GABRIELA HASE SIQUEIRA
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- Binding of human plasminogen by the lipoprotein LipL46 of Leptospira interrogans(2018) SANTOS, Jadson V.; PEREIRA, Priscila R. M.; FERNANDES, Luis G. V.; SIQUEIRA, Gabriela Hase; SOUZA, Gisele O. de; SOUZA FILHO, Antonio; VASCONCELLOS, Silvio A.; HEINEMANN, Marcos B.; CHAPOLA, Erica G. B.; NASCIMENTO, Ana L. T. O.Leptospirosis is a widespread zoonosis caused by pathogenic Leptospira. Bacteria disseminate via the bloodstream and colonize the renal tubules of reservoir hosts. Leptospiral surface-exposed proteins are important targets, because due to their location they can elicit immune response and mediate adhesion and invasion processes. LipL46 has been previously reported to be located at the leptospiral outer membrane and recognized by antibodies present in serum of infected hamsters. In this study, we have confirmed the cellular location of this protein by immunofluorescence and FACS. We have cloned and expressed the recombinant protein LipL46 in its soluble form. LipL46 was recognized by confirmed leptospirosis human serum, suggesting its expression during infection. Binding screening of LipL46 with extracellular matrix (ECM) and plasma components showed that this protein interacts with plasminogen. The binding is dose-dependent on protein concentration, but saturation was not reached with the range of protein concentration used. Kringle domains of plasminogen and lysine residues of the recombinant protein are involved in the binding because the lysine analog, amino caproic acid (ACA) almost totally inhibited the reaction. The interaction of LipL46 with plasminogen generates plasmin in the presence of plasminogen activator uPA. Because plasmin generated at the leptospiral surface can degrade ECM molecules and decrease opsonophagocytosis, we tentatively infer that Lip46 has a role in helping the invasion process of pathogenic Leptospira.
- 14 Years of History on Sustainability: Waste Management FMUSP/IMT/SVOC(2018) MARQUES, Fabio Luiz Navarro; SARAIVA, Arlete Araujo; CHAVES, Adilson Caetano Cesario; SILVA, Ana Maria Goncalves da; KANASHIRO, Edite Hatsumi Yamashiro; POMPEU, Eduardo; SIQUEIRA, Gabriela Hase; BERNARDO, Joana Sueli Maziero; APOLINARIO, Lilian; SANCHEZ, Maria Carmen Arroyo; GUIMARAES, Maria Ines Calil Cury; MAUAD, Thais; SOUZA, Felipe Neme; AULER JR., Jose Otavio CostaHigh regulation in environmental protection and sustainability was established in Brazil around 2003. From that time, the board of directors of the Faculty of Medicine, Tropical Medicine Institute, Death Verification Service, and Medical Investigation Laboratories, of the University of Sao Paulo created the Waste Management Committee to organize and implement actions to comply with Brazilian legislation. This paper outlines the main actions taken by the Committee and Board of directors of the institutions, presenting it in ages. During the first five years were developed works to know the passive/regular discharge of infectious agents, chemicals, radioactive compounds, recyclable and common garbage. From this data, were constructed stations for provisory disposal, transportation flow and general rules were established, and training was given to staff and students. During the following five years, or in the second phase of actions plans, efforts were focused on improving the management of the process and increasing the gathering of recyclable materials. Now, in the third phase, actions have been developed aiming to eliminate devices that use mercury and mercury vapor lamps from FMUSP building; furthermore, composting of food and garden material is in the evaluation process. These actions gave to FMUSP two Prize Friend of the Environment (2010 and 2016), offered by Health Secretary of Sao Paulo State, and these experience will be shared in this paper. However, it is necessary to have in mind that this work was done under Brazilian regulations, but certainly, it can be adjusted to all countries.
- The role of Lsa23 to mediate the interaction of Leptospira interrogans with the terminal complement components pathway(2017) SIQUEIRA, Gabriela H.; SOUZA, Gisele O. de; HEINEMANN, Marcos B.; VASCONCELLOS, Silvio A.; NASCIMENTO, Ana L. T. O.Leptospirosis is a severe worldwide zoonotic disease caused by pathogenic Leptospira spp. It has been demonstrated that pathogenic leptospires are resistant to the bactericidal activity of normal human serum while saprophytic strains are susceptible. Pathogenic strains have the ability to bind soluble complement regulators and these activities are thought to contribute to bacterial immune evasion. One strategy used by some pathogens to evade the complement cascade, which is not well explored, is to block the terminal pathway. We have, thus, examined whether leptospires are able to interact with components of the terminal complement pathway. ELISA screening using anti-leptospires serum has shown that the pathogenic, virulent strain L. interrogans L1-130 can bind to immobilized human C8 (1 kg). However, virulent and saprophyte L biflexa strains showed the ability to interact with C8 and C9, when these components were employed at physiological concentration (50 mu g/mL), but the virulent strain seemed more competent. Lsa23, a putative leptospiral adhesin only present in pathogenic strains, interacts with C8 and C9 in a dose-dependent mode, suggesting that this protein could mediate the binding of virulent Leptospira with these components. To our knowledge, this is the first work reporting the binding of Leptospira to C8 and C9 terminal complement components, suggesting that the inhibition of this pathway is part of the strategy used by leptospires to evade the innate immunity.
- Characterization of two new putative adhesins of Leptospira interrogans(2017) FIGUEREDO, Jupciana M.; SIQUEIRA, Gabriela H.; SOUZA, Gisele O. de; HEINEMANN, Marcos B.; VASCONCELLOS, Silvio A.; CHAPOLA, Erica G. B.; NASCIMENTO, Ana L. T. O.We here report the characterization of two novel proteins encoded by the genes LIC11122 and LIC12287, identified in the genome sequences of Leptospira interrogans, annotated, respectively, as a putative sigma factor and a hypothetical protein. The CDSs LIC11122 and LIC12287 have signal peptide SPII and SPI and are predicted to be located mainly at the cytoplasmic membrane of the bacteria. The genes were cloned and the proteins expressed using Escherichia coli. Proteinase K digestion showed that both proteins are surface exposed. Evaluation of interaction of recombinant proteins with extracellular matrix components revealed that they are laminin binding and they were called Lsa19 (LIC11122) and Lsa14 (LIC12287), for Leptospiral-surface adhesin of 19 and 14 kDa, respectively. The bindings were dose-dependent on protein concentration, reaching saturation, fulfilling the ligand-binding criteria. Reactivity of the recombinant proteins with leptospirosis human sera has shown that Lsa19 and, to a lesser extent, Lsa14, are recognized by antibodies, suggesting that, most probably, Lsa19 is expressed during infection. The proteins interact with plasminogen and generate plasmin in the presence of urokinase-type plasminogen activator. Plasmin generation in Leptospira has been associated with tissue penetration and immune evasion strategies. The presence of a sigma factor on the cell surface playing a secondary role, probably mediating host -pathogen interaction, suggests that LIC11122 is a moonlighting protein candidate. Although the biological significance of these putative adhesins will require the generation of mutants, our data suggest that Lsa19 is a potential candidate for future evaluation of its role in adhesion/colonization activities during L. interrogans infection.