0


免疫学与癌症

Immunology and Cancer
课程网址: http://videolectures.net/mitworld_chen_iac/  
主讲教师: Jianzhu Chen
开课单位: 麻省理工学院
开课时间: 2011-02-21
课程语种: 英语
中文简介:
陈建柱阐述了利用免疫系统对抗癌症的棘手挑战。他从基础知识开始:身体如何利用两个层次的防御病原体:天然免疫和适应性免疫。陈对后一种保护特别感兴趣,因为它可以识别和记忆细胞内外“几乎无限数量”的特定病原体。 骨髓中产生的B细胞可以产生清除细菌的抗体,而源自胸腺的T细胞则可以追踪病毒和其他细胞内的威胁。它们的工作原理是识别抗原(外来物质)并表达受体——细胞表面蛋白——与这些抗原结合。 早期,免疫系统学会区分什么是自我,什么是病原体。陈说,它形成了“自我容忍的层次”,如果没有这些层次,身体可能会对自己发起攻击。但是癌症可以操纵免疫系统的这一有用功能。有些肿瘤表达化学物质,或召唤自然产生的抑制细胞,以防止T细胞攻击它们。因此,陈说,要对癌症产生免疫反应,你“需要诱导对自我的反应,你必须克服免疫系统固有的耐受机制。” 陈看到了克服“肿瘤诱导耐受”的可能性的证据例如,一些肿瘤会自发缩小,并且在肿瘤部位会聚集免疫细胞。研究人员主要关注三个领域:在癌症治疗中使用抗体或T细胞;开发一种能诱导肿瘤特异性抗体或T细胞的治疗性疫苗;以及设计一种预防癌症的疫苗,这种疫苗可以诱导B细胞或T细胞对特定癌症的记忆。还有很多艰苦的工作要做:识别肿瘤相关抗原,陈说,其中大部分被人体视为“正常的自身蛋白质”然后是针对这些肿瘤相关抗原的T或B细胞。
课程简介: Jianzhu Chen lays out the thorny challenges of harnessing the immune system to fight cancer. He starts with the basics: how the body employs two levels of defense against pathogens: native and adaptive immunity. The latter type of protection specifically interests Chen, because it can recognize and remember “an almost unending number” of specific pathogens, both inside and outside cells. B cells, produced in the bone marrow, can generate antibodies for clearing out bacteria, and T cells, originating in the thymus, go after viruses and other intracellular threats. They work by identifying an antigen (foreign substance) and expressing receptors -- cell surface proteins -- that bind to those antigens. Early on, the immune system learns to distinguish between what is self and what is a pathogen. It develops, says Chen, “layers of self-tolerance,” without which the body might launch an assault on itself. But cancers can manipulate this useful feature of the immune system. Some tumors express chemicals, or summon naturally occurring suppressor cells in order to prevent T-cells from attacking them. So, says Chen, to mount an immune response against cancer, says Chen, you “need to induce a response against the self—you have to overcome the built-in tolerance mechanism of the immune system.” Chen sees evidence of the possibility of overcoming “tumor-induced tolerance.” For instance, some tumors spontaneously shrink, and there’s an accumulation of immune cells at tumor sites. Researchers are focusing on three areas: using antibodies or T cells in cancer therapy; developing a therapeutic vaccine that would induce cancer specific antibodies or T-cells; and designing a vaccine to prevent cancer that would induce the memory of B or T cells for a specific cancer. Much hard work remains: identifying tumor associated antigens, most of which, says Chen, the body sees as “normal self proteins;” and then coming up with T or B cells specifically targeting these tumor associated antigens.
关 键 词: 癌症; 免疫系统; 适应性免疫
课程来源: 视频讲座网
数据采集: 2021-12-26:zkj
最后编审: 2021-12-26:zkj
阅读次数: 59