Improved outcome of Trypanosoma cruzi infection in rats following treatment in early life with suspensions of heat-killed environmental Actinomycetales

FONTANELLA GH, PASCUTTI MF, DAURELIO L, PEREZ AR, NOCITO AL, WOJDYLA D, BOTTASSO O, REVELLI SILVIA, STANFORD JL.

VACCINE

Elsevier

Año: 2007 vol. 25 p. 3492 - 3500

0264-410X

The well-established model of Chagas’ disease in “l” rats was used to evaluate the effects of three injections of heat-killed Gordonia bronchialis, Rhodococcus coprophilus or saline on Trypanosoma cruzi parasitaemia and acute and chronic myocarditis, sequelae of the infection. Two vaccinating injections were given prior to challenge with T. cruzi, and the third, immunotherapeutic, injection was given seven days after challenge. Treatment with either actinomycete significantly reduced acute parasitaemia (p<0.04), modified cellular infiltration during acute myocarditis and limited chronic myocarditis (p<0.03) in comparison with the saline-treated control animals. Immunological investigations showed that both bacterial preparations achieved their results through different mechanisms. The relevance of our findings to human Chagas’ disease is discussed.