Fig 2. Inhibition of T. cruzi G strain MT internalization and host cell lysosome spreading by purified G-MUC.

(A) HeLa cells were incubated for 1 h with MT of G or CL strain, in absence or in the presence of mucins purified from G strain (G-MUC) or CL strain (CL-MUC), and the number of intracellular parasites was quantified. Values are the means ± four independent assays. Note the significant decrease in G strain MT invasion in the presence of G-MUC (*P<0.001). (B) HeLa cells, grown in ELISA microtiter plates, were fixed and incubated for 1 h with MUC-G or MUC-CL at the indicated concentrations. Binding of mucin was revealed by mAb 2B10. The assay was performed in triplicates. (C) HeLa cells were incubated for 30 min with G strain or CL strain MT and processed for immunofluorescence analysis for detection of actin (red), nucleus (blue) and mucin (green). Confocal microscopy visualization, under 63x objective, showed thick F-actin filaments in cells incubated with G strain and overall disruption of F-actin in cells incubated with CL strain. Arrows indicate the site of MT entry with disrupted cortical actin. Scale bar = 10 μm. (D) HeLa cells were incubated for 30 min in absence or in the presence of MUC-G and processed for detection of actin (red), nucleus (blue) and lysosome (green). Thick actin bundles were observed in cells incubated with MUC-G. Scale bar = 20 μm.