FIG. 1.

A/J mice infected with T. cruzi or immunized with cardiac myosin develop severe myocarditis. A/J mice were infected with 10⁴ T. cruzi trypomastigotes (infected) or immunized with 300 μg of myosin in CFA (immunized). Control mice were injected with PBS (uninfected) or immunized with CFA-PBS (unimmunized). At 21 d.p.i., cardiac sections from these mice were stained with hematoxylin and eosin. All infected (n = 5) and immunized (n = 5) mice developed severe myocarditis, with myocyte necrosis and mononuclear cellular infiltration. No myocarditis was observed in uninfected (n = 5) or unimmunized mice (n = 5). Arrowhead indicates the pseudocyst magnified in the inset. Bars, 50 μm.