Figure 2

Vaccination with IRV leads to the expression of the gut homing receptor LPAM-1 on B cells in blood, spleen and mesenteric lymph node (mLN). Mice were vaccinated with IRV either via the microneedle (MN) patch or intramuscular (IM) injection with the indicated doses or with a placebo control. Organs and peripheral blood were collected from unvaccinated animals (baseline), 2 days after each dose (day 2, 23, and 44) and at the study end (day 63). (a) Percentages of surface marker positive cells were determined by gating on the positive population in the appropriate histogram. (b) Proportions of B220⁺CD80⁺LPAM-1⁺ (activated B cells) in blood, spleen, and mLN at the indicated time points after MN patch vaccination. (c) Proportions of B220⁺CD80⁺LPAM-1⁺ in blood, spleen, and mLN at the indicated time points after IM vaccination. Data shown in (a) are representative of one mouse vaccinated with 5 µg IRV on day 44. Shown in (b) and (c) are the mean and s.d. of data from 4 (baseline) or 5 mice. Mann-Whitney test was used for statistical analysis comparing vaccinated animals with appropriate placebo controls. Upper p value indicator for 5 µg IRV vaccination; lower p value indicator for 1 µg IRV vaccination. If only one p value indicator is present, this indicator applies to both, 1 µg and 5 µg IRV vaccination. ns: not significant p > 0.05; *p ≤ 0.05; **p ≤ 0.01; MN: microneedle; IM: intramuscular; mLN: mesenteric lymph node.