Figure 5.

Effect of irradiation on B cell and antibody memory. C57BL/6 mice were infected with (A) 200 pfu of LCMV-WE i.v.; (B) 2 × 10⁶ pfu of LCMV-Armstrong i.p.; or immunized with (C) 10 μg of Baculo-derived LCMV-NP protein. Thirty days after the infection/immunization, mice were irradiated with 650 or 850 rad or left nonirradiated as indicated by the arrow. Mice irradiated with 850 rad were substituted with 2 × 10⁷ naive bone marrow and 2 × 10⁷ naive spleen cells. LCMV-NP-binding antibodies were assessed up to day 125 after infection. (D) As in C but mice were immunized with 2 × 10⁶ pfu of VSV-IND i.v. and irradiated 60 days later. Ten days later, 2 × 10⁷ splenocytes isolated from the above irradiated and nonirradiated donor mice were adoptively transferred into nonirradiated recipient mice. Half of the recipient mice were also infected with 2 × 10⁶ pfu of VSV-NJ 12 days earlier (closed symbols); 2 × 10⁶ pfu of UV-inactivated VSV-IND was injected into all mice (+20 min) and neutralizing IgG antibody titers were analyzed (▪ are negative controls, and ●, ○ are positive controls). Results are shown as means ± SD of 3–4 mice per group. Each experiment was repeated 2–3 times with comparable results.