RESUMO
The genome of the liverwort Marchantia polymorpha is an important step toward development of a new plant model system (Bowman et al., 2017). Liverworts may be the sister taxon to all other land plants, and the genome shows features that illuminate the ancestor of all land plants and give insights into how plant systems function and evolved.
Assuntos
Embriófitas , Marchantia/genética , PlantasRESUMO
Recently published near full-length KSHV genomes from a Cameroon Kaposi sarcoma case-control study showed strong evidence of viral recombination and mixed infections, but no sequence variations associated with disease. Using the same methodology, an additional 102 KSHV genomes from 76 individuals with KSHV-associated diseases have been sequenced. Diagnoses comprise all KSHV-associated diseases (KAD): Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated large cell lymphoma (KSHV-LCL), a type of multicentric Castleman disease (KSHV-MCD), and KSHV inflammatory cytokine syndrome (KICS). Participants originated from 22 different countries, providing the opportunity to obtain new near full-length sequences of a wide diversity of KSHV genomes. These include near full-length sequence of genomes with KSHV K1 subtypes A, B, C, and F as well as subtype E, for which no full sequence was previously available. High levels of recombination were observed. Fourteen individuals (18%) showed evidence of infection with multiple KSHV variants (from two to four unique genomes). Twenty-six comparisons of sequences, obtained from various sampling sites including PBMC, tissue biopsies, oral fluids, and effusions in the same participants, identified near complete genome conservation between different biological compartments. Polymorphisms were identified in coding and non-coding regions, including indels in the K3 and K15 genes and sequence inversions here reported for the first time. One such polymorphism in KSHV ORF46, specific to the KSHV K1 subtype E2, encoded a mutation in the leucine loop extension of the uracil DNA glycosylase that results in alteration of biochemical functions of this protein. This confirms that KSHV sequence variations can have functional consequences warranting further investigation. This study represents the largest and most diverse analysis of KSHV genome sequences to date among individuals with KAD and provides important new information on global KSHV genomics.
Assuntos
Genoma Viral , Herpesvirus Humano 8 , Sarcoma de Kaposi , Humanos , Herpesvirus Humano 8/genética , Sarcoma de Kaposi/virologia , Sarcoma de Kaposi/genética , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Polimorfismo Genético , Idoso , Infecções por Herpesviridae/genética , Infecções por Herpesviridae/virologia , Etnicidade/genética , Hiperplasia do Linfonodo Gigante/virologia , Hiperplasia do Linfonodo Gigante/genética , FilogeniaRESUMO
In sub-Saharan Africa, Kaposi's sarcoma-associated herpesvirus (KSHV) is endemic, and Kaposi's sarcoma (KS) is a significant public health problem. Until recently, KSHV genotype analysis was performed using variable gene regions, representing a small fraction of the genome, and thus the contribution of sequence variation to viral transmission or pathogenesis are understudied. We performed near full-length KSHV genome sequence analysis on samples from 43 individuals selected from a large Cameroonian KS case-control study. KSHV genomes were obtained from 21 KS patients and 22 control participants. Phylogenetic analysis of the K1 region indicated the majority of sequences were A5 or B1 subtypes and all three K15 alleles were represented. Unique polymorphisms in the KSHV genome were observed including large gene deletions. We found evidence of multiple distinct KSHV genotypes in three individuals. Additionally, our analyses indicate that recombination is prevalent suggesting that multiple KSHV infections may not be uncommon overall. Most importantly, a detailed analysis of KSHV genomes from KS patients and control participants did not find a correlation between viral sequence variations and disease. Our study is the first to systematically compare near full-length KSHV genome sequences between KS cases and controls in the same endemic region to identify possible sequence variations associated with disease risk.
Assuntos
Herpesvirus Humano 8 , Sarcoma de Kaposi , Camarões/epidemiologia , Estudos de Casos e Controles , Herpesvirus Humano 8/genética , Humanos , Filogenia , Sarcoma de Kaposi/epidemiologia , Sarcoma de Kaposi/genéticaRESUMO
In most algae, NO3- assimilation is tightly controlled and is often inhibited by the presence of NH4+. In the marine, non-colonial, non-diazotrophic cyanobacterium Synechococcus UTEX 2380, NO3- assimilation is sensitive to NH4+ only when N does not limit growth. We sequenced the genome of Synechococcus UTEX 2380, studied the genetic organization of the nitrate assimilation related (NAR) genes, and investigated expression and kinetics of the main NAR enzymes, under N or light limitation. We found that Synechococcus UTEX 2380 is a ß-cyanobacterium with a full complement of N uptake and assimilation genes and NAR regulatory elements. The nitrate reductase of our strain showed biphasic kinetics, previously observed only in freshwater or soil diazotrophic Synechococcus strains. Nitrite reductase and glutamine synthetase showed little response to our growth treatments, and their activity was usually much higher than that of nitrate reductase. NH4+ insensitivity of NAR genes may be associated with the stimulation of the binding of the regulator NtcA to NAR gene promoters by the high 2-oxoglutarate concentrations produced under N limitation. NH4+ sensitivity in energy-limited cells fits with the fact that, under these conditions, the use of NH4+ rather than NO3- decreases N-assimilation cost, whereas it would exacerbate N shortage under N limitation.
Assuntos
Synechococcus , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Nitrato Redutase/genética , Nitrato Redutase/metabolismo , Nitratos/metabolismo , Nitrogênio/metabolismo , Synechococcus/genética , Synechococcus/metabolismoRESUMO
Species within the genus Chara have variable salinity tolerance. Their close evolutionary relationship with embryophytes makes their study crucial to understanding the evolution of salt tolerance and key evolutionary processes shared among the phyla. We examined salt-tolerant Chara longifolia and salt-sensitive Chara australis for mechanisms of salt tolerance and their potential role in adaptation to salt. We hypothesize that there are shared mechanisms similar to those in embryophytes, which assist in conferring salt tolerance in Chara, including a cation transporter (HKT), a Na+ /H+ antiport (NHX), a H+ -ATPase (AHA), and a Na+ -ATPase (ENA). Illumina transcriptomes were created using cultures grown in freshwater and exposed to salt stress. The presence of these candidate genes, identified by comparing with genes known from embryophytes, has been confirmed in both species of Chara, with the exception of ENA, present only in salt-tolerant C. longifolia. These transcriptomes provide evidence for the contribution of these mechanisms to differences in salt tolerance in the two species and for the independent evolution of the Na+ -ATPase. We also examined genes that may have played a role in important evolutionary processes, suggested by previous work on the Chara braunii genome. Among the genes examined, cellulose synthase protein (GT43) and response regulator (RRB) were confirmed in both species. Genes absent from all three Chara species were members of the GRAS family, microtubule-binding protein (TANGLED1), and auxin synthesizers (YUCCA, TAA). Results from this study shed light on the evolutionary relationship between Chara and embryophytes through confirmation of shared salt tolerance mechanisms, as well as unique mechanisms that do not occur in angiosperms.
Assuntos
Chara , Carofíceas , Proteínas de Transporte , Transporte de Íons , Tolerância ao SalRESUMO
Without an approved vaccine or treatments, Ebola outbreak management has been limited to palliative care and barrier methods to prevent transmission. These approaches, however, have yet to end the 2014 outbreak of Ebola after its prolonged presence in West Africa. Here we show that a combination of monoclonal antibodies (ZMapp), optimized from two previous antibody cocktails, is able to rescue 100% of rhesus macaques when treatment is initiated up to 5 days post-challenge. High fever, viraemia and abnormalities in blood count and blood chemistry were evident in many animals before ZMapp intervention. Advanced disease, as indicated by elevated liver enzymes, mucosal haemorrhages and generalized petechia could be reversed, leading to full recovery. ELISA and neutralizing antibody assays indicate that ZMapp is cross-reactive with the Guinean variant of Ebola. ZMapp exceeds the efficacy of any other therapeutics described so far, and results warrant further development of this cocktail for clinical use.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Doença pelo Vírus Ebola/tratamento farmacológico , Imunização Passiva , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Ebolavirus/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Guiné , Cobaias , Doença pelo Vírus Ebola/sangue , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Macaca mulatta/imunologia , Macaca mulatta/virologia , Masculino , Dados de Sequência Molecular , Alinhamento de Sequência , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/imunologia , Viremia/tratamento farmacológico , Viremia/imunologia , Viremia/virologiaRESUMO
Countermeasures against potential biothreat agents remain important to US Homeland Security, and many of these pharmaceuticals could have dual use in the improvement of global public health. Junin virus, the causative agent of Argentine hemorrhagic fever (AHF), is an arenavirus identified as a category A high-priority agent. There are no Food and Drug Administration (FDA) approved drugs available for preventing or treating AHF, and the current treatment option is limited to administration of immune plasma. Whereas immune plasma demonstrates the feasibility of passive immunotherapy, it is limited in quantity, variable in quality, and poses safety risks such as transmission of transfusion-borne diseases. In an effort to develop a monoclonal antibody (mAb)-based alternative to plasma, three previously described neutralizing murine mAbs were expressed as mouse-human chimeric antibodies and evaluated in the guinea pig model of AHF. These mAbs provided 100% protection against lethal challenge when administered 2 d after infection (dpi), and one of them (J199) was capable of providing 100% protection when treatment was initiated 6 dpi and 92% protection when initiated 7 dpi. The efficacy of J199 is superior to that previously described for all other evaluated drugs, and its high potency suggests that mAbs like J199 offer an economical alternative to immune plasma and an effective dual use (bioterrorism/public health) therapeutic.
Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Antivirais/farmacologia , Febre Hemorrágica Americana/tratamento farmacológico , Febre Hemorrágica Americana/imunologia , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Cobaias , Humanos , Vírus Junin , Camundongos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/farmacologiaRESUMO
Respiratory syncytial virus (RSV) can cause devastating lower respiratory tract infections in preterm infants or when other serious health problems are present. Immunoprophylaxis with palivizumab (Synagis), a humanized IgG1 mAb, is the current standard of care for preventing RSV infection in at-risk neonates. We have explored the contribution of effector function to palivizumab efficacy using a plant-based expression system to produce palivizumab N-glycan structure variants with high homogeneity on different antibody isotypes. We compared these isotype and N-glycoform variants with commercially available palivizumab with respect to both in vitro receptor and C1q binding and in vivo efficacy. Whereas the affinity for antigen and neutralization activity of each variant were indistinguishable from those of palivizumab, their Fcγ receptor binding profiles were very different, which was reflected in either a reduced or enhanced ability to influence the RSV lung titer in challenged cotton rats. Enhanced Fcγ receptor binding was associated with reduced viral lung titers compared with palivizumab, whereas abrogation of receptor binding led to a drastic reduction in efficacy. The results support the hypotheses that classic antibody neutralization is a minor component of efficacy by palivizumab in the cotton rat and that antibody-dependent cell-mediated cytotoxicity activity can significantly enhance the efficacy of this antiviral mAb.
Assuntos
Anticorpos Antivirais/química , Anticorpos Antivirais/uso terapêutico , Polissacarídeos/metabolismo , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , Sigmodontinae/virologia , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/farmacologia , Complemento C1q/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Masculino , Testes de Neutralização , Ligação Proteica/efeitos dos fármacos , Receptores Fc/metabolismo , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Sigmodontinae/imunologia , Resultado do TratamentoRESUMO
The link between elevated LDL-C, low HDL-C, elevated triglycerides, and an increased risk for cardiovascular disease has solidified over the past decades. Concomitantly, the number of agents to treat dyslipidemia proliferated in clinical trials, proving or refuting their clinical efficacy. Many of these agents' role in reducing cardiovascular disease morbidity and mortality is now clear. Recently, there has been an explosion in emerging therapeutics for the primary and secondary prevention of cardiovascular disease through the control of dyslipidemia. This article reviews standard, new, and emerging treatments for hyperlipidemia.
Assuntos
Doenças Cardiovasculares , Dislipidemias , Hiperlipidemias , Humanos , Hiperlipidemias/tratamento farmacológico , Doenças Cardiovasculares/complicações , Dislipidemias/tratamento farmacológicoRESUMO
As observed during the 2013-2016 Ebola virus disease epidemic, containment of filovirus outbreaks is challenging and made more difficult by the lack of approved vaccine or therapeutic options. Marburg and Ravn viruses are highly virulent and cause severe and frequently lethal disease in humans. Monoclonal antibodies (mAbs) are a platform technology in wide use for autoimmune and oncology indications. Previously, we described human mAbs that can protect mice from lethal challenge with Marburg virus. We demonstrate that one of these mAbs, MR191-N, can confer a survival benefit of up to 100% to Marburg or Ravn virus-infected rhesus macaques when treatment is initiated up to 5 days post-inoculation. These findings extend the small but growing body of evidence that mAbs can impart therapeutic benefit during advanced stages of disease with highly virulent viruses and could be useful in epidemic settings.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Infecções por Filoviridae/tratamento farmacológico , Filoviridae/fisiologia , Doença do Vírus de Marburg/tratamento farmacológico , Marburgvirus/fisiologia , Animais , Proteção Cruzada , Infecções por Filoviridae/virologia , Cobaias , Humanos , Macaca fascicularis , Macaca mulatta , Doença do Vírus de Marburg/virologia , Projetos PilotoRESUMO
Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was identified in 2012 as the causative agent of a severe, lethal respiratory disease occurring across several countries in the Middle East. To date there have been over 1600 laboratory confirmed cases of MERS-CoV in 26 countries with a case fatality rate of 36%. Given the endemic region, it is possible that MERS-CoV could spread during the annual Hajj pilgrimage, necessitating countermeasure development. In this report, we describe the clinical and radiographic changes of rhesus monkeys following infection with 5×10(6) PFU MERS-CoV Jordan-n3/2012. Two groups of NHPs were treated with either a human anti-MERS monoclonal antibody 3B11-N or E410-N, an anti-HIV antibody. MERS-CoV Jordan-n3/2012 infection resulted in quantifiable changes by computed tomography, but limited other clinical signs of disease. 3B11-N treated subjects developed significantly reduced lung pathology when compared to infected, untreated subjects, indicating that this antibody may be a suitable MERS-CoV treatment.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Antivirais/administração & dosagem , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/patologia , Pulmão/patologia , Coronavírus da Síndrome Respiratória do Oriente Médio/fisiologia , Animais , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Humanos , Pulmão/virologia , Macaca mulatta , MasculinoRESUMO
We report on real-time Raman spectroscopic studies of optically trapped living cells and organelles using an inverted confocal laser-tweezers-Raman-spectroscopy (LTRS) system. The LTRS system was used to hold a single living cell in a physiological solution or to hold a functional organelle within a living cell and consequently measured its Raman spectra. We have measured the changes in Raman spectra of a trapped yeast cell as the function of the temperature of the bathing solution and studied the irreversible cell degeneration during the heat denaturation. In addition, we measured the in-vitro Raman spectra of the nuclei within living pine cells and B. sporeformer, Strep. salivarius, and E. coli bacteria suspended in solution and showed the possibility of using LTRS system as a sensor for rapid identification of microbes in a fluid.
RESUMO
Recent incidents in the United States and abroad have heightened concerns about the use of ricin toxin as a bioterrorism agent. In this study, we produced, using a robust plant-based platform, four chimeric toxin-neutralizing monoclonal antibodies that were then evaluated for the ability to passively protect mice from a lethal-dose ricin challenge. The most effective antibody, c-PB10, was further evaluated in mice as a therapeutic following ricin exposure by injection and inhalation.
Assuntos
Antitoxinas/administração & dosagem , Imunização Passiva/métodos , Planticorpos/administração & dosagem , Intoxicação/prevenção & controle , Ricina/antagonistas & inibidores , Ricina/toxicidade , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Neutralizantes/administração & dosagem , Feminino , Camundongos Endogâmicos BALB C , Análise de Sobrevida , Resultado do TratamentoRESUMO
Due to the fast-acting nature of ricin, staphylococcal enterotoxin B (SEB), and Clostridium perfringens epsilon toxin (ETX), it is necessary that therapeutic interventions following a bioterrorism incident by one of these toxins occur as soon as possible after intoxication. Moreover, because the clinical manifestations of intoxication by these agents are likely to be indistinguishable from each other, especially following aerosol exposure, we have developed a cocktail of chimeric monoclonal antibodies that is capable of neutralizing all three toxins. The efficacy of this cocktail was demonstrated in mouse models of lethal dose toxin challenge.