Interstitial dendritic cells of the heart harbor Trypanosoma cruzi antigens in experimentally infected dogs: Importance for the pathogenesis of chagasic myocarditis

Heart sections from 16 mongrel dogs, two normal controls and 14 infected wi th Trypanosoma cruzi, were submitted to immunohistochemical staining with e ither rabbit anti-cow S100 Protein monoclonal antibody or rabbit anti-ir. c ruzi purified specific antibody, using the peroxidase technique to investig ate: the participation of the interstitial dendritic cells of the heart (ID Cs) in myocarditis of Chagas disease. Trypanosoma cruzi antigens were revea led as granular and dense deposits in LDC membrane in the heart of infected dogs both during acute and chronic myocarditis, but not in normal controls . Anti-S100 Protein labeled the IDCs, both in normal and infected dogs and a significant increase in the numbers of IDCs occurred in the myocardium, p roportionally to the intensity of the inflammatory infiltration. These find ings suggest that IDCs, probably by presenting T. cruzi antigens to immune- competent cells, play an important role in the pathogenesis of Chagas disea se.