Extended Data Fig. 3. Alum particles are internalized by B cells in vitro.

(a) TEM images of sections of Ramos B cells in the absence of alum. Representative images are shown from a total of 20 cells imaged. (b) glVRC01-expressing Ramos B cells (2 million/mL) were incubated with pSer₈-eOD (1 ug/mL) and alum (10 ug/mL) for 1 hour prior to fixation. Arrowheads point to electron dense alum nanofiber clusters. Representative images are shown from a total of 25 cells imaged.