Figure 4.

T. gondii blocks IFN-γ-induced MHC class II expression irrespective of inhibition of DNA methyltransferases. RAW264.7 cells were treated with 5-aza-2-deoxycytidine (AZA) for 7 days, before being infected with T. gondii and/or activated with IFN-γ. Surface expression of MHC class II was determined at ~42 h p.i. by flow cytometry, after fluorescence staining of cells using H2-A/E-specific antibodies (A,B) or isotype control antibodies (C). (A) Representative histograms of mock- and AZA-treated cells being left non-activated, non-infected (red), IFN-γ-activated (black), or T. gondii-infected and IFN-γ-activated (green); figures within the plots indicate mean fluorescence intensities of the respective cell population. (B,C) Bars represent mean fluorescence intensities ± S.E.M. from five biological replicates; significant differences between groups were identified by ANOVA (*p < 0.05).