Fig 3.

p24-specific serum IgG elicited by pP24-Mtb immunization. Mice were immunized 4 times with pP24-Mtb, pP24, or pcDNA3.1 (vector) at 2-week intervals. (A and B) Serum M. tuberculosis-specific IgG (A) and p24-specific IgG (B) were detected by ELISA at the indicated time points. (C to E) p24-specific antibody titers (C), serum IgG subclasses (D), and avidity (E) were determined 2 weeks after the last immunization. Each bar represents the average value plus SD (error bar) for 6 mice, measured in duplicate experiments. Values that are statistically significantly different (P < 0.05) are indicated by a short horizontal line and an asterisk. ND, not detected.