RESUMEN
Viable metacyclic forms of T. cruzi, Y strain, treated with an adequate dose of actinomycin D (50 micrograms Act-D/ml/10(7) parasites/ml for 72 h at 28 degrees C) showed the following properties: 1) they lost their ability to replicate in culture medium, in blood and in tissues of normal mice and were no longer able to incorporate tritiated thymidine; 2) they could not penetrate into Vero cells and could not replicate inside normal macrophages; 3) they retained their immunogenicity and the ability to protect mice against a virulent infection; 4) they did not induce histological lesions as described in chronic experimental Chagas' disease.
Asunto(s)
Antiprotozoarios , Enfermedad de Chagas/fisiopatología , Dactinomicina/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Replicación del ADN/efectos de los fármacos , Femenino , Macrófagos/parasitología , Ratones , Ratones Endogámicos BALB C , Trypanosoma cruzi/patogenicidad , Trypanosoma cruzi/fisiología , Células VeroRESUMEN
The subcutaneous (s.c.) vaccination of DBA/2 mice with 4 weekly doses of 3 x 10(7) living metacyclic forms of T. cruzi, Y strain, obtained from culture in axenic medium and treated for 24 h with actinomycin-D (50 micrograms/10(7) parasites), a drug that promotes an irreversible blockade of the parasite replication, do not induce any detectable degree of humoral and cellular immunosuppression as assessed by a) the production of anti-SRBC antibodies, b) the permanence of delayed cutaneous reaction to T. cruzi antigen, to PPD and DNCB and c) the degree of blastogenic transformation of spleen lymphocytes in the presence of the specific antigen.
Asunto(s)
Dactinomicina/farmacología , Tolerancia Inmunológica/inmunología , Trypanosoma cruzi/inmunología , Vacunación , Animales , Formación de Anticuerpos , Antígenos de Protozoos/inmunología , Femenino , Técnica de Placa Hemolítica , Hipersensibilidad Tardía , Inmunidad Celular , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos DBARESUMEN
O BCG, em soluçäo lipídica, injetado por via intravenosa, foi capaz de reverter a imunosupressäo humoral provocada pelo mastocitoma P-815, em camundongos singênicos DBA/2, aumentando tanto o número de células formadoras de placas hemolíticas quanto os títulos de anticorpos hemaglutinantes do soro. Näo foram encontradas diferenças significativas nos títulos de anticorpos hemaglutinantes da classe IgG. Nenhum efeito bloqueador pôde ser notado na progressäo normal do tumor
Asunto(s)
Ratones , Animales , Femenino , Formación de Anticuerpos , Inmunoglobulina G , Sarcoma de Mastocitos/inmunología , Mycobacterium bovis , Técnica de Placa Hemolítica , Ratones Endogámicos DBARESUMEN
Viable BCG bacilli, in a lipid emulsion, inoculated intravenously, were capable of reverting the profound humoral immunosuppression induced in adult DBA/2 mice by the mastocytoma P-815. BCG increased not only the number of hemolytic plaque forming cells, but also the serum titers of hemagglutinating IgM antibodies. However, no blocking effect was detected on normal tumor progression.
Asunto(s)
Inmunoglobulina M/metabolismo , Sarcoma de Mastocitos/inmunología , Mycobacterium bovis/inmunología , Animales , Formación de Anticuerpos , Femenino , Técnica de Placa Hemolítica , Ratones , Ratones Endogámicos DBAAsunto(s)
Recién Nacido , Humanos , Masculino , Femenino , Formación de Anticuerpos , Vacuna BCG , Inmunidad CelularAsunto(s)
Lactante , Preescolar , Humanos , Masculino , Femenino , Formación de Anticuerpos , Vacuna BCG , Inmunidad CelularRESUMEN
Studies were carried out with the leukocyte migration inhibition tests using soluble and particulate antigens (PPD, somatic antigens of T. cruzi, M. bovis (BCG) and leukocytes from patients sensitized to PPD and patients with chronic Chagas' disease. The results obtained showed that the stimulatory capacity of particulate antigens are greater than that of soluble antigens.
Asunto(s)
Leucocitos/inmunología , Factores Inhibidores de la Migración de Macrófagos , Linfocitos T/inmunología , Antígenos , Humanos , Mycobacterium bovis/inmunología , Mycobacterium tuberculosis/inmunología , Trypanosoma cruzi/inmunologíaRESUMEN
The humoral and cellular immunity of 23 children with ages between 1 and 5 years, nonreactors to 10 mu of PPD, were investigated after oral vaccination with one dose of 100 mg of fresh oral BCG, Rio de Janeiro strain (Moreau strain). The tests performed shortly before and 70 days after vaccination showed that the schedule used was neither sufficient to stimulate the production of antibody anti-PPD, nor to change the levels of serum immunoglobulins and T, T-active and B blood lymphocytes. However, about 60% of the children became responsive to 10 mu of PPD after treatment and all gave positive reactions to PPD on "in vitro" assays of leukocyte migration inhibition. New schedules for oral vaccination with fresh BCG are in progress in our laboratory.