Expression of ICAM-1 and ICAM-2 on B cells and LFA-1 on T cells in response to immunization. (A) Flow cytometric plot and histograms showing gating strategy and ICAM expression on follicular (Fo) and germinal center (GC) B cells in popliteal LNs of mice, 7 d after immunization with NP-OVA. Graph shows quantification of mean fluorescence intensity (MFI) of ICAM-1 and ICAM-2. Data are pooled from two independent experiments with a total of six to 12 mice per group. (B) Representative histograms depicting ICAM-1 and ICAM-2 expression on adoptively transferred B1-8^hi B cells (day 0) and NP-specific Igλ⁺ B1-8^hi B cells, 7 d after immunization. Graphs show fold increase in ICAM-1 and ICAM-2 expression over time of NP-specific B cells (Igλ⁺) and follicular polyclonal B cells. Data are pooled from two independent experiments with a total of six mice per group. (C) Flow cytometric plots and histograms depicting the gating strategy for T cell subsets and their LFA-1 (αL) expression 7 d after immunization with NP-OVA. Data are pooled from two independent experiments with a total of six mice per group. (D) LFA-1 expression on endogenous naive T cells and on transferred TdTomato⁺ OT-II T cells 3 d after immunization. Data are pooled from two independent experiments with a total of eight mice per group. **, P = 0.01; ***, P < 0.001; two-tailed Student’s t test. Each dot in the graphs represents a single mouse; lines represent the mean; error bars represent SEM.