RESUMO
AIMS: In this work, we aimed to evaluate the effects of the Leishmania infantum chagasi infection on the liver of vaccinated mice, considering parameters of tissue damage and the inflammatory response elicited by vaccination. MAIN METHODS: We used recombinant LPG3 protein (rLPG3) as immunogen in BALB/c mice before challenge with promastigote forms of L. infantum chagasi. The animals were separated into five groups: NI: non-infected animals; NV: non-vaccinated; SAP: treated with saponin; rLPG3: immunized with rLPG3; rLPG3 + SAP: immunized with rLPG3 plus SAP. The experiment was conducted in replicate, and the vaccination protocol consisted of three subcutaneous doses of rLPG3 (40 µg + two boosters of 20 µg). The mice were challenged two weeks after the last immunization. KEY FINDINGS: Our results showed that rLPG3 + SAP immunization decreased the parasite burden in 99 %, conferring immunological protection in the liver of the infected animals. Moreover, the immunization improved the antioxidant defenses, increasing CAT and GST activity, while reducing the levels of oxidative stress markers, such as H2O2 and NO3/NO2, and carbonyl protein in the organ. As a consequence, rLPG3 + SAP immunization preserved tissue integrity and reduced the granuloma formation, inflammatory infiltrate and serum levels of AST, ALT, and ALP. SIGNIFICANCE: Taken together, these results showed that rLPG3 vaccine confers liver protection against L. infantum chagasi in mice, while maintaining the liver tissue protected against the harmful inflammatory effects caused by the vaccine followed by the infection.
Assuntos
Glicoesfingolipídeos/imunologia , Leishmania infantum/imunologia , Leishmaniose/prevenção & controle , Leishmaniose/parasitologia , Hepatopatias Parasitárias/prevenção & controle , Hepatopatias Parasitárias/parasitologia , Vacinas Protozoárias/imunologia , Proteínas Recombinantes/imunologia , Animais , Anticorpos Antiprotozoários , Antioxidantes , Modelos Animais de Doenças , Imunização , Leishmaniose/patologia , Hepatopatias Parasitárias/patologia , Camundongos , Estresse Oxidativo , Carga Parasitária , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
La infección por Echinococcus sp. es hipoendémica en Venezuela. Sólo cuatro casos de hidatidosis autóctona por E. vogeli han sido reportados, tres de ellos en la región de la Guayana venezolana. En Febrero del año 2009 se realizó el diagnóstico clínico-sero-epidemiológico de hidatidosis poliquística en una paciente femenina de la etnia Yanomami, procedente de Parima B, Alto Orinoco, en la Amazonía venezolana. Se resolvió con tratamiento médico y quirúrgico por laparoscopia y se evidenció en el quiste la presencia de ganchos rostelares compatibles con E. vogeli. En Abril del 2009 en una segunda paciente Yanomami de igual procedencia, se le diagnosticó hidatidosis por E. vogeli siendo operada exitosamente por cirugía laparoscópica asistida por robot. Dos casos humanos en una misma población y la presencia de factores de riesgo como la tenencia de perros domésticos y la comunicación por informantes indígenas del hallazgo de quistes en hígados de animales de cacería (Cuniculus paca o lapa y Dasyprocta sp. o picure), hacen pensar en transmisión activa en la cuenca del Alto Orinoco y en zonas selváticas de la Guayana venezolana. El presente, es el primer registro de casos de hidatidosis poliquística en indígenas de la etnia Yanomami.
Infection by Echinococcus sp. is hypoendemic in Venezuela. Only four cases of autochthonous E. vogeli hydatidosis have been reported, including three in the Venezuelan region of Guayana. In February 2009, based on epidemiological data, signs and symptoms and serological tests, a female patient of the Yanomami ethnic group, was diagnosed with a polycystic hydatid disease in Parima B, Alto Orinoco, in the Venezuelan Amazon. Rostellar hooks compatible with E. vogeli were found in the cyst. It was resolved with medical and surgical treatment by laparoscopy. A second Yanomami patient from the same location was diagnosed with E. vogeli hydatidosis in April 2009, being successfully operated with robot-assisted laparoscopy. Two human cases in the same population and the presence of risk factors such as domestic dog ownership and findings of cysts in livers of hunted animals (such as Cuniculus and Dasyprocta sp.) reported by indigenous informants, suggest active transmission in the Upper Orinoco basin and forested areas of the Venezuelan Guayana. These are the first reported cases of polycystic hydatid disease of the Yanomami ethnic group.
Assuntos
Humanos , Feminino , Equinococose Hepática/diagnóstico , Equinococose Hepática/epidemiologia , Equinococose Hepática/etnologia , Equinococose Hepática/parasitologia , Equinococose Hepática/prevenção & controle , Equinococose/diagnóstico , Equinococose/epidemiologia , Equinococose/etnologia , Equinococose/parasitologia , Equinococose/transmissão , Hepatopatias Parasitárias/diagnóstico , Hepatopatias Parasitárias/epidemiologia , Hepatopatias Parasitárias/etnologia , Hepatopatias Parasitárias/parasitologia , Hepatopatias Parasitárias/patologia , Hepatopatias Parasitárias/prevenção & controle , VenezuelaRESUMO
A Schistosoma mansoni adult worm cDNA expression library was screened using rabbit IgG against PIII, an adult worm protein fraction, already known to possess protective and immunomodulating effects to a challenge infection in mice. A positive cDNA clone was selected and characterized. The cDNA screened encodes a protein (P44) with an ORF of 1089 bp and an amino acid sequence of 363 residues with a predictable molecular weight of 44 kDa. The P44 amino acid sequence exhibits 100% identity to the fructose 1,6 bisphosphate aldolase of S. mansoni, 66% to Homo sapiens and 66% to Mus musculus. The cDNA was cloned into a pGEX-4T-3 vector and expressed in Escherichia coli as a fusion protein (GST/P44). Mice vaccinated with recombinant P44 were able to develop high levels of IgG or IgG1 and displayed low levels of IgG2a isotype. Moreover, immunization of mice with this antigen induced a significant protection of 57% against a challenge infection and significant decrease in hepatic granuloma formation. Our results demonstrate that granuloma modulation can be targeted for pathology elimination through vaccination. This represents an advance in schistosome vaccinology and allows for the development of a therapeutic as well as a prophylactic vaccine.
Assuntos
Antígenos de Helmintos/imunologia , Frutose-Bifosfato Aldolase/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/genética , Antígenos de Helmintos/uso terapêutico , Escherichia coli , Feminino , Frutose-Bifosfato Aldolase/genética , Frutose-Bifosfato Aldolase/uso terapêutico , Biblioteca Gênica , Vetores Genéticos , Granuloma/sangue , Granuloma/imunologia , Granuloma/parasitologia , Granuloma/prevenção & controle , Humanos , Hepatopatias Parasitárias/sangue , Hepatopatias Parasitárias/imunologia , Hepatopatias Parasitárias/parasitologia , Hepatopatias Parasitárias/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Esquistossomose mansoni/prevenção & controle , Alinhamento de Sequência , Análise de Sequência de Proteína , VacinasRESUMO
This study was performed in order to define Schistosoma mansoni antigens that are able to function as modulator agents in the granulomatous hypersensitivity to parasite eggs in BALB/c and C57BL/6 mice. A fraction of S. mansoni, designated PIII, derived from adult worm antigen preparation (SWAP) was obtained using anion-exchange chromatography on an FPLC system. Immunization of mice with PIII in the presence of Corynebacterium parvum and Al(OH)3 as adjuvant induced an immune response in this animals as determined by ELISA and spleen cell proliferation assays against S. mansoni antigens SEA, SWAP and PIII. In addition, PIII caused a significant degree of protection against a challenge infection in immunized mice as observed by the decrease on worm burden recovered from the portal system. We also showed that PIII profoundly inhibited the vigorous anamnestic granulomatous response to eggs in the liver and lungs. This suppression correlated with a significant decrease in granuloma size. From these results we conclude that the PIII preparation contains antigens that can mediate protective anti-parasite immunity and downregulate granulomatous hypersensitivity to S. mansoni eggs.