Extended Data Fig. 8: Inhibiting aspartic protease activity in the lysosome has minimal effect on antigen cross-presentation by macrophages.
From: A lysosome-targeted DNA nanodevice selectively targets macrophages to attenuate tumours
a, PepA-DNA design: one strand is conjugated with PepA on its 5’ end and the other with Alexa Fluor 647 to monitor uptake. b, Catalytic activity assays for lysosomal cysteine proteases (CTSB, CTSL; 5 nM) or aspartic proteases (CTSD, CTSE; 5 nM) in the presence of vehicle (Veh; PBS) or PepA-DNA (25 nM). Results are plotted as fluorescence intensity at time t, relative to time 0 (I/Io). n = 3/group. c–f, Peritoneal macrophages were isolated and treated with vehicle (Veh; PBS), DNA, PepA, or PepA-DNA (100 nM) for the indicated times and various functional endpoints were measured. c, Effect of PepA-DNA (2 h) on DQ-OVA degradation. n = 3/group. d, Quantification of MHCI-bound OVA257-264 on peritoneal macrophages 3 h post treatment with OVA protein or OVA257-264 peptide. n = 3/group. e–f, pMel-CD8+ T cell activation (e) and proliferation (f) after 72 h of co-culture with peritoneal macrophages pre-stimulated with irradiated B16F10 cells (irrB16). n = 3/group. Statistical significance was calculated via two-tailed Student’s t-test (P < 0.05 values are provided); error bars indicate the mean of independent experiments ± s.e.m. ns; not significant. All measurements (n) are biological replicates.
