研究人员在日前在线出版的《自然—免疫学》期刊上报告，免疫感应器的活性和肿瘤逃逸免疫系统的能力间存在一种看似不合逻辑的联系。这个意料之外的结果揭示了癌症治疗的一个新靶标。
这个辅助系统是由一串级联状的蛋白质组成，当感染出现时，它会像火警系统一样向免疫系统发出警告。一个奇怪的曲折中，Lambris和同事发现肿瘤激活了一种补充蛋白质C5，这样，在事实上抑制了免疫系统的抗肿瘤反应。
这是一个令人惊异的结果，作者通过观察发现，被激活的蛋白质征召“抑制”细胞到相应位点。这些行动解除了其他免疫细胞的功能，阻止它们杀死肿瘤。重要的是，他们的研究显示，阻止C5的活性能降低小鼠肿瘤的生长，其效果相当于抗肿瘤药物泰素(taxol)的治疗效果。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Immunology，9, 1225 - 1235，Maciej M Markiewski，John D Lambris
Modulation of the antitumor immune response by complement
Maciej M Markiewski1, Robert A DeAngelis1, Fabian Benencia2,4, Salome K Ricklin-Lichtsteiner1, Anna Koutoulaki1, Craig Gerard3, George Coukos2 & John D Lambris1
The involvement of complement-activation products in promoting tumor growth has not yet been recognized. Here we show that the generation of complement C5a in a tumor microenvironment enhanced tumor growth by suppressing the antitumor CD8+ T cell–mediated response. This suppression was associated with the recruitment of myeloid-derived suppressor cells into tumors and augmentation of their T cell–directed suppressive abilities. Amplification of the suppressive capacity of myeloid-derived suppressor cells by C5a occurred through regulation of the production of reactive oxygen and nitrogen species. Pharmacological blockade of the C5a receptor considerably impaired tumor growth to a degree similar to the effect produced by the anticancer drug paclitaxel. Thus, our study demonstrates a therapeutic function for complement inhibition in the treatment of cancer.
1 Department of Pathology and Laboratory Medicine, Medical School of the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
2 Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
3 Pulmonary Division, Children's Hospital, Boston, Massachusetts 02215, USA.
4 Present address: Department of Biomedical Sciences, College of Osteopathic Medicine and Biomedical Engineering Program, Russ College of Engineering and Technology, University of Ohio, Athens, Ohio 45701, USA.
