A binary module for microbiota-mediated regulation of γδ17 cells, hallmarked by microbiota-driven expression of programmed cell death protein 1.

Little is known about how microbiota regulate innate-like γδ T cells or how these restrict their effector functions within mucosal barriers, where microbiota provide chronic stimulation. Here, we show that microbiota-mediated regulation of γδ17 cells is binary, where microbiota instruct in situ interleukin-17 (IL-17) production and concomitant expression of the inhibitory receptor programmed cell death protein 1 (PD-1). Microbiota-driven expression of PD-1 and IL-17 and preferential adoption of a PD-1high phenotype are conserved for γδ17 cells across multiple mucosal barriers. Importantly, microbiota-driven PD-1 inhibits in situ IL-17 production by mucosa-resident γδ17 effectors, linking microbiota to their simultaneous activation and suppression. We further show the dynamic nature of this microbiota-driven module and define an inflammation-associated activation state for γδ17 cells marked by augmented PD-1, IL-17, and lipid uptake, thus linking the microbiota to dynamic subset-specific activation and metabolic remodeling to support γδ17 effector functions in a microbiota-dense tissue environment.

Osteopontin (OPN)/SPP1: from its biochemistry to biological functions in the innate immune system and the central nervous system (CNS).

Osteopontin (OPN) is a multifunctional protein, initially identified in osteosarcoma cells with its role of mediating osteoblast adhesion. Later studies revealed that OPN is associated with many inflammatory conditions caused by infections, allergic responses, autoimmunity and tissue damage. Many cell types in the peripheral immune system express OPN with various functions, which could be beneficial or detrimental. Also, more recent studies demonstrated that OPN is highly expressed in the central nervous system (CNS), particularly in microglia during CNS diseases and development. However, understanding of mechanisms underlying OPN's functions in the CNS is still limited. In this review, we focus on peripheral myeloid cells and CNS-resident cells to discuss the expression and functions of OPN.

Sweetness and positivity together aren't a happy ending: Case controlled study amongst severe COVID-19 for impact of diabetes mellitus on survival.

Background: India is the epicenter of diabetes mellitus (DM). The relationship between COVID and DM in age/gender-matched non-diabetics has not been studied yet. The role of DM in predicting the disease severity and outcome in COVID patients might provide new insight for effective management. Methods: We conducted a prospective comparative study at a COVID care center from 25th April-31st May 2021. Among 357 severe-COVID patients screened, all consecutive diabetes (n-113) and age/gender-matched non-diabetes (n-113) patients were recruited. All diabetics and non-diabetics at admission were subjected to high resolution computed tomography (HRCT) chest and inflammatory markers (C-reactive protein (CRP), D-dimer, ferritin, interleukin-6 (IL-6), lactate dehydrogenase (LDH), Neutrophil-Lymphocyte Ratio (NLR)) before starting anti- COVID therapy. Statistical analysis was done using JMP 15·0 ver·3·0·0. Results: The prevalence of DM among the screened population (n-357) was 38·37%. The mean age of the study population was 61y with male preponderance (57%). There was no statistical difference in the HRCT-score or inflammatory markers in the two groups except for higher NLR (p-0·0283) in diabetics. Diabetics had significantly inferior overall survival (OS) (p-0·0251) with a 15d-OS of diabetics vs. non-diabetics being 58·87%, 72·67%, and 30d-OS of diabetics vs. non-diabetics being 46·76%, 64·61%, respectively. The duration of the hospital stay was not statistically different in the two groups (p-0·2). Conclusion: The mortality is significantly higher in severe-COVID patients with DM when compared to age/gender-matched non-diabetics. There was no significant difference in most inflammatory markers/CT at admission between the two groups.

Curettage versus wide resection followed by arthrodesis/arthroplasty for distal radius Giant cell tumours: A meta-analysis of treatment and reconstruction methods.

Purpose: Primary aim of this review was to compare the two treatment modalities-curettage and wide excision (WE)- of Giant cell tumours of distal radius along with the methods of reconstruction viz. arthrodesis (AD) and arthroplasty (AP), and determine which had a better outcome. Methods: PubMed and Cochrane library databases were systematically searched using a well-defined search strategy by two independent reviewers. Inclusion/exclusion criteria were predetermined using the PICO format. MINORS tool was used to evaluate study quality. Recurrence rate (RR) was the chief oncological determinant whereas range of motion, grip strength, disability of arm, shoulder and hand (DASH) and musculoskeletal tumour society (MSTS) scores and complication rates were the functional outcome measures used. Results: For the first part, a total of 11 articles (284 patients) were analysed. The second half- AP versus AD-included four studies (71 patients). Quantitative analysis revealed a significantly higher RR (Odds ratio (OR) 8.6 [95% CI, 3.4, 21.75]) with curettage. WE, on the other hand, was associated with a higher complication rate (OR 0.3[ 95% CI, 0.14, 0.62]) and lower grip strength (Standard Mean Difference (SMD) 18.08[95% CI, 13.78, 22.37]). Complication rates were also significantly higher with wrist AP (OR 6.36[ 95% CI, 1.72, 23.52]). Remaining functional parameters failed to show any significant difference between either group. Conclusion: WE is the preferred surgical strategy in terms of lower RR and functionally equivalent results. In terms of the choice of reconstruction following WE, there is a trend towards higher patient satisfaction after wrist AD.

Assessment of Six-Minute Walk Test Among Discharge-Ready Severe COVID-19 Patients: A Cross-Sectional Study.

Background Among patients hospitalized for severe pneumonia due to coronavirus disease (COVID-19), clinical stability and normal resting peripheral oxygen saturation (SpO2) levels are widely used as a discharge criterion after recovery. It is unknown whether a test to assess the functional exercise capacity, like a six-minute walk test (6MWT), can add to the appropriateness of discharge criteria. Methods A cross-sectional study was conducted at a tertiary care COVID-19 hospital in India from 01st to 31st May 2021. All patients considered fit for discharge after recovery from "severe" COVID-19 pneumonia were subjected to 6MWT. Fitness for discharge was assessed by clinical stability and resting SpO2 above 93% for three consecutive days. Patients were considered to have failed the 6MWT if there was ≥4% fall in SpO2 or if they could not complete the test. Serum samples were analyzed for levels of C-reactive protein (CRP), interleukin-6 (IL-6), and lactate dehydrogenase (LDH) at the time of discharge. Results Fifty-three discharge-ready patients with a mean age of 54.54 ± 14.35 years with a male preponderance (60.38%) were analyzed. Thirty-three (62.26%) patients failed the 6MWT with a median six-minute walk distance (6MWD) of 270 m (60-360). A total of 45 (84.91%) patients had a fall in SpO2 during the test. The median change in SpO2 (∆SpO2) was 5% ranging from -6% to 8%. Serum LDH was significantly higher among patients who failed the 6MWT with a median LDH of 334 IU/L (38.96-2339) versus 261 IU/L (49.2-494) (p = 0.02). The difference was not significant for CRP or IL-6. There was no statistically significant correlation between the inflammatory markers with either 6MWD or (∆SpO2). Conclusion Two-thirds of the patients considered fit for discharge after recovery from severe COVID-19 pneumonia failed 6MWT, implying reduced functional exercise capacity and exertional hypoxia. Serum LDH levels were higher in these patients but not in other inflammatory markers. None of the inflammatory markers at discharge correlated with 6MWD or ∆SpO2 of 6MWT.

The AIM2 inflammasome is activated in astrocytes during the late phase of EAE.

Inflammasomes are a class of innate immune signaling platforms that activate in response to an array of cellular damage and pathogens. Inflammasomes promote inflammation under many circumstances to enhance immunity against pathogens and inflammatory responses through their effector cytokines, IL-1ß and IL-18. Multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), are autoimmune conditions influenced by inflammasomes. Despite work investigating inflammasomes during EAE, little remains known concerning the role of inflammasomes in the central nervous system (CNS) during the disease. Here, we used multiple genetically modified mouse models to monitor activated inflammasomes in situ based on oligomerization of apoptosis-associated speck-like protein containing a CARD (ASC) in the spinal cord. Using inflammasome reporter mice, we found heightened inflammasome activation in astrocytes after the disease peak. In contrast, microglia and CNS-infiltrated myeloid cells had few activated inflammasomes in the CNS during EAE. Astrocyte inflammasome activation during EAE was dependent on absent in melanoma 2 (AIM2), but low IL-1ß release and no significant signs of cell death were found. Thus, the AIM2 inflammasome activation in astrocytes may have a distinct role from traditional inflammasome-mediated inflammation.

Headache of Wearing PPE; A Survey for Neurological Symptoms with PPE amongst Health Care Workers.

Background: The COVID-19 pandemic has put the entire medical fraternity into a very challenging and demanding situation. Along with always being at the risk of COVID infection, healthcare workers (HCWs) are also facing neurological problems due to long working hours in personal protective equipment (PPE). These symptoms and their characteristics need to be observed and studied in-depth to understand the problems experienced by HCWs and to design new solutions to overcome such problems. Objectives: This study intends to evaluate the various neurological manifestations among the HCWs wearing PPE for prolonged periods. Materials and Methods: We conducted a questionnaire-based cross-sectional study at a Covid care center from western India from April 20 to June 01, 2021 by using a self-administered web-based questionnaire. A total of 256 HCWs were surveyed. The de-identified data were analyzed using JMP 15.0.0. Results: Among a total of 256 HCWs surveyed for this study, the majority (58.6%) were aged 24-35 years, with a male preponderance (65.62%, n = 168). Participants included doctors (41%), nurses (35%), paramedical staff (22%), and housekeeping staff (1%). The symptoms encountered among the HCWs wearing the PPE were headache, classified further as donning headache in 112 (44.98%), doffing headache in 56 (26.24%), slowed mentation in 48 (21.05%), and excessive sleepiness in 86 (38.74%), which affected their work performance. The age of the HCWs had a significant correlation with all the symptoms. Conclusion: Headache, slowed mentation, and excessive sleepiness was encountered among the HCWs wearing PPE, which depended upon the duration of PPE usage. The most common symptom was headache, which was of moderate to severe intensity.

Secreted osteopontin from CD4+ T cells limits acute graft-versus-host disease.

Osteopontin (OPN) has been considered a potential biomarker of graft-versus-host disease (GVHD). However, the function of OPN in GVHD is still elusive. Using a mouse model of acute GVHD (aGVHD), we report that OPN generated by CD4+ T cells is sufficient to exert a beneficial effect in controlling aGVHD through limiting gastrointestinal pathology, a major target organ of aGVHD. CD4+ T cell-derived OPN works on CD44 expressed in intestinal epithelial cells (IECs) and abates cell death of IECs. OPN also modulates gut microbiota with enhanced health-associated commensal bacteria Akkermansia. Importantly, we use our in vivo mouse mutant model to specifically express OPN isoforms and demonstrate that secreted OPN (sOPN), not intracellular OPN (iOPN), is solely responsible for the protective role of OPN. This study demonstrates that sOPN generated by CD4+ T cells is potent enough to limit aGVHD.

Impact of COVID-19 on Patient Trends and Outcome: Results from a Tertiary Care Burn and Plastic Unit in Northern India.

Background Burn and trauma injuries need emergency care and resuscitation, which required uninterrupted delivery of inpatient care services during the coronavirus disease 2019 (COVID-19) pandemic. Burn patients are physiologically immunocompromised, increasing the risk of COVID-19 infection in them. This study analyzes the impact of COVID-19 pandemic on patient trends in a burn and plastic unit and assesses the effect of COVID-19 infection in burns. Methods This single-center, retrospective observational case-control study was conducted in the Department of Burns, Plastic and Maxillofacial Surgery of a tertiary care hospital in New Delhi, India. Patient data was collected from April 1, 2019 to August 10, 2019 and from April 1, 2020 to August 10, 2020. All data of burns and trauma patients collected was analyzed and compared. Results There were total 350 admissions during COVID time period and 562 admissions during non-COVID time period. The admission rate, type of burn injury, and death rate did not vary significantly during the two time periods. Thermal burn was the most common type of burn injury. There were total 18 cases diagnosed to be COVID-19 positive during the pandemic. There were two deaths among COVID-19 positive burn cases. Conclusion This study finds no difference in patient patterns during COVID and non-COVID time period. Amongst burn patients, no increased risk of COVID-19 infection is seen with larger body surface area of burns. No increase in mortality is seen in burn patients infected with COVID-19.

Dectin-1 limits autoimmune neuroinflammation and promotes myeloid cell-astrocyte crosstalk via Card9-independent expression of Oncostatin M.

Pathologic roles of innate immunity in neurologic disorders are well described, but their beneficial aspects are less understood. Dectin-1, a C-type lectin receptor (CLR), is largely known to induce inflammation. Here, we report that Dectin-1 limited experimental autoimmune encephalomyelitis (EAE), while its downstream signaling molecule, Card9, promoted the disease. Myeloid cells mediated the pro-resolution function of Dectin-1 in EAE with enhanced gene expression of the neuroprotective molecule, Oncostatin M (Osm), through a Card9-independent pathway, mediated by the transcription factor NFAT. Furthermore, we find that the Osm receptor (OsmR) functioned specifically in astrocytes to reduce EAE severity. Notably, Dectin-1 did not respond to heat-killed Mycobacteria, an adjuvant to induce EAE. Instead, endogenous Dectin-1 ligands, including galectin-9, in the central nervous system (CNS) were involved to limit EAE. Our study reveals a mechanism of beneficial myeloid cell-astrocyte crosstalk regulated by a Dectin-1 pathway and identifies potential therapeutic targets for autoimmune neuroinflammation.

Th1-Dependent Cryptococcus-Associated Immune Reconstitution Inflammatory Syndrome Model With Brain Damage.

Cryptococcus-associated immune reconstitution inflammatory syndrome (C-IRIS) is identified upon immune reconstitution in immunocompromised patients, who have previously contracted an infection of Cryptococcus neoformans (Cn). C-IRIS can be lethal but how the immune system triggers life-threatening outcomes in patients is still poorly understood. Here, we establish a mouse model for C-IRIS with Cn serotype A strain H99, which is highly virulent and the most intensively studied. C-IRIS in mice is induced by the adoptive transfer of CD4+ T cells in immunocompromised Rag1-deficient mice infected with a low inoculum of Cn. The mice with C-IRIS exhibit symptoms which mimic clinical presentations of C-IRIS. This C-IRIS model is Th1-dependent and shows host mortality. This model is characterized with minimal lung injury, but infiltration of Th1 cells in the brain. C-IRIS mice also exhibited brain swelling with resemblance to edema and upregulation of aquaporin-4, a critical protein that regulates water flux in the brain in a Th1-dependent fashion. Our C-IRIS model may be used to advance our understanding of the paradoxical inflammatory phenomenon of C-IRIS in the context of neuroinflammation.

Avulsion Injuries of Right Hemidiaphragm: Report of Two Case Scenarios with Different Outcomes.

Avulsion injuries of domes of the diaphragm are rare injuries and may occur following lateral thoracoabdominal trauma. We share our experience of two cases of avulsion injuries of the right dome of the diaphragm. Our first case presented within a week following blunt trauma to the abdomen, and on thoracotomy, an effective repair was performed by restoring attachment of the diaphragm to the parietes. Our second case presented with severe respiratory distress, 1½ months after sustaining blunt injury chest and abdomen in a road traffic accident and on thoracotomy was found to have a completely necrosed right hemidiaphragm, and hence, no repair could be performed. However, the patient could not be weaned off ventilator and died after 3 months of primary injury. These cases highlight the importance of early diagnosis and repair of diaphragmatic injuries for a favorable outcome.

Understanding mechanisms underlying the pathology of immune reconstitution inflammatory syndrome (IRIS) by using animal models.

PURPOSE OF REVIEW: Despite the increasing number of clinical reports on immune reconstitution inflammatory syndrome (IRIS), mechanistic understanding of IRIS is still largely limited. The main focus of this review is to summarize animal studies, which were performed to better understand the cellular and molecular mechanisms underlying the pathology of IRIS. RECENT FINDINGS: Three IRIS animal models have been reported. They are Mycobacterial IRIS (M-IRIS), cryptococcal IRIS (C-IRIS) and Pneumocystis-IRIS. M-IRIS animal model suggested that, rather than lymphopenia itself, the failure to clear the pathogen by T cells results in excessive priming of the innate immune system. If this happens before T cell reconstitution, hosts likely suffer IRIS upon T cell reconstitution. Interestingly, T cells specific to self-antigens, not only pathogen-specific, could drive IRIS as well. SUMMARY: The mechanism to develop IRIS is quite complicated, including multiple layers of host immune responses; the innate immune system that detects pathogens and prime host immunity, and the adaptive immune system that is reconstituted but hyper-activated particularly through CD4+ T cells. Animal models of IRIS, although there are still small numbers of studies available, have already provided significant insights on the mechanistic understanding of IRIS.

Alpha-1 Antitrypsin Inhibits ATP-Mediated Release of Interleukin-1ß via CD36 and Nicotinic Acetylcholine Receptors.

While interleukin (IL)-1ß is a potent pro-inflammatory cytokine involved in host defense, high levels can cause life-threatening sterile inflammation including systemic inflammatory response syndrome. Hence, the control of IL-1ß secretion is of outstanding biomedical importance. In response to a first inflammatory stimulus such as lipopolysaccharide, pro-IL-1ß is synthesized as a cytoplasmic inactive pro-form. Extracellular ATP originating from injured cells is a prototypical second signal for inflammasome-dependent maturation and release of IL-1ß. The human anti-protease alpha-1 antitrypsin (AAT) and IL-1ß regulate each other via mechanisms that are only partially understood. Here, we demonstrate that physiological concentrations of AAT efficiently inhibit ATP-induced release of IL-1ß from primary human blood mononuclear cells, monocytic U937 cells, and rat lung tissue, whereas ATP-independent IL-1ß release is not impaired. Both, native and oxidized AAT are active, suggesting that the inhibition of IL-1ß release is independent of the anti-elastase activity of AAT. Signaling of AAT in monocytic cells involves the lipid scavenger receptor CD36, calcium-independent phospholipase A2ß, and the release of a small soluble mediator. This mediator leads to the activation of nicotinic acetylcholine receptors, which efficiently inhibit ATP-induced P2X7 receptor activation and inflammasome assembly. We suggest that AAT controls ATP-induced IL-1ß release from human mononuclear blood cells by a novel triple-membrane-passing signaling pathway. This pathway may have clinical implications for the prevention of sterile pulmonary and systemic inflammation.

Identification of Novel Short C-Terminal Transcripts of Human SERPINA1 Gene.

Human SERPINA1 gene is located on chromosome 14q31-32.3 and is organized into three (IA, IB, and IC) non-coding and four (II, III, IV, V) coding exons. This gene produces α1-antitrypsin (A1AT), a prototypical member of the serpin superfamily of proteins. We demonstrate that human peripheral blood leukocytes express not only a product corresponding to the transcript coding for the full-length A1AT protein but also two short transcripts (ST1C4 and ST1C5) of A1AT. In silico sequence analysis revealed that the last exon of the short transcripts contains an Open Reading Frame (ORF) and thus putatively can produce peptides. We found ST1C4 expression across different human tissues whereas ST1C5 was mainly restricted to leukocytes, specifically neutrophils. A high up-regulation (10-fold) of short transcripts was observed in isolated human blood neutrophils after activation with lipopolysaccharide. Parallel analyses by liquid chromatography-mass spectrometry identified peptides corresponding to C-terminal region of A1AT in supernatants of activated but not naïve neutrophils. Herein we report for the first time a tissue specific expression and regulation of short transcripts of SERPINA1 gene, and the presence of C-terminal peptides in supernatants from activated neutrophils, in vitro. This gives a novel insight into the studies on the transcription of SERPINA1 gene.

Why do some adults with PiMZ α1-antitrypsin develop bronchiectasis? [corrected]

Recurrent infections of the upper airways in early life may be a warning sign of inherited α1-antitrypsin deficiency http://ow.ly/iJsF300kbyV.

α-Linoleic acid enhances the capacity of α-1 antitrypsin to inhibit lipopolysaccharide induced IL-1ß in human blood neutrophils.

Alpha1-antitrypsin (A1AT, SERPINA1), a major circulating inhibitor of neutrophil elastase (NE) and proteinase-3 (PR3), has been proposed to reduce the processing and release of IL-1ß. Since the anti-inflammatory properties of A1AT are influenced by the presence of polyunsaturated fatty acids, we compared effects of fatty acid-free (A1AT-0) and α-linoleic acid bound (A1AT-LA) forms of A1AT on lipopolysaccharide (LPS)-induced synthesis of IL-1ß precursor and the release of IL-1ß from human blood neutrophils. The presence of A1AT-LA or A1AT-0 significantly reduced LPS induced release of mature IL-1ß. However, only A1AT-LA reduced both steady state mRNA levels of IL-1ß and the secretion of mature IL-1ß. In LPS-stimulated neutrophils, mRNA levels of TLR2/4, NFKBIA, P2RX7, NLRP3, and CASP1 decreased significantly in the presence of A1AT-LA but not A1AT-0. A1AT-0 and A1AT-LA did not inhibit the direct enzymatic activity of caspase-1, but we observed complexes of either form of A1AT with NE and PR3. Consistent with the effect on TLR and IL-1ß gene expression, only A1AT-LA inhibited LPS-induced gene expression of NE and PR3. Increased gene expression of PPAR-γ was observed in A1AT-LA treated neutrophils without of LPS stimulation, and the selective PPAR-γ antagonist (GW9662) prevented the reduction in IL-1ß by A1AT-LA. We conclude from our data, that the ability of A1AT to reduce TLR and IL-1ß gene expression depends on its association with LA. Moreover, the anti-inflammatory properties of A1AT-LA are likely to be mediated by the activation of PPAR-γ.