Figure 4.

B‐cell rejuvenation does not confer enhanced immunity in old mice. (a, b) young, old, and old depletion (hCD20Tg) (65 days after depletion) mice were immunized intraperitoneally with OVA, HEL, and BSA emulsified in aluminum hydroxide. Mice were bled 14 days later, and anti‐OVA, anti‐HEL, and anti‐BSA IgG antibody titers were determined by ELISA. Shown are titers for individual mice (n = 6–12 in each group) (a) and group mean with 95% CI (b). (c) Young (n = 12), old (n = 12), and old depletion (65 days after depletion) (n = 12) mice were transferred from the SPF facility into a dirty facility and were followed for 30 weeks for survival. Shown is the Kaplan–Meier survival plot for each group. Significance was determined using the log‐rank test