Figure 2. HLA-A2 is cleaved by α-secretase-like proteases.
(a) Treatment with TAPI-1 (50 μM for 3 h), an α-secretase inhibitor, attenuates HLA-A2 CTF production compared with untreated cells (CTL). Accumulation of HLA-A2 CTF with the PS1/γ-secretase inhibitor DAPT alone is significantly reduced upon co-treatment with TAPI-1 and DAPT. HLA-A2 is stained with an anti-V5 antibody. Transferrin receptor is shown as control. (b) HLA-A2 is cleaved by the α-secretase ADAM-10. Overexpression of ADAM-10 in B104 rat neuroblastoma cells stably expressing HLA-A2 shows that HLA-A2 CTF accumulation by PS1/γ-secretase inhibition is further enhanced in ADAM-10-expressing cells. HLA-A2 is stained with an anti-V5 antibody. GAPDH (glyceraldehyde-3-phosphate dehydrogenase) is used as a loading control. FL, full-length.