1,039 research outputs found

    Optodynamic simulation of ő≤-adrenergic receptor signalling

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    Optogenetics has provided a revolutionary approach to dissecting biological phenomena. However, the generation and use of optically active GPCRs in these contexts is limited and it is unclear how well an opsin-chimera GPCR might mimic endogenous receptor activity. Here we show that a chimeric rhodopsin/ő≤(2) adrenergic receptor (opto-ő≤(2)AR) is similar in dynamics to endogenous ő≤(2)AR in terms of: cAMP generation, MAP kinase activation and receptor internalization. In addition, we develop and characterize a novel toolset of optically active, functionally selective GPCRs that can bias intracellular signalling cascades towards either G-protein or arrestin-mediated cAMP and MAP kinase pathways. Finally, we show how photoactivation of opto-ő≤(2)AR in vivo modulates neuronal activity and induces anxiety-like behavioural states in both fiber-tethered and wireless, freely moving animals when expressed in brain regions known to contain ő≤(2)ARs. These new GPCR approaches enhance the utility of optogenetics and allow for discrete spatiotemporal control of GPCR signalling in vitro and in vivo

    Spatiotemporal Control of Opioid Signaling and Behavior

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    SummaryOptogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here, we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically sensitive, mu-opioid-like receptor, which we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels and internalizes with kinetics similar to that of the mu-opioid receptor. To assess in vivo utility, we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways

    Progressive CD4+ central‚Äďmemory T cell decline results in CD4+ effector‚Äďmemory insufficiency and overt disease in chronic SIV infection

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    Primary simian immunodeficiency virus (SIV) infections of rhesus macaques result in the dramatic depletion of CD4+ CCR5+ effector‚Äďmemory T (TEM) cells from extra-lymphoid effector sites, but in most infections, an increased rate of CD4+ memory T cell proliferation appears to prevent collapse of effector site CD4+ TEM cell populations and acute-phase AIDS. Eventually, persistent SIV replication results in chronic-phase AIDS, but the responsible mechanisms remain controversial. Here, we demonstrate that in the chronic phase of progressive SIV infection, effector site CD4+ TEM cell populations manifest a slow, continuous decline, and that the degree of this depletion remains a highly significant correlate of late-onset AIDS. We further show that due to persistent immune activation, effector site CD4+ TEM cells are predominantly short-lived, and that their homeostasis is strikingly dependent on the production of new CD4+ TEM cells from central‚Äďmemory T (TCM) cell precursors. The instability of effector site CD4+ TEM cell populations over time was not explained by increasing destruction of these cells, but rather was attributable to progressive reduction in their production, secondary to decreasing numbers of CCR5‚ąí CD4+ TCM cells. These data suggest that although CD4+ TEM cell depletion is a proximate mechanism of immunodeficiency, the tempo of this depletion and the timing of disease onset are largely determined by destruction, failing production, and gradual decline of CD4+ TCM cells

    Profound CD4+/CCR5+ T cell expansion is induced by CD8+ lymphocyte depletion but does not account for accelerated SIV pathogenesis

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    Depletion of CD8+ lymphocytes during acute simian immunodeficiency virus (SIV) infection of rhesus macaques (RMs) results in irreversible prolongation of peak-level viral replication and rapid disease progression, consistent with a major role for CD8+ lymphocytes in determining postacute-phase viral replication set points. However, we report that CD8+ lymphocyte depletion is also associated with a dramatic induction of proliferation among CD4+ effector memory T (TEM) cells and, to a lesser extent, transitional memory T (TTrM) cells, raising the question of whether an increased availability of optimal (activated/proliferating), CD4+/CCR5+ SIV ‚Äútarget‚ÄĚ cells contributes to this accelerated pathogenesis. In keeping with this, depletion of CD8+ lymphocytes in SIV‚ąí RMs led to a sustained increase in the number of potential CD4+ SIV targets, whereas such depletion in acute SIV infection led to increased target cell consumption. However, we found that the excess CD4+ TEM cell proliferation of CD8+ lymphocyte‚Äďdepleted, acutely SIV-infected RMs was completely inhibited by interleukin (IL)-15 neutralization, and that this inhibition did not abrogate the rapidly progressive infection in these RMs. Moreover, although administration of IL-15 during acute infection induced robust CD4+ TEM and TTrM cell proliferation, it did not recapitulate the viral dynamics of CD8+ lymphocyte depletion. These data suggest that CD8+ lymphocyte function has a larger impact on the outcome of acute SIV infection than the number and/or activation status of target cells available for infection and viral production

    A simian hemorrhagic fever virus isolate from persistently infected baboons efficiently induces hemorrhagic fever disease in Japanese macaques

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    Simian hemorrhagic fever virus is an arterivirus that naturally infects species of African nonhuman primates causing acute or persistent asymptomatic infections. Although it was previously estimated that 1% of baboons are SHFV-positive, more than 10% of wild-caught and captive-bred baboons tested were SHFV positive and the infections persisted for more than 10 years with detectable virus in the blood (100‚Äď1000 genomes/ml). The sequences of two baboon SHFV isolates that were amplified by a single passage in primary macaque macrophages showed a very high degree of identity to each other as well as to the genome of SHFV-LVR, a laboratory strain isolated in the 1960s. Infection of Japanese macaques with 100 PFU of a baboon isolate consistently produced high level viremia, pro-inflammatory cytokines, elevated tissue factor levels and clinical signs indicating coagulation defects. The baboon virus isolate provides a reliable BSL2 model of viral hemorrhagic fever disease in macaques

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Differential cross section measurements for the production of a W boson in association with jets in proton‚Äďproton collisions at ‚ąös = 7 TeV