LUIZA DE CAMPOS REIS
Projetos de Pesquisa
Unidades Organizacionais
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina
2 resultados
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- Comparison of antibody repertories against Staphylococcus aureus in healthy and infected dairy cows with a distinct mastitis history and vaccinated with a polyvalent mastitis vaccine(2020) CUNHA, A. F.; ANDRADE, H. M.; SOUZA, F. N.; FIALHO JUNIOR, L. C.; ROSA, D. L. S. O.; SANCHEZ, E. M. Ramos; GIDLUND, M.; GOTO, H.; BRITO, M. A. V. P.; GUIMARAES, A. S.; LAGE, A. P.; REIS, L. C.; LIBERA, A. M. M. P. Della; HEINEMANN, M. B.; CERQUEIRA, M. M. O. P.Staphylococcus aureus is one of the pathogens most frequently isolated from cases of mastitis worldwide. To decrease the effect of S. aureus mastitis in dairy farming, alternative strategies for controlling mastitis are needed that depend on a better knowledge of cowto-cow variations in S. aureus antibody production. The present study sought to explore the diversity of S. aureus antibodies produced by dairy cows with a distinct mastitis history and vaccinated with a polyvalent mastitis vaccine. We obtained protein extracts from S. aureus isolates derived from persistent subclinical mastitis. Proteins were fractionated using 2-dimensional gel electrophoresis and Western blotting. Then, Western blotting membranes were exposed to sera from 24 dairy cows that had been divided into the following groups: vaccinated dairy cows that were infected with S. aureus, further subdivided according to whether they (a) remained infected by S. aureus or (b) recovered from the intramammary infection; unvaccinated dairy cows infected with S. aureus; and vaccinated healthy dairy cows with no history of S. aureus mastitis. Proteins found to be reactive by Western blot were identified by mass spectrometry (MALDI/TOF-TOF). Our most important finding was that F0F1 ATP synthase subunit a, succinyl-diaminopimelate desuccinylase, and cysteinyl-tRNA synthetase were potential candidate proteins for the prevention of S. aureus mastitis. This study strengthens the notion that variations among animals should not be ignored and shows that the heterogeneity of antibody production against anti-staphylococcal antigens in animals may enable the identification of new immunotherapy targets.
- Orange-Emitting ZnSe:Mn2+ Quantum Dots as Nanoprobes for Macrophages(2020) KHAN, Zahid U.; UCHIYAMA, Mayara K.; KHAN, Latif U.; RAMOS-SANCHEZ, Eduardo M.; REIS, Luiza Campos; NAKAMURA, Marcelo; GOTO, Hiro; SOUZA, Ana O. De; ARAKI, Koiti; BRITO, Hermi F.; GIDLUND, MagnusThe biocompatibility, bionanointeraction, uptake efficiency, and entry pathway of luminescent nanomaterials are the key factors to understand development of an efficient bionanoprobe. The foremost objective of this work is to explore the potential of 3-mercaptopropionic acid (3-MPA) capped ZnSe:xMn(2+) (x = 5, 10, and 15 mol %) quantum dots (QDs) for the development of bionanoprobe used in future biological and clinical applications. For this purpose, highly intense orange-emitting activator Mn2+ ion doped ZnSe QDs were synthesized via a high-temperature organometallic method and rendered water-soluble by a ligand exchange approach. The morphological and physicochemical characterizations displayed the ultrasmall zinc-blend cubic crystal structure of QDs with an elliptical shape nanocrystals and average diameter of 4 nm. The luminescent nanomaterials exhibited orange emission centered at 584 nm under excitation at 385 nm. The biocompatibility, time-dependent cellular uptake, and the uptake mechanism of QDs were studied in RAW 264.7 macrophages, accomplished by various cytotoxicity assays, CytoViva hyperspectral enhanced dark-field and dual-mode fluorescence (DMF) microscopy, and transmission electron microscopy (TEM) images. The cytotoxicity study did not confirm any noticeable deleterious effect of QDs within incubation for 6 h. The fluorescence images of cells incubated with QDs showed efficient emission, which is a manifestation that QDs are photochemically stable in the intracellular environment. The cellular uptake findings demonstrated that the QDs were predominantly internalized via clathrin- and caveolae-mediated pathways. After the uptake, QDs aggregates appeared inside the vesicles in the cytoplasm, and their number and size gradually increased as a function of time. Nevertheless, the fluorescent QDs presented remarkable colloidal stability in various media, biocompatibility within the designated time, efficient time-dependent uptake, and distinct entry pathway in RAW macrophages, suggesting promising candidates to explore for the development of future bionanoprobes.