Killing in vitro of Trypanosoma cruzi by macrophages from mice immunized with T. cruzi or BCG, and absence of cross immunity on challenge in vivo

Abstract

Peritoneal macrophages from T. cruzi immune mice were resistant to infection in vitro with culture forms of the parasite. Macrophage resistance appeared in infected mice about 21 days postinfection when parasitemia was still rising. Resistance in vitro was nonspecific since macrophages from BCG immune mice were resistant to T. cruzi, and since macrophages from T. cruzi immune mice were resistant to infection in vitro with Listeria. Despite the findings in vitro, mice immunized with BCG or Listeria were not resistant to challenge with T. cruzi even when the parasites were opsonized.