RESUMO
To evaluate the prevalence of toxocariasis in children in Jaboatão dos Guararapes, Pernambuco in northeastern Brazil, 215 serum samples were examined by an enzyme-linked immunosorbent assay (ELISA) using a recombinant Toxocara canis antigen. In the ELISA, 26 (12.1%) of 215 subjects were positive. In a dot-blot assay using 53 of 215 serum samples, the diagnostic results correlated with those obtained by the ELISA. Moreover, it has been confirmed that the recombinant T. canis antigen was highly specific for toxocariasis by ELISA using serum samples positive for antibody to Ascaris lumbricoides. Considering the specificity of the recombinant antigen to toxocariasis, the ELISA or dot-blot assay using the recombinant T. canis antigen is recommended in tropical and sub-tropical regions where various parasitic infections are commonly endemic.
Assuntos
Antígenos de Helmintos/imunologia , Toxocara canis/imunologia , Toxocaríase/diagnóstico , Animais , Antígenos de Helmintos/genética , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Prevalência , Proteínas Recombinantes/imunologia , Testes Sorológicos , Sorologia , Toxocaríase/parasitologiaRESUMO
The ICOS-B7RP-1-mediated T cell costimulatory pathway has been implicated crucial for T cell activation and differentiation. In this study, we investigated the role of this costimulation in the regulation of immune responses to parasitic infections by using blocking antibody against B7RP-1 as well as ICOS-deficient mice. The administration of anti-B7RP-1 monoclonal antibody (mAb) significantly suppressed the footpad swelling in susceptible BALB/c mice upon Leishmania major infection. The observation was consistent not only with the significant suppression of IL-4, IL-5 and IL-10 secretion from lymph node cells, which were derived from L. major-infected mice, but also with the significant reduction of total serum IgE and IgG(1) in anti-B7RP-1 mAb-treated BALB/c mice. Infection of ICOS-deficient mice with L. major also suggested the impaired Th2 immune responses in the absence of this costimulation. The immunological function of ICOS-B7RP-1 costimulatory pathway in infection was further confirmed by infecting anti-B7RP-1 mAb-treated wild type or ICOS-deficient mice with Nippostrongylus brasiliensis. The characteristic elevation of total serum IgE and eosinophilia upon N. brasiliensis infection was suppressed by blocking this costimulation. Moreover, the protection to N. brasiliensis adult worms was suppressed in anti-B7RP-1 mAb-treated wild type or ICOS-deficient mice. These results suggest the crucial role of this costimulatory pathway in the regulation of Th2-biased T cell differentiation and in host immune responses against L. major and N. brasiliensis infections.
Assuntos
Antígenos de Diferenciação de Linfócitos T/fisiologia , Antígeno B7-1/fisiologia , Sistema Imunitário/fisiologia , Leishmaniose Cutânea/imunologia , Infecções por Strongylida/imunologia , Animais , Antígenos de Diferenciação de Linfócitos T/imunologia , Antígeno B7-1/imunologia , Sistema Imunitário/imunologia , Ligante Coestimulador de Linfócitos T Induzíveis , Proteína Coestimuladora de Linfócitos T Induzíveis , Leishmania major/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Nippostrongylus/imunologia , Células Th2/imunologia , Células Th2/fisiologiaRESUMO
Complex II (Succinate-ubiquinone oxidoreductase) is an importnat enzyme complex for the tricarboxylic acid cycle and the aerobic respiratory chain of motochondria and procaryotic organisms (12, 24). Complex II catalyzes the oxidation of succinate to fumarate (Succinate dehydrogenase: sdh) and transfers its reducing equivalent to ubiquinone in the aerobic respiration