CHRISTIANE YUMI OZAKI
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Neurologia, Faculdade de Medicina
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina
4 resultados
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- Pleiotropic Effect of Hormone Insulin-Like Growth Factor-I in Immune Response and Pathogenesis in Leishmaniases(2021) REIS, Luiza C.; RAMOS-SANCHEZ, Eduardo Milton; ARAUJO, Fernanda N.; LEAL, Ariane F.; OZAKI, Christiane Y.; SEVILLANO, Orlando R.; USCATA, Bernardina A.; GOTO, HiroLeishmaniases are diseases caused by several Leishmania species, and many factors contribute to the development of the infection. Because the adaptive immune response does not fully explain the outcome of Leishmania infection and considering that the initial events are crucial in the establishment of the infection, we investigated one of the growth factors, the insulin-like growth factor-I (IGF-I), found in circulation and produced by different cells including macrophages and present in the skin where the parasite is inoculated. Here, we review the role of IGF-I in leishmaniasis experimental models and human patients. IGF-I induces the growth of different Leishmania species in vitro and alters the disease outcome increasing the parasite load and lesion size, especially in L. major- and L. amazonensis-infected mouse leishmaniasis. IGF-I affects the parasite interacting with the IGF-I receptor present on Leishmania. During Leishmania-macrophage interaction, IGF-I acts on the arginine metabolic pathway, resulting in polyamine production both in macrophages and Leishmania. IGF-I and cytokines interact with reciprocal influences on their expression. IL-4 is a hallmark of susceptibility to L. major in murine leishmaniasis, but we observed that IGF-I operates astoundingly as an effector element of the IL-4. Approaching human leishmaniasis, patients with mucosal, disseminated, and visceral diseases presented surprisingly low IGF-I serum levels, suggesting diverse effects than parasite growth. We observed that low IGF-I levels might contribute to the inflammatory response persistence and delayed lesion healing in human cutaneous leishmaniasis and the anemia development in visceral leishmaniasis. We must highlight the complexity of infection revealed depending on the Leishmania species and the parasite's developmental stages. Because IGF-I exerts pleiotropic effects on the biology of interaction and disease pathogenesis, IGF-I turns up as an attractive tool to explore biological and pathogenic processes underlying infection development. IGF-I pleiotropic effects open further the possibility of approaching IGF-I as a therapeutical target.
conferenceObject CHOLESTEROL ESTER TRANSFER PROTEIN (CETP) EXPRESSION IN MICE PROMOTES CONTROL OF EXPERIMENTAL CUTANEOUS LEISHMANIASIS(2021) OZAKI, C. Y.; DANTAS, F. E.; SANTANA, K. G.; TAFURI, W.; SOTTO, M. N.; GOTO, H.; CAZITA, P. M.- Different Assay Conditions for Detecting the Production and Release of Heat-Labile and Heat-Stable Toxins in Enterotoxigenic Escherichia coli Isolates(2013) ROCHA, Leticia B.; OZAKI, Christiane Y.; HORTON, Denise S. P. Q.; MENEZES, Caroline A.; SILVA, Anderson; FERNANDES, Irene; MAGNOLI, Fabio C.; VAZ, Tania M. I.; GUTH, Beatriz E. C.; PIAZZA, Roxane M. F.Enterotoxigenic Escherichia coli (ETEC) produce heat-labile (LT) and/or heat-stable enterotoxins (ST). Despite that, the mechanism of action of both toxins are well known, there is great controversy in the literature concerning the in vitro production and release of LT and, for ST, no major concerns have been discussed. Furthermore, the majority of published papers describe the use of only one or a few ETEC isolates to define the production and release of these toxins, which hinders the detection of ETEC by phenotypic approaches. Thus, the present study was undertaken to obtain a better understanding of ST and LT toxin production and release under laboratory conditions. Accordingly, a collection of 90 LT-, ST-, and ST/LT-producing ETEC isolates was used to determine a protocol for toxin production and release aimed at ETEC detection. For this, we used previously raised anti-LT antibodies and the anti-ST monoclonal and polyclonal antibodies described herein. The presence of bile salts and the use of certain antibiotics improved ETEC toxin production/release. Triton X-100, as chemical treatment, proved to be an alternative method for toxin release. Consequently, a common protocol that can increase the production and release of LT and ST toxins could facilitate and enhance the sensitivity of diagnostic tests for ETEC using the raised and described antibodies in the present work.
- Recombinant PilS: Cloning, Expression and Biochemical Characterization of a Pil-Fimbriae Subunit(2022) MUNHOZ, Danielle D.; SILVA, Jessika C. A.; FREITAS, Natalia C.; IWAI, Leo K.; AIRES, Karina A.; OZAKI, Christiane Y.; SOUZA, Cristiane S.; ROCHA, Leticia B.; SILVA, Miriam A.; HENRIQUE, Izabella M.; ELIAS, Waldir P.; CARVALHO, Eneas; MORGANTI, Ligia; CHURA-CHAMBI, Rosa M.; PIAZZA, Roxane M. F.Pil-fimbriae is a type IV pili member, which is a remarkably versatile component with a wide variety of functions, including motility, attachment to different surfaces, electrical conductance, DNA acquisition, and secretion of a broad range of structurally distinct protein substrates. Despite the previous functional characterization of Pil, more studies are required to understand the regulation of Pil expression and production, since the exact mechanisms involved in these steps are still unknown. Therefore it is extremely important to have a protein with the correct secondary and tertiary structure that will enable an accurate characterization and a specific antisera generation. For this reason, the aim of this work was to generate potential tools for further investigations to comprehend the mechanisms involved in Pil regulation and its role in pathogenic E. coli infections with the obtaining of a precise native-like recombinant PilS and the corresponding antisera. The pilS gene was successfully cloned into an expression vector, and recombinant PilS (rPilS) was efficiently solubilized and purified by metal affinity chromatography. Protein characterization analyses indicated that rPilS presented native-like secondary and tertiary structures after the refolding process. The generated anti-rPilS sera efficiently recognized recombinant and native proteins from atypical enteropathogenic E. coli strains.