Exfoliative Toxins of Staphylococcus aureus

Virulent strains of Staphylococcus aureus secrete exfoliative toxins (ETs) that cause the loss of cell‐cell adhesion in the superficial epidermis. S. aureus ETs are serine proteases, which exhibit exquisite substrate specificity, and their mechanisms of action are extremely complex. To date, four different serotypes of ETs have been identified and three of them (ETA, ETB and ETD) are associated with toxin‐mediated staphylococcal syndromes related to human infections leading to diseases of medical and veterinary importance

Exfoliative toxin E, a new Staphylococcus aureus virulence factor with host-specific activity

Exfoliative toxin E, a new [i]Staphylococcus aureus[/i] virulence factor with host-specific activity. Microbes, 15e Congrès National de la SF

Lista de gêneros de Hymenoptera (Insecta) do Espírito Santo, Brasil

The first checklist of genera of Hymenoptera from Espírito Santo state, Brazil is presented. A total of 973 genera of Hymenoptera is listed, of which 555 (57%) are recorded for the first time from this state. Ichneumonoidea and Chalcidoidea are the two superfamilies with the most genera, 241 and 203 respectively. Braconidae, with 141 genera, are the richest family.The first checklist of genera of Hymenoptera from Espírito Santo state, Brazil is presented. A total of 973 genera of Hymenoptera is listed, of which 555 (57%) are recorded for the first time from this state. Ichneumonoidea and Chalcidoidea are the two superfamilies with the most genera, 241 and 203 respectively. Braconidae, with 141 genera, are the richest family.Fil: Azevedo, Celso O.. Universidade Federal do Espírito Santo; BrasilFil: Molin, Ana Dal. Texas A&M University; Estados UnidosFil: Penteado-Dias, Angelica. Universidade Federal do São Carlos; BrasilFil: Macedo, Antonio C. C.. Secretaria do Meio Ambiente do Estado de São Paulo; BrasilFil: Rodriguez-V, Beatriz. Universidad Nacional Autónoma de México; MéxicoFil: Dias, Bianca Z. K.. Universidade Federal do Espírito Santo; BrasilFil: Waichert, Cecilia. State University of Utah; Estados UnidosFil: Aquino, Daniel Alejandro. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Smith, David. Smithsonian Institution; Estados UnidosFil: Shimbori, Eduardo M.. Universidade Federal do São Carlos; BrasilFil: Noll, Fernando B.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Gibson, Gary. Agriculture and Agri-Food Canada; CanadáFil: Onody, Helena. Universidade Federal do São Carlos; BrasilFil: Carpenter, James M.. American Museum of Natural History; Estados UnidosFil: Lattke, John. Universidad Nacional de Loja; EcuadorFil: Ramos, Kelli dos S.. Universidade de Sao Paulo; BrasilFil: Williams, Kevin. Florida State Collection of Arthropods; Estados UnidosFil: Masner, Lubomir. Agriculture and Agri-Food Canada; CanadáFil: Kimsey, Lynn. University of California; Estados UnidosFil: Tavares, Marcelo T.. Universidade Federal do Espírito Santo; BrasilFil: Olmi, Massimo. Università degli Studi della Tuscia; ItaliaFil: Buffington, Matthew L.. United States Department of Agriculture; Estados UnidosFil: Ohl, Michael. Staatliches Museum fur Naturkunde Stuttgart; AlemaniaFil: Sharkey, Michael. University of Kentucky; Estados UnidosFil: Johnson, Norman F.. Ohio State University; Estados UnidosFil: Kawada, Ricardo. Universidade Federal do Espírito Santo; BrasilFil: Gonçalves, Rodrigo B.. Universidade Federal do Paraná; BrasilFil: Feitosa, Rodrigo. Universidade Federal do Paraná; BrasilFil: Heydon, Steven. University of California; Estados UnidosFil: Guerra, Tânia M.. Universidade Federal do Espírito Santo; BrasilFil: da Silva, Thiago S. R.. Universidade Federal do Espírito Santo; BrasilFil: Costa, Valmir. Instituto Biológico; Brasi

Granulocyte-Colony Stimulating Factor-Overexpressing Mesenchymal Stem Cells Exhibit Enhanced Immunomodulatory Actions Through the Recruitment of Suppressor Cells in Experimental Chagas Disease Cardiomyopathy

Genetic modification of mesenchymal stem cells (MSCs) is a promising strategy to improve their therapeutic effects. Granulocyte-colony stimulating factor (G-CSF) is a growth factor widely used in the clinical practice with known regenerative and immunomodulatory actions, including the mobilization of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Here we evaluated the therapeutic potential of MSCs overexpressing G-CSF (MSC_G-CSF) in a model of inflammatory cardiomyopathy due to chronic Chagas disease. C57BL/6 mice were treated with wild-type MSCs, MSC_G-CSF, or vehicle (saline) 6 months after infection with Trypanosoma cruzi. Transplantation of MSC_G-CSF caused an increase in the number of circulating leukocytes compared to wild-type MSCs. Moreover, G-CSF overexpression caused an increase in migration capacity of MSCs to the hearts of infected mice. Transplantation of either MSCs or MSC_G-CSF improved exercise capacity, when compared to saline-treated chagasic mice. MSC_G-CSF mice, however, were more potent than MSCs in reducing the number of infiltrating leukocytes and fibrosis in the heart. Similarly, MSC_G-CSF-treated mice presented significantly lower levels of inflammatory mediators, such as IFNγ, TNFα, and Tbet, with increased IL-10 production. A marked increase in the percentage of Tregs and MDSCs in the hearts of infected mice was seen after administration of MSC_G-CSF, but not MSCs. Moreover, Tregs were positive for IL-10 in the hearts of T. cruzi-infected mice. In vitro analysis showed that recombinant hG-CSF and conditioned medium of MSC_G-CSF, but not wild-type MSCs, induce chemoattraction of MDSCs in a transwell assay. Finally, MDSCs purified from hearts of MSC_G-CSF transplanted mice inhibited the proliferation of activated splenocytes in a co-culture assay. Our results demonstrate that G-CSF overexpression by MSCs potentiates their immunomodulatory effects in our model of Chagas disease and suggest that mobilization of suppressor cell populations such as Tregs and MDSCs as a promising strategy for the treatment of chronic Chagas disease. Finally, our results reinforce the therapeutic potential of genetic modification of MSCs, aiming at increasing their paracrine actions

Redundancy and the Evolution of Cis-Regulatory Element Multiplicity

The promoter regions of many genes contain multiple binding sites for the same transcription factor (TF). One possibility is that this multiplicity evolved through transitional forms showing redundant cis-regulation. To evaluate this hypothesis, we must disentangle the relative contributions of different evolutionary mechanisms to the evolution of binding site multiplicity. Here, we attempt to do this using a model of binding site evolution. Our model considers binding sequences and their interactions with TFs explicitly, and allows us to cast the evolution of gene networks into a neutral network framework. We then test some of the model's predictions using data from yeast. Analysis of the model suggested three candidate nonadaptive processes favoring the evolution of cis-regulatory element redundancy and multiplicity: neutral evolution in long promoters, recombination and TF promiscuity. We find that recombination rate is positively associated with binding site multiplicity in yeast. Our model also indicated that weak direct selection for multiplicity (partial redundancy) can play a major role in organisms with large populations. Our data suggest that selection for changes in gene expression level may have contributed to the evolution of multiple binding sites in yeast. We conclude that the evolution of cis-regulatory element redundancy and multiplicity is impacted by many aspects of the biology of an organism: both adaptive and nonadaptive processes, both changes in cis to binding sites and in trans to the TFs that interact with them, both the functional setting of the promoter and the population genetic context of the individuals carrying them

Most Networks in Wagner's Model Are Cycling

In this paper we study a model of gene networks introduced by Andreas Wagner in the 1990s that has been used extensively to study the evolution of mutational robustness. We investigate a range of model features and parameters and evaluate the extent to which they influence the probability that a random gene network will produce a fixed point steady state expression pattern. There are many different types of models used in the literature, (discrete/continuous, sparse/dense, small/large network) and we attempt to put some order into this diversity, motivated by the fact that many properties are qualitatively the same in all the models. Our main result is that random networks in all models give rise to cyclic behavior more often than fixed points. And although periodic orbits seem to dominate network dynamics, they are usually considered unstable and not allowed to survive in previous evolutionary studies. Defining stability as the probability of fixed points, we show that the stability distribution of these networks is highly robust to changes in its parameters. We also find sparser networks to be more stable, which may help to explain why they seem to be favored by evolution. We have unified several disconnected previous studies of this class of models under the framework of stability, in a way that had not been systematically explored before

DNA Vaccines against Dengue Virus Type 2 Based on Truncate Envelope Protein or Its Domain III

Two DNA vaccines were constructed encoding the ectodomain (domains I, II and III) of the DENV2 envelope protein (pE1D2) or only its domain III (pE2D2), fused to the human tissue plasminogen activator signal peptide (t-PA). The expression and secretion of recombinant proteins was confirmed in vitro in BHK cells transfected with the two plasmids, detected by immunofluorescence or immunoprecipitation of metabolically labeled gene products, using polyclonal and monoclonal antibodies against DENV2. Besides, results reveal that the ectodomain of the E protein can be efficiently expressed in vivo, in a mammalian system, without the prM protein that is hypothesized to act as a chaperonin during dengue infection. Balb/c mice were immunized with the DNA vaccines and challenged with a lethal dose of DENV2. All pE1D2-vaccinated mice survived challenge, while 45% of animals immunized with the pE2D2 died after infection. Furthermore, only 10% of pE1D2-immunized mice presented some clinical signs of infection after challenge, whereas most of animals inoculated with the pE2D2 showed effects of the disease with high morbidity degrees. Levels of neutralizing antibodies were significantly higher in pE1D2-vaccinated mice than in pE2D2-immunized animals, also suggesting that the pE1D2 vaccine was more protective than the pE2D2

Erratum to: The study of cardiovascular risk in adolescents – ERICA: rationale, design and sample characteristics of a national survey examining cardiovascular risk factor profile in Brazilian adolescents

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