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1.
PLoS Biol ; 19(5): e3001182, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33979323

RESUMO

Melanin, a black-brown pigment found throughout all kingdoms of life, has diverse biological functions including UV protection, thermoregulation, oxidant scavenging, arthropod immunity, and microbial virulence. Given melanin's broad roles in the biosphere, particularly in insect immune defenses, it is important to understand how exposure to ubiquitous environmental contaminants affects melanization. Glyphosate-the most widely used herbicide globally-inhibits melanin production, which could have wide-ranging implications in the health of many organisms, including insects. Here, we demonstrate that glyphosate has deleterious effects on insect health in 2 evolutionary distant species, Galleria mellonella (Lepidoptera: Pyralidae) and Anopheles gambiae (Diptera: Culicidae), suggesting a broad effect in insects. Glyphosate reduced survival of G. mellonella caterpillars following infection with the fungus Cryptococcus neoformans and decreased the size of melanized nodules formed in hemolymph, which normally help eliminate infection. Glyphosate also increased the burden of the malaria-causing parasite Plasmodium falciparum in A. gambiae mosquitoes, altered uninfected mosquito survival, and perturbed the microbial composition of adult mosquito midguts. Our results show that glyphosate's mechanism of melanin inhibition involves antioxidant synergy and disruption of the reaction oxidation-reduction balance. Overall, these findings suggest that glyphosate's environmental accumulation could render insects more susceptible to microbial pathogens due to melanin inhibition, immune impairment, and perturbations in microbiota composition, potentially contributing to declines in insect populations.


Assuntos
Anopheles/efeitos dos fármacos , Glicina/análogos & derivados , Melaninas/metabolismo , Mariposas/efeitos dos fármacos , Animais , Anopheles/imunologia , Cryptococcus neoformans/patogenicidade , Dípteros/efeitos dos fármacos , Dípteros/imunologia , Glicina/metabolismo , Glicina/farmacologia , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Infecções/imunologia , Infecções/metabolismo , Infecções/fisiopatologia , Insetos/efeitos dos fármacos , Insetos/imunologia , Lepidópteros/efeitos dos fármacos , Lepidópteros/imunologia , Mariposas/imunologia , Plasmodium falciparum/patogenicidade , Virulência , Glifosato
2.
Proc Natl Acad Sci U S A ; 118(30)2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34301899

RESUMO

Individuals with depression are prone to maladaptive patterns of thinking, known as cognitive distortions, whereby they think about themselves, the world, and the future in overly negative and inaccurate ways. These distortions are associated with marked changes in an individual's mood, behavior, and language. We hypothesize that societies can undergo similar changes in their collective psychology that are reflected in historical records of language use. Here, we investigate the prevalence of textual markers of cognitive distortions in over 14 million books for the past 125 y and observe a surge of their prevalence since the 1980s, to levels exceeding those of the Great Depression and both World Wars. This pattern does not seem to be driven by changes in word meaning, publishing and writing standards, or the Google Books sample. Our results suggest a recent societal shift toward language associated with cognitive distortions and internalizing disorders.


Assuntos
Transtornos Cognitivos/epidemiologia , Idioma/história , Registros/estatística & dados numéricos , Feminino , Alemanha/epidemiologia , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Masculino , Espanha/epidemiologia , Estados Unidos/epidemiologia
3.
J Immunol ; 202(1): 56-68, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30510068

RESUMO

Perivascular accumulation of lymphocytes can be a prominent histopathologic feature of various human inflammatory skin diseases. Select examples include systemic sclerosis, spongiotic dermatitis, and cutaneous lupus. Although a large body of work has described various aspects of the endothelial and vascular smooth muscle layers in these diseases, the outer adventitial compartment is poorly explored. The goal of the current study was to characterize perivascular adventitial fibroblast states in inflammatory human skin diseases and relate these states to perivascular lymphocyte accumulation. In normal skin, adventitial fibroblasts are distinguished by CD90 expression, and dense perivascular lymphocytic infiltrates are uncommon. In systemic sclerosis, this compartment expands, but lymphocyte infiltrates remain sparse. In contrast, perivascular adventitial fibroblast expression of VCAM1 is upregulated in spongiotic dermatitis and lupus and is associated with a dense perivascular T cell infiltrate. VCAM1 expression marks transitioned fibroblasts that show some resemblance to the reticular stromal cells in secondary lymphoid organs. Expanded adventitial compartments with perivascular infiltrates similar to the human settings were not seen in the inflamed murine dermis. This species difference may hinder the dissection of aspects of perivascular adventitial pathology. The altered perivascular adventitial compartment and its associated reticular network form a niche for lymphocytes and appear to be fundamental in the development of an inflammatory pattern.


Assuntos
Dermatite/imunologia , Fibroblastos/fisiologia , Inflamação/imunologia , Lúpus Eritematoso Discoide/imunologia , Escleroderma Sistêmico/imunologia , Pele/imunologia , Linfócitos T/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antígenos Thy-1/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo , Adulto Jovem
4.
Proc Natl Acad Sci U S A ; 115(18): 4607-4612, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29666239

RESUMO

The French Revolution brought principles of "liberty, equality, fraternity" to bear on the day-to-day challenges of governing what was then the largest country in Europe. Its experiments provided a model for future revolutions and democracies across the globe, but this first modern revolution had no model to follow. Using reconstructed transcripts of debates held in the Revolution's first parliament, we present a quantitative analysis of how this body managed innovation. We use information theory to track the creation, transmission, and destruction of word-use patterns across over 40,000 speeches and a thousand speakers. The parliament as a whole was biased toward the adoption of new patterns, but speakers' individual qualities could break these overall trends. Speakers on the left innovated at higher rates, while speakers on the right acted to preserve prior patterns. Key players such as Robespierre (on the left) and Abbé Maury (on the right) played information-processing roles emblematic of their politics. Newly created organizational functions-such as the Assembly president and committee chairs-had significant effects on debate outcomes, and a distinct transition appears midway through the parliament when committees, external to the debate process, gained new powers to "propose and dispose." Taken together, these quantitative results align with existing qualitative interpretations, but also reveal crucial information-processing dynamics that have hitherto been overlooked. Great orators had the public's attention, but deputies (mostly on the political left) who mastered the committee system gained new powers to shape revolutionary legislation.

5.
Ann Rheum Dis ; 79(3): 379-386, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31767698

RESUMO

OBJECTIVES: Determine global skin transcriptome patterns of early diffuse systemic sclerosis (SSc) and how they differ from later disease. METHODS: Skin biopsy RNA from 48 patients in the Prospective Registry for Early Systemic Sclerosis (PRESS) cohort (mean disease duration 1.3 years) and 33 matched healthy controls was examined by next-generation RNA sequencing. Data were analysed for cell type-specific signatures and compared with similarly obtained data from 55 previously biopsied patients in Genetics versus Environment in Scleroderma Outcomes Study cohort with longer disease duration (mean 7.4 years) and their matched controls. Correlations with histological features and clinical course were also evaluated. RESULTS: SSc patients in PRESS had a high prevalence of M2 (96%) and M1 (94%) macrophage and CD8 T cell (65%), CD4 T cell (60%) and B cell (69%) signatures. Immunohistochemical staining of immune cell markers correlated with the gene expression-based immune cell signatures. The prevalence of immune cell signatures in early diffuse SSc patients was higher than in patients with longer disease duration. In the multivariable model, adaptive immune cell signatures were significantly associated with shorter disease duration, while fibroblast and macrophage cell type signatures were associated with higher modified Rodnan Skin Score (mRSS). Immune cell signatures also correlated with skin thickness progression rate prior to biopsy, but did not predict subsequent mRSS progression. CONCLUSIONS: Skin in early diffuse SSc has prominent innate and adaptive immune cell signatures. As a prominently affected end organ, these signatures reflect the preceding rate of disease progression. These findings could have implications in understanding SSc pathogenesis and clinical trial design.


Assuntos
Imunidade Adaptativa/genética , Imunidade Inata/genética , Esclerodermia Difusa/genética , Esclerodermia Difusa/imunologia , Adulto , Biomarcadores/análise , Biópsia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Prospectivos , Sistema de Registros , Análise de Regressão , Esclerodermia Difusa/patologia , Análise de Sequência de RNA , Índice de Gravidade de Doença , Pele/imunologia , Pele/patologia , Transcriptoma
6.
Nature ; 553(7689): 405, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32094825
7.
Nature ; 553(7689): 405, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29368719
8.
Am J Dermatopathol ; 41(1): 16-28, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30320623

RESUMO

BACKGROUND: CD90 fibroblasts have been described arising from and replacing the homeostatic CD34 network in scleroderma, but have not been specifically examined in other forms of cutaneous fibrosis. OBJECTIVES: To address expression, timelines, and spatial relationships of CD90, CD34, and smooth muscle actin (SMA) expressing fibroblasts in scars and to examine for the presence of a CD34-to-CD90 transition. METHODS: One hundred and seventeen scars (reparative/hypertrophic/keloidal) were evaluated for CD90, CD34, and SMA expression. Double-staining immunohistochemistry for CD90/CD34 was performed to identify CD90/CD34 transitioning cells, confirmed by double-color immunofluorescence. In addition, some scars were double-stained with CD90/SMA, CD90/procollagen-1, or SMA/procollagen-1 to evaluate spatial relationships and active collagen synthesis. Expression was graded as diffuse, minority, and negative. RESULTS: Most scars demonstrate a CD90/CD34 pattern, and dual CD90/CD34 fibroblasts were observed in 91% of scars. In reparative scars, CD90 expression reverses to a CD34/CD90 state with maturation. Pathologic scars exhibit prolonged CD90 expression. Both CD90 and SMA fibroblasts collagenize scars, although CD90 fibroblasts are more prevalent. CONCLUSIONS: CD90 fibroblasts likely arise from the resting CD34 fibroblastic network. Actively collagenizing scar fibroblasts exhibit a CD90/CD34 phenotype, which is prolonged in pathologic scars. CD90 fibroblasts are likely important players in cutaneous scarring.


Assuntos
Antígenos CD34/metabolismo , Cicatriz Hipertrófica/metabolismo , Fibroblastos/metabolismo , Queloide/metabolismo , Regeneração , Pele/metabolismo , Antígenos Thy-1/metabolismo , Actinas/metabolismo , Biomarcadores/metabolismo , Cicatriz Hipertrófica/patologia , Colágeno Tipo I/metabolismo , Fibroblastos/patologia , Fibrose , Imunofluorescência , Humanos , Queloide/patologia , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Fenótipo , Pró-Colágeno/metabolismo , Pele/patologia , Fatores de Tempo
10.
Energy Econ ; 73: 307-325, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31073254

RESUMO

The Energy Modeling Forum (EMF) 32 study compares a range of coordinated scenarios to explore implications of U.S. climate policy options and technological change on the electric power sector. Harmonized policy scenarios (including mass-based emissions limits and various power-sector-only carbon tax trajectories) across 16 models provide comparative assessments of potential impacts on electric sector investment and generation outcomes, emissions reductions, and economic implications. This paper compares results across these policy alternatives, including a variety of technological and natural gas price assumptions, and summarizes robust findings and areas of disagreement across participating models. Under a wide range of policy, technology, and market assumptions, model results suggest that future coal generation will decline relative to current levels while generation from natural gas, wind, and solar will increase, though the pace and extent of these changes vary by policy scenario, technological assumptions, region, and model. Climate policies can amplify trends already under way and make them less susceptible to future market changes. The model results provide useful insights to a range of stakeholders, but future research focused on intersectoral linkages in emission reductions (e.g., the role of electrification), effects of energy storage, and better coverage of bioenergy with carbon capture and storage (BECCS) can improve insights even further.

11.
Am J Pathol ; 186(10): 2650-64, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27565038

RESUMO

Tissue injury triggers the activation and differentiation of multiple cell types to minimize damage and initiate repair processes. In systemic sclerosis, these repair processes appear to run unchecked, leading to aberrant remodeling and fibrosis of the skin and multiple internal organs, yet the fundamental pathological defect remains unknown. We describe herein a transition wherein the abundant CD34(+) dermal fibroblasts present in healthy human skin disappear in the skin of systemic sclerosis patients, and CD34(-), podoplanin(+), and CD90(+) fibroblasts appear. This transition is limited to the upper dermis in several inflammatory skin diseases, yet in systemic sclerosis, it can occur in all regions of the dermis. In vitro, primary dermal fibroblasts readily express podoplanin in response to the inflammatory stimuli tumor necrosis factor and IL-1ß. Furthermore, we show that on acute skin injury in both human and murine settings, this transition occurs quickly, consistent with a response to inflammatory signaling. Transitioned fibroblasts partially resemble the cells that form the reticular networks in organized lymphoid tissues, potentially linking two areas of fibroblast research. These results allow for the visualization and quantification of a basic stage of fibroblast differentiation in inflammatory and fibrotic diseases in the skin.


Assuntos
Fibrose/patologia , Glicoproteínas de Membrana/metabolismo , Escleroderma Sistêmico/patologia , Antígenos Thy-1/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Diferenciação Celular , Derme/imunologia , Derme/patologia , Feminino , Fibroblastos/imunologia , Fibroblastos/patologia , Fibrose/imunologia , Humanos , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Escleroderma Sistêmico/imunologia , Pele/imunologia , Pele/patologia , Fator de Necrose Tumoral alfa/metabolismo
12.
F1000Res ; 13: 54, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38681509

RESUMO

Fibroblasts are ubiquitous cells that can adopt many functional states. As tissue-resident sentinels, they respond to acute damage signals and shape the earliest events in fibrotic and immune-mediated inflammatory diseases. Upon sensing an insult, fibroblasts produce chemokines and growth factors to organize and support the response. Depending on the size and composition of the resulting infiltrate, these activated fibroblasts may also begin to contract or relax thus changing local stiffness within the tissue. These early events likely contribute to the divergent clinical manifestations of fibrotic and immune-mediated inflammatory diseases. Further, distinct changes to the cellular composition and signaling dialogue in these diseases drive progressive fibroblasts specialization. In fibrotic diseases, fibroblasts support the survival, activation and differentiation of myeloid cells, granulocytes and innate lymphocytes, and produce most of the pathogenic extracellular matrix proteins. Whereas, in immune-mediated inflammatory diseases, sequential accumulation of dendritic cells, T cells and B cells programs fibroblasts to support local, destructive adaptive immune responses. Fibroblast specialization has clear implications for the development of effective induction and maintenance therapies for patients with these clinically distinct diseases.


Assuntos
Fibroblastos , Fibrose , Inflamação , Humanos , Fibroblastos/imunologia , Fibroblastos/patologia , Inflamação/imunologia , Inflamação/patologia , Animais
13.
Cell Rep ; 43(4): 114087, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38583152

RESUMO

Microbial invasions underlie host-microbe interactions resulting in pathogenesis and probiotic colonization. In this study, we explore the effects of the microbiome on microbial invasion in Drosophila melanogaster. We demonstrate that gut microbes Lactiplantibacillus plantarum and Acetobacter tropicalis improve survival and lead to a reduction in microbial burden during infection. Using a microbial interaction assay, we report that L. plantarum inhibits the growth of invasive bacteria, while A. tropicalis reduces this inhibition. We further show that inhibition by L. plantarum is linked to its ability to acidify its environment via lactic acid production by lactate dehydrogenase, while A. tropicalis diminishes the inhibition by quenching acids. We propose that acid from the microbiome is a gatekeeper to microbial invasions, as only microbes capable of tolerating acidic environments can colonize the host. The methods and findings described herein will add to the growing breadth of tools to study microbe-microbe interactions in broad contexts.


Assuntos
Drosophila melanogaster , Animais , Drosophila melanogaster/microbiologia , Microbiota , Acetobacter/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Lactobacillus plantarum/metabolismo , Concentração de Íons de Hidrogênio , Ácido Láctico/metabolismo , Ácido Láctico/farmacologia
14.
Microbiol Resour Announc ; 12(11): e0060223, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37830846

RESUMO

Lactiplantibacillus plantarum and Acetobacter tropicalis are bacterial symbionts commonly isolated from decaying fruits and from the microbiome of Drosophila melanogaster. Studies have shown that these organisms interact synergistically, imparting beneficial effects on the host. Here, we report whole-genome sequences of these microbes obtained from long and short reads.

15.
bioRxiv ; 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36711873

RESUMO

Microbial invasions underlie host-microbe interactions that result in microbial pathogenesis and probiotic colonization. While these processes are of broad interest, there are still gaps in our understanding of the barriers to entry and how some microbes overcome them. In this study, we explore the effects of the microbiome on invasions of foreign microbes in Drosophila melanogaster. We demonstrate that gut microbes Lactiplantibacillus plantarum and Acetobacter tropicalis improve survival during invasion of a lethal gut pathogen and lead to a reduction in microbial burden. Using a novel multi-organism interactions assay, we report that L. plantarum inhibits the growth of three invasive Gram-negative bacteria, while A. tropicalis prevents this inhibition. A series of in vitro and in vivo experiments revealed that inhibition by L. plantarum is linked to its ability to acidify both internal and external environments, including culture media, fly food, and the gut itself, while A. tropicalis diminishes the inhibition by quenching acids. We propose that acid produced by the microbiome serves as an important gatekeeper to microbial invasions, as only microbes capable of tolerating acidic environments can colonize the host. The methods described herein will add to the growing breadth of tools to study microbe-microbe interactions in broad contexts.

16.
Sci Immunol ; 8(82): eadd8945, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-37027478

RESUMO

Macrophages are central orchestrators of the tissue response to injury, with distinct macrophage activation states playing key roles in fibrosis progression and resolution. Identifying key macrophage populations found in human fibrotic tissues could lead to new treatments for fibrosis. Here, we used human liver and lung single-cell RNA sequencing datasets to identify a subset of CD9+TREM2+ macrophages that express SPP1, GPNMB, FABP5, and CD63. In both human and murine hepatic and pulmonary fibrosis, these macrophages were enriched at the outside edges of scarring and adjacent to activated mesenchymal cells. Neutrophils expressing MMP9, which participates in the activation of TGF-ß1, and the type 3 cytokines GM-CSF and IL-17A coclustered with these macrophages. In vitro, GM-CSF, IL-17A, and TGF-ß1 drive the differentiation of human monocytes into macrophages expressing scar-associated markers. Such differentiated cells could degrade collagen IV but not collagen I and promote TGF-ß1-induced collagen I deposition by activated mesenchymal cells. In murine models blocking GM-CSF, IL-17A or TGF-ß1 reduced scar-associated macrophage expansion and hepatic or pulmonary fibrosis. Our work identifies a highly specific macrophage population to which we assign a profibrotic role across species and tissues. It further provides a strategy for unbiased discovery, triage, and preclinical validation of therapeutic targets based on this fibrogenic macrophage population.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos , Fibrose Pulmonar , Humanos , Camundongos , Animais , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Interleucina-17/metabolismo , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Cicatriz , Macrófagos/patologia , Inflamação/patologia , Proteínas de Ligação a Ácido Graxo/metabolismo , Glicoproteínas de Membrana , Receptores Imunológicos
17.
J Virol ; 85(18): 9527-42, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21752919

RESUMO

Monkeypox virus (MPXV) is an orthopoxvirus closely related to variola virus, the causative agent of smallpox. Human MPXV infection results in a disease that is similar to smallpox and can also be fatal. Two clades of MPXV have been identified, with viruses of the central African clade displaying more pathogenic properties than those within the west African clade. The monkeypox inhibitor of complement enzymes (MOPICE), which is not expressed by viruses of the west African clade, has been hypothesized to be a main virulence factor responsible for increased pathogenic properties of central African strains of MPXV. To gain a better understanding of the role of MOPICE during MPXV-mediated disease, we compared the host adaptive immune response and disease severity following intrabronchial infection with MPXV-Zaire (n = 4), or a recombinant MPXV-Zaire (n = 4) lacking expression of MOPICE in rhesus macaques (RM). Data presented here demonstrate that infection of RM with MPXV leads to significant viral replication in the peripheral blood and lungs and results in the induction of a robust and sustained adaptive immune response against the virus. More importantly, we show that the loss of MOPICE expression results in enhanced viral replication in vivo, as well as a dampened adaptive immune response against MPXV. Taken together, these findings suggest that MOPICE modulates the anti-MPXV immune response and that this protein is not the sole virulence factor of the central African clade of MPXV.


Assuntos
Monkeypox virus/imunologia , Monkeypox virus/patogenicidade , Mpox/imunologia , Mpox/patologia , Proteínas Virais/metabolismo , Fatores de Virulência/metabolismo , Imunidade Adaptativa , Animais , Linfócitos B/imunologia , Sangue/virologia , DNA Viral/química , DNA Viral/genética , Modelos Animais de Doenças , Feminino , Deleção de Genes , Pulmão/virologia , Macaca mulatta , Masculino , Dados de Sequência Molecular , Mpox/virologia , Doenças dos Primatas/imunologia , Doenças dos Primatas/patologia , Doenças dos Primatas/virologia , Análise de Sequência de DNA , Pele/patologia , Linfócitos T/imunologia , Proteínas Virais/genética , Fatores de Virulência/genética
18.
Sci Rep ; 12(1): 15044, 2022 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-36057691

RESUMO

Mass communication over social media can drive rapid changes in our sense of collective identity. Hashtags in particular have acted as powerful social coordinators, playing a key role in organizing social movements like the Gezi park protests, Occupy Wall Street, #metoo, and #blacklivesmatter. Here we quantify collective identity from the use of hashtags as self-labels in over 85,000 actively-maintained Twitter user profiles spanning 2017-2019. Collective identities emerge from a graph model of individuals' overlapping self-labels, producing a hierarchy of graph clusters. Each cluster is bound together and characterized semantically by specific hashtags key to its formation. We define and apply two information-theoretic measures to quantify the strength of identities in the hierarchy. First we measure collective identity coherence to determine how integrated any identity is from local to global scales. Second, we consider the conspicuousness of any identity given its vocabulary versus the global identity map. Our work reveals a rich landscape of online identity emerging from the hierarchical alignment of uncoordinated self-labeling actions.


Assuntos
Mídias Sociais , Comunicação , Humanos
19.
PLoS Pathog ; 5(11): e1000657, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19911054

RESUMO

Simian varicella virus (SVV), the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV). Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox) in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.


Assuntos
Modelos Animais de Doenças , Infecções por Herpesviridae , Macaca mulatta/virologia , Varicellovirus/patogenicidade , Animais , Linfócitos B/imunologia , Proliferação de Células , DNA Viral/análise , Infecções por Herpesviridae/metabolismo , Infecções por Herpesviridae/patologia , Herpesvirus Humano 3 , Humanos , Imuno-Histoquímica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/imunologia , Varicellovirus/genética , Carga Viral
20.
Oecologia ; 165(2): 511-20, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21110206

RESUMO

Symbiotic dinitrogen (N(2)) fixation is often invoked to explain the N richness of tropical forests as ostensibly N(2)-fixing trees can be a major component of the community. Such arguments assume N(2) fixers are fixing N when present. However, in laboratory experiments, legumes consistently reduce N(2) fixation in response to increased soil N availability. These contrasting views of N(2) fixation as either obligate or facultative have drastically different implications for the N cycle of tropical forests. We tested these models by directly measuring N(2)-fixing root nodules and nitrogenase activity of individual canopy-dominant legume trees (Inga sp.) across several lowland forest types. Fixation was substantial in disturbed forests and some gaps but near zero in the high N soils of mature forest. Our findings suggest that canopy legumes closely regulate N(2) fixation, leading to large variations in N inputs across the landscape, and low symbiotic fixation in mature forests despite abundant legumes.


Assuntos
Ecossistema , Fabaceae/metabolismo , Fixação de Nitrogênio , Nitrogênio/metabolismo , Árvores/metabolismo , Fabaceae/crescimento & desenvolvimento , Modelos Biológicos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Simbiose , Árvores/crescimento & desenvolvimento , Clima Tropical
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