Fig. 2.

Bacterial antigen presentation requires cell migration from the site of infection. (A–C) C57BL/6 mice were infected s.c. with Salmonella-EαRFP for 4 (A), 8 (B), or 24 (C) h before cervical lymph nodes were recovered, and Eα:I-A^b complexes and B cell follicles were detected by staining with Y-Ae and anti-B220. (D and E) In a separate experiment, C57BL/6 mice were infected s.c. with Salmonella-EαRFP for 24 h with an intact injection site (D) or after injection site removal 1 h after infection (E). Cervical lymph nodes were recovered and processed as above. The images depict the location of pEα:I-A^b complexes (red) and B cell-follicles (blue). The optical thickness of each image is 9 μm.