Cell-to-cell transfer of Leishmania amazonensis amastigotes is mediated by immunomodulatory LAMP-rich parasitophorous extrusions

The last step of Leishmania intracellular life cycle is the egress of amastigotes from the host cell and their uptake by adjacent cells. Using multidimensional live imaging of long-term-infected macrophage cultures we observed that Leishmania amazonensis amastigotes were transferred from cell to cell when the donor host macrophage delivers warning signs of imminent apoptosis. They were extruded from the macrophage within zeiotic structures (membrane blebs, an apoptotic feature) rich in phagolysosomal membrane components. the extrusions containing amastigotes were selectively internalized by vicinal macrophages and the rescued amastigotes remain viable in recipient macrophages. Host cell apoptosis induced by micro-irradiation of infected macrophage nuclei promoted amastigotes extrusion, which were rescued by non-irradiated vicinal macrophages. Using amastigotes isolated from LAMP1/LAMP2 knockout fibroblasts, we observed that the presence of these lysosomal components on amastigotes increases interleukin 10 production. Enclosed within host cell membranes, amastigotes can be transferred from cell to cell without full exposure to the extracellular milieu, what represents an important strategy developed by the parasite to evade host immune system.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Escola Paulista Medi, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Inst Trop Med, Lab Soroepidemiol & Imunobiol, São Paulo, BrazilFdn Oswaldo Cruz FIOCRUZ, INCT DT, Salvador, BrazilUniversidade Federal de São Paulo, Fac Med, Dept Prevent Med, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Medi, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Inst Trop Med, Lab Soroepidemiol & Imunobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Fac Med, Dept Prevent Med, São Paulo, BrazilFAPESP: 10/19335-4Web of Scienc

Immunization of Experimental Dogs With Salivary Proteins From Lutzomyia longipalpis, Using DNA and Recombinant Canarypox Virus Induces Immune Responses Consistent With Protection Against Leishmania infantum

Metacyclic Leishmania promastigotes are transmitted by sand flies that inject parasites and saliva into the host's skin. Previous studies have demonstrated that DNA plasmids encoding Lutzomyia longipalpis salivary proteins LJM17 and LJL143, when used to immunize dogs, resulted in a systemic and local Th1 cell-mediated immunity that interfered in parasite survival in vitro. Here we evaluated the ability of these same salivary antigens to induce anti-Leishmania immunity and to confer protection by immunizing dogs using a novel vaccination strategy more suitable for use in the field. The strategy consisted of a single dose of plasmid followed by two doses of recombinant Canarypoxvirus (rCanarypoxvirus) expressing L. longipalpis salivary proteins (LJM17 or LJL143). Thirty days after the final immunization, dogs were intradermally challenged with 107Leishmania infantum promastigotes in the presence of L. longipalpis saliva. We followed the experimentally infected dogs for 10 months to characterize clinical, parasitological, and immunological parameters. Upon vaccination, all immunized dogs presented strong and specific humoral responses with increased serum concentrations of IFN-γ, TNF, IL-7, and IL-15. The serum of dogs immunized with LJM17 also exhibited high levels of IL-2, IL-6, and IL-18. L. infantum infection was established in all experimental groups as evidenced by the presence of anti-Leishmania IgG, and by parasite detection in the spleen and skin. Dogs immunized with LJM17-based vaccines presented higher circulating levels of IFN-γ, IL-2, IL-6, IL-7, IL-15, IL-18, TNF, CXCL10, and GM-CSF post-infection when compared with controls. Results demonstrated that relevant Leishmania-specific immune responses were induced following vaccination of dogs with L. longipalpis salivary antigen LJM17 administered in a single priming dose of plasmid DNA, followed by two booster doses of recombinant Canarypox vector. Importantly, a significant increase in pro-inflammatory cytokines and chemokines known to be relevant for protection against leishmaniasis was evidenced after challenging LJM17-vaccinated dogs as compared to controls. Although similar results were observed following immunization with LJL143, the pro-inflammatory response observed after immunization was attenuated following infection. Collectively, these data suggest that the LJM17-based vaccine induced an immune profile consistent with the expected protective immunity against canine leishmaniosis. These results clearly support the need for further evaluation of the LJM17 antigen, using a heterologous prime-boost vaccination strategy against canine visceral leishmaniosis (CVL)

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

In Search of Biomarkers for Pathogenesis and Control of Leishmaniasis by Global Analyses of Leishmania-Infected Macrophages

Leishmaniasis is a vector-borne, neglected tropical disease with a worldwide distribution that can present in a variety of clinical forms, depending on the parasite species and host genetic background. The pathogenesis of this disease remains far from being elucidated because the involvement of a complex immune response orchestrated by host cells significantly affects the clinical outcome. Among these cells, macrophages are the main host cells, produce cytokines and chemokines, thereby triggering events that contribute to the mediation of the host immune response and, subsequently, to the establishment of infection or, alternatively, disease control. There has been relatively limited commercial interest in developing new pharmaceutical compounds to treat leishmaniasis. Moreover, advances in the understanding of the underlying biology of Leishmania spp. have not translated into the development of effective new chemotherapeutic compounds. As a result, biomarkers as surrogate disease endpoints present several potential advantages to be used in the identification of targets capable of facilitating therapeutic interventions considered to ameliorate disease outcome. More recently, large-scale genomic and proteomic analyses have allowed the identification and characterization of the pathways involved in the infection process in both parasites and the host, and these analyses have been shown to be more effective than studying individual molecules to elucidate disease pathogenesis. RNA-seq and proteomics are large-scale approaches that characterize genes or proteins in a given cell line, tissue, or organism to provide a global and more integrated view of the myriad biological processes that occur within a cell than focusing on an individual gene or protein. Bioinformatics provides us with the means to computationally analyze and integrate the large volumes of data generated by high-throughput sequencing approaches. The integration of genomic expression and proteomic data offers a rich multi-dimensional analysis, despite the inherent technical and statistical challenges. We propose that these types of global analyses facilitate the identification, among a large number of genes and proteins, those that hold potential as biomarkers. The present review focuses on large-scale studies that have identified and evaluated relevant biomarkers in macrophages in response to Leishmania infection

Deciphering the Role Played by Autophagy in Leishmania Infection

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2019-12-10T16:35:25Z No. of bitstreams: 1 Veras, P.S.T. Deciphering....pdf: 2656851 bytes, checksum: 47e32a3b983116aac9bbbfd38a5df64f (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2019-12-10T16:54:43Z (GMT) No. of bitstreams: 1 Veras, P.S.T. Deciphering....pdf: 2656851 bytes, checksum: 47e32a3b983116aac9bbbfd38a5df64f (MD5)Made available in DSpace on 2019-12-10T16:54:43Z (GMT). No. of bitstreams: 1 Veras, P.S.T. Deciphering....pdf: 2656851 bytes, checksum: 47e32a3b983116aac9bbbfd38a5df64f (MD5) Previous issue date: 2019Fundação de Amparo à Pesquisa do Estado da Bahia (PV, http://www.fapesb.ba.gov.br), Conselho Nacional de Pesquisa e Desenvolvimento Científico (PV, http://www.cnpq.br). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal deNível Superior— Brasil (CAPES)—Finance Code 001. PV holds a grant fromCNPq for productivity in research (307832/2015-5).Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Laboratório Parasito-Hospedeiro e Epidemiologia. Salvador, BA, Brasil / National Institute of Science and Technology of Tropical Diseases. Salvador, BA, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Parasito-Hospedeiro e Epidemiologia. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Parasito-Hospedeiro e Epidemiologia. Salvador, BA, Brasil.In recent decades, studies have shown that, depending on parasite species and host background, autophagy can either favor infection or promote parasite clearance. To date, relatively few studies have attempted to assess the role played by autophagy in Leishmania infection. While it has been consistently shown that Leishmania spp. induce autophagy in a variety of cell types, published results regarding the effects of autophagic modulation on Leishmania survival are contradictory. The present review, after a short overview of the general aspects of autophagy, aims to summarize the current body of knowledge surrounding how Leishmania spp. adaptively interact with macrophages, the host cells mainly involved in controlling leishmaniasis. We then explore the scarce studies that have investigated interactions between these parasite species and the autophagic pathway, and finally present a critical perspective on how autophagy influences infection outcome

In Search of Biomarkers for Pathogenesis and Control of Leishmaniasis by Global Analyses of Leishmania-Infected Macrophages

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2018-10-19T17:46:58Z No. of bitstreams: 1 Veras PS In search of Biomarkers....2018.pdf: 570607 bytes, checksum: 210e729195b45b2a10cdf51ab688a017 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2018-10-19T18:22:19Z (GMT) No. of bitstreams: 1 Veras PS In search of Biomarkers....2018.pdf: 570607 bytes, checksum: 210e729195b45b2a10cdf51ab688a017 (MD5)Made available in DSpace on 2018-10-19T18:22:19Z (GMT). No. of bitstreams: 1 Veras PS In search of Biomarkers....2018.pdf: 570607 bytes, checksum: 210e729195b45b2a10cdf51ab688a017 (MD5) Previous issue date: 2018Fundação de Amparo à Pesquisa do Estado da Bahia (PV http://www.fapesb.ba. gov.br), Conselho Nacional de Pesquisa e Desenvolvimento Científico (PV http://www.cnpq.br). PV holds a grant from CNPq for productivity in research (307832/2015-5).Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Laboratório de Interação Parasito-Hospedeiro e Epidemiologia. Salvador, BA, Brasil / National Institute of Tropical Disease. Brasilia, DF, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Centro de Integração de Dados e Conhecimento para a Saúde. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Laboratório de Interação Parasito-Hospedeiro e Epidemiologia. Salvador, BA, Brasil.Leishmaniasis is a vector-borne, neglected tropical disease with a worldwide distribution that can present in a variety of clinical forms, depending on the parasite species and host genetic background. The pathogenesis of this disease remains far from being elucidated because the involvement of a complex immune response orchestrated by host cells significantly affects the clinical outcome. Among these cells, macrophages are the main host cells, produce cytokines and chemokines, thereby triggering events that contribute to the mediation of the host immune response and, subsequently, to the establishment of infection or, alternatively, disease control. There has been relatively limited commercial interest in developing new pharmaceutical compounds to treat leishmaniasis. Moreover, advances in the understanding of the underlying biology of Leishmania spp. have not translated into the development of effective new chemotherapeutic compounds. As a result, biomarkers as surrogate disease endpoints present several potential advantages to be used in the identification of targets capable of facilitating therapeutic interventions considered to ameliorate disease outcome. More recently, large-scale genomic and proteomic analyses have allowed the identification and characterization of the pathways involved in the infection process in both parasites and the host, and these analyses have been shown to be more effective than studying individual molecules to elucidate disease pathogenesis. RNA-seq and proteomics are large-scale approaches that characterize genes or proteins in a given cell line, tissue, or organism to provide a global and more integrated view of the myriad biological processes that occur within a cell than focusing on an individual gene or protein. Bioinformatics provides us with the means to computationally analyze and integrate the large volumes of data generated by high-throughput sequencing approaches. The integration of genomic expression and proteomic data offers a rich multi-dimensional analysis, despite the inherent technical and statistical challenges. We propose that these types of global analyses facilitate the identification, among a large number of genes and proteins, those that hold potential as biomarkers. The present review focuses on large-scale studies that have identified and evaluated relevant biomarkers in macrophages in response to Leishmania infection

Traffic-Related Air Pollution Effect on Fast Glycemia of Aged Obese Type 2 Diabetic Mice

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2017-05-29T15:56:48Z No. of bitstreams: 1 Matsuda M traffic-related-air-pollution-effect-on-fast-glycemia-of-aged-obese-type-2-diabetic-mice-2155-9880.1000255.pdf: 651133 bytes, checksum: 949d59d733374dfc48fd0fb9d2ef07e8 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2017-05-29T16:20:38Z (GMT) No. of bitstreams: 1 Matsuda M traffic-related-air-pollution-effect-on-fast-glycemia-of-aged-obese-type-2-diabetic-mice-2155-9880.1000255.pdf: 651133 bytes, checksum: 949d59d733374dfc48fd0fb9d2ef07e8 (MD5)Made available in DSpace on 2017-05-29T16:20:38Z (GMT). No. of bitstreams: 1 Matsuda M traffic-related-air-pollution-effect-on-fast-glycemia-of-aged-obese-type-2-diabetic-mice-2155-9880.1000255.pdf: 651133 bytes, checksum: 949d59d733374dfc48fd0fb9d2ef07e8 (MD5) Previous issue date: 2013Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Grant 2008/57717-6 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) grant 2008/57717-6.University of São Paulo Medical School. Laboratory of Investigation in Ophthalmology. São Paulo, SP, BrasiUniversity of São Paulo Medical School. Experimental Air Pollution Laboratory of Pathology Department. São Paulo, SP, BrasilFederal University of Bahia. Medical School. Department of Pathology and Forensic Medicine. Salvador, BA, BrazilFederal University of Bahia. Medical School. Department of Pathology and Forensic Medicine. Salvador, BA, BrazilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, BrasilUniversity of São Paulo Medical School. Experimental Air Pollution Laboratory of Pathology Department. São Paulo, SP, BrasilUniversity of São Paulo Medical School. Experimental Air Pollution Laboratory of Pathology Department. São Paulo, SP, Brasil / Pro-Sangue Foundation. São Paulo, SP, BrasilRecent experimental data have provided associations between ambient PM2.5 (fine particulate matter; diameter ≤ 2.5 μm) and propensity to inflammation and chronic diseases especially among susceptible groups, such as elderly people. There is cumulative evidence that type-2 diabetes mellitus is a chronic inflammatory state aggravated by factors that promote endothelium inflammation. Accordingly our hypothesis that the exposure of aged obese population to PM2.5 might aggravate type-2 diabetes, we used a model of aged, diet-induced obese mice. C57BL6 male mice were fed with regular chow (n=30; RC) or high-fat chow (n=36; HF) during one-year and randomly assigned to filtered (FA-RC, n=16; FA-HF, n=19) or PM2.5 concentrated air (600 μg.m-3) (EXP-RC, n=14; EXPHF, n=17) chambers to have a daily 1 hour exposition during consecutive 30- days. Fast glycemia was measured before the animals were euthanized. The Institution’s Ethics Committee approved all experimental procedures. Heart mRNA content of selected migration, signalization and adhesion proteins were measured by SYBR Green fluorescence Real Time RT-PCR protocol using appropriate primers. There were no difference between RC-EXP and RC-FA nor between HF-EXP and HF-FA body weight. Regarding fast glycemia, both, RC and HF groups, were diabetic, but only the HF group was affected by acute exposure to PM2.5 (mean ± SD, EXP-HF vs FA- HF, 172.8 ± 23.4 vs 156.7 ± 17.6, p <0.05; EXP-RC vs FA-RC, 149.8 ± 19.2, 139.7 ± 15.3, ns; ANOVA). The gene expression profile of E-selectin, IL-6, VCAM-1, ICAM-1 and MMP-9, was differently affected by PM2.5 in heart and lung. Proteins activated by inflammatory stimuli involved in the inhibition of insulin signaling are being investigated