Fig. 4. Treatment with B cells mitigated the A/S-induced delirium-like behaviors in mice.

a. Experimental scheme: B cells (6 x 10⁶) were negatively sorted from donor mice (4 months old female mice) using EasySep^™ and injected (2 x 10⁶) into recipient-aged mice, followed by control condition and A/S, and behavioral tests. b. Representative flow cytograms of B cells in the blood of recipient mice. c. B cell amounts in the mice with control condition plus vehicle treatment and the mice with A/S plus B cell treatment. d. B cell treatment attenuated the A/S-induced increases in blood Tau-PT217 amounts in the aged mice. Quantitative western blot showing that B cell treatment attenuated the A/S-induced increases in cortex Tau-PT217 in the mice (e and f). Treatment with B cells mitigated the A/S-induced delirium-like behaviors in mice demonstrated in individual tests (g) and composite Z score (h). N = 10 - 12 mice in each group of behavioral test, and N = 4 - 6 mice in each flow cytometry, nanoneedle, and western blot study as demonstrated in each panel of the figure. The Student's t-test was used to analyze the data presented in c. Two-way ANOVA and the post-hoc analysis with Bonferroni were used to analyze the data presented in d, f, and h. The P values refer to the difference in B cell amounts, Tau-PT217 amounts, and Z score between the control condition and A/S in the mice. Error bar indicates standard deviation. Tau-PT217, Tau phosphorylated at threonine 217; A/S, anesthesia and surgery.