Fig. 4.

Human mo-DCs and mo-Mac are inefficient for the transfer of exogenous proteins into their cytosol. a, b Purified DCs and macrophages from tumor ascites, derived in vitro from monocytes, or DCs derived in vitro from CD34⁺ precursors were loaded with a cell-permeable FRET-sensitive substrate of β-lactamase, and incubated with or without exogenous β-lactamase. After 3 h, cleavage was measured by flow cytometry. a Representative results of six (tumor ascites), ten (in vitro monocyte-derived), or eight (in vitro CD34⁺ cell-derived) independent experiments. b Quantification of β-lactamase transfer. Symbols represent individual donors. N = 6 for tumor ascites, N = 10 for in vitro monocyte-derived cells, and N = 8 for CD34⁺ cell-derived cells. **p < 0.01, Wilcoxon non-parametric test. c Purified DCs or macrophages were incubated with β-lactamase coupled to Atto dye 633 at 4 or 37 °C during 3 h. Representative results of three independent experiments