Therapeutic effects of Ag85A plasmid DNA vaccines in a mouse model of multi-drug resistant Mycobacterium tuberculosis infection / 中华微生物学和免疫学杂志

ABSTRACT

Objective To study the therapeutic effects of Ag85A plasmid DNA vaccines in a mouse model of multi-drug resistant-(MDR-) Mycobacterium tuberculosis infection. Methods BALB/c mice were infected with Mycobacterium tuberculosis clinical strain HB361 with isoniazid and rifampin resist-ance by intratail-vein injection and were subsequently divided into 6 groups. At the third day after infection, the mice were treated with saline (group A), vector pVAX1 (greup B), rifampin (group C), vaccae (group D), Ag85A plasmid DNA vaccines (group E),rifampin and Ag85A plasmid DNA vaccines (group F) for 60 d. The lungs and spleens from the mice were taken and their pathological changes, weight and number of myeobacterial colony were examined at the third week after the end of treatment. Results At third week af-ter the end of treatment, the gross pathological observation and histopathological examination in lung showed that the lung lesions were limited, the profile of the alveoli was relatively clear, and normal structure could be seen in 2/3 areas of the lung sections in group D, E and F. The extent of lung lesion was 50% in group D,20% in group E and F. The pathological changes in group A, B, and C were more severer than those in group D, E and F. Compared with group A, the colony-forming units (CFU) in the lungs from mice in group D,E and F decreased 52%, 68%, 78%, respectively. The CFU in the spleens from mice in group D,E and F decreased 48%, 65%, 79%, respectively. Conclusion Ag85A plasmid DNA vaccines alone or Ag85A plasmid DNA vaccines along with chemotherapy have significant therapeutic effects on the mouse model of MDR-Mycobacterium tuberculosis infection.