Figure 2.

Proteolytic endosomal inhibitors partially decrease the secretion of K^b peptides from Salmonella-infected macrophages. IFN-γ-activated macrophage monolayers were treated with: (a) no inhibitor (b) 20 mm ammonium chloride, or (c) 1 mm leupeptin for 30 min at 37° before infection with Salmonella. The co-cultures with RMA-S were performed as described in Fig. 1. Both ammonium chloride and leupeptin were also added at the time of co-culture initiation. As control, RMA-S alone were also treated with the inhibitors for 18 hr. MHC class I K^b expression on RMA-S cells was analysed by FACS staining as described in Fig. 1. The histograms show RMA-S stained with an isotype-control antibody (Ic), K^b expression on RMA-S cultured alone (S) and K^b expression on the gated population of RMA-S cells from co-culture with non-infected macrophages (S-Non-Inf-Mφ) and with infected macrophages (S-Inf-Mφ). RMA-S cells from the co-cultured with macrophages. The results from one of six experiments are shown. Values in parenthesis correspond to mean fluorescence channel.