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Plasmacytoid dendritic cells (pDC) are key players in viral immunity and produce IFN-[alpha] after HIV-1 exposure, which in turn regulates TNF-related apoptosis-inducing ligand (TRAIL) expression by CD[4.sup.+] T cells. We show here that infectious and noninfectious HIV-1 virions induce activation of pDC into TRAIL-expressing IFN-producing killer pDC (IKpDC). IKpDC expressed high levels of activation markers (HLA-DR, CD80, CD83, and CD86) and the migration marker CCR7. Surprisingly, CXCR4 and CCR5 were down-regulated on IKpDC. We also show that HIV-1-induced IKpDC depended on Toll-like receptor 7 (TLR7) activation. HIV-1 or TLR7 agonist-exposed IKpDC induced apoptosis of the CD[4.sup.+] T cell line SupT1 via the TRAIL pathway. Furthermore, IFN-[alpha] produced after HIV-induced TLR7 stimulation was responsible for TRAIL expression and the down-regulation of both CXCR4 and CCR5 by IKpDC. In contrast, activation and migration markers were not regulated by IFN-[alpha]. Finally, IFN-[alpha] increased the survival of IKpDC. We characterized a subset of pDC with a killer activity that is activated by endosomal-associated viral RNA and not by infection. apoptosis | endocytosis | AT-2 HIV-1 | CCR5 | CXCR4

Background: Although social distancing is a key public health response during viral pandemics, psychosocial stressors, such as social isolation, have been implicated in adverse health outcomes in general [1] and in the context of infectious disease, such as human immunodeficiency virus (HIV) [2, 3]. A comprehensive understanding of the direct pathophysiologic effects of psychosocial stress on viral pathogenesis is needed to provide strategic and comprehensive care to patients with viral infection.Methods: To determine the effect of psychosocial stress on HIV pathogenesis during acute viral infection without sociobehavioral confounders inherent in human cohorts, we compared commonly measured parameters of HIV progression between singly (n = 35) and socially (n = 41) housed simian immunodeficiency virus (SIV)-infected pigtailed macaques (Macaca nemestrina).Results: Singly housed macaques had a higher viral load in the plasma and cerebrospinal fluid and demonstrated greater CD4 T-cell declines and more CD4 and CD8 T-cell activation compared with socially housed macaques throughout acute SIV infection.Conclusions: These data demonstrate that psychosocial stress directly impacts the pathogenesis of acute SIV infection and imply that it may act as an integral variable in the progression of HIV infection and potentially of other viral infections. [ABSTRACT FROM AUTHOR]

The greatest question facing today's huge Russian Federation is whether its eighty-nine components - republics, oblasts, and krais - will find enough common ground to remain one country, or will [...]

Cost as an independent variable is a key tool in the thrust to reduce total ownership cost for defense systems. While the need for CAIV is driven by cost constraints, [...]

Maternal inflammation has been linked to neurodevelopmental and neuropsychiatric disorders such as cerebral palsy, schizophrenia, and autism. We had previously shown that intrauterine inflammation resulted in a decrease in serotonin, one of the tryptophan metabolites, and a decrease in serotonin fibers in the sensory cortex of newborns in a rabbit model of cerebral palsy. In this study, we hypothesized that maternal inflammation results in alterations in tryptophan pathway enzymes and metabolites in the placenta and fetal brain. We found that intrauterine endotoxin administration at gestational day 28 (G28) resulted in a significant upregulation of indoleamine 2,3-dioxygenase (IDO) in both the placenta and fetal brain at G29 (24 h after treatment). This endotoxin- mediated IDO induction was also associated with intense microglial activation, an increase in interferon gamma expression, and increases in kynurenine and the kynurenine pathway metabolites kynurenine acid and quinolinic acid, as well as a significant decrease in 5-hydroxyindole acetic acid (a precursor of serotonin) levels in the periventricular region of the fetal brain. These results indicate that maternal inflammation shunts tryptophan metabolism away from the serotonin to the kynurenine pathway, which may lead to excitotoxic injury along with impaired development of serotonin-mediated thalamocortical fibers in the newborn brain. These findings provide new targets for prevention and treatment of maternal inflammation-induced fetal and neonatal brain injury leading to neurodevelopmental disorders such as cerebral palsy and autism. [ABSTRACT FROM AUTHOR]

Induction of the kynurenine pathway (KP) of tryptophan (TRP) catabolism has been proposed to contribute to T cell dysfunction during human/simian immunodeficiency virus (SIV) infection via depletion of local TRP levels and production of immunomodulatory KP metabolites. However, while changes in TRP and KP metabolites have been observed in plasma, their levels in lymphoid tissues and levels of enzymes downstream of indoleamine 2,3-dioxygenase (IDO1) have been relatively unexplored. We used our SIV-infected pigtailed macaque model to analyze longitudinal changes in KP metabolites and enzymes by gas chromatography/mass spectrometry and NanoString nCounter gene expression analysis, respectively, in spleen and blood compared to changes previously established in brain and CSF. We found that TRP levels were remarkably stable in tissue sites despite robust depletion in the circulating plasma and CSF. We also demonstrated that intracellular TRP reserves were maintained in cultured cells even in the presence of depleted extracellular TRP levels. Kynurenine (KYN), 3-hydroxykynurenine, quinolinic acid, and the KP enzymes all displayed highly divergent patterns in the sites examined, though IDO1 expression always correlated with local KYN/TRP ratios. Finally, we demonstrated by fluorescence-activated cell sorting that myeloid dendritic cells and cells of monocytic lineage were the highest producers of IDO1 in chronically infected spleens. Overall, our study reveals insights into the tissue-specific regulation of KP enzymes and metabolites and, in particular, highlights the multiple mechanisms by which cells and tissues seek to prevent TRP starvation during inflammation. [ABSTRACT FROM AUTHOR]

HIV-1 causes a progressive impairment of immune function. HIV-2 is a naturally attenuated form of HIV, and HIV-2 patients display a slow-progressing disease. The leading hypothesis for the difference in disease phenotype between HIV-1 and HIV-2 is that more efficient T cell–mediated immunity allows for immune-mediated control of HIV-2 infection, similar to that observed in the minority of HIV-1–infected long-term nonprogressors. Understanding how HIV-1 and HIV-2 differentially influence the immune function may highlight critical mechanisms determining disease outcome. We investigated the effects of exposing primary human peripheral blood cells to HIV-1 or HIV-2 in vitro. HIV-2 induced a gene expression profile distinct from HIV-1, characterized by reduced type I IFN, despite similar upregulation of IFN-stimulated genes and viral restriction factors. HIV-2 favored plasmacytoid dendritic cell (pDC) differentiation into cells with an APC phenotype rather than IFN-α–producing cells. HIV-2, but not HIV-1, inhibited IFN-α production in response to CpG-A. The balance between pDC maturation into IFN-α–producing cells or development of an APC phenotype differentiates the early response against HIV-1 and HIV-2. We propose that divergent paths of pDC differentiation driven by HIV-1 and HIV-2 cause the observed differences in pathogenicity between the two viruses. [ABSTRACT FROM AUTHOR]

Background: Gametogenesis and fertilization play crucial roles in malaria transmission. While male gametes are thought to be amongst the simplest eukaryotic cells and are proven targets of transmission blocking immunity, little is known about their molecular organization. For example, the pathway of energy metabolism that power motility, a feature that facilitates gamete encounter and fertilization, is unknown. Methods: Plasmodium berghei microgametes were purified and analysed by whole-cell proteomic analysis for the first time. Data are available via ProteomeXchange with identifier PXD001163. Results: 615 proteins were recovered, they included all male gamete proteins described thus far. Amongst them were the 11 enzymes of the glycolytic pathway. The hexose transporter was localized to the gamete plasma membrane and it was shown that microgamete motility can be suppressed effectively by inhibitors of this transporter and of the glycolytic pathway. Conclusions: This study describes the first whole-cell proteomic analysis of the malaria male gamete. It identifies glycolysis as the likely exclusive source of energy for flagellar beat, and provides new insights in original features of Plasmodium flagellar organization. [ABSTRACT FROM AUTHOR]

Chronic activation of plasmacytoid dendritic cells (pDCs) is an important contributor to the immunopathogenesis of HIV infection. The quinolone derivative chloroquine (CQ) prevents endosomal acidification, required for toll-like receptor sensing of HIV by pDCs, and is currently under clinical trial as an immunotherapeutic approach. We tested three different 6-desfluoroquinolones (6-DFQs), structurally related to CQ and endowed with antiretroviral activity, for their ability to inhibit HIV-induced pDC activation and interferon (IFN)-α production in peripheral blood mononuclear cells (PBMCs) in vitro. PBMCs from six healthy donors were cultured overnight with aldrithiol-2 (AT-2)-inactivated HIV-1MN in the presence or absence of 6-DFQs or CQ. IFN-α production was measured by ELISA; pDC and monocyte activation was analyzed by flow cytometry. Incubation with HIV labeled with the fluorescent dye DyLight-488 (DL488) was used to test virus uptake by flow cytometry. We found that the 6-DFQs effectively inhibited HIV-induced IFN-α similar to CQ, but only 6-DFQs also inhibited the upregulation of the pDC activation marker CD83. Interestingly, HIV-induced expression of the costimulatory molecule CD80 and, to a lesser extent CD86, was further enhanced on pDCs by 6-DFQs, but not CQ. Conversely, 6-DFQs and CQ had similar inhibitory effects on HIV-induced monocyte activation, consistent with the primary mechanism being associated with IFN-α signaling. Finally, 6-DFQs interfered with HIV interaction with pDCs and monocytes, but not myeloid DCs. Our data indicate that 6-DFQs may interfere with pDC-mediated and IFN-α-dependent immunopathogenesis while supporting pDC differentiation into mature antigen-presenting cells by favoring expression of costimulatory molecules. [ABSTRACT FROM AUTHOR]

HIV immune pathogenesis is postulated to involve two major mechanisms: 1) chronic innate immune responses that drive T cell activation and apoptosis and 2) induction of immune regulators that suppress T cell function and proliferation. Both arms are elevated chronically in lymphoid tissues of non-natural hosts, which ultimately develop AIDS. However, these mechanisms are not elevated chronically in natural hosts of SIV infection that avert immune pathogenesis despite similarly high viral loads. In this study we investigated whether minocycline could modulate these pathogenic antiviral responses in non-natural hosts of HIV and SIV. We found that minocycline attenuated in vitro induction of type I interferon (IFN) and the IFN-stimulated genes indoleamine 2,3-dioxygenase (IDO1) and TNF-related apoptosis inducing ligand (TRAIL) in human plasmacytoid dendritic cells and PBMCs exposed to aldrithiol-2 inactivated HIV or infectious influenza virus. Activation-induced TRAIL and expression of cytotoxic T-lymphocyte antigen 4 (CTLA-4) in isolated CD4+ T cells were also reduced by minocycline. Translation of these in vitro findings to in vivo effects, however, were mixed as minocycline significantly reduced markers of activation and activation-induced cell death (CD25, Fas, caspase-3) but did not affect expression of IFNβ or the IFN-stimulated genes IDO1, FasL, or Mx in the spleens of chronically SIV-infected pigtailed macaques. TRAIL expression, reflecting the mixed effects of minocycline on activation and type I IFN stimuli, was reduced by half, but this change was not significant. These results show that minocycline administered after infection may protect against aspects of activation-induced cell death during HIV/SIV immune disease, but that in vitro effects of minocycline on type I IFN responses are not recapitulated in a rapid progressor model in vivo. [ABSTRACT FROM AUTHOR]

Newborn screening using dried plasma spots offers preanalytical advantages over conventional cards for plasma-associated targets of interest. Herein we present dried plasma spot-based methods for measuring metabolites using a 250+ compound liquid chromatography tandem mass spectrometry library. Quality assurance reduced this library to 134, and from these, 30 compounds determined the normal newborn reference ranges. [ABSTRACT FROM AUTHOR]

Central nervous system (CNS) invasion during acute-stage HIV-infection has been demonstrated in a small number of individuals, but there is no evidence of neurological impairment at this stage and virus infection in brain appears to be controlled until late-stage disease. Using our reproducible SIV macaque model to examine the earliest stages of infection in the CNS, we identified immune responses that differentially regulate inflammation and virus replication in the brain compared to the peripheral blood and lymphoid tissues. SIV replication in brain macrophages and in brain of SIV-infected macaques was detected at 4 days post-inoculation (p.i.). This was accompanied by upregulation of innate immune responses, including IFNβ, IFNβ-induced gene MxA mRNA, and TNFα. Additionally, IL-10, the chemokine CCL2, and activation markers in macrophages, endothelial cells, and astrocytes were all increased in the brain at four days p.i. We observed synchronous control of virus replication, cytokine mRNA levels and inflammatory markers (MHC Class II, CD68 and GFAP) by 14 days p.i.; however, control failure was followed by development of CNS lesions in the brain. SIV infection was accompanied by induction of the dominant-negative isoform of C/EBPβ, which regulates SIV, CCL2, and IL6 transcription, as well as inflammatory responses in macrophages and astrocytes. This synchronous response in the CNS is in part due to the effect of the C/EBPβ on virus replication and cytokine expression in macrophage-lineage cells in contrast to CD4+ lymphocytes in peripheral blood and lymphoid tissues. Thus, we have identified a crucial period in the brain when virus replication and inflammation are controlled. As in HIV-infected individuals, though, this control is not sustained in the brain. Our results suggest that intervention with antiretroviral drugs or anti-inflammatory therapeutics with CNS penetration would sustain early control. These studies further suggest that interventions should target HIV-infected individuals with increased CCL2 levels or HIV RNA in the CNS. [ABSTRACT FROM AUTHOR]

A new method is presented for attenuating time dependent composition or temperature variations in fluid streams. We refer to this new method as temporal mixing, or mixing in time. Temporal mixing involves passing fluid streams through a vessel or configuration of vessels that exhibits a certain residence time distribution (RTD). While conventional configurations, such as a buffer tank or stirred tank, provide some attenuation, new temporal mixing configurations are described that exhibit a higher degree of attenuation. A number of simpleflow configurations exhibiting limited temporal mixing are analyzed, and a theoretical configuration exhibiting ideal temporal mixing is proposed. The ideal temporal mixing configuration is characterized by a perfectly flat RTD, which totally eliminates all periodic variations at the outlet of the configuration. Although this ideal case cannot be realized in practice, a vessel that closely approximates a flat RTD is described. Simulations based on real plant data are used to show that this vessel significantly improves the attenuation achieved over that attained with conventional methods. A number of temporal mixing vessels have been installed that demonstrate improved operation and a significant reduction in operating costs for world-class hydrogen facilities. [ABSTRACT FROM AUTHOR]

Two young women presented with acute bleeding disorders and were subsequently found to have coeliac disease. [ABSTRACT FROM PUBLISHER]

The Ig-like transcript (ILT) 7 is a surface molecule selectively expressed by human plasmacytoid dendritic cells (pDCs). ILT7 cross-linking suppresses pDC activation and type I IFN (IFN-I) secretion following TLR7/9 engagement. The bone marrow stromal cell Ag 2 (BST2, aka HM1.24, tetherin, or CD317) is expressed by different cell types upon exposure to IFN-I and is a natural ligand for ILT7. In this study, we show that ILT7 expression decreased spontaneously in pDCs upon in vitro culture, which correlates with pDC differentiation measured as increased side scatter properties and CCR7 expression. TLR7/9 ligands, as well as HIV, induced BST2 upregulation on all tested cell types except T cells, which required TCR stimulation to respond to TLR9L-induced IFN-I. IFN-γ, IL-4, IL-10, and TNF-α had only marginal effects on BST2 expression in blood leukocytes compared with TLR9L. Preincubation with ILT7 cross-linking Ab inhibited IFN-I production in PBMCs treated with TLR7/9L or HIV, whereas BST2 blockade did not affect IFN-I responses even when BST2 upregulation was further boosted with TCR agonists or immunoregulatory cytokines. Our data indicate that BST2-mediated ILT7 cross-linking may act as a homeostatic regulatory mechanism on immature circulating pDC, rather than a negative feedback for activated mature pDCs that have downregulated ILT7. [ABSTRACT FROM AUTHOR]

Minocycline is a tetracycline family antibiotic that has anti-inflammatory and immunomodulatory properties. These properties have shown promise in the treatment of conditions such as rheumatoid arthritis, Huntington disease, and multiple sclerosis. As lymphocyte activation is involved in the pathogenesis of many of these diseases, T cells are postulated to be a primary target in minocycline therapy. Previous studies have demonstrated attenuation of CD4+ T cell activation by minocycline, but a specific mechanism has not been elucidated. In this study, we investigated the effect of minocycline on the activity of three key transcription factors regulating CD4+ T cell activation: NF-κB, AP-1 (activator protein 1), and NFAT (nuclear factor of activated T) cells. Our data demonstrate that minocycline selectively impairs NFAT-mediated transcriptional activation, a result of increased phosphorylation and reduced nuclear translocation of the isoform NFAT1. Minocycline increased the activity of the NFAT kinase GSK3 and decreased intracellular Ca2+ flux, both of which facilitate NFAT1 phosphorylation. These findings provide a novel mechanism for minocycline induced suppression of CD4+ T cell activation and may better inform the application of minocycline as an immunomodulatory agent. [ABSTRACT FROM AUTHOR]

Exosomes, also known as microvesicles (EMVs), are nanosized membranous particles secreted from nearly all mammalian cell types. These nanoparticles play critical roles in many physiological processes including cell-cell signaling, immune activation, and suppression and are associated with disease states such as tumor progression. The biological functions of EMVs are highly dependent on their protein composition, which can dictate pathogenicity. Although some mechanisms have been proposed for the regulation of EMV protein trafficking, little attention has been paid to N-linked glycosylation as a potential sorting signal. Previous work from our laboratory found a conserved glycan signature for EMVs, which differed from that of the parent cell membranes, suggesting a potential role for glycosylation in EMV biogenesis. In this study, we further explore the role of glycosylation in EMV protein trafficking. We identify EMV glycoproteins and demonstrate alteration of their recruitment as a function of their glycosylation status upon pharmacological manipulation. Furthermore, we show that genetic manipulation of the glycosylation levels of a specific EMV glycoprotein, EWI-2, directly impacts its recruitment as a function of N-linked glycan sites. Taken together, our data provide strong evidence that N-linked glycosylation directs glycoprotein sorting into EMVs. [ABSTRACT FROM AUTHOR]