FIGURE 3.

Cytokine levels and immune cell composition after X-31ca vaccination. (A–C) Mice (n = 4 per group) were vaccinated with 10⁶ PFU of X-31ca, and BAL fluids were collected daily for 6 days. In BAL fluids, the mean concentration of IFN-α and IFN-β was determined by ELISA and the levels of IFN-γ, IL-6, and TNF-α were measured by Luminex (A). The dotted line represents the limit of detection; IFN-α: 5, IFN-β: 0.5, IFN-γ: 3.49, TNF-α: 1.14, IL-6: 2.23 pg/mL, respectively. To investigate the immune cell subsets, cells obtained from BAL were stained with fluorescence antibodies as presented in the Methods and analyzed by flow cytometry (B,C) (^∗P < 0.05, ^∗∗P < 0.01 compared with the PBS control group).