ABSTRACT
The humoral and cellular immune responses as well as the resistance to infection with bloodstream forms of T. cruzi were studied in mice immunized with acidic antigenic fractions from parasite cytosol, F III and F IV, plus Bordetella pertussis as adjuvant. The immunization with F III induced positive ITH and DTH responses to homologous antigens. In mice immunized with F IV, the ITH was negative and four out of six animals presented positive DTH reactions. In both groups of mice the analysis of IgG against T. cruzi showed that the major isotype elicited was IgG1. Specific IgE was also detected in sera from F III immunized mice, thus confirming the presence of homocytotropic antibodies. The parasitemias reached by F III and F IV immunized mice after challenge were lower than those of the controls showing in this way a partial protection against the acute infection. The histological studies of heart and skeletal muscle performed two months after the infection revealed variable mononuclear infiltration in all infected mice despite immunization
Subject(s)
Animals , Antigen-Antibody Reactions/immunology , Antigens, Protozoan/immunology , Cytosol/immunology , Immunization , Trypanosoma cruzi/immunology , Antibodies, Protozoan/blood , Chagas Disease/immunology , Chagas Disease/parasitology , Chagas Disease/pathology , Hypersensitivity, Delayed/immunology , Hypersensitivity, Delayed/parasitology , Hypersensitivity, Delayed/pathology , Hypersensitivity, Immediate/immunology , Hypersensitivity, Immediate/pathologyABSTRACT
Foi realizado o estudo histológico do material obtido nas biópsias do local de inoculaçäo do antígeno para teste de Montenegro (T.M.) nos seguintes grupos de indivíduos: I) Seis pacientes com leismaniose cutânea comprovados parasitologicamente, com Montenegro positivo; II) Cinco indivíduos normias, näo residentes em zona endêmica, com Montenegro negativo; III) Nove soldados participantes de ensaios clínicos com vacina anti-LTA - MAYRINK e cols. 1979 e que tiveram o TM positivo 35 dias após vacinaçäo. IV) Um último grupo constituído de quatro soldados, também participantes de ensaio clínico com a mesma vacina acima, dois vacinados que näo mostraram TM positivo 35 días após vacinaçäo dois que receberam placebo. As biópsias foram realizadas 48 horas após a inoculaçäo do antígeno. O material foi fixado em formol à 10% (pH 7.2). Histologicamente, excetivando o grupo II (controle negativo), os grupos I-III-IV mostraram diferenças quantitativas no infiltrado mononuclear. Os quadros histológicos de cada grupo säo descritos e discutidos