, and suggests that phagocytic signaling molecules may be novel therapeutic targets for epilepsy.