Figure 7. Isotype-switched resident-like memory B cells localize in the lungs of wP-primed mice.

(A) AID-Cre-Tomato mice, primed and boosted (day 30) with homologous and heterologous aP and wP vaccine combinations, received tamoxifen at days 7, 10, and 31. Analysis was performed 50 days after boost. (B) Representative flow cytometry analysis of d-Tomato⁺ cells selected from B220⁺CD45.2^– resident lung B cells. d-Tomato⁺GL7^– cells were further analyzed for the expression of IgM and IgG1 membrane Ab isotypes. (C) Numbers of total d-Tomato⁺ resident memory cells (graph on the left) and their isotype subclasses (graph on the right) are shown. (D) dLN, splenic, and lung total d-Tomato⁺ memory B cells belonging to the wP:wP condition were analyzed for the expression of CD73, CD80, and PD-L2 markers. A representative flow cytometry plot is shown. Geometric MFI relative to each membrane marker is indicated in the graphs for all organs. Each point in the graphs (C and D) depicts an individual mouse. At least 2 independent experiments were performed for each analysis. Means (±SEM) are shown. Kruskal-Wallis analysis with uncorrected Dunn’s test was performed to compare the different conditions. *P < 0.05, **P < 0.01, ****P < 0.0001.