Figure 6.
The role of secondary lymphoid organs in the maintenance of B cell and antibody memory. (A) Splenocytes (107) plus 107 bone marrow cells from VSV-IND-primed (2 × 106 pfu 60 days earlier) C57BL/6 mice were adoptively transferred into ALY × ALY mice. Twenty minutes later, 2 × 108 pfu of UV-inactivated VSV-IND were injected into recipient mice. Day 20 after the adoptive transfer, half of the recipient ALY × ALY mice were splenectomized. Neutralizing antibody titers were followed up to 360 days after the adoptive transfer. Antibody titers in splenectomized and nonsplenectomized ALY × ALY mice were also followed after transfer of 500 μl of VSV-IND immune serum (pooled of VSV-IND memory mice infected 60 days previously with 2 × 106 pfu of VSV-IND). (B) C57BL/6 mice were infected with 2 × 106 pfu of VSV-IND i.v. Sixty days later, 2 × 107 splenocytes from these mice or naive C57BL/6 mice were transferred into ALY × ALY recipient mice. At the same time, 2 × 107 splenocytes of VSV-NJ-primed (2 × 106 pfu i.v., 14 days earlier) mice were transferred into the same recipient mice as a source of primed T help. Four days later, half of the ALY × ALY recipient mice were splenectomized. All mice were boosted with 2 × 108 pfu of UV-inactivated VSV-IND 7 days after splenectomy and VSV-IND-neutralizing antibody titers were determined 22 days later. Results are shown as means ± SD of 3–4 mice per group. The experiments were repeated twice with comparable results.