48 research outputs found
Patterns of genetic diversity in three plant lineages endemic to the Cape Verde Islands
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. The file attached is the published version of the article
CD6, a Rheostat-Type Signalosome That Tunes T Cell Activation
Following T cell receptor triggering, T cell activation is initiated and amplified by the assembly at the TCR/CD3 macrocomplex of a multitude of stimulatory enzymes that activate several signaling cascades. The potency of signaling is, however, modulated by various inhibitory components already at the onset of activation, long before co-inhibitory immune checkpoints are expressed to help terminating the response. CD5 and CD6 are surface glycoproteins of T cells that have determinant roles in thymocyte development, T cell activation and immune responses. They belong to the superfamily of scavenger receptor cysteine-rich (SRCR) glycoproteins but whereas the inhibitory role of CD5 has been established for long, there is still controversy on whether CD6 may have similar or antagonistic functions on T cell signaling. Analysis of the structure and molecular associations of CD5 and CD6 indicates that these molecules assemble at the cytoplasmic tail a considerable number of signaling effectors that can putatively transduce diverse types of intracellular signals. Biochemical studies have concluded that both receptors can antagonize the flow of TCR-mediated signaling; however, the impact that CD5 and CD6 have on T cell development and T cell-mediated immune responses may be different. Here we analyze the signaling function of CD6, the common and also the different properties it exhibits comparing with CD5, and interpret the functional effects displayed by CD6 in recent animal models
Delivery of LLKKK18 loaded into self-assembling hyaluronic acid nanogel for tuberculosis treatment
uberculosis (TB), a disease caused by the human pathogen Mycobacterium tuberculosis, recently joined HIV/AIDS on the top rank of deadliest infectious diseases. Low patient compliance due to the expensive, long-lasting and multi-drug standard therapies often results in treatment failure and emergence of multi-drug resistant strains. In this scope, antimicrobial peptides (AMPs) arise as promising candidates for TB treatment.
Here we describe the ability of the exogenous AMP LLKKK18 to efficiently kill mycobacteria. The peptide's potential was boosted by loading into self-assembling Hyaluronic Acid (HA) nanogels. These provide increased stability, reduced cytotoxicity and degradability, while potentiating peptide targeting to main sites of infection. The nanogels were effectively internalized by macrophages and the peptide presence and co-localization with mycobacteria within host cells was confirmed. This resulted in a significant reduction of the mycobacterial load in macrophages infected in vitro with the opportunistic M. avium or the pathogenic M. tuberculosis, an effect accompanied by lowered pro-inflammatory cytokine levels (IL-6 and TNF-). Remarkably, intra-tracheal administration of peptide-loaded nanogels significantly reduced infection levels in mice infected with M. avium or M. tuberculosis, after just 5 or 10 every other day administrations. Considering the reported low probability of resistance acquisition, these findings suggest a great potential of LLKKK18-loaded nanogels for TB therapeutics.This study was supported by the Portuguese Foundation for Science
and Technology (FCT) under the scope of the strategic funding of UID/
BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-
006684). The authors also acknowledge the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). The authors thank Dr. Hugo Osório (Proteomics Lab at I3S – Institute for Health Research and Innovation, Porto, Portugal) for the MALDI-ToF analysis. JPS acknowledges FCT
for the financial support provided by grant SFRH/BPD/64958/2010
Spontaneous healing of Mycobacterium ulcerans lesions in the guinea pig model
Buruli Ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans infection. BU is characterized by a wide range of clinical forms, including non-ulcerative cutaneous lesions that can evolve into severe ulcers if left untreated. Nevertheless, spontaneous healing has been reported to occur, although knowledge on this process is scarce both in naturally infected humans and experimental models of infection. Animal models are useful since they mimic different spectrums of human BU disease and have the potential to elucidate the pathogenic/protective pathway(s) involved in disease/healing. In this time-lapsed study, we characterized the guinea pig, an animal model of resistance to M. ulcerans, focusing on the macroscopic, microbiological and histological evolution throughout the entire experimental infectious process. Subcutaneous infection of guinea pigs with a virulent strain of M. ulcerans led to early localized swelling, which evolved into small well defined ulcers. These macroscopic observations correlated with the presence of necrosis, acute inflammatory infiltrate and an abundant bacterial load. By the end of the infectious process when ulcerative lesions healed, M. ulcerans viability decreased and the subcutaneous tissue organization returned to its normal state after a process of continuous healing characterized by tissue granulation and reepethelialization. In conclusion, we show that the experimental M. ulcerans infection of the guinea pig mimics the process of spontaneous healing described in BU patients, displaying the potential to uncover correlates of protection against BU, which can ultimately contribute to the development of new prophylactic and therapeutic strategies.The research leading to these results has received funding from the European Community's Seventh Framework Program (FP7/2007-2013) under grant agreement No 241500 (BuruliVac). This work was additionally financed from the Health Services of the Fundacao Calouste Gulbenkian under the grant Proc.No94776 LJ; from the Fundacao para a Ciencia e Tecnologia (FCT), cofunded by Programa Operacional Regional do Norte (ON.2-O Novo Norte); from the Quadro de Referencia Estrategico Nacional (QREN) through the Fundo Europeu de Desenvolvimento Regional (FEDER) and from the Projeto Estrategico - LA 26 - 2013-2014 (PEst-C/SAU/LA0026/2013). A.G. Fraga and G. Trigo received an individual FCT fellowship (SFRH/BPD/68547/2010 and SFRH/BPD/64032/2009), C.M. Goncalves received an individual QREN fellowship (UMINHO/BPD/40/2013), and E. Marcq received funding from the Life Long Learning Erasmus program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Previsão da incidência da leishmaniose visceral usando o modelo de média móvel integrado autorregressivo sazonal (SARIMA) no Maranhão, Brasil
Universidade Federal do Maranhão. Programa de Pós‑graduação Strictu Sensu em Saúde e Ambiente. São Luís, MA, Brasil.Universidade Estadual do Maranhão - Campus Caxias. Programa de Pós‑graduação Strictu Sensu em Biodiversidade, Ambiente e Saúde. Caxias, MA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Universidade Federal do Maranhão. Programa de Pós‑graduação Strictu Sensu em Saúde e Ambiente. São Luís, MA, Brasil.Universidade Estadual do Maranhão - Campus Caxias. Programa de Pós‑graduação Strictu Sensu em Biodiversidade, Ambiente e Saúde. Caxias, MA, Brasil.Universidade Estadual do Maranhão - Campus Caxias. Programa de Pós‑graduação Strictu Sensu em Biodiversidade, Ambiente e Saúde. Caxias, MA, Brasil.Universidade Estadual do Maranhão - Campus Caxias. Programa de Pós‑graduação Strictu Sensu em Biodiversidade, Ambiente e Saúde. Caxias, MA, Brasil.Universidade Federal do Maranhão. Programa de Pós‑graduação Strictu Sensu em Saúde e Ambiente. São Luís, MA, Brasil.Universidade Federal do Maranhão. Programa de Pós‑graduação Strictu Sensu em Saúde e Ambiente. São Luís, MA, Brasil.Visceral leishmaniasis (VL) is an infectious disease predominant in countries located in the tropics. The prediction of occurrence of infectious diseases through epidemiologic modeling has revealed to be an important tool in the understanding of its occurrence dynamic. The objective of this study was to develop a forecasting model for the incidence of VL in Maranhão using the Seasonal Autoregressive Integrated Moving Average model (SARIMA). We collected monthly data regarding VL cases from the National Disease Notification System (SINAN) corresponding to the period between 2001 and 2018. The Box‑Jenkins method was applied in order to adjust a SARIMA prediction model for VL general incidence and by sex (male or female) for the period between January 2019 and December 2013. For 216 months of this time series, 10,431 cases of VL were notified in Maranhão, with an average of 579 cases per year. With regard to age range, there was a higher incidence among the pediatric public (0 to 14 years of age). There was a predominance in male cases, 6437 (61.71%). The Box‑Pierce test figures for overall, male and female genders supported by the results of the Ljung‑Box test suggest that the autocorrelations of residual values act as white noise. Regarding monthly occurrences in general and by gender, the SARIMA models (2,0,0) (2,0,0), (0,1,1) (0,1,1) and (0,1,1) (2, 0, 0) were the ones that mostly adjusted to the data respectively. The model SARIMA has proven to be an adequate tool for predicting and analyzing the trends in VL incidence in Maranhão. The time variation determination and its prediction are decisive in providing guidance in health measure intervention
Antimicrobial activity of Mycobacteriophage D29 Lysin B during Mycobacterium ulcerans infection
Buruli Ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Although the current antibiotic treatment for BU is effective, daily administrations for a prolonged period of time, combined with potential risk of severe side effects, negatively impact on patient adherence. In that sense, we tested the efficacy of an alternative strategy based on Lysin B (LysB), a phage encoded lipolytic enzyme that degrades the mycolylarabinogalactan-peptidoglycan complex present in the mycobacterial cell wall. In this study, we show that LysB not only displays lytic activity against M. ulcerans isolates in vitro, but also leads to a decrease of M. ulcerans proliferation in infected mouse footpads. These findings highlight the potential use of lysins as a novel therapeutic approach against this neglected tropical disease.The projectwas developed withinthescopeof the projectsNORTE-01-0145-FEDER-000013and NORTE-01-0145-FEDER-000023,supported by the Northern Portugal Regional Operational Programme (NORTE2020),under the Portugal2020 Partnership Agreement through FEDER.This work was also supported by BioTecNorte operation (NORTE-01-0145-FEDER -000004) funded by the European Regional Development Fund under the scope of NORTE2020.This study was supportedby the Portuguese Foundation for Scienceand Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit; the Competitiveness Factors Operational Programme (COMPETE 2020) projectsPOCI-01-0145-FEDER-006684 and POCI-01-0145-FEDER-007038; and the project PTDC/BBB-BSS/6471/2014 (POCI-01-0145-FEDER-016678). This study was also supported by Infect-ERA grant Infect-ERA/0002/2015 :BU_SPONT_HEAL. AGF,GT, and HO wouldlike to acknowledge FCT for the individual fellowships SFRH/BPD/112903/2015, SFRH/BPD/64032/2009,and SFRH/BPD/111653/2015,respectively. CMG received an individual QRENfellowship (UMINHO/BPD/15/2014). GangaGen acknowledges CSIR/ OSDD,Govt of India,for funding this project.The funders had no role in study design,data collection and analysis, decision to publish, or preparation of the manuscriptinfo:eu-repo/semantics/publishedVersio
Development of Inhalable Superparamagnetic Iron Oxide Nanoparticles (SPIONs) in microparticulate system for antituberculosis drug delivery
Tuberculosis (TB) is an infectious disease which affects millions of people worldwide. Inhalable polymeric dry powders are promising alternatives as anti-TB drug carriers to the alveoli milieu and infected macrophages, with potential to significantly improve the therapeutics efficiency. Here, the development of a magnetically responsive microparticulate system for pulmonary delivery of an anti-TB drug candidate (P3) is reported. Microparticles (MPs) are developed based on a cast method using calcium carbonate sacrificial templates and incorporate superparamagnetic iron oxide nanoparticles to concentrate MPs in alveoli and enable drug on demand release upon actuation of an external alternate magnetic field (AMF). The MPs are shown to be suitable for P3 delivery to the lower airways and for alveolar macrophage phagocytosis. The developed MPs reveal unique and promising features to be used as an inhalable dry powder allowing the AMF control over dosage and frequency of drug delivery anticipating improved TB treatments.The authors wish to acknowledge the financial support from the
Portuguese Foundation for Science and Technology (FCT) for the postdoctoral grant of M.S.M. (SFRH/BPD/110868/2015) and R.M.A.D
(SFRH/BPD/112459/2015), FCT grant of E.T. (IF/01390/2014) and
Recognize project (UTAP-ICDT/CTM-BIO/0023/2014). This article
is also a result of the project “Accelerating tissue engineering and
personalized medicine discoveries by the integration of key enabling
nanotechnologies, marine-derived biomaterials and stem cells,”
supported by Norte Portugal Regional Operational Programme
(NORTE 2020), under the PORTUGAL 2020 Partnership Agreement,
through the European Regional Development Fund (ERDF). The authors
acknowledge the financial support from the European Union Framework
Programme for Research and Innovation HORIZON 2020, under the
TEAMING Grant Agreement No. 739572 – The Discoveries CTR.info:eu-repo/semantics/publishedVersio