Inefficient Complement System Clearance of Trypanosoma cruzi Metacyclic Trypomastigotes Enables Resistant Strains to Invade Eukaryotic Cells

The complement system is the main arm of the vertebrate innate immune system against pathogen infection. For the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, subverting the complement system and invading the host cells is crucial to succeed in infection. However, little attention has focused on whether the complement system can effectively control T. cruzi infection. To address this question, we decided to analyse: 1) which complement pathways are activated by T. cruzi using strains isolated from different hosts, 2) the capacity of these strains to resist the complement-mediated killing at nearly physiological conditions, and 3) whether the complement system could limit or control T. cruzi invasion of eukaryotic cells. The complement activating molecules C1q, C3, mannan-binding lectin and ficolins bound to all strains analysed; however, C3b and C4b deposition assays revealed that T. cruzi activates mainly the lectin and alternative complement pathways in non-immune human serum. Strikingly, we detected that metacyclic trypomastigotes of some T. cruzi strains were highly susceptible to complement-mediated killing in non-immune serum, while other strains were resistant. Furthermore, the rate of parasite invasion in eukaryotic cells was decreased by non-immune serum. Altogether, these results establish that the complement system recognizes T. cruzi metacyclic trypomastigotes, resulting in killing of susceptible strains. The complement system, therefore, acts as a physiological barrier which resistant strains have to evade for successful host infection

Complement C2 Receptor Inhibitor Trispanning Confers an Increased Ability to Resist Complement-Mediated Lysis in Trypanosoma cruzi

The ability to resist complement differs between theYand Colombiana Trypanosoma cruzi strains.Wefound that the Y strain of T. cruzi was more able to resist the classical and lectin pathways of complement activation than the Colombiana strain. The complement C2 receptor inhibitor trispanning gene (CRIT) is highly conserved in both strains. At the protein level, CRIT is expressed only in stationary-phase epimastigotes of the Y but not the Colombiana strain and is expressed in infectious metacyclic trypomastigotes of both strains. Y strain epimastigotes with an overexpressed CRIT gene (pTEX-CRIT) had higher survival in normalhumanserum (NHS). Overexpression of the Y strain CRIT gene in Colombiana epimastigote forms increased the parasite's resistance to lysis mediated by the classical and lectin pathways but not to lysis mediated by alternative pathways. CRIT involvement on the parasite surface was confirmed by showing that the lytic activity ofNHSagainst epimastigotes could be restored by adding excess C

Internações em UTI por causas obstétricas

The objective was to analyze the admission of women of childbearing age to an Obstetric Intensive Care Unit. A cross-sectional, documentary and retrospective study was carried out in an Obstetric Intensive Care Unit, located in Fortaleza/Ceará, with women of childbearing age admitted to the unit in 2016. Data were collected from 106 medical records that met the inclusion criteria during the month of April 2017, using a semi-structured form, and analyzed by means of descriptive statistics. The majority of the women were between 20 and 29 years old, common-law married, with complete secondary education, primiparous, had initiated prenatal care in the first trimester of pregnancy, and attended 4 to 6 consultations. Among the direct obstetric causes (61.1%), the most frequent were Eclampsia (34.4%), HELLP syndrome (15.1%) and Severe preeclampsia (11%). The indirect obstetric causes (38.9%) included Renal insufficiency (13.5%), Acute lung edema (11.5%) and Heart disease (9.6%). Data revealed a fragile health care for women within the pregnant-puerperal cycle.Su objetivo es analizar los ingresos de mujeres en edad fértil en una Unidad de Cuidados Intensivos Obstétrica. Estudio transversal, documental y retrospectivo, realizado en una Unidad de Cuidados Intensivos Obstétrica, ubicada en Fortaleza / Ceará, con la presencia de mujeres en edad fértil admitidas en la unidad en el año 2016. Los datos fueron recolectados de los registros que atendieron a los criterios de inclusión. Durante el mes de abril de 2017, mediante un formulario semiestructurado y analizado por medio de estadística descriptiva, siendo incluidos 106 registros. La mayoría de las mujeres tenía un grupo de edad entre 20 y 29 años, pardas, en unión estable, con enseñanza media completa, primíperas, con inicio del prenatal en el primer trimestre gestacional, con 4 a 6 consultas. Entre las causas obstétricas directas (61,1%) las principales fueron Eclampsia (34,4%), Síndrome de Hellp (15,1%) y Pre-eclampsia grave (11%) y para las causas obstétricas indirectas (38,9 (%), Se observan las siguientes: Insuficiencia renal (13,5%), Edema agudo de pulmón (11,5%) y Cardiopatía (9,6%). Los datos revelan una línea tenue en lo que concierne a la atención a la salud de las mujeres dentro del ciclo gravídico-puerperal.Objetivou-se analisar as internações de mulheres em idade fértil em uma Unidade de Terapia Intensiva Obstétrica. Estudo transversal, documental e retrospectivo, realizado em uma Unidade de Terapia Intensiva Obstétrica, localizada em Fortaleza/Ceará, com a presença de mulheres em idade fértil admitidas na unidade no ano de 2016. Os dados foram coletados dos prontuários que atenderam aos critérios de inclusão, durante o mês de abril de 2017, mediante um formulário semiestruturado e analisados por meio de estatística descritiva, sendo incluídos 106 prontuários. A maioria das mulheres tinham faixa etária entre 20 a 29 anos, pardas, em união estável, com ensino médio completo, primíperas, com início do pré-natal no 1º trimestre gestacional, com 4 a 6 consultas. Dentre as causas obstétricas diretas (61,1%) as principais foram Eclâmpsia (34,4%), Síndrome de Hellp (15,1%) e Pré-eclâmpsia grave (11%) e para as causas obstétricas indiretas (38,9%) destacam-se Insuficiência renal (13,5%), Edema agudo de pulmão (11,5%) e Cardiopatia (9,6%). Os dados revelam uma linha ténue no que concerne a atenção a saúde da mulheres dentro do ciclo gravídico-puerperal

Plasmodium Secretion Induces Hepatocyte Lysosome Exocytosis and Promotes Parasite Entry.

The invasion of a suitable host hepatocyte by Plasmodium sporozoites is an essential step in malaria infection. We demonstrate that in infected hepatocytes, lysosomes are redistributed away from the nucleus, and surface exposure of lysosome-associated membrane protein 1 (LAMP1) is increased. Lysosome exocytosis in infected cells occurs independently of sporozoite traversal. Instead, a sporozoite-secreted factor is sufficient for the process. Knockdown of SNARE proteins involved in lysosome-plasma membrane fusion reduces lysosome exocytosis and Plasmodium infection. In contrast, promoting fusion between the lysosome and plasma membrane dramatically increases infection. Our work demonstrates parallels between Plasmodium sporozoite entry of hepatocytes and infection by the excavate pathogen Trypanosoma cruzi and raises the question of whether convergent evolution has shaped host cell invasion by divergent pathogens

Lexis and grammar of mitochondrial RNA processing in Trypanosomes

Trypanosoma brucei spp. cause African human and animal trypanosomiasis, a burden on health and economy in Africa. These hemoflagellates are distinguished by a kinetoplast nucleoid containing mitochondrial DNAs of two kinds: maxicircles encoding ribosomal RNAs (rRNAs) and proteins and minicircles bearing guide RNAs (gRNAs) for mRNA editing. All RNAs are produced by a phage-type RNA polymerase as 3' extended precursors, which undergo exonucleolytic trimming. Most pre-mRNAs proceed through 3' adenylation, uridine insertion/deletion editing, and 3' A/U-tailing. The rRNAs and gRNAs are 3' uridylated. Historically, RNA editing has attracted major research effort, and recently essential pre- and postediting processing events have been discovered. Here, we classify the key players that transform primary transcripts into mature molecules and regulate their function and turnover

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

The phosphoinositide regulatory network in Trypanosoma brucei: Implications for cell-wide regulation in eukaryotes.

The unicellular eukaryote Trypanosoma brucei undergoes extensive cellular and developmental changes during its life cycle. These include regulation of mammalian stage surface antigen variation and surface composition changes between life stages; switching between glycolysis and oxidative phosphorylation; differential mRNA editing; and changes in posttranscriptional gene expression, protein trafficking, organellar function, and cell morphology. These diverse events are coordinated and controlled throughout parasite development, maintained in homeostasis at each life stage, and are essential for parasite survival in both the host and insect vector. Described herein are the enzymes and metabolites of the phosphatidylinositol (PI) cellular regulatory network, its integration with other cellular regulatory systems that collectively control and coordinate these numerous cellular processes, including cell development and differentiation and the many associated complex processes in multiple subcellular compartments. We conclude that this regulation is the product of the organization of these enzymes within the cellular architecture, their activities, metabolite fluxes, and responses to environmental changes via signal transduction and other processes. We describe a paradigm for how these enzymes and metabolites could function to control and coordinate multiple cellular functions. The significance of the PI system's regulatory functions in single-celled eukaryotes to metazoans and their potential as chemotherapeutic targets are indicated