Navegando por Palavras-chave "Glycolipid"

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    Caracterização biofísica de vesículas catiônicas de dodab contendo C24:1 beta-glicosilceramida (βGlcCer)
    (Universidade Federal de São Paulo (UNIFESP), 2019-05-30) Martins, Leticia de Souza [UNIFESP]; Rozenfeld, Julio Henrique Kravcuks [UNIFESP]; http://lattes.cnpq.br/4232139220639334; http://lattes.cnpq.br/8580993475540515; Universidade Federal de São Paulo (UNIFESP)
    Objective: To characterize the structure of DODAB vesicles containing βGlcCer using differential scanning calorimetry (DSC), electron paramagnetic resonance (EPR) spectroscopy and fluorescence microscopy. Methods: Pure vesicles of DODAB, βGlcCer, and also mixed vesicles of DODAB plus βGlcCer were prepared from lipid films resulting from the evaporation of chloroform: methanol solutions. EPR, DSC and fluorescence microscopy experiments were performed using 5 mol%, 9 mol% and 16 mol% of βGlcCer in relation to the total lipid concentration. Results: It was shown that βGlcCer destabilized the gel phase of DODAB vesicles by decreasing the gel phase packing. Thus, βGlcCer induced a decrease in the phase transition temperature and cooperativity of DODAB vesicles, as seen in DSC thermograms. EPR spectra also showed that βGlcCer induced an increase in the order and / or rigidity of the DODAB fluid phase. Despite their different structures, a similar effect of loosening of the gel phase and stiffening of the fluid phase was observed when low cholesterol fractions were incorporated into the DODAB vesicles. Conclusion: βGlcCer is completely miscible with DODAB at all fractions tested, since no domains were observed by fluorescence microscopy or ESR spectra. Structural characterization of DODAB vesicles containing βGlcCer may be important for the development of novel immunotherapeutic tools such as vaccine adjuvants.
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    Co-administration of alpha-GalCer analog and TLR4 agonist induces robust CD8(+) T-cell responses to PyCS protein and WT-1 antigen and activates memory-like effector NKT cells
    (Academic Press Inc Elsevier Science, 2016) Coelho-dos-Reis, Jordana G.; Huang, Jing; Tsao, Tiffany; Pereira, Felipe V. [UNIFESP]; Funakoshi, Ryota; Nakajima, Hiroko; Sugiyama, Haruo; Tsuji, Moriya
    In the present study, the combined adjuvant effect of 7DW8-5, a potent alpha-GalCer-analog, and monophosphoryl lipid A (MPLA), a TLR4 agonist, on the induction of vaccine-induced CD8(+) T-cell responses and protective immunity was evaluated. Mice were immunized with peptides corresponding to the CD8+ T-cell epitopes of a malaria antigen, a circumsporozoite protein of Plasmodium yoelff, and a tumor antigen, a Wilms Tumor antigen-1 (WT-1), together with 7DW8-5 and MPLA, as an adjuvant. These immunization regimens were able to induce higher levels of CD8+ T-cell responses and, ultimately, enhanced levels of protection against malaria and tumor challenges compared to the levels induced by immunization with peptides mixed with 7DW8-5 or MPLA alone. Co-administration of 7DW8-5 and MPLA induces activation of memory-like effector natural killer T (NKT) cells, i.e. CD44(+) CD62L(-) NKT cells. Our study indicates that 7DW8-5 greatly enhances important synergistic pathways associated to memory immune responses when co-administered with MPLA, thus rendering this combination of adjuvants a novel vaccine adjuvant formulation. (C) 2016 Elsevier Inc. All rights reserved.
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    Tridimensional ultrastructure and glycolipid pattern studies of Trypanosoma dionisii
    (Elsevier B.V., 2013-12-01) Oliveira, Miriam Pires de Castro [UNIFESP]; Ramos, Thiago Cesar Prata [UNIFESP]; Pinheiro, Adriana Maria Viana Nunes [UNIFESP]; Bertini, Silvio [UNIFESP]; Takahashi, Helio Kiyoshi [UNIFESP]; Straus, Anita Hilda [UNIFESP]; Freymüller-Haapalainen, Edna [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Trypanosoma (Schizotrypanum) dionisii is a non-pathogenic bat trypanosome closely related to Trypanosoma cruzi, the etiological agent of Chaga's disease. Both kinetoplastids present similar morphological stages and are able to infect mammalian cells in culture. in the present study we examined 3D ultrastructure aspects of the two species by serial sectioning epimastigote and trypomastigote forms, and identified common carbohydrate epitopes expressed in T. dionisii, T. cruzi and Leishmania major. A major difference in 3D morphology was that T. dionisii epimastigote forms present larger multivesicular structures, restricted to the parasite posterior region. These structures could be related to T. cruzi reservosomes and are also rich in cruzipain, the major cysteine-proteinase of T. cruzi. We analyzed the reactivity of two monoclonal antibodies: MEST-1 directed to galactofuranose residues of glycolipids purified from Paracoccidioides brasiliensis, and BST-1 directed to glycolipids purified from T. cruzi epimastigotes. Both antibodies were reactive with T. dionisii epimastigotes by indirect immunofluorescense, but we noted differences in the location and intensity of the epitopes, when compared to T. cruzi. in summary, despite similar features in cellular structure and life cycle of T. dionisii and T. cruzi, we observed a unique morphological characteristic in T. dionisii that deserves to be explored. (C) 2013 Elsevier B.V. All rights reserved.