FIG. 2.

Antibody response against MoPn EBs. (A) Serum antibody. BALB/c mice (five per group) were immunized as described in the legend to Fig. 1. Serum samples were collected 2 weeks after boosting. MoPn-specific IgG2a and IgG1 in serum were tested by ELISA. An optical density of 0.5 was the cutoff point. The data are means ± SEM. ∗∗, P < 0.01 compared with N, IS, and pc/IS. (B) IgA antibody against MoPn EBs in extracts of mouse lung homogenates. BALB/c mice (five per group) were immunized as above. The mice were challenged with 1,000 IFU of MoPn EBs 14 days after the last immunization and sacrificed on day 10 postinfection. The lungs of the mice were ground and centrifuged at 10,000 rpm. IgA antibody in the supernatant of the lung extracts was tested by ELISA against MoPn EBs. ∗∗, P < 0.001, compared with ISCOM alone and P < 0.05 compared with pc/IS or EB.