Figure 4.

LT-α-expressing cells are required for formation of GCs in spleen but not in LNs. RAG-1^−/− mice were irradiated and reconstituted with spleen cells from either wild-type (a and c) or LT-α^−/− (b and d) mice. At the same time, they were immunized i.v. with SRBCs, and then 10 days later sections of spleen (a and b) and LNs (c and d) were stained with PNA-biotin (blue) and anti-MOMA-1 (brown). (×100.)