Fig. 6

Two signals induce Tnfr1 mRNA expression, and PTX inhibits rTNF-induced astrocyte invasion by Trypanosoma cruzi. a Astrocytes were pre-treated with rTNF (1 ng/mL) and infected (MOI 1:1), and supernatants were collected after 4 and 24 h of infection and analyzed for TNF by CBA. b Tnfr1 transcription was detected by RT-qPCR in astrocyte cultures pre-treated with rTNF (1 ng/mL), infected (MOI 1:1) and analyzed 4 h postinfection. ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001 untreated (−)/non-infected (NI) vs. other conditions. ^### p < 0.001 non-infected (NI) vs. T. cruzi-infected. c Experimental scheme showing that C57BL/6 primary astrocyte cultures were pre-treated with PTX (addition 30 min before rTNF; 10, 30, 100 μg/mL), treated with rTNF (1 ng/mL), and infected with T. cruzi. After 4 h of infection, the numbers of parasites per 100 cells and the frequency of infected cells were analyzed. Data are presented as the means ± SEM of triplicates. ^* p < 0.05 untreated (−/−) vs. other conditions. ^# p < 0.05, ^## p < 0.01 rTNF-treated vs. PTX-treated, rTNF-treated infected astrocytes