Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
Proc Natl Acad Sci U S A. 2010 Mar 9;107(10):4573-8. doi: 10.1073/pnas.0909133107. Epub 2010 Feb 18.
Protein tyrosine phosphatases are often exploited and subverted by pathogenic bacteria to cause human diseases. The tyrosine phosphatase mPTPB from Mycobacterium tuberculosis is an essential virulence factor that is secreted by the bacterium into the cytoplasm of macrophages, where it mediates mycobacterial survival in the host. Consequently, there is considerable interest in understanding the mechanism by which mPTPB evades the host immune responses, and in developing potent and selective mPTPB inhibitors as unique antituberculosis (antiTB) agents. We uncovered that mPTPB subverts the innate immune responses by blocking the ERK1/2 and p38 mediated IL-6 production and promoting host cell survival by activating the Akt pathway. We identified a potent and selective mPTPB inhibitor I-A09 with highly efficacious cellular activity, from a combinatorial library of bidentate benzofuran salicylic acid derivatives assembled by click chemistry. We demonstrated that inhibition of mPTPB with I-A09 in macrophages reverses the altered host immune responses induced by the bacterial phosphatase and prevents TB growth in host cells. The results provide the necessary proof-of-principle data to support the notion that specific inhibitors of the mPTPB may serve as effective antiTB therapeutics.
蛋白酪氨酸磷酸酶经常被致病菌利用和颠覆,从而导致人类疾病。结核分枝杆菌的酪氨酸磷酸酶 mPTPB 是一种重要的毒力因子,它被细菌分泌到巨噬细胞的细胞质中,在那里介导分枝杆菌在宿主中的存活。因此,人们非常有兴趣了解 mPTPB 逃避宿主免疫反应的机制,并开发有效的、选择性的 mPTPB 抑制剂作为独特的抗结核(antiTB)药物。我们发现,mPTPB 通过阻断 ERK1/2 和 p38 介导的 IL-6 产生,以及通过激活 Akt 通路促进宿主细胞存活,从而颠覆先天免疫反应。我们通过点击化学组装的二齿苯并呋喃水杨酸衍生物组合文库,发现了一种有效的、选择性的 mPTPB 抑制剂 I-A09,它具有高效的细胞活性。我们证明,在巨噬细胞中用 I-A09 抑制 mPTPB 可以逆转细菌磷酸酶诱导的宿主免疫反应的改变,并防止宿主细胞中的结核分枝杆菌生长。这些结果提供了必要的原理验证数据,支持了这样一种观点,即 mPTPB 的特异性抑制剂可能作为有效的抗结核治疗药物。