Figure A4.

Addition of mouse ICAM-1 targeting peptide to SI enhances the ICAM-1 targeting specificity and internalization of SI in NOD LG acini. LGs from 12–14 week male NOD mice were removed and minced into 1 mm³ pieces with scalpels and sequentially grown in serum-free culture media containing 5 µg/mL laminin, 0.1 µM carbachol, and 1 nM thyroxine. Cells were seeded on a Matrigel^TM coat for live cell imaging on 35 mm glass-bottomed dishes at 6 × 10⁶ cells per dish and incubated at 37 °C for 2–3 h prior to experiments. Acini were then treated with 30 μM rhodamine-labeled (rh)-SI or IBP-SI at 37 °C for 1 h. Rh-IBP-SI (red) exhibits significantly higher surface binding, internalization, and co-localization with LysoTracker (green), a biomarker for low pH compartments, in NOD LG acini than its SI counterpart. White arrowheads indicate the co-localization of IBP-SI and LysoTracker. Scale bar = 10 µm.