Adenosine Triphosphate Release From Influenza-Infected Lungs Enhances Neutrophil Activation and Promotes Disease Progression.

Background: Adenosine triphosphate (ATP) enhances neutrophil responses, but little is known about the role of ATP in influenza infections.

Methods: We used a mouse influenza model to study if ATP release is associated with neutrophil activation and disease progression.

Results: Influenza infection increased pulmonary ATP levels 5-fold and plasma ATP levels 3-fold vs healthy mice.

Effects of low-dose acetylsalicylic acid on the inflammatory response to experimental sleep restriction in healthy humans.

Background: Sleep deficiencies, such as manifested in short sleep duration or insomnia symptoms, are known to increase the risk for multiple disease conditions involving immunopathology. Inflammation is hypothesized to be a mechanism through which deficient sleep acts as a risk factor for these conditions. Thus, one potential way to mitigate negative health consequences associated with deficient sleep is to target inflammation.

Expression of immune checkpoint molecules TIGIT and TIM-3 by tumor-infiltrating lymphocytes predicts poor outcome in sinonasal mucosal melanoma.

Background: Sinonasal mucosal melanoma (SNMM) is a rare but aggressive tumor with a poor prognosis. The co-inhibitory receptors T cell immunoglobulin and mucinodomain containing-3 (TIM-3), lymphocyte activation gene-3 (LAG-3) and T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) are promising new targets in anti-cancer immunotherapy. The expression profiles of these immune checkpoint molecules (ICMs) and potential prognostic implications have not been characterized in SNMM yet.

Impaired ATP hydrolysis in blood plasma contributes to age-related neutrophil dysfunction.

Background: The function of polymorphonuclear neutrophils (PMNs) decreases with age, which results in infectious and inflammatory complications in older individuals. The underlying causes are not fully understood. ATP release and autocrine stimulation of purinergic receptors help PMNs combat microbial invaders.

P2X1 and P2X7 Receptor Overexpression Is a Negative Predictor of Survival in Muscle-Invasive Bladder Cancer.

Bladder cancer is amongst the most common causes of cancer death worldwide. Muscle-invasive bladder cancer (MIBC) bears a particularly poor prognosis. Overexpression of purinergic P2X receptors (P2XRs) has been associated with worse outcome in several malignant tumors.

ATP breakdown in plasma of children limits the antimicrobial effectiveness of their neutrophils.

Neutrophils (PMNs) require extracellular ATP and adenosine (ADO) to fight bacterial infections, which often have life-threatening consequences in pediatric patients. We wondered whether the ATP and ADO levels in the plasma of children change with age and if these changes influence the antimicrobial efficacy of the PMNs of these children. We measured plasma concentrations of ATP and ADO and the activities of the enzymes responsible for the breakdown of these mediators in plasma samples from healthy children and adolescents (n = 45) ranging in age from 0.

Optimized flow cytometry assays to monitor neutrophil activation in human and mouse whole blood samples.

Polymorphonuclear neutrophils (PMNs) protect the host from invading microorganisms. However, excessively activated PMNs can also cause damage to host tissues under inflammatory conditions. Here we developed simple assays to determine the activation state of PMNs in human whole blood that contains soluble mediators known to influence PMN functions.

Tumor-infiltrating lymphocytes predict survival in ≥ pT2 urothelial bladder cancer.

Tumor-infiltrating lymphocytes (TILs) are associated with improved survival in several types of cancers, including genitourinary cancers. However, multiple different scoring methods used to assess TILs complicate the comparison of different studies and are not always suitable for daily practice. In 2014, the International TILs Working Group (ITWG) proposed a simple and robust assessment method for a more standardized evaluation of TILs.

Extracellular mitochondria drive CD8 T cell dysfunction in trauma by upregulating CD39.

Rationale: The increased mortality and morbidity seen in critically injured patients appears associated with systemic inflammatory response syndrome (SIRS) and immune dysfunction, which ultimately predisposes to infection. Mitochondria released by injury could generate danger molecules, for example, ATP, which in turn would be rapidly scavenged by ectonucleotidases, expressed on regulatory immune cells.

Objective: To determine the association between circulating mitochondria, purinergic signalling and immune dysfunction after trauma.

Optimized HPLC method to elucidate the complex purinergic signaling dynamics that regulate ATP, ADP, AMP, and adenosine levels in human blood.

ATP released into the bloodstream regulates immune responses and other physiological functions. Excessive accumulation of extracellular ATP interferes with these functions, and elevated plasma ATP levels could indicate infections and other pathological disorders. However, there is considerable disagreement about what constitutes normal plasma ATP levels.

Evaluation of an image enhancement system for the assessment of nasal and paranasal sinus diseases.

Purpose: Dysplasia and cancer of the upper aerodigestive tract are characterized by significant neoangiogenesis. This can be recognized by optical methods like the Storz Professional Image Enhancement System (SPIES). Up to now, there are no reports of using this novel technique for examining nasal diseases.

Prognostic Value of Tumor-Infiltrating Lymphocytes in Sinonasal Mucosal Melanoma.

Objectives/hypothesis: Tumor-infiltrating lymphocytes (TILs) predict better outcome in several types of cancers. However, the prognostic value of TILs in sinonasal mucosal melanoma (SNMM) is uncertain. Here, we investigated whether TILs can be used as a prognostic indicator for survival in SNMM.

Endoscopic endonasal repair of complete bilateral choanal atresia in neonates.

Reported success rates of endoscopic choanal atresia (CA) surgery vary substantially due to a high heterogeneity in and between study groups. Comprehensive data on the unique patient cohort of newborns with bilateral CA are scarce. Our study aimed to close this gap by using narrow inclusion criteria and standardized surgical outcome parameters.

Mitochondria Synergize With P2 Receptors to Regulate Human T Cell Function.

Intracellular ATP is the universal energy carrier that fuels many cellular processes. However, immune cells can also release a portion of their ATP into the extracellular space. There, ATP activates purinergic receptors that mediate autocrine and paracrine signaling events needed for the initiation, modulation, and termination of cell functions.

Structural and functional characterization of engineered bifunctional fusion proteins of CD39 and CD73 ectonucleotidases.

Extracellular diphosphate and triphosphate nucleotides are released from activated or injured cells to trigger vascular and immune P purinergic receptors, provoking inflammation and vascular thrombosis. These metabokines are scavenged by ectonucleoside triphosphate diphosphohydrolase-1 (E-NTPDase1 or CD39). Further degradation of the monophosphate nucleoside end products occurs by surface ecto-5'-nucleotidase (NMPase) or CD73.

Negative feedback control of neuronal activity by microglia.

Microglia, the brain's resident macrophages, help to regulate brain function by removing dying neurons, pruning non-functional synapses, and producing ligands that support neuronal survival. Here we show that microglia are also critical modulators of neuronal activity and associated behavioural responses in mice. Microglia respond to neuronal activation by suppressing neuronal activity, and ablation of microglia amplifies and synchronizes the activity of neurons, leading to seizures.

The purinergic receptor P2Y11 choreographs the polarization, mitochondrial metabolism, and migration of T lymphocytes.

T cells must migrate to encounter antigen-presenting cells and perform their roles in host defense. Here, we found that autocrine stimulation of the purinergic receptor P2Y11 regulates the migration of human CD4 T cells. P2Y11 receptors redistributed from the front to the back of polarized cells where they triggered intracellular cAMP/PKA signals that attenuated mitochondrial metabolism at the back.

Frontline Science: P2Y11 receptors support T cell activation by directing mitochondrial trafficking to the immune synapse.

T cells form an immune synapse (IS) with antigen-presenting cells (APCs) to detect antigens that match their TCR. Mitochondria, pannexin-1 (panx1) channels, and P2X4 receptors congregate at the IS where mitochondria produce the ATP that panx1 channels release in order to stimulate P2X4 receptors. P2X4 receptor stimulation causes cellular Ca influx that up-regulates mitochondrial metabolism and localized ATP production at the IS.

Airway brush cells generate cysteinyl leukotrienes through the ATP sensor P2Y2.

Chemosensory epithelial cells (EpCs) are specialized cells that promote innate type 2 immunity and protective neurally mediated reflexes in the airway. Their effector programs and modes of activation are not fully understood. Here, we define the transcriptional signature of two choline acetyltransferase-expressing nasal EpC populations.

Adenosine 5'-Monophosphate Protects from Hypoxia by Lowering Mitochondrial Metabolism and Oxygen Demand.

Ischemia and reperfusion injury following severe trauma or cardiac arrest are major causes of organ damage in intensive care patients. The brain is particularly vulnerable because hypoxia rapidly damages neurons due to their heavy reliance on oxidative phosphorylation. Therapeutic hypothermia can reduce ischemia-induced brain damage, but cooling procedures are slow and technically difficult to perform in critical care settings.

Frontline Science: Escherichia coli use LPS as decoy to impair neutrophil chemotaxis and defeat antimicrobial host defense.

Bacterial infections and sepsis are leading causes of morbidity and mortality in critically ill patients. Currently, there are no effective treatments available to improve clinical outcome in sepsis. Here, we elucidated a mechanism by which Escherichia coli (E.

Autocrine stimulation of P2Y1 receptors is part of the purinergic signaling mechanism that regulates T cell activation.

Previous studies have shown that T cell receptor (TCR) and CD28 coreceptor stimulation involves rapid ATP release, autocrine purinergic feedback via P2X receptors, and mitochondrial ATP synthesis that promote T cell activation. Here, we show that ADP formation and autocrine stimulation of P2Y1 receptors are also involved in these purinergic signaling mechanisms. Primary human CD4 T cells and the human Jurkat CD4 T cell line express P2Y1 receptors.

Lipopolysaccharide suppresses T cells by generating extracellular ATP that impairs their mitochondrial function via P2Y11 receptors.

T cell suppression contributes to immune dysfunction in sepsis. However, the underlying mechanisms are not well-defined. Here, we show that exposure of human peripheral blood mononuclear cells to bacterial lipopolysaccharide (LPS) can rapidly and dose-dependently suppress interleukin-2 (IL-2) production and T cell proliferation.