Cells must amplify external signals to orient and migrate in chemotactic gradient fields. We find that human neutrophils release adenosine triphosphate (ATP) from the leading edge of cell surface direct orientation by feedback through P2Y2 nucleotide receptors. Neutrophils rapidly hydrolyze released ATP then acts via A3-type receptors, which are recruited edge, promote migration. Thus, autocrine A3 receptors provide signal amplification, controlling sensing migration neutrophils.

T-cell activation requires the influx of extracellular calcium, although mechanistic details regarding such are not fully defined. Here, we show that P2X(7) receptors play a key role in calcium and downstream signaling events associated with T cells. By real-time PCR immunohistochemistry, find Jurkat cells human CD4(+) express abundant receptors. We show, using novel fluorescent microscopy technique, receptor (TCR) stimulation triggers rapid release ATP (<100 microM). This is required for...

We have recently shown that A3 adenosine receptors and P2Y2 purinergic play an important role in neutrophil chemotaxis. Chemotaxis of neutrophils to sites infections is critical for immune defense. However, excessive accumulation the lungs can cause acute lung tissue damage. Here we assessed sequestration a mouse model sepsis. Sepsis was induced by cecal ligation puncture (CLP) using adult male C57BL/6J mice (wild type [WT]), homozygous receptor knockout (A3KO) mice, (P2Y2KO) mice. Animals...

Abstract Hypertonic stress activates T cells by inducing the controlled release of ATP through pannexin-1 hemichannels and activation ATP-gated ion channels P2X1, P2X4, P2X7. saline (HS) resuscitation increases cell function inhibits posttraumatic anergy, which can reduce immunosuppression sepsis in trauma patients. We have previously shown that HS induces cellular enhances function. However, mechanism subsequent regulation remain poorly understood. In present study, we show inhibition gap...

T cell suppression in sepsis is a well-known phenomenon; however, the underlying mechanisms are not fully understood. Previous studies have shown that stimulation up-regulates mitochondrial adenosine triphosphate (ATP) production to fuel purinergic signaling necessary for adequate responses. Here we show basal ATP production, release, and of P2X1 receptors represent standby mechanism antigen recognition. Inhibition this process impairs vigilance ability cells trigger activation, up-regulate...

The transcriptional regulator deformed epidermal autoregulatory factor 1 (DEAF1) has been suggested to play a role in maintaining peripheral tolerance by controlling the transcription of tissue antigen genes lymph node stromal cells (LNSCs). Here, we demonstrate that DEAF1 also regulates translation LNSCs poorly characterized eukaryotic initiation 4 gamma 3 (Eif4g3) encodes eIF4GII. Eif4g3 gene expression was reduced pancreatic nodes Deaf1-KO mice, non-obese diabetic and type diabetes...

Prediabetic NOD mice exhibit hyperglucagonemia, possibly due to an intrinsic α-cell defect. Here, we show that the expression of a potential glucagon inhibitor, adenosine A1 receptor (Adora1), is gradually diminished in α-cells mice, autoantibody-positive (AA+) and overtly type 1 diabetic (T1D) patients during progression disease. We demonstrated islet inflammation was associated with loss Adora1 through alternative splicing Adora1. Expression spliced variant (Adora1-Var) upregulated...

Hypertonic saline (HS) holds promise as a novel resuscitation fluid for the treatment of trauma patients because HS inhibits polymorphonuclear neutrophil (PMN) activation and thereby prevents host tissue damage associated posttraumatic complications. However, depending on conditions cell activation, can increase PMN degranulation, which could exacerbate in victims. The cellular mechanism by increases degranulation is unknown. In present study, we tested whether HS-induced ATP release from...

During inflammation and sepsis, accumulation of activated neutrophils causes lung tissue damage organ failure. Effective clearance reduces the risk failure; however, its mechanisms are poorly understood. Because lungs rich in gammadeltaT cells, we investigated physiological role these cells protection from infiltrating neutrophils. In a mouse model found that survivors contained significantly higher numbers than those mice died sepsis. The number correlated inversely with degree damage. LPS...

Activation of polymorphonuclear neutrophils (PMN) is a critical event leading to host tissue injury and organ damage after trauma. Hypertonic saline (HS) resuscitation prevents PMN activation in vitro animal models. Here, we studied how clinical parameters timing requirements influence the efficacy HS suppressing activation.Twenty-six injured patients 16 healthy volunteers were included as study subjects. To affect HS, whole blood samples from collected 24 hours admission, treated with...

Type 1 Diabetes (T1D) occurs as a result of the autoimmune destruction pancreatic β-cells by self-reactive T cells. The etiology this disease is complex and difficult to study due lack disease-relevant tissues from pre-diabetic individuals. In study, we performed gene expression analysis on human pancreas obtained Network Pancreatic Organ Donors with (nPOD), showed that 155 genes were differentially expressed ≥2-fold in pancreata autoantibody-positive (AA+) at-risk individuals compared...

Hypertonic saline (HS) treatment promotes interleukin (IL)-2 production and enhances T-cell activation by the release of cellular adenosine triphosphate (ATP) that activates P2 nucleotide receptors. Released ATP can be hydrolyzed to adenosine, which inhibits activation. We examined if affects response T cells HS treatment, found amount released from is a function concentration duration exposure. Physiologically relevant concentrations (<40 mmol/L) induced rapid release, with highest within 1...

Peripheral tolerance is partially controlled by the expression of peripheral tissue antigens (PTAs) in lymph node stromal cells (LNSCs). We previously identified a transcriptional regulator, deformed epidermal autoregulatory factor 1 (Deaf1), that can regulate PTA LNSCs pancreatic nodes (PLNs). During pathogenesis type diabetes (T1D), Deaf1 spliced to form dominant-negative isoform Deaf1-Var1. Here we show Deaf1-Var1 correlates with severity disease NOD mice and reduced PLNs do not develop...

Adenosine has been demonstrated to inhibit gastric acid secretion. In the rat stomach, this inhibitory effect may be mediated indirectly by increasing release of somatostatin-like immunoreactivity (SLI). Results show that adenosine analogs augmented SLI in isolated vascularly perfused stomach. The rank order potency stimulating was 2-<i>p</i>-(2-carboxyethyl)phenethylamino-5′-<i>N</i>-ethylcarboxamidoadenosine (CGS 21680) ≈ 5′-<i>N</i>-ethylcarboxamidoadenosine &gt; 2-chloroadenosine...

The natural history of type 1 diabetes (T1D) is challenging to investigate, especially as pre-diabetic individuals are difficult identify. Numerous T1D consortia have been established collect whole blood for gene expression analysis from with or at risk develop T1D. However, no universally accepted protocol their collection, differences in sample processing may lead variances the results. Here, we examined whether choice collection tube and RNA extraction kit leads genes that changed during...

Regulatory T cells (T regs ) normally maintain self-tolerance. recognize “self” such that when they are not working properly, as in autoimmunity, the immune system can attack and destroy one’s own tissues. Current therapies for autoimmunity rely on relatively ineffective too often toxic to “treat” destructive inflammation. Restoring defective endogenous regulation (self-tolerance) would represent a paradigm shift therapy of these diseases. One recent approach restore self-tolerance is use...

Adenosine has been demonstrated to inhibit gastric acid secretion. In the rat stomach, this inhibitory effect may be mediated indirectly by inhibition of gastrin release. Results show that A₁ receptor agonist <i>N</i>⁶-cyclopentyladenosine (CPA) suppressed immunoreactive (IRG) release in a concentration-dependent manner. CPA significantly inhibited IRG at 0.001 μM and maximally 1 μM. At concentrations 0.1 μM, A_2A receptor-selective...

Ghrelin, a potent orexigenic hormone released from the stomach, is important in regulating energy metabolism. Abnormal ghrelin levels are associated with eating disorders and metabolic diseases. However, factors involved regulation of release remain unclear. Here, we examined involvement adenosine signaling control perfused mouse stomach. Adenosine stimulated concentration-dependently, A_2A receptor-selective antagonists...

Multiple pathways contribute to the pathophysiological development of type 1 diabetes (T1D); however, exact mechanisms involved are unclear. We performed differential gene expression analysis in pancreatic islets NOD mice versus age-matched congenic NOD.B10 controls identify genes that may disease pathogenesis. Novel related extracellular matrix and glucagon insulin signaling/secretion were changed during early inflammation. During “respective” insulitis, encoding multiple chemosensory...