We aim at investigating the role of blood born macrophages on the brain reaction to Trypanosoma cruzi infection in suckling rats. This infection provoked the appearance of numerous ED1(+) cells in the neural parenchyma and increased the amount of meningeal and perivascular ED2(+) macrophages. CD8(+) and NKR(+) cells also occurred. Parenchymal blood vessels showed strong ICAM-1 and decreased occludin immunoreactivities. Selective depletion of peripheral macrophages by clodronate liposomes decreased tissue parasitism, nodular lesions, ICAM-1 upregulation and leukocyte infiltration. Occludin immunoreactivity remained as in uninfected animals. Our results indicate a role for blood-born macrophages in both parasite invasion and brain reaction. Microglia activation cannot be discarded.
Analgesics, Non-Narcotic Animals