Fig. 3.

Phenotype of MPs induced by Tc infection and chronic Chagas disease. a, b MPs were harvested from in vitro infected human PBMCs (as in Fig. 1, 2). Plasma samples from seropositive chagasic subjects categorized as CA and CS, and NH controls (n = 10 per group) were centrifuged (Materials and Methods) and MPs were harvested. Human MPs were labeled with fluorescence-conjugated antibodies against human molecules and analyzed by flow cytometry. The frequency of surface markers of various cellular origin on MPs isolated from control and Tc-infected PBMCs (a) and chagasic subjects (b) are shown. c C57BL/6 mice were challenged with Tc (10,000 parasites/mouse, n = 5 mice/group/experiment, 2 experiments), and plasma MPs were collected at day 120 after infection, corresponding to the chronic disease phase. The MPs were labeled with fluorescence-conjugated antibodies against mouse molecules and analyzed by flow cytometry. Bar graphs (mean ± SEM) show the percent frequency of surface markers of various cellular origin on MPs isolated from media of Tc-infected PBMCs or the plasma of chronically infected human patients and experimental mice. Significance (* p < 0.05) is plotted with respect to normal controls.