[ODP6F] f. Immune Mechanism, Development of Vaccines

[ODP-176] Difference of anti-oxidative stress responses between BCG Tokyo 172 type I and type II

Keiichi Taniguchi¹, Daisuke Hayashi², Naomi Yasuda³, Mao Nakayama³, Saotomo Itoh¹, Saburo Yamamoto², Naoya Ohara⁴, Shigeaki Hida¹, Kikuo Onozaki¹, ○Takemasa Takii^1,3 (¹Dept. Molecular Health Sciences, Grad. Sch. Pharmaceutical Sciences, Nagoya City Univ., ²Japan BCG Laboratory, ³Dept. Mycobacterium Reference and Research, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, ⁴Dept. Oral Microbiology, Grad. Sch. Medicine, Dentistry, and Pharmaceutical Sciences, Okayama Univ.)

The genomic analysis revealed that the vaccine seed lot of Mycobacterium bovis bacillus Calmette Guérin (BCG) Tokyo 172 contains two sub-clones (type I and II), which type I lucks 22-bp deletion in region of differences (RD) 16. In this study we evaluated susceptibility of oxidative stress in vivo and host cells between the type I and type II bacilli. The susceptibility against hydrogen peroxide in the type I bacilli was weaker than that in the type II bacilli. The induction of katG mRNA expression in the type I bacilli after the exposure of hydrogen peroxide was higher than that in type II bacilli. These results indicated that BCG Tokyo 172 type I would be more resistant to oxidative stress. We further investigate survival activity in the macrophage cell line, RAW 264.7 and THP-1. The number of the type II bacilli was lower than those of type I bacilli and was segmented in the presence of apocynin, a specific inhibitor NADPH oxidase. These results suggest that BCG Tokyo 172 type II would be affected by oxidative stress especially hydrogen peroxide in vitro and in host cells. The productions of interleukin 1 and tumor necrosis factor from RAW264.7 and THP-1 cells infected with type I bacilli was higher than those with the type II bacilli. Therefore, our study would provide very important information about quality control and safety of BCG vaccine Tokyo 172.