Langerin and caveolin-1 are present in Birbeck Granules. MUTZ-LCs were analyzed by immuno-electron microscopy for the presence of BGs that appear tubular (filled arrows) or tennis racquet shaped (A). Sections were stained for langerin with 10 nm gold particles (B), caveolin-1 with 10 nm gold particles (C), langerin and caveolin with 10 nm and 15 nm gold particles, respectively (D). MUTZ-LCs were incubated for 24 hours with HIV-1 and stained for p24-HIV-1 and CD63 or LAMP2 with 10 nm and 15 nm gold particles (E). Bars represent 200 nm and these data are representative of two independent experiments.