Figure 4. Cross-presentation of α₂M-chaperoned peptides is dependent on proteasomes and vesicular trafficking.

a) α₂M complexed to the ova 19-mer peptide (P) was incubated with bone marrow-derived dendritic cells in the presence or absence of the proteasome inhibitor lactacystin. Controls include cells incubated with peptide alone, ova8 or ovalbumin protein (ova) or PBS (none). B3Z activation was monitored at A₅₉₅ after addition of substrate. b) α₂M or gp96 complexed to the ova 19-mer peptide (P) were incubated with bone marrow-derived dendritic cells in the presence or absence of BFA. Controls include cells incubated with ova 19-mer peptide alone (P), ova8 or ovalbumin protein (ova) or PBS (none). B3Z activation was monitored at A₅₉₅ after addition of substrate. Error bars in (a,b) represent standard deviation of duplicates.