The Molecular Microbiology Group is dedicated to basic researches on immune response to infections of tropical area, especially tuberculosis. Through analyses of interaction between host immune system and Mycobacterium tuberculosis (Mtb), the causative bacteria of tuberculosis, we intended to develop new strategy to control tuberculosis. Mtb produces virulent factors which interfere activation of host immunity but mechanisms of the interference are not well clarified. Among the Mtbderived factors, we focus on Zmp1 which suppress proinflammatory response and anti-mycobacterial activity of host immunity. We have established Mtb var. BCG strains deficient in Zmp1, and are analyzing influence of Zmp1 on immune response in in vitro and in vivo infection models using the Zmp1-deficient Mtb. With cutting edge molecular biology techniques, we have also identified host ligands of Zmp1 and analyses of molecular mechanism of Zmp1-mediated immunosuppression are ongoing. It is expected that findings obtained from the research will give us new methodology to control tuberculosis via vaccine development or discovery of drugs which block immunosuppressive activity of Mtb.
Our Group members also hold posts in the Graduate School of Medicine (Department of Host Defense) and participate in the Graduate Education Program at the University of the Ryukyus.
Fig. 1 結核菌の病原因子、Zmp1を薬剤耐性遺伝子（hygR）と置換して欠損（KO）させた結核菌 BCG株の作製。
Fig. 2 Zmp1欠損結核菌BCG株の肺感染による炎症性サイトカインIL-17A産生γδT細胞数の誘導増強。
Fig. 3 結核菌が分泌する病原因子Zmp1による感染防御免疫抑制の模式図。Zmp1が感染マクロファージのNLRP3インフラマソーム依存的IL-1β産生とそれに引き続く殺菌活性増強を抑制する。
|Assistant Prof.||Masayuki UMEMURA|
|Assistant Prof.||Giichi TAKAESU|
|Adjunct Associate Prof.||Toshihiro KONNO|