Temperature Trajectory Sub-phenotypes and the Immuno-Inflammatory Response in Pediatric Sepsis.

Objective: Heterogeneity has hampered sepsis trials, and sub-phenotyping may assist with enrichment strategies. However, biomarker-based strategies are difficult to operationalize. Four sub-phenotypes defined by distinct temperature trajectories in the first 72 h have been reported in adult sepsis.

Influence of Immune Cell Subtypes on Mitochondrial Measurements in Peripheral Blood Mononuclear Cells From Children with Sepsis.

Introduction: Peripheral blood mononuclear cells (PBMCs) are commonly used to compare mitochondrial function in patients with versus without sepsis, but how these measurements in this mixed cell population vary by composition of immune cell subtypes is not known, especially in children. We determined the effect of changing immune cell composition on PBMC mitochondrial respiration and content in children with and without sepsis.

Methods: PBMC mitochondrial respiration and citrate synthase (CS) activity, a marker of mitochondrial content, were measured in 167 children with sepsis at three timepoints (day 1-2, 3-5, and 8-14) and once in 19 nonseptic controls.

Mitochondrial Dysfunction is Associated With an Immune Paralysis Phenotype in Pediatric Sepsis.

Objective: Immune dysregulation is a defining feature of sepsis, but the role for mitochondria in the development of immunoparalysis in pediatric sepsis is not known. We sought to determine if mitochondrial dysfunction measured in peripheral blood mononuclear cells (PBMCs) is associated with immunoparalysis and systemic inflammation in children with sepsis.

Design: Prospective observational study.

Diet-induced microbial autofluorescence confounds flow cytometry of ex vivo isolated fecal microbes.

Microbial flow cytometry is a powerful emerging technology with a broad range of applications including the study of complex microbial communities. Immunologists are increasingly using this technology to study antibody responses against pathogenic and commensal microbes. We employed microbial flow cytometry to quantify the proportion of fecal microbes bound by six different Ig isotypes: IgA, IgM, IgG1, IgG2b, IgG2c, and IgG3.

Persistent Mitochondrial Dysfunction Linked to Prolonged Organ Dysfunction in Pediatric Sepsis.

Objectives: Limited data exist about the timing and significance of mitochondrial alterations in children with sepsis. We therefore sought to determine if alterations in mitochondrial respiration and content within circulating peripheral blood mononuclear cells were associated with organ dysfunction in pediatric sepsis.

Design: Prospective observational study SETTING:: Single academic PICU.

High-throughput BioSorter quantification of relative mitochondrial content and membrane potential in living Caenorhabditis elegans.

Mitochondrial respiratory chain disease is caused by a wide range of individually rare genetic disorders that impair cellular energy metabolism. While fluorescence microscopy analysis of nematodes fed MitoTracker Green (MTG) and tetramethylrhodamine ethyl ester (TMRE) can reliably quantify relative mitochondrial density and membrane potential, respectively, in C. elegans models of mitochondrial dysfunction, it is a tedious process with limitations in the number and age of animals that can be studied.

Substance P-mediated chemokine production promotes monocyte migration.

The neuropeptide SP has physiologic and pathophysiologic roles in CNS and peripheral tissues and is involved in crosstalk between nervous and immune systems in various conditions, including HIV and SIV infection. Increased SP levels were demonstrated in plasma of HIV individuals as well as in the CNS of SIV-infected, nonhuman primates. SP increases HIV infection in macrophages through interaction with its receptor, NK1R.

Decreased PD-1 Expression on CD8 Lymphocyte Subsets and Increase in CD8 Tscm Cells in Children with HIV Receiving Raltegravir.

We investigated the effect of combination antiretroviral therapy (cART) on immune recovery, particularly on the percentages of PD-1-positive cells within the major leukocyte subsets. Cryopreserved peripheral blood mononuclear cells and plasma samples collected longitudinally from a subset of 13 children and adolescents (between 9.7 and 18.

Safety and Efficacy of High-Dose Daily Vitamin D3 Supplementation in Children and Young Adults Infected With Human Immunodeficiency Virus.

Background: Suboptimal vitamin D (vitD) status is common in children and young adults infected with human immunodeficiency virus (HIV). The vitD supplemental dose needed to normalize vitD status in this population is unknown.

Methods: In this double-blind trial, subjects infected with HIV ages 8.

Reduction of soluble CD163, substance P, programmed death 1 and inflammatory markers: phase 1B trial of aprepitant in HIV-1-infected adults.

Objective: We evaluated safety, antiviral, immunomodulatory and anti-inflammatory properties of aprepitant - a neurokinin 1 receptor antagonist.

Design: Phase IB randomized, placebo-controlled, double-blinded study.

Methods: Eighteen patients were randomized (nine to aprepitant and nine to placebo).

Activation of Rab8 guanine nucleotide exchange factor Rabin8 by ERK1/2 in response to EGF signaling.

Exocytosis is tightly regulated in many cellular processes, from neurite expansion to tumor proliferation. Rab8, a member of the Rab family of small GTPases, plays an important role in membrane trafficking from the trans-Golgi network and recycling endosomes to the plasma membrane. Rabin8 is a guanine nucleotide exchange factor (GEF) and major activator of Rab8.

Mitochondrial dysfunction in peripheral blood mononuclear cells in pediatric septic shock.

Objectives: Mitochondrial dysfunction in peripheral blood mononuclear cells has been linked to immune dysregulation and organ failure in adult sepsis, but pediatric data are limited. We hypothesized that pediatric septic shock patients exhibit mitochondrial dysfunction within peripheral blood mononuclear cells which in turn correlates with global organ injury.

Design: Prospective observational study.

High-dose vitamin D3 supplementation in children and young adults with HIV: a randomized, placebo-controlled trial.

Background: Suboptimal vitamin D status is prevalent in HIV-infected patients and associated with increased risk of disease severity and morbidity. We aimed to determine 12-month safety and efficacy of daily 7000 IU vitamin D3 (vitD3) versus placebo to sustain increased serum 25-hydroxyvitamin D (25(OH)D) and improve immune status in HIV-infected subjects.

Methods: This was a double-blind trial of perinatally acquired HIV (PHIV)-infected subjects or behaviorally acquired HIV (BHIV)-infected subjects (5.

Autosomal dominant hypoparathyroidism caused by germline mutation in GNA11: phenotypic and molecular characterization.

Context: Most cases of autosomal dominant hypoparathyroidism (ADH) are caused by gain-of-function mutations in CASR or dominant inhibitor mutations in GCM2 or PTH.

Objective: Our objectives were to identify the genetic basis for ADH in a multigenerational family and define the underlying disease mechanism.

Subjects: Here we evaluated a multigenerational family with ADH in which affected subjects had normal sequences in these genes and were shorter than unaffected family members.

HIV infection of macrophages is enhanced in the presence of increased expression of CD163 induced by substance P.

Activation of NK1R by SP contributes to increased HIV-1 infection in macrophages. The scavenger receptor CD163 is expressed on cells of monocyte-macrophage origin. Our main goal was to determine if there is interplay among SP, CD163 expression, and HIV infection in macrophages.

Mechanisms of action of anesthetics for the modulation of perioperative thrombosis: evidence for immune mechanisms from basic and clinical studies.

Thrombotic events occurring in either arteries or veins are the primary causes of fatal perioperative cardiovascular events. Risk factors for deep vein thrombosis, several of which are evidently associated with specific surgical procedures, are quite different from those for arterial thrombosis (e.g.

Analog of somatostatin vapreotide exhibits biological effects in vitro via interaction with neurokinin-1 receptor.

Objectives: Vapreotide, a synthetic analog of somatostatin, has analgesic activity most likely mediated through the blockade of neurokinin-1 receptor (NK1R), the substance P (SP)-preferring receptor. The ability of vapreotide to interfere with other biological effects of SP has yet to be investigated.

Methods: We studied the ability of vapreotide to antagonize NK1R in three different cell types: immortalized U373MG human astrocytoma cells, human monocyte-derived macrophages (MDM) and a human embryonic kidney cell line, HEK293.

Substance P enhances HIV-1 infection in human fetal brain cell cultures expressing full-length neurokinin-1 receptor.

The associations between the neurokinin-1 receptor (NK-1R), substance P (SP), and HIV-1 were investigated in neurosphere-derived cultures of microglial-depleted human fetal brain cells (HFBC). Full-length NK-1R was identified in HFBC cultures. SP treatment of the HFBC increased intracellular calcium mobilization and decreased electrical impedance, both of which were blocked by the NK-1R antagonist aprepitant.

Neurokinin 1 receptor mediates membrane blebbing and sheer stress-induced microparticle formation in HEK293 cells.

Cell-derived microparticles participate in intercellular communication similar to the classical messenger systems of small and macro-molecules that bind to specialized membrane receptors. Microparticles have been implicated in the regulation of a variety of complex physiopathologic processes, such as thrombosis, the control of innate and adaptive immunity, and cancer. The neurokinin 1 receptor (NK1R) is a Gq-coupled receptor present on the membrane of a variety of tissues, including neurons in the central and peripheral nervous system, immune cells, endocrine and exocrine glands, and smooth muscle.

Substance P induces rapid and transient membrane blebbing in U373MG cells in a p21-activated kinase-dependent manner.

U373MG astrocytoma cells endogenously express the full-length neurokinin 1 receptor (NK1R). Substance P (SP), the natural ligand for NK1R, triggers rapid and transient membrane blebbing and we report that these morphological changes have different dynamics and intracellular signaling as compared to the changes that we have previously described in HEK293-NK1R cells. In both cell lines, the SP-induced morphological changes are Gq-independent, and they require the Rho, Rho-associated coiled-coil kinase (ROCK) signaling pathway.

A randomized, placebo controlled, double masked phase IB study evaluating the safety and antiviral activity of aprepitant, a neurokinin-1 receptor antagonist in HIV-1 infected adults.

Background: Neurokinin-1 receptor (NK1R) antagonists have anti-HIV activity in monocyte-derived macrophages, decrease CCR5 expression and improve natural killer cell function ex vivo. Aprepitant is a NK1R antagonist approved by FDA as an antiemetic.

Methods: We conducted a phase IB randomized, placebo controlled, double masked study to evaluate the safety, antiviral activity, pharmacokinetics and immune-modulatory effects of aprepitant in HIV-infected adults not receiving antiretroviral therapy, with CD4+ cell count ≥350 cells/mm(3) and plasma viral load ≥2,000 copies/ml.

Anti-HIV-1 activity of the neurokinin-1 receptor antagonist aprepitant and synergistic interactions with other antiretrovirals.

Objectives: Neurokinin-1 receptor (NK1R) antagonists interfere with binding of neuropeptide substance P to NK1R and exhibit novel anti-HIV-1 activities. Since NK1R antagonists effectively penetrate the blood-brain barrier to reduce the inflammatory response within the brain, we wished to evaluate their potential as anti-HIV-1 candidates for targeting HIV-1 infections of the central nervous system.

Design: A series of small molecule agents were evaluated for anti-NK1R and anti-HIV-1 activity using peripheral blood mononuclear cells (PBMCs).

Substance P inhibits natural killer cell cytotoxicity through the neurokinin-1 receptor.

SP is a potent neuroimmunomodulator that functions through ligating members of the neurokinin receptor family, one of which, NK1R, is widely expressed in immune cells. As in humans, circulating SP levels are increased in pathologic states associated with impairment of NK cell functions, such as depression and HIV infection, we hypothesized that SP has a direct, inhibitory effect upon NK cells. We have studied a clonal human NK cell line (YTS) as well as ex vivo human NK cells and have determined that truncated and full-length NK1R isoforms are expressed in and SP bound by ex vivo NK cells and the YTS NK cell line.

Neurokinin-1 receptor (NK1-R) expression in the brains of SIV-infected rhesus macaques: implications for substance P in NK1-R immune cell trafficking into the CNS.

Recent studies suggest a link between neuropsychiatric disorders and HIV/SIV infection. Most evidence indicates that monocytes/macrophages are the primary cell type infected within the CNS and that they contribute to CNS inflammation and neurological disease. Substance P (SP), a pleotropic neuropeptide implicated in inflammation, depression, and immune modulation via interaction with its cognate receptor, the neurokinin 1 receptor (NK1-R), is produced by monocyte/macrophages.

Neurokinin 1 receptor isoforms and the control of innate immunity.

Substance P is the prototype tachykinin peptide and triggers a variety of biological effects in both the nervous and immune system. Two naturally occurring variants of the neurokinin 1 receptor (NK1R) mediate the effects of SP: a 'classic' full-length receptor and a truncated (tail-less) form that lacks 96 amino acid residues at the C-terminus. Most research has focused on the full length receptor and the truncated NK1R has not been extensively explored.