Efeitos in vivo e in vitro da lectina de Synadenium carinatum sobre a infecção murina por Leishmania (Leishmania) amazonensis

by Afonso Cardoso, Sandra Regina

Abstract (Summary)
Introduction: Leishmaniasis are illnesses caused by protozoan of the genus Leishmania,intracellular parasites of macrophages, that appears under diverse clinical forms. Thecellular immune response is the effective protective response against these intracellularparasites. Lectins are capable to induce the production, by murine mononuclear cells, ofinterferon gamma (IFN - ? ), IL-12 and TNF-?, important molecules in an immune responsefor a Th1 profile, required to control this parasitism.Objectives: To analyze the biological effect of the latex lectin of the Synadeniumcarinatum (ScLL), associate or not to the soluble Leishmania antigen (SLA), on the murineinfection by L. (L.) amazonensis, evaluating its immunostimulating profile in cutaneouslesions and in infected macrophages.Materials and Methods: To evaluate the adjuvant potential of ScLL, groups of five micehad been immunized with different concentrations of this lectin associated or not to SLA.The infection of these animals was monitored weekly by measuring the infected paw during10 weeks, when were evaluated the cellular and humoral immune responses through DTHand ELISA, respectively, as well as the expression of the IFN-?, IL-4, IL-12, TNF-? andiNOS cytokines in the place of the lesion. The immunostimulating effect of ScLL wasevaluated in culture of murine peritoneal macrophages stimulated with this lectin after 24,48 and 72 hours of infection by L (L.) amazonensis, when the culture supernatants wereharvested for the determination of NO and IL-12 production. The genic expression ofcytokines as IL-1?, IL-12, TNF- ? and iNOS and the intracellular parasitic load wereanalyzed 24, 48 and 72 hours after infection.Results: The ScLL lectin, in the concentration of 10 ?g/ml was capable to stimulate theexpression of IL-1?, TNF-? and iNOS cytokines, in vitro, as well as reducing in asignificant way, the proliferation of parasites in the interior of macrophages. In vivo, thislectin was capable to protect the immunized mice partially, controlling the development ofthe lesion and inducing the expression of IFN-?, IL-12, TNF-? and iNOS cytokines. Highlevels of IgG2a and low levels of IgG1 were detected in the serum of the immunizedanimals, being correlated with the control of the infection.Conclusions: The ScLL lectin conferred partial protection to the animals immunized afterchallenge with L. (L.) amazonensis, inducing a profile of immune response capable tocontrol the parasitism in vivo e in vitro. Jointly, the data obtained with ScLL suggests that itcan be used as adjuvant in experimental models of vaccination against L. (L.) amazonensis.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Maria Aparecida de Souza; Jose Fernando de Castro Figueiredo; Maria Inês Machado; Reynaldo Dietze; Marcelo Simão Ferreira

School:Universidade Federal de Uberlândia

School Location:Brazil

Source Type:Master's Thesis

Keywords:L. (L.) amazonensis Synadenium carinatum Lectina Leishmania Lectin Adjuvant Murine infection


Date of Publication:05/09/2006

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