Mouse TB models and DNA vaccine treatment
The preparation of the mouse TB model and the immunotherapy with DNA vaccine were conducted in our previous study (31). In brief,96 MTB H37Rv-infected female BALB/c mice were randomly divided into the following groups: (1) phosphate-buffered saline (PBS); (2) 10 µgag85a/b DNA IM; (3) 50 µg ag85a/b DNA IM; (4) 100 µgag85a/b DNA IM; (5) 200 µg ag85a/b DNA IM; (6) 10 µgag85a/b DNA IM+EP; (7) 50 µg ag85a/b DNA IM+EP; (8) 100 µgag85a/b DNA IM+EP; (9) 200 µg ag85a/b DNA IM+EP. On the third day after MTB infection, the mice were immunized three times at two-week intervals, respectively. EP was performed at 36 Voltage and 25 Hz, and six pulses of 10 ms in 3mm depth of thigh muscle of the hind leg of a mouse using a TERESA Gene Delivery Device (TERESA Health Technology Co., LTD, Shanghai, China).