Fig. 4

TNF fuels parasite growth and egression of trypomastigote forms from astrocytes. a C57BL/6 primary astrocyte cultures were treated with rTNF 2 h before T. cruzi infection, and cultures were analyzed after 8, 24, and 48 h of infection. The numbers of parasites per 100 cells and percentage of infected cells are shown. Estimation of the variation rate of parasite growth A-B-C (0.62), B-D-E (0.71), and F-G-H (1.80). b Astrocytes were treated with rTNF (1 ng/mL): prior to infection and removed after (pre), prior to and after infection (pre/post), or only after infection (post). The numbers of intracellular forms of the parasite per 100 astrocytes and trypomastigote forms present in the supernatants are shown. Data are presented as the means ± SEM of triplicates. ^* p < 0.05; ^** p < 0.01; ^*** p < 0.001 untreated (NT) controls vs. rTNF treatment under the distinct experimental conditions