HSP70 and HSP90 Differentially Regulate Translocation of Extracellular Antigen to the Cytosol for Cross-Presentation
Figure 4
Translocation of fixed-OVA to the cytosol is less efficient than native OVA. 0.5 mg/mL AF647-labeled native OVA (a) and fixed OVA (b) were pulsed onto PKH67-labeled DC2.4 cells for 5 minutes, washed, and subjected to ImageStream analysis. The relative frequency of cells in R5 of native and fixed OVA, thus, internalization (+)/colocalization (−), was 12.6% and 8.9%, respectively. (c) AF647-labeled native or fixed-OVA was pulsed onto PKH67-labeled DC2.4 cells for 5 minutes, washed and subjected to fluorescence microscopy analysis. (d) The same experiments were done as in (a), except that DC2.4 cells were treated with or without Endo-Porter as indicated. The percentage of cells in R5 of native and fixed-OVA were plotted as a bar graph. Note: DC2.4 cells used in ((a)–(c)) were pretreated with 10 M MG115 15 minutes prior to and during incubation with OVA in order to prevent proteasome activity. Data are mean ± SD of two separate experiments. **.
