Large Numbers Of Neutrophils Research Articles

Chemokine expression profile of an innate granuloma.

Granulomas are defined by the presence of organized layers of immune cells that include macrophages. Granulomas are often characterized as a way for the immune system to contain an infection and prevent its dissemination. We recently established a mouse infection model where Chromobacterium violaceum induces the innate immune system to form granulomas in the liver. This response successfully eradicates the bacteria and returns the liver to homeostasis. Here, we sought to characterize the chemokines involved in directing immune cells to form the distinct layers of a granuloma. We use spatial transcriptomics to investigate the spatial and temporal expression of all CC and CXC chemokines and their receptors within this granuloma response. The expression profiles change dynamically over space and time as the granuloma matures and then resolves. To investigate the importance of monocyte-derived macrophages in this immune response, we studied the role of CCR2 during C. violaceum infection. Ccr2 -/- mice had negligible numbers of macrophages, but large numbers of neutrophils, in the C. violaceum-infected lesions. In addition, lesions had abnormal architecture resulting in loss of bacterial containment. Without CCR2, bacteria disseminated and the mice succumbed to the infection. This indicates that macrophages are critical to form a successful innate granuloma in response to C. violaceum.

Embolic necrosuppurative pneumonia in domestic cats induced by a novel Neisseria species.

Three cats, aged 2 to 11 years, presented to the University of Minnesota Veterinary Diagnostic Laboratory over a 3-year period following euthanasia or death due to respiratory distress. Thoracic radiographs revealed nodular, soft tissue opacities throughout the lung fields in all cases. On postmortem examination, approximately 60% to 80% of the lung parenchyma were expanded by multifocal to coalescing, well-demarcated, beige, semi-firm nodules. Histologically, large numbers of neutrophils, fewer macrophages, fibrin, and cellular and karyorrhectic debris effaced the pulmonary parenchyma. The inflammatory foci contained aggregates of gram-negative cocci. 16s rRNA Sanger sequencing and whole-genome sequencing identified the bacteria isolated from the lung of all cats under aerobic conditions as a novel Neisseria spp. Based on whole-genome sequence analysis, all 3 sequences shared 92.71% and 92.67% average nucleotide identity with closely related Neisseria animaloris NZ LR134440T and Neisseria animaloris GCA 002108605T, respectively. The in silico DNA-DNA hybridization identity compared to our isolates was 46.6% and 33.8% with strain DSM Neisseria zoodegmatis 21642 and strain DSM 21643, respectively. All 3 sequences have less than 95% average nucleotide identity and less than 70% DNA-DNA hybridization identity, suggesting that the 3 isolates are a novel species of the genus Neisseria. Infection with Neisseria spp. induces an embolic pneumonia in cats that radiographically and pathologically resembles a metastatic neoplastic process and should be considered among the etiologic differential diagnoses in cases of infectious pulmonary disease with a disseminated, nodular lung pattern.

The transplant rejection response involves neutrophil and macrophage adhesion-mediated trogocytosis and is regulated by NFATc3

The anti-foreign tissue (transplant rejection) response, mediated by the immune system, has been the biggest obstacle to successful organ transplantation. There are still many enigmas regarding this process and some aspects of the underlying mechanisms driving the immune response against foreign tissues remain poorly understood. Here, we found that a large number of neutrophils and macrophages were attached to the graft during skin transplantation. Furthermore, both types of cells could autonomously adhere to and damage neonatal rat cardiomyocyte mass (NRCM) in vitro. We have demonstrated that Complement C3 and the receptor CR3 participated in neutrophils/macrophages-mediated adhesion and damage this foreign tissue (NRCM or skin grafts). We have provided direct evidence that the damage to these tissues occurs by a process referred to as trogocytosis, a damage mode that has never previously been reported to directly destroy grafts. We further demonstrated that this process can be regulated by NFAT, in particular, NFATc3. This study not only enriches an understanding of host-donor interaction in transplant rejection, but also provides new avenues for exploring the development of novel immunosuppressive drugs which prevent rejection during transplant therapy.

Inflammatory invasion on human vaginal mucosa correlated with combined drug treatment and recurrence in recurrent vulvovaginal candidiasis.

Recurrent vulvovaginal candidiasis (RVVC) is a chronic, difficult to treat vaginal infection, caused by Candida species, which affects women of all ages and ethnic and social background. Most RVVC studies use animal models, and there is still a lack of observation on human tissue samples and effective therapy to reduce recurrence. We observed CD163+ macrophages and NLRP3 expression by immunohistochemistry, also investigated bacteria and fungi co-invasion by fluorescence in situ hybridization from 144 human vaginal biopsy tissues (48 RVVC, 48 VVC, 48 healthy volunteers), and we also explored the effect of combining metronidazole in the treatment of RVVC. A large number of neutrophils, lymphocytes and plasma cells infiltrated the mucosa, basement membrane and submucosa, accompanied by significantly overexpressed NLRP3 inflammasome. While CD163+ macrophages often infiltrated under the basement membrane in patients with RVVC, 29.2% of cases were found Gardnerella and fungi jointly invaded the vaginal mucosas. RVVC vaginal mucosal histopathology revealed mucosal inflammatory responses dominated by neutrophils, which may involve activation of NLRP3 and immune tolerance of M2 macrophages (CD163+ ). Fluconazole combined with metronidazole can achieve higher efficiency (95.8% vs. 70.8%) and reduce the recurrence rate more (8.3% vs. 37.5%) at 6-month follow-up. Inflammatory invasion on human vaginal mucosa correlated with combined drug treatment and recurrence in RVVC. The combined medication will need to further evaluate in future.

Intramural dissection of the esophagus is a rare complication of eosinophilic esophagitis in children

Eosinophilic esophagitis (EoE) is characterized by endoscopic signs and detection of more than 15 eosinophils per high-power field of view in biopsy specimens of the esophageal mucosa. Due to deep chronic eosinophilic inflammation, it can cause complications: esophageal stenosis, rarely perforation. Intramural esophageal dissection (IED) is a previously undescribed complication of EoE in children. We present a case of IED in a 15-year-old boy, which clinically manifested itself as sudden epigastric pain radiating to the back and nausea against the background of acute respiratory viral infection. According to endoscopy, CT and X-ray contrast study, a double-barreled esophagus with two cavities was detected - the esophagus itself and a blind "pocket", histologically in which granulation tissue and active inflammation with a large number of neutrophils were found. The initial histological examination did not reveal significant eosinophilic infiltration in the esophagus. The boy received a course of esomeprazole and was re-examined 6 months later. The radiographic picture was the same, and endoscopic examination revealed characteristic signs of EoE: longitudinal grooves and erosions, transverse rings, and narrowing of the esophageal lumen. In the middle third, the picture of a double-barreled esophagus was still preserved, but without signs of acute detachment, but with a dense septum between the two cavities of the esophagus. Histologically, the infiltrate contained more than 50 eosinophils in the field of view. The diagnosis was eosinophilic esophagitis complicated by RTI. A strict hypoallergenic diet was prescribed, excluding obligate allergens, budesonide 1 mg 2 times a day in the form of a gel. Endoscopic dissection of the esophageal septum was performed, its patency was restored. After 2 months, the boy was examined again while continuing drug therapy and diet. He had no complaints, radiologically the patency of the esophagus was not impaired. Endoscopically, the esophagus was freely passable, there was only a small fold at the site of the operation, longitudinal grooves and small erosions in the lower third remained. Histologically, the number of eosinophils decreased significantly. Therapy was continued. This clinical case demonstrates the possibility of developing RDI as a complication of EoE. The course of EoE can be asymptomatic, and RDI is the first manifestation of the disease. The endoscopic picture of a double-barreled esophagus is a consequence of dissection. The combination of a hypoallergenic diet, topical steroids and endoscopic septectomy is effective in the treatment of EoE with RDI.

Regulation of emergency granulopoiesis during infection.

During acute infectious and inflammatory conditions, a large number of neutrophils are in high demand as they are consumed in peripheral organs. The hematopoietic system rapidly responds to the demand by turning from steady state to emergency granulopoiesis to expedite neutrophil generation in the bone marrow (BM). How the hematopoietic system integrates pathogenic and inflammatory stress signals into the molecular cues of emergency granulopoiesis has been the subject of investigations. Recent studies in the field have highlighted emerging concepts, including the direct sensing of pathogens by BM resident or sentinel hematopoietic stem and progenitor cells (HSPCs), the crosstalk of HSPCs, endothelial cells, and stromal cells to convert signals to granulopoiesis, and the identification of novel inflammatory molecules, such as C/EBP-β, ROS, IL-27, IFN-γ, CXCL1 with direct effects on HSPCs. In this review, we will provide a detailed account of emerging concepts while reassessing well-established cellular and molecular players of emergency granulopoiesis. While providing our views on the discrepant results and theories, we will postulate an updated model of granulopoiesis in the context of health and disease.

A monocyte-leptin-angiogenesis pathway critical for repair post-infection.

During infection, inflammatory monocytes are thought to be key for bacterial eradication, but this is hard to reconcile with the large numbers of neutrophils that are recruited for each monocyte that migrates to the afflicted tissue, and the much more robust microbicidal functions of the neutrophils. However, unlike neutrophils, monocytes have the capacity to convert to situationally specific macrophages that may have critical functions beyond infection control1,2. Here, using a foreign body coated with Staphylococcus aureus and imaging over time from cutaneous infection to wound resolution, we show that monocytes and neutrophils are recruited in similar numbers with low-dose infection but not with high-dose infection, and form a localization pattern in which monocytes surround the infection site, whereas neutrophils infiltrate it. Monocytes did not contribute to bacterial clearance but converted to macrophages that persisted for weeks after infection, regulating hypodermal adipocyte expansion and production of the adipokine hormone leptin. In infected monocyte-deficient mice there was increased persistent hypodermis thickening and an elevated leptin level, which drove overgrowth of dysfunctional blood vasculature and delayed healing, with a thickened scar. Ghrelin, which opposes leptin function3, was produced locally by monocytes, and reduced vascular overgrowth and improved healing post-infection. In sum, we find that monocytes function as a cellular rheostat by regulating leptin levels and revascularization during wound repair.

Abstract P3080: S100A8/9 Is A Key Regulator For Normal Heart Function During Pseudomonas Aeruginosa Infection

Rationale: P. aeruginosa ( P.a ) infection can cause severe pneumonia in ICU patients that leads to cardiac inflammation and cardiac dysfunction. Growing evidence indicates that a large number of neutrophils are recruited to the site of P.a. infection and releases S100A8/9 into the microenvironment. S100A8/9 has been shown to activate both the immune system (TLR4/RAGE) and has bactericidal properties. Often, hyperactivation of the inflammatory responses by S100A8/9 causes cardiac inflammation and dysfunction. Thus, we hypothesize that excessive production of S100A8/9 restrict bacterial growth and enhances the host immune response in order to control the infection and preserve heart function. Objective: To identify the mechanism of S100A8/9 mediated cardiac inflammation and cardiac dysfunction during P. aeruginosa infection. Methods and Results: To investigate the role of S100A8/9 in cardiac inflammation and cardiac dysfunction, we infected wild type (WT) and S100A8/9KO mice with P.a. intranasally. We monitored bodyweight at 24h intervals and measured weight loss, survival, and bacterial burden in the lungs and heart. We performed multicolor flow cytometry on BAL cells and heart cells for immune cell phenotyping and ELISA for cytokine levels. Also, we measured cardiac electric activity (EKG) and heart function (echocardiography). We found that bacterial burden in the lungs and heart was higher in S100A8/9KO mice than in WT, which correlated with increased mortality. We found severe cardiac electrical abnormalities (second-degree AV block) in S100A8/9KO mice and left ventricular dysfunction. However, there was no significant difference in the BALF immune cell phenotypes of both S100A8/9KO and WT infected mice. Finally, the S100A8/9 inhibitor enhanced the survival of P.a. infected mice. Conclusion: Our data demonstrate that neutrophil recruitment and release of S100A8/9 is critical to control bacterial growth in the lungs, however, uncontrolled neutrophil accumulation leads to excessive production of S100A8/9. Hyperactivation of the immune system by excessive S100A8/9 leads to systemic inflammation and bacterial dissemination of the heart. Furthermore, our studies revealed that blocking S100A8/9 receptor binding enhances the survival of mice during P.a. infection.

Role and mechanism of signal transducer and activator of transcription protein STAT1/3/5 in hyperoxia-induced acute lung injury

To investigate whether signal transducer and activator of transcription (STAT1/3/5) have a protective effect on hyperoxia-induced acute lung injury (HALI) and its mechanism. Seventy C57BL/6J mice were randomly divided into five groups: normoxia control group, HALI group, and STAT1/3/5 inhibitor groups, with 14 mice in each group. The HALI model was established by exposure to more than 90% hyperoxia for 48 hours; three STAT inhibitor groups were pretreated by intraperitoneal injection of STAT1 inhibitor 40 mg/kg and STAT3 inhibitor 5 mg/kg, and STAT5 inhibitor 10 mg/kg for 1 week. Six blood samples were randomly collected from each group, and microRNA-21 (miR-21) expression was measured by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Lung tissue of the sacrificed mice was obtained, and enzyme linked immunosorbent assay (ELISA) was used to detect the contents of tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-1β), superoxide dismutase (SOD), malonic dialdehyde (MDA), and matrix metalloproteinase 9 (MMP9). The water content of lung tissue was calculated. The pathological changes in lung tissue were observed under the light microscope, and the pathological score of lung injury was performed. Western blotting was used to detect the expression of phosphorylated STAT (p-STAT1, p-STAT3, p-STAT5) in lung tissue. The 7-day cumulative survival rates of the remaining 8 mice in each group were analyzed using Kaplan-Meier survival curves. Under the light microscope, the alveolar structures in the HALI group and the STAT1 inhibitor group were destroyed, a large number of neutrophils (NEU) infiltrated in the alveoli and lung interstitium, which were thickened. The pathological score of lung injury and the water content of the lung tissue was significantly increased. In STAT3 inhibitor and STAT5 inhibitor groups, the alveolar cavity was clear, the degree of NEU infiltration and the thickness of lung interstitium were lower than those in HALI group, the pathological score of lung injury and the water content of lung tissue were significantly decreased, especially in STAT3 inhibitor group. Compared with the normoxia control group, the contents of TNF-α, IL-6, IL-1β, MDA, and MMP9, and the expression levels of p-STAT3 and p-STAT5 in the HALI group were significantly increased. In contrast, the content of SOD and the expression of miR-21 were significantly decreased. Compared with the HALI group, the contents of TNF-α, IL-6, IL-1β, MDA, and MMP9 in the STAT3 inhibitor group and STAT5 inhibitor group were significantly decreased. At the same time, the content of SOD and the expression of miR-21 were significantly increased, especially in STAT3 inhibitor group [TNF-α (μg/L): 42.53±3.25 vs. 86.36±5.48, IL-6 (ng/L): 68.46±4.28 vs. 145.00±6.89, IL-1β (μg/L): 28.74±3.53 vs. 68.00±5.64, MDA (μmol/g): 20.33±2.74 vs. 42.58±3.45, and MMP9 (ng/L): 128.55±6.35 vs. 325.13±6.65, SOD (kU/g): 50.53±4.19 vs. 22.53±3.27, miR-21 (2-ΔΔCt): 0.550±0.018 vs. 0.316±0.037, all P < 0.05]. Kaplan-Meier survival curve analysis showed that the 7-day cumulative survival rates of the STAT3 inhibitor group and STAT5 inhibitor group were significantly higher than those of the HALI group [62.5% (5/8), 37.5% (3/8) vs. 12.5% (1/8), both P < 0.05]. Inhibition of STAT3 hyperactivation may suppress the inflammatory response, regulate oxidative stress, improve lung permeability through regulating the expression of miR-21, which exert lung protection in HALI.

Investigating the Three-Way Interaction between Gastric Epithelial Cells, Human Neutrophils, and Helicobacter pylori

Abstract Neutrophils are the most abundant white blood cells in humans and are the first line of defense against pathogens with respect to innate immunity. Helicobacter pylori are gram-negative bacteria that infect the gastric epithelium and play an important role in the development of ulcers and gastric cancer. Large numbers of neutrophils are recruited to the gastric epithelium where they become heavily infected. We demonstrated previously that when neutrophils are infected by H. pylori it extends their short lifespan. In addition, these cells display unique characteristic such as nuclear hypersegmentation that are indicative of N1-like subtype differentiation which may increase bacterial virulence. Studies by other groups have examined H. pylori-epithelial cell interactions but notably absent are three-way co-cultures that examine simultaneous interactions of neutrophils with bacteria and gastric epithelial cells. Addressing this knowledge gap is the focus of my project. Specifically, I am investigating the dynamics of infection in these co-cultures and determining whether the infected PMNs alter epithelial cell function or viability. Using immunofluorescence I am determining bacterial localization, analyzing PMN nuclear morphology, and determining the extent of changes in epithelial cell junctions and the actin cytoskeleton over 24 hours. Additionally, I am using flow cytometry, lactate dehydrogenase release assays, western blotting and microscopy to quantify cell death, including apoptosis, to test the hypothesis that infected PMNs are more toxic to the epithelium than the bacteria alone. Ultimately, our studies are expected to advance understanding of the role of neutrophils in H. pylori pathogenesis.

NADPH oxidase-derived reactive oxygen species production activates the ERK1/2 pathway in neutrophil extracellular traps formation by Streptococcus agalactiae isolated from clinical mastitis bovine

Streptococcus agalactiae (S. agalactiae) continues to be challenging for milk quality in some countries and leads to huge economic losses. A large number of neutrophils are recruited into inflammatory foci when S. agalactiae infection occurs, and most studies have focused on the interaction between neutrophil extracellular traps (NETs) and this bacterium in the context of human pathogenicity. However, there is little information on the NET formation mechanism induced by S. agalactiae in the context of bovine mastitis. Here, neutrophils isolated from BALB/c mice were infected with S. agalactiae SAG-FX17, and NET formation was evaluated. SAG-FX17 could induce NADPH oxidase-derived reactive oxygen species (NOX-ROS)-dependent NET formation, and 21.8% of bacteria could be eliminated by NETs via NET DNA and associated proteins. SAG-FX17 could induce the phosphorylation of p38 MAPK, ERK1/2 MAPK, and JNK/SAPK in neutrophils. However, only ERK1/2 MAPK was shown to play an important role in SAG-FX17-induced NET formation. Importantly, NOX-ROS production occurs upstream of ERK1/2 MAPK activation and then induces NET release. ERK1/2 MAPK phosphorylation can, in turn, enhance NOX-ROS generation, which further contributes to NET release and bacterial elimination. This study provides evidence of the molecular mechanism underlying serotype Ia S. agalactiae SAG-FX17-induced NET formation and the interaction between bacteria and NETs, and these findings will increase our knowledge about bacterial mastitis in dairy cattle and contribute to the prevention and clinical treatment of bovine mastitis.

Mycobacterium tuberculosis Rv0309 Dampens the Inflammatory Response and Enhances Mycobacterial Survival.

To reveal functions of novel Mycobacterium tuberculosis (M. tb) proteins responsible for modulating host innate immunity is essential to elucidation of mycobacterial pathogenesis. In this study, we aimed to identify the role of a putative protein Rv0309 encoded within RD8 of M. tb genome in inhibiting the host inflammatory response and the underlying mechanism, using in-vitro and in-vivo experiments. A recombinant M. smegmatis strain Ms_rv0309 expressing Rv0309 and a mutant Bacillus Calmette-Guérin (BCG)ΔRS01790 strain with deletion of BCG_RS01790, 100% homologue of Rv0309 in BCG, were constructed. Rv0309 was found to localize in the cell wall and be able to decrease cell wall permeability. Purified recombinant rRv0309 protein inhibited lipopolysaccharide-induced IL-6 release in RAW264.7 cells. BCG_RS01790 in BCG or Rv0309 in Ms_rv0309 strain greatly inhibited production of IL-6, IL-1β, and TNF-α in RAW264.7 cells. Similarly, BCGΔRS01790 strongly induced expression of these cytokines compared with wild-type BCG and complement strain, cBCGΔRS01790::RS01790. Further BCG_RS01790 or Rv0309 suppressed cytokine production through NF-κB p65/IκBα and MAPK ERK/JNK signaling. Importantly, BCG_RS01790 in BCG and Rv0309 in Ms_rv0309 strain enhanced mycobacterial survival in macrophages. Mice infected with BCGΔRS01790 exhibited high levels of IFN-γ, TNF-α and IL-1β, and large numbers of neutrophils and lymphocytes in the early stage, and minimal lung bacterial load and inflammatory damage in late stage of the experiment. In conclusion, the cell wall protein Rv0309 or BCG_RS01790 enhanced mycobacterial intracellular survival after infection likely through inhibition of the pro-inflammatory response and decrease of bacterial cell wall permeability, thereby contributing to mycobacterial pathogenesis.

Effects of temperature-sensitive hydroxybutyl chitosan hydrogel on wound healing of full-thickness skin defect in rats

Effects of temperature-sensitive hydroxybutyl chitosan hydrogel on wound healing of full-thickness skin defect in rats

Neutrophils in Streptococcus suis Infection: From Host Defense to Pathology.

Streptococcus suis is a swine pathogen and zoonotic agent responsible for economic losses to the porcine industry. Infected animals may develop meningitis, arthritis, endocarditis, sepsis and/or sudden death. The pathogenesis of the infection implies that bacteria breach mucosal host barriers and reach the bloodstream, where they escape immune-surveillance mechanisms and spread throughout the organism. The clinical manifestations are mainly the consequence of an exacerbated inflammation, defined by an exaggerated production of cytokines and recruitment of immune cells. Among them, neutrophils arrive first in contact with the pathogens to combat the infection. Neutrophils initiate and maintain inflammation, by producing cytokines and deploying their arsenal of antimicrobial mechanisms. Furthermore, neutrophilic leukocytosis characterizes S. suis infection, and lesions of infected subjects contain a large number of neutrophils. Therefore, this cell type may play a role in host defense and/or in the exacerbated inflammation. Nevertheless, a limited number of studies addressed the role or functions of neutrophils in the context of S. suis infection. In this review, we will explore the literature about S. suis and neutrophils, from their interaction at a cellular level, to the roles and behaviors of neutrophils in the infected host in vivo.

NECROTIZING PNEUMONIA AND MASSIVE AIR LEAK IN A PATIENT WITH COVID-19

TOPIC: Cardiothoracic Surgery TYPE: Global Case Reports INTRODUCTION: To observe the pathological characteristics and the clinical significance of COVID 19 infected pneumonia causing degeneration and necrosis of parenchymal cells, thrombus in small and medium vessels. Pulmonary pathological changes of fatal COVID-19 are diffuse alveolar damage that is presents in the acute exudative stage and the organic proliferative stage. There is alveolar cavity formation, fibrinous exudate, fibroblastic proliferation in alveolar septum, and alveolar epithelial cell injuries. A large number of neutrophils and monocytes infiltration is present in most cases and bacteria and fungi are detected in some cases, suggesting a serious combination to generate lung necrosis and huge air leak. CASE PRESENTATION: The case of a 50 years old female with severe COVID 19 pneumonia, requiring admission to the ICU during her hospitalization present bilateral pneumothorax that was solved with bilateral chest tube, one week later present persistent right pneumothorax and a continuous air leak that prevented ventilation, surgical intervention was decided as a result of the ventilatory, hemodynamic deterioration and state of sepsis finding in the right lower lung focal hemorrhage, organization of exudates in various cavities in the lung, and pulmonary fibrosis generating degeneration and necrosis of parenchymal cells, formation of thrombus in small vessels, and pathological changes of chronic diseases were observed with fibrous tissue, firm adhesions DISCUSSION: Infectious disease by COVID 19 pneumonia can generate cavitary lung process, necrotizing pneumonia, lung abscess and septic pulmonary embolism. Being able to aggregate infections that include cavitating fungal and superinfection of preexisting spaces. Accompanied by infarction from thromboembolic disease. In these cases, we found an extensive lung necrosis with a grade 4 air leak, accompanied by intraparenchymal purulent fibrin, infected cavities with fluid and bronchial necrosis as well as blood vessel thrombosis CONCLUSIONS: The management of this pathology include treatment as any lung necrosis with major resection and reinforcement of the bronchial stump with the considerations of the aerosol that are generated by bronchial necrosis and parenchyma, the initial approach includes immediate obturation of the bronchus and subsequently continue with vascular dissection. Which indicates that COVID pneumonia can present in a short time all the changes of acute and chronic disease. Generally, an acute or subacute process suggests bacterial and fungal causes of pulmonary abscesses, necrotizing pneumonias, and septic emboli. And a chronic process suggests mycobacterial, fungal, viral, or parasitic infections;malignancy or autoimmune disorders REFERENCE #1: Anaesthesia. 2020 Nov;75(11):1509-1516. doi: 10.1111/anae.15112. Epub 2020 Jun 2. Management of the airway and lung isolation for thoracic surgery during the COVID-19 pandemic: Recommendations for clinical practice endorsed by the Association for Cardiothoracic Anaesthesia and Critical Care and the Society for Cardiothoracic Surgery in Great Britain and IrelandM Thornton 1, D Reid 1, B Shelley 2 3, M Steven 1 REFERENCE #2: Anaesthesia. 2020 Nov;75(11):1509-1516. doi: 10.1111/anae.15112. Epub 2020 Jun 2.Management of the airway and lung isolation for thoracic surgery during the COVID-19 pandemic: Recommendations for clinical practice endorsed by the Association for Cardiothoracic Anaesthesia and Critical Care and the Society for Cardiothoracic Surgery in Great Britain and IrelandM Thornton 1, D Reid 1, B Shelley 2 3, M Steven 1 REFERENCE #3: Am Fam Physician. 1991 Nov;44(5):1719-21.Necrotizing aspiration pneumoniaD Disler 1, S A Deluca DISCLOSURES: No relevant relationships by Gabriela Alejandra Buerba Romero Valdes, source=Web Response No relevant relationships by Gabriela Del Angel Millan, source=Web Response No relevant relationships by EMMANUEL PENA GOMEZ PORTUGAL, source=Web Response No relevant relationships by ALMA SOLANO NIETO, source= eb Response

Single intratracheal exposure to SARS‐CoV‐2 S1 spike protein induces acute lung injury in K18‐hACE2 transgenic mice

The SARS‐CoV‐2 pandemic has infected more than 85,900,000 people and provoked the death of more than 1.9 million worldwide. Therapeutic options remain limited, and vaccines may exhibit narrow efficacy, due to short supplies, delays in distribution and the emergence of new resistant strains. It is mandatory to study new therapeutic approaches that modulate the strong inflammatory response observed in the lung, prevent respiratory failure and improve outcomes. The study of SARS‐CoV‐2 pathogenicity in vivo is challenging due to the necessary biosafety laboratory regulations. Thus, we developed an acute lung injury model by intratracheally instilling the S1 subunit of SARS‐CoV‐2 Spike S protein (400 µg/kg, 2 ml/kg body weight) in K18‐hACE2 transgenic mice that overexpress the human receptor for SARS‐CoV‐2 Spike protein S, ACE2, and investigated outcomes 72 hours later. Mice exhibited an acute decline in body weight during the first 48 hours following instillation, compared to saline‐instilled controls. At 72 hours, bronchoalveolar lavage fluid demonstrated a dramatic increase in white blood cell content, particularly neutrophils, and marked proteinosis compared to controls. Histologic examination of lung tissue revealed hyaline membranes, alveolar septal thickening, and a large number of neutrophils in the interstitial and alveolar spaces of Spike protein S exposed mice. We propose that a single exposure of K18‐hACE2 mice to SARS‐CoV‐2 Spike Protein S subunit S1 may represent a valid model of COVID‐19, allow the study of the molecular mechanisms of SARS‐CoV‐2 induced lung injury and be useful in the investigation of potential new therapeutic approaches to the management of COVID‐19 as well as future coronavirus‐dependent respiratory diseases.

Distinct roles of PI3Kδ and PI3Kγ in a toluene diisocyanate-induced murine asthma model

TDI-induced asthma is characterized by neutrophil-dominated airway inflammation and often associated with poor responsiveness to steroid treatment. Both PI3Kδ and PI3Kγ have been demonstrated to play important proinflammatory roles in ovalbumin-induced asthma. We’ve already reported that blocking pan PI3K effectively attenuated TDI-induced allergic airway inflammation. Yet the specific functions of PI3Kδ and PI3Kγ in TDI-induced asthma are still unclear. Male BALB/c mice were first dermally sensitized and then challenged with TDI to generate an asthma model. Sellective inhibitors of PI3Kδ (IC-87114, AMG319) and PI3Kγ (AS252424, AS605240) were respectively given to the mice after each airway challenge. Treatment with IC-87114 or AMG319 after TDI exposure led to significantly decreased airway hyperresponsiveness (AHR), less neutrophil and eosinophil accumulation, attenuated airway smooth muscle (ASM) thickening, less M1 and M2 macrophages in lung, as well as lower levels of IL-4, IL-5, IL-6 and IL-18 in bronchoalveolar lavage fluid (BALF) and recovered IL-10 production. While mice treated with AS252424 or AS605240 had increased AHR, more severe ASM thickening, larger numbers of neutrophils and eosinophils, more M1 but less M2 macrophages, and higher BALF levels of IL-4, IL-5, IL-6, IL-10, IL-12, IL-18 when compared with those treated with vehicle. These data revealed that pharmacological inhibition of PI3Kδ attenuates TDI-induced airway inflammation while PI3Kγ inhibition exacerbates TDI-induced asthma, indicating distinct biological functions of PI3Kδ and PI3Kγ in TDI-induced asthma.

Analysis of Systemic and Cutaneous Inflammatory Immune Response in Canine Atopic Dermatitis

Background: Canine atopic dermatitis (CAD) is a chronic and inflammatory disease present in veterinary dermatological practice. The inflammation in CAD is triggered by environmental allergens and skin microorganisms, which are responsible for the worsening of cutaneous lesions. This continuous activation of skin inflammatory process can induce the production of free radicals that also contribute to cellular damage and ultimately leads to changes in blood parameters in dogs with CAD. Although there are reports of inflammatory parameters in CAD, there are a lack of studies correlating skin lesions, blood leukocytes and oxidative stress. Based on that,this study aimed to evaluate the integumentary and systemic inflammatory response in dogs with atopic dermatitis. Materials, Methods &amp; Results: Dogs with confirmed diagnosis of canine atopic dermatitis (n = 10) were divided in two groups according to CADESI-IV: AI, with CADESI between 0-10, AII, with CADESI between 10-34, and control group (n = 5). Blood-biochemical and histological analysis were performed to access systemic and cutaneous inflammatory response. AII group tended to higher neutrophil and eosinophil counts, as well as neutrophil/lymphocyte ratio (NLR) when compared to AI. The albumin was lower in AII compared to AI and control (P &lt; 0.05), while total bilirubin and malondialdehyde (MDA) did not differ between groups. NLR (r = 0.64 and P = 0.04) and MDA (r = 0.54 and P = 0.1) were positively correlated with CADESI, while albumin was negatively correlated with CADESI (r = -0.79 and P = 0.005). Histopathological analysis revealed a larger number of neutrophils, macrophages and mast cells in AI and AII than in control group (P &lt; 0.05). Discussion: In this study it was possible to evaluate the systemic and cutaneous leukocyte dynamics in CAD. Skin inflammation induces the production of chemotactic molecules contribute to neutrophil outflow from blood vessel toward the affected tissue, which can be visualized as perivascular inflammatory infiltrate and exocytosis. At systemic level, there was a tendency to increase in total leukocytes and circulating neutrophil count in group AII, as well as in neutrophil/lymphocyte ratio (NLR), when compared to AI. The NLR is a widely available and inexpensive laboratory biomarker that quantifies systemic inflammation, being used in human medicine to evaluate prognosis in different types of cancer. In our study, dogs in AII group showed an increased NLR compared to AI and control, which demonstrates the influence of skin injury in systemic parameters. Furthermore, AII group is composed of dogs with greater lesion state, which reflects in higher NLR values. Since this disease is known by its chronicity and may remain stable for years, NLR may be a novel biomarker to evaluate acute exacerbation in CAD and could potentially explain why some patients have longer crisis duration and frequent flares. The maintenance of the inflammatory state also induces the production of oxidizing substances, which possibly exceed the total antioxidant capacity, generating a situation of oxidative stress, which can result in damage to membrane lipids and release of their products. MDA is reliable and is the most commonly used marker of the overall lipid peroxidation level and the presence of oxidative stress. This result may be related with the antioxidant system, such as albumin and bilirubin, which was able to promote an efficient control of oxidant substances. In conclusion, the presented data demonstrated an inflammatory process progression as well as introduced NLR as a potential marker of disease exacerbation in CAD.

Extensive eye-oral-bronchial mucosal nodules with eosinopgillia: a rare case report and literature review

BackgroundMucosal nodules can be caused by infection, inflammation and neoplastic disease. Many noninfectious diseases, such as eosinophilia, amyloidosis, sarcoidosis, Wegener’s granuloma, langerhans cell histiocytosis etc., are associated with the formation of multisytem mucosal nodules, especially significant bronchial lesions. Detailed medical history, comprehensive metabolic profile, biopsy specimen and imaging examinations are required for differentiating among these disorders. The process of diagnosis and treatment of our patient’s mucosal nodules was challenging, which could be helpful to similar cases.Case presentationWe represent a case of a 29-year-old woman with plentiful nodules of unknown origin on extensive mucous membranes. Biopsy specimen reports inflammatory lesions with large numbers of neutrophils, lymphocytes, and varying degrees of eosinophils. Treatment of anti-infection, anti-tussive and anti-allergic was ineffective, but glucocorticoid showed great improvement to her symptoms.ConclusionWe experienced a rare case with plentiful nodules of unknown origin on extensive mucous membranes. She may be a specific phenotype of eosinophilia or may be a novel multisystem disease with respiratory system as the primary symptom. The diagnosis of our patient remains unclear, but tentative glucocorticoid therapy was beneficial.

Investigation of the response of tear-film neutrophils to interleukin 8 and their sensitivity to centrifugation, fixation, and incubation

During eye closure, a large number of neutrophils (polymorphonuclear neutrophils, PMNs) invade the ocular surface and are often referred to as tear-film PMNs. While immunophenotyping experiments have been performed on tear-film PMNs, the impact of commonly used experimental procedures on their phenotype as well as their response to interleukin-8 (IL-8), a physiological inflammatory mediator, have not yet been investigated. A gentle eye wash method was used to collect cells at home. In the morning upon awaking, participants washed their eyes with sterile phosphate buffer saline (PBS) and collected the runoff into a sterile polypropylene tube. The cell collection was then delivered to the lab within two hours. The effects of centrifugation, incubation and fixation with paraformaldehyde (PFA) before (pre-fixed staining) or after (post-fixed staining) incubation with antibodies were characterized. Tear-film PMNs as well as blood PMNs (used for comparison) were also stimulated with IL-8. To assess the reproducibility of cell collection and variability in receptor expression over time, participants were also asked to collect cells three times over a period of a month. The change in expression of surface receptors, CD11b, CD16, CD55, CD66b, important inflammatory and activation markers, and CD45 (PAN leukocyte marker) was assessed by flow cytometry. Fixing tear-film PMNs prior to the staining with antibodies resulted in a significant (fivefold or more) reduction in the expression of CD11b, CD16 and CD45 when compared to unfixed samples, while CD16 was the only receptor to undergo significant downregulation upon post-staining fixation. Furthermore, additional centrifugation step prior to antibody incubation as well as long (4 h) incubation at 37 °C resulted in significant reductions in expression of CD11b, CD16 and CD55 when compared to control samples. As opposed to blood PMNs, stimulating tear-film PMNs with IL-8 did not induce any significant changes in expression of CD11b, CD16, CD55 and CD66b. When working with collected tear-film PMNs, our results suggest that any additional centrifugation and incubation step should be avoided, or at least limited, and post fixation staining is recommended in order to preserve cell phenotype and cell integrity of tear film PMNs. Our study also adds further information on the reproducibility of the gentle eye wash as well as the inability of tear-film PMNs to modulate their surface receptors upon stimulation with IL-8. The latter may be due to prior exposure to IL-8, activation in the closed-eye environment, or a reduced ability to respond to inflammatory stimulus. Further mechanistic studies will be needed to gain a better understanding of the tear-film neutrophil phenotype.