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Found 34725 matches. Displaying 101-110
Swanstrom AE, Jacques A, Del Prete GQ, Bieniasz P, Hatziioannou T, Gorelick R, Lifson JD
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Short Communication: Ultrasensitive Immunoassay for Assessing Residual Simian-Tropic HIV in Nonhuman Primate Models of AIDS

Persistence of replication-competent viral reservoirs during infection remains a barrier to HIV cure, despite the ability of combination antiretroviral therapy (cART) to effectively suppress viral replication. Simian-tropic HIV (stHIV) is a minimally chimeric HIV-1 that is comprised of 94% HIV-1 sequence, contains HIV-1 drug and immunologic targets, and is capable of replicating to high levels and causing authentic HIV-like pathogenesis leading to clinical AIDS in pigtail macaques. Suppression of stHIV replication by cART provides a model for study of viral reservoirs and HIV-specific intervention strategies targeting them. Accurate measurement of reservoir size is crucial for evaluating the effect of any such intervention strategies. Although there are a variety of assays that allow for indirect monitoring of viral reservoir size ex vivo, they each quantify a different aspect of viral reservoirs, and are characterized by conceptual and/or technical limitations. Measurement of viral protein in ex vivo cell culture assays captures the immunologically relevant viral-antigen producing component of the reservoir. This study demonstrates the utility of an ultrasensitive digital HIV Gag p24 immunoassay, which enabled earlier, and more sensitive detection of viral protein in culture supernatants from stimulated CD4+ T cells from stHIV-infected pigtail macaques receiving cART compared with conventional enzyme-linked immunosorbent assay. Protein measurements were highly correlated with cell-free stHIV RNA, as measured by quantitative reverse transcription polymerase chain reaction. This ultrasensitive p24 assay can be used to complement other reservoir measurement tools to assess ongoing replication and reactivation of infectious virus from reservoirs in stHIV-infected pigtail macaques.
Abramowicz H, Abt I, Adamczyk L, Adamus M, Aggarwal R, Antonelli S, Aushev V, Behnke O, Behrens U, Bertolin A, Bloch I, Brock I, Brook NH, Brugnera R, Bruni A, Bussey PJ, Caldwell A, Capua M, Catterall CD, Chwastowski J, Ciborowski J, Ciesielski R, Cooper-Sarkar AM, Corradi M, Dementiev RK, Devenish RCE, Dusini S, Ferrando J, Foster B, Gallo E, Garfagnini A, Geiser A, Gizhko A, Gladilin LK, Golubkov YA, Grzelak G, Gwenlan C, Hlushchenko O, Hochman D, Ibrahim ZA, Iga Y, Jomhari NZ, Kadenko I, Kananov S, Karshon U, Kaur P, Kisielewska D, Klanner R, Klein U, Korzhavina IA, Kotanski A, Kovalchuk N, Kowalski H, Krupa B, Kuprash O, Kuze M, Levchenko BB, Levy A, Libov V, Lisovyi M, Lohr B, Lohrmann E, Longhin A, Lukina OY, Makarenko I, Malka J, Masciocchi S, Idris FM, Nasir NM, Myronenko V, Nagano K, Nam JD, Nicassio M, Onderwaater J, Onishchuk Y, Paul E, Pidhurskyi I, Pokrovskiy NS, Polini A, Przybycien M, Quintero A, Ruspa M, Saxon DH, Schioppa M, Schneekloth U, Schorner-Sadenius T, Selyuzhenkov I, Shchedrolosiev M, Shcheglova LM, Shyrma Y, Skillicorn IO, Slominski W, Solano A, Stanco L, Stefaniuk N, Stern A, Stopa P, Surrow B, Sztuk-Dambietz J, Tassi E, Tokushuku K, Tomaszewska J, Tsurugai T, Turcato M, Turkot O, Tymieniecka T, Verbytskyi A, Abdullah WATW, Wichmann K, Wing M, Yamada S, Yamazaki Y, Zarnecki AF, Zawiejski L, Zenaiev O, Zhautykov BO
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Limits on contact interactions and leptoquarks at HERA

PHYSICAL REVIEW D 2019 MAY 29; 99(9):? Article 092006
High-precision HERA data corresponding to a luminosity of around 1 fb(-1) have been used in the framework of eeqq contact interactions (CI) to set limits on possible high-energy contributions beyond the Standard Model to electron-quark scattering. Measurements of the inclusive deep inelastic cross sections in neutral and charged current ep scattering were considered. The analysis of the ep data has been based on simultaneous fits of parton distribution functions including contributions of CI couplings to ep scattering. Several general CI models and scenarios with heavy leptoquarks were considered. Improvements in the description of the inclusive HERA data were obtained for a few models. Since a statistically significant deviation from the Standard Model cannot be established, limits in the TeV range were set on all models considered.
Pavlides C, Donishi T, Ribeiro S, Mello CV, Blanco W, Ogawa S
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Hippocampal functional organization: A microstructure of the place cell network encoding space

A clue to hippocampal function has been the discovery of place cells, leading to the 'spatial map' theory. Although the firing attributes of place cells are well documented, little is known about the organization of the spatial map. Unit recording studies, thus far, have reported a low coherence between neighboring cells and geometric space, leading to the prevalent view that the spatial map is not topographically organized. However, the number of simultaneously recorded units is severely limited, rendering construction of the spatial map nearly impossible. To visualize the functional organization of place cells, we used the activity-dependent immediate early gene Zif268 in combination with behavioral, pharmacological and electrophysiological methods, in mice and rats exploring an environment. Here, we show that in animals confined to a small part of a maze, principal cells in the CA1/CA3 subfields of the dorsal hippocampus immunoreactive (IR) for Zif268 adhere to a 'cluster type' organization. Unit recordings confirmed that the Zif268 IR clusters correspond to active place cells, while blockade of NMDAR (which alters place fields) disrupted the Zif268 IR clusters. Contrary to the prevalent view that the spatial map consists of a non-topographic neural network, our results provide evidence for a 'cluster type' functional organization of hippocampal neurons encoding for space.
Nasca C, Watson-Lin K, Bigio B, Robakis TK, Myoraku A, Wroolie TE, McEwen BS, Rasgon N
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Childhood trauma and insulin resistance in patients suffering from depressive disorders

Objective: Insulin resistance (IR) is a metabolic dysfunction often co-morbid with major depressive disorder (MDD). The paths to development of MDD remain largely unspecified, highlighting a need for identification of risk factors. Here, we tested whether specific subscales of childhood trauma as well as family history of type-2 diabetes (Fam-Hx-Dm2) are risk factors for development of metabolic dysfunction and severity of depressive symptoms. Research design and methods: We used a sample of 45 adults suffering from MDD that was well-characterized for insulin resistance and sensitivity as assessed by measures of fasting plasma glucose (FPG) plasma insulin (FPI) levels, body mass index (BMI), weight, homeostasis model assessment of insulin sensitivity (HOMA), Matsuda index as well as both glucose and insulin responses to oral glucose challenges, Severity of depressive symptoms was assessed with the Hamilton Depression Rating Scale (HDRS-21). Physical, sexual and emotional abuse as well as physical and emotional neglect were assessed with the Childhood Trauma Questionnaire. First-or second-degree relatives with type-2 diabetes defined fam-Hx-DM2. Results: Individuals reporting higher rates of emotional abuse were more likely to have greater IR as showed by elevated FPI levels and HOMA. No association was found with any of the other subscales of childhood trauma (e.g., physical abuse). Similarly, Fam-Hx-DM2 was associated with greater degree of IR as shown by elevated FPI, HOMA, but also FPG, weight and BMI. Moreover, we report a relationship and interaction between Fam-Hx-DM2 and emotional abuse on severity of depressive symptoms. Specifically, emotional abuse and Fam-HX-DM2 predicted severity of depressive symptoms at HDRS-21. Also, severity of depressive symptoms was greater with higher reported rates of emotional abuse but only in patients with negative Fam-HX-Dm2. Individuals reporting higher emotional abuse and negative Fam-Hx-Dm2 also showed higher FPG levels. Conversely, individuals reporting higher emotional abuse and positive Fam-Hx-Dm2 showed higher FPI levels. This data suggest that Fam-Hx-Dm2 may define two different metabolic endophenotypes. Conclusions: Our findings suggest that Fam-HX-DM2 and emotional abuse represent separate risk factors for developing metabolic dysfunction (i.e.: IR) in patients suffering from MDD, and that the effects of emotional abuse on psychiatric illness may depend upon the personal characteristics, including Farn-Hx-DM2.
Furst DE, Belasco J, Louie JS
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Genetic and inflammatory factors associated with psoriatic arthritis: Relevance to diagnosis and management

CLINICAL IMMUNOLOGY 2019 MAY; 202(?):59-75
Psoriatic arthritis (PsA) is a heterogeneous chronic inflammatory musculoskeletal condition with complex pathophysiology. In recent years, understanding of the pathogenesis of PsA has improved substantially. Several genetic and inflammatory factors have been identified and studied as targets for new biologic disease-modifying therapies. This review presents findings from a detailed literature assessment conducted to identify genes and biomarkers associated with PsA and its most common comorbidities. This literature assessment identifies genes and biomarkers that may be predictive of the onset and severity of PsA, places them in the context of our understanding of PsA pathogenesis, and explores potential connections between the pathways involved in PsA and current biologic therapeutics used to treat PsA. Knowledge of the genetics and inflammatory factors associated with disease pathogenesis can support the targeted development of new biologic therapies and biomarkers for PsA.
Kuchibhotla KV, Sten TH, Papadoyannis ES, Elnozahy S, Fogelson KA, Kumar R, Boubenec Y, Hoiland PC, Ostojic S, Froemke RC
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Dissociating task acquisition from expression during learning reveals latent knowledge

NATURE COMMUNICATIONS 2019 MAY 14; 10(?):? Article 2151
Performance on cognitive tasks during learning is used to measure knowledge, yet it remains controversial since such testing is susceptible to contextual factors. To what extent does performance during learning depend on the testing context, rather than underlying knowledge? We trained mice, rats and ferrets on a range of tasks to examine how testing context impacts the acquisition of knowledge versus its expression. We interleaved reinforced trials with probe trials in which we omitted reinforcement. Across tasks, each animal species performed remarkably better in probe trials during learning and inter-animal variability was strikingly reduced. Reinforcement feedback is thus critical for learning-related behavioral improvements but, paradoxically masks the expression of underlying knowledge. We capture these results with a network model in which learning occurs during reinforced trials while context modulates only the read-out parameters. Probing learning by omitting reinforcement thus uncovers latent knowledge and identifies context- not "smartness"- as the major source of individual variability.
Yook JS, Rakwal R, Shibato J, Takahashi K, Koizumi H, Shima T, Ikemoto MJ, Oharomari LK, McEwen BS, Soya H
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Leptin in hippocampus mediates benefits of mild exercise by an antioxidant on neurogenesis and memory

Regular exercise and dietary supplements with antioxidants each have the potential to improve cognitive function and attenuate cognitive decline, and, in some cases, they enhance each other. Our current results reveal that low-intensity exercise (mild exercise, ME) and the natural antioxidant carotenoid astaxanthin (AX) each have equivalent beneficial effects on hippocampal neurogenesis and memory function. We found that the enhancement by ME combined with AX in potentiating hippocampus-based plasticity and cognition is mediated by leptin (LEP) made and acting in the hippocampus. In assessing the combined effects upon wild-type (WT) mice undergoing ME with or without an AX diet for four weeks, we found that, when administrated alone, ME and AX separately enhanced neurogenesis and spatial memory, and when combined they were at least additive in their effects. DNA microarray and bioinformatics analyses revealed not only the up-regulation of an antioxidant gene, ABHD3, but also that the up-regulation of LEP gene expression in the hippocampus of WT mice with ME alone is further enhanced by AX. Together, they also increased hippocampal LEP (h-LEP) protein levels and enhanced spatial memory mediated through AKT/STAT3 signaling. AX treatment also has direct action on human neuroblastoma cell lines to increase cell viability associated with increased LEP expression. In LEP-deficient mice (ob/ob), chronic infusion of LEP into the lateral ventricles restored the synergy. Collectively, our findings suggest that not only h-LEP but also exogenous LEP mediates effects of ME on neural functions underlying memory, which is further enhanced by the antioxidant AX.
Esterhazy D, Canesso MCC, Mesin L, Muller PA, de Castro TBR, Lockhart A, ElJalby M, Faria AMC, Mucida D
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Compartmentalized gut lymph node drainage dictates adaptive immune responses

NATURE 2019 MAY 2; 569(7754):126-130
The intestinal immune system has the challenging task of tolerating foreign nutrients and the commensal microbiome, while excluding or eliminating ingested pathogens. Failure of this balance leads to conditions such as inflammatory bowel diseases, food allergies and invasive gastrointestinal infections(1). Multiple immune mechanisms are therefore in place to maintain tissue integrity, including balanced generation of effector T (T-H) cells and FOXP3(+) regulatory T (pT(reg)) cells, which mediate resistance to pathogens and regulate excessive immune activation, respectively(1-4). The gut-draining lymph nodes (gLNs) are key sites for orchestrating adaptive immunity to luminal perturbations(5-7). However, it is unclear how they simultaneously support tolerogenic and inflammatory reactions. Here we show that gLNs are immunologically specific to the functional gut segment that they drain. Stromal and dendritic cell gene signatures and polarization of T cells against the same luminal antigen differ between gLNs, with the proximal small intestine-draining gLNs preferentially giving rise to tolerogenic responses and the distal gLNs to pro-inflammatory T cell responses. This segregation permitted the targeting of distal gLNs for vaccination and the maintenance of duodenal pTreg cell induction during colonic infection. Conversely, the compartmentalized dichotomy was perturbed by surgical removal of select distal gLNs and duodenal infection, with effects on both lymphoid organ and tissue immune responses. Our findings reveal that the conflict between tolerogenic and inflammatory intestinal responses is in part resolved by discrete gLN drainage, and encourage antigen targeting to specific gut segments for therapeutic immune modulation.
Law LMJ, Razooky BS, Li MMH, You S, Jurado A, Rice CM, MacDonald MR
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ZAP's stress granule localization is correlated with its antiviral activity and induced by virus replication

PLOS PATHOGENS 2019 MAY; 15(5):? Article e1007798
Cellular antiviral programs encode molecules capable of targeting multiple steps in the virus lifecycle. Zinc-finger antiviral protein (ZAP) is a central and general regulator of antiviral activity that targets pathogen mRNA stability and translation. ZAP is diffusely cytoplasmic, but upon infection ZAP is targeted to particular cytoplasmic structures, termed stress granules (SGs). However, it remains unclear if ZAP's antiviral activity correlates with SG localization, and what molecular cues are required to induce this localization event. Here, we use Sindbis virus (SINV) as a model infection and find that ZAP's localization to SGs can be transient. Sometimes no apparent viral infection follows ZAP SG localization but ZAP SG localization always precedes accumulation of SINV non-structural protein, suggesting virus replication processes trigger SG formation and ZAP recruitment. Data from single-molecule RNA FISH corroborates this finding as the majority of cells with ZAP localization in SGs contain low levels of viral RNA. Furthermore, ZAP recruitment to SGs occurred in ZAP-expressing cells when co-cultured with cells replicating full-length SINV, but not when co-cultured with cells replicating a SINV replicon. ZAP recruitment to SGs is functionally important as a panel of alanine ZAP mutants indicate that the anti-SINV activity is correlated with ZAP's ability to localize to SGs. As ZAP is a central component of the cellular antiviral programs, these data provide further evidence that SGs are an important cytoplasmic antiviral hub. These findings provide insight into how antiviral components are regulated upon virus infection to inhibit virus spread.
Reich B, Zhou Y, Goldstein E, Srivats SS, Contoreggi NH, Kogan JF, McEwen BS, Kreek MJ, Milner TA, Gray JD
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Chronic immobilization stress primes the hippocampal opioid system for oxycodone-associated learning in female but not male rats

SYNAPSE 2019 MAY; 73(5):? Article e22088
In adult female, but not male, Sprague Dawley rats, chronic immobilization stress (CIS) increases mossy fiber (MF) Leu-Enkephalin levels and redistributes delta- and mu-opioid receptors (DORs and MORs) in hippocampal CA3 pyramidal cells and GABAergic interneurons to promote excitation and learning processes following subsequent opioid exposure. Here, we demonstrate that CIS females, but not males, acquire conditioned place preference (CPP) to oxycodone and that CIS "primes" the hippocampal opioid system in females for oxycodone-associated learning. In CA3b, oxycodone-injected (Oxy) CIS females relative to saline-injected (Sal) CIS females exhibited an increase in the cytoplasmic and total densities of DORs in pyramidal cell dendrites so that they were similar to Sal- and Oxy-CIS males. Consistent with our earlier studies, Sal- and Oxy-CIS females but not CIS males had elevated DOR densities in MF-CA3 dendritic spines, which we have previously shown are important for opioid-mediated long-term potentiation. In the dentate gyrus, Oxy-CIS females had more DOR-labeled interneurons than Sal-CIS females. Moreover, Sal- and Oxy-CIS females compared to both groups of CIS males had elevated levels of DORs and MORs in GABAergic interneuron dendrites, suggesting capacity for greater synthesis or storage of these receptors in circuits important for opioid-mediated disinhibition. However, more plasmalemmal MORs were on large parvalbumin-containing dendrites of Oxy-CIS males compared to Sal-CIS males, suggesting a limited ability for increased granule cell disinhibition. These results suggest that low levels of DORs in MF-CA3 synapses and hilar GABAergic interneurons may contribute to the attenuation of oxycodone CPP in males exposed to CIS.