Fig. 4
NVRBD-MLipo elicited in vivo AMs activation and mucosal immune response. (A) Timeline of the in vivo vaccination. Mice were immunized with different groups on days 0, 7, and 14 (25 µg RBD/mouse, n = 5). Serum, BALF and nasal wash were collected on days 18, 28 and 42, lung and spleen were collected on day 18. FCM analysis of CD80+ CD11b+ (B), CD86+ CD11b+ (C) AMs proportion in lungs on day 18 (n = 5). (D)The secretion level of IL-6, IL-12, TNF-α, IFN-γ in the BALF collected on day 18 (n = 5). FCM analysis of CD4+ CD3+ (E) and IFN-γ+ CD8+ (F) T cells, CD19+ IgD+ B cells (G) proportion in lungs on day 18 (n = 5). RBD-specific IgA titers in BALF assessed by ELISA on days 18 (H), 28 (I) and 42 (J) (n = 4). Data expressed as means ± SD. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001