LUIZ FELIPE DOMINGUES PASSERO
Projetos de Pesquisa
Unidades Organizacionais
LIM/50 - Laboratório de Patologia das Moléstias Infecciosas, Hospital das Clínicas, Faculdade de Medicina
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
- Leishmania (V.) braziliensis and L. (L.) amazonensis promote differential expression of dendritic cells and cellular immune response in murine model(2012) CARVALHO, A. K.; SILVEIRA, F. T.; PASSERO, L. F. D.; GOMES, C. M. C.; CORBETT, C. E. P.; LAURENTI, M. D.The expression of Langerhans cell (LC) and dermal dendritic cell (dDC) as well as T CD4+ and CD8+ immune responses was evaluated in the skin of BALB/c mice experimentally infected by L. (L.) amazonensis (La) and L. (V.) braziliensis (Lb). At 4th and 8th weeks post infection (PI), skin biopsies were collected to determine the parasite load and CD207+, CD11c+, CD4+, CD8+, iNOS+ cellular densities. Cytokine (IFN-?, IL-4 and IL-10) profiles were also analysed in draining lymph node. At 4th week, the densities of CD207+ and CD11c+ were higher in the La infection, while in the Lb infection, these markers revealed a significant increase at 8th week. At 4th week, CD4+ and CD8+ were higher in the La infection, but at 8th week, there was a substantial increase in both markers in the Lb infection. iNOS+ was higher in the Lb infection at 4th and 8th weeks. In contrast, the parasite load was higher in the La infection at 4th and 8th weeks. The concentration of IFN-? was higher in the Lb infection, but IL-4 and IL-10 were higher in the La infection at 4th and 8th weeks. These results confirm the role of the Leishmania species in the BALB/c mice disease characterized by differences in the expression of dendritic cells and cellular immune response.
- Analysis of iron superoxide dismutase-encoding DNA vaccine on the evolution of the Leishmania amazonensis experimental infection(2015) CAMPOS, B. L. S.; SILVA, T. N.; RIBEIRO, S. P.; CARVALHO, K. I. L.; KALLAS, E. G.; LAURENTI, M. D.; PASSERO, L. F. D.The present work aimed to evaluate the immunogenicity of Leishmania amazonensis iron superoxide dismutase (SOD) -encoding DNA experimental vaccine and the protective properties of this DNA vaccine during infection. The SOD gene was subcloned into the pVAX1 plasmid, and it was used to immunize BALB/c mice. Twenty-one days after the last immunization, mice were sacrificed (immunogenicity studies) or subcutaneously challenged with L. amazonensis (studies of protection), and alterations in cellular and humoral immune responses were evaluated, as well as the course of infection. Mice only immunized with pVAX1-SOD presented increased frequencies of CD4(+) IFN-gamma(+), CD8(+) IFN- gamma(+) and CD8(+) IL-4(+) lymphocytes; moreover, high levels of IgG2a were detected. After challenge, mice that were immunized with pVAX1-SOD had increased frequencies of the CD4(+) IL- 4(+), CD8(+) IFN-gamma(+) and CD8(+) IL-4(+) T lymphocytes. In addition, the lymph node cells produced high amounts of IFN-gamma and IL-4 cytokines. Increased IgG2a was also detected. The pattern of immunity induced by pVAX1-SOD partially protected the BALB/c mice from a challenge with L. amazonensis, as the animals presented reduced parasitism and lesion size when compared to controls. Taken together, these results indicate that leishmanial SOD modulates the lymphocyte response, and that the elevation in IFN-gamma possibly accounted for the decreased skin parasitism observed in immunized animals.
- Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation(2012) PASSERO, Luiz Felipe D.; CARVALHO, Ana Kely; BORDON, Maria L. A. C.; BONFIM-MELO, Alexis; CARVALHO, Karina; KALLAS, Esper G.; SANTOS, Bianca B. A.; TOYAMA, Marcos H.; PAES-LEME, Adriana; CORBETT, Carlos E. P.; LAURENTI, Marcia D.Background: Leishmania (Viannia) shawi parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from L. (V.) shawi promastigotes were demonstrated using BALB/c mice, the susceptibility model for this parasite. In order to identify protective fractions, SLA was fractionated by reverse phase HPLC and five antigenic fractions were obtained. Methods: F1 fraction was purified from L. (V.) shawi parasite extract by reverse phase HPLC. BALB/c mice were immunized once a week for two consecutive weeks by subcutaneous routes in the rump, using 25 mu g of F1. After 1 and 16 weeks of last immunization, groups were challenged in the footpad with L. (V.) shawi promastigotes. After 2 months, those same mice were sacrificed and parasite burden, cellular and humoral immune responses were evaluated. Results: The F1 fraction induced a high degree of protection associated with an increase in IFN-gamma, a decrease in IL-4, increased cell proliferation and activation of CD8(+)T lymphocytes. Long-term protection was acquired in F1-immunized mice, associated with increased CD4(+) central memory T lymphocytes and activation of both CD4+ and CD8(+) T cells. In addition, F1-immunized groups showed an increase in IgG2a levels. Conclusions: The inductor capability of antigens to generate memory lymphocytes that can proliferate and secrete beneficial cytokines upon infection could be an important factor in the development of vaccine candidates against American Tegumentary Leishmaniasis.
- Anti-leishmanial effects of purified compounds from aerial parts of Baccharis uncinella C. DC. (Asteraceae)(2011) PASSERO, Luiz Felipe D.; BONFIM-MELO, Alexis; CORBETT, Carlos Eduardo P.; LAURENTI, Marcia D.; TOYAMA, Marcos H.; TOYAMA, Daniela O. de; ROMOFF, Paulete; FAVERO, Oriana A.; GRECCO, Simone S. dos; ZALEWSKY, Cynthia A.; LAGO, Joo Henrique G.Species of Baccharis exhibit antibiotic, antiseptic, wound-healing, and anti-protozoal properties, and have been used in the traditional medicine of South America for the treatment of several diseases. In the present work, the fractionation of EtOH extract from aerial parts of Baccharis uncinella indicated that the isolated compounds caffeic acid and pectolinaringenin showed inhibitory activity against Leishmania (L.) amazonensis and Leishmania (V.) braziliensis promastigotes, respectively. Moreover, amastigote forms of both species were highly sensible to the fraction composed by oleanolic + ursolic acids and pectolinaringenin. Caffeic acid also inhibited amastigote forms of L. (L.) amazonensis, but this effect was weak in L. (V.) braziliensis amastigotes. The treatment of infected macrophages with these compounds did not alter the levels of nitrates, indicating a direct effect of the compounds on amastigote stages. The results presented herein suggest that the active components from B. uncinella can be important to the design of new drugs against American tegumentar leishmaniases.
- Treatment with triterpenic fraction purified from Baccharis uncinella leaves inhibits Leishmania (Leishmania) amazonensis spreading and improves Th1 immune response in infected mice(2014) YAMAMOTO, Eduardo Seiji; CAMPOS, Bruno Luiz S.; LAURENTI, Marcia Dalastra; LAGO, Joao H. G.; GRECCO, Simone dos Santos; CORBETT, Carlos E. P.; PASSERO, Luiz Felipe D.The current medications used to treat leishmaniasis have many side effects for patients; in addition, some cases of the disease are refractory to treatment. Therefore, the search for new leishmanicidal compounds is indispensable. Recently, it was demonstrated that oleanolic- and ursolic-containing fraction from Baccharis uncinella leaves eliminated the promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and L. (Viannia) braziliensis without causing toxic effects for J774 macrophages. Thus, the aim of the present work was to characterize the therapeutic effect of the triterpenic fraction in L. (L.) amazonensis-infected BALB/c mice. Oleanolic- and ursolic acid-containing fraction was extracted from B. uncinella leaves using organic solvents and chromatographic procedures. L. (L.) amazonensis-infected BALB/c mice were treated intraperitoneally with triterpenic fraction during five consecutive days with 1.0 and 5.0 mg/kg of triterpenic fraction, or with 10.0 mg/kg of amphotericin B drug. Groups of mice treated with the triterpenic fraction, presented with decreased lesion size and low parasitism of the skin-both of which were associated with high amounts of interleukin-12 and interferon gamma. The curative effect of this fraction was similar to amphotericin B-treated mice; however, the final dose, required to eliminate amastigotes, was lesser than amphotericin B. Moreover, triterpenic fraction did not cause microscopic alterations in liver, spleen, heart, lung, and kidney of experimental groups. This work suggests that this fraction possesses compounds that are characterized by leishmanicidal and immunomodulatory activities. From this perspective, the triterpenic fraction can be explored as a new therapeutic agent for use against American Tegumentar Leishmaniasis.
- Differential modulation of macrophage response elicited by glycoinositolphospholipids and lipophosphoglycan from Leishmania (Viannia) shawi(2015) PASSERO, Luiz F. D.; ASSIS, Rafael R.; SILVA, Thays N. F. da; NOGUEIRA, Paula M.; MACEDO, Diego H.; PESSOA, Natalia L.; CAMPOS, Marco A.; LAURENTI, Marcia D.; SOARES, Rodrigo P.In this work, some aspects of the glycobiology of Leishmattia shawl were examined, as it is a causative agent of cutaneous leishmaniasis in the New World. Additionally, the interaction of L. shawl's main glycoconjugates [lipophosphoglycan (LPG) and glycoinositolphospholipids (GIPLs)] with macrophages was evaluated in vitro. L. shawl LPG was devoid of side-chains in its repeat units, whereas monosaccharide analysis showed that GIPLs were suggestive of mannose-rich (type I or hybrid). In order to evaluate the biological roles of those molecules, BALB/c resident peritoneal macrophages were incubated with these glycoconjugates for 24 h, and the levels of nitric oxide (NO), tumor necrosis factor (TNF)-alpha, interleukin (IL)-12p70 and IL-10, were determined. In general, the GIPLs exhibited a greater proinflammatory role than the LPGs did. However, for the first time, the GIPLs from this species were able to trigger the production of IL-10, an anti-inflammatory cytokine. In conclusion, L shawl glycoconjugates were able to interact with the innate immune compartment. These data reinforce the role of parasite glycoconjugates during parasite and host cell interactions.