主页 > 医学信息 >
【drug-news】一种新型GAD疫苗有望成为治疗I型糖尿
ScienceDaily 2006-9-16
UCLA的研究者们研制出了一种针对I型糖尿病的新型疫苗，目前正处于临床II期测试阶段，所得的结果非常乐观。此项技术现在已转让Diamyd Medical用于医学上的进一步研究。
I型糖尿病通常的发病群体是少年儿童，它的起因是免疫系统攻击胰腺，并且破坏合成胰岛素的细胞。而这种新型疫苗是一种GAD蛋白，即谷氨酸脱羧酶。它将合成神经元信号传导过程中的一种重要递质，而且这种递质在合成胰岛素的胰腺细胞调节葡萄糖水平的交流过程中，将充当化学递质。
从未得I型糖尿病的人体血样中，研究者发现可以测得GAD的自身抗体。因为在发病前，免疫系统将缓慢地攻击胰岛细胞，甚至这个过程可以持续七年后才出现病症。所以通过测GAD自身抗体这个工具，可以在发病前五年就检测早期的自免疫反应。
UCLA的Kaufman博士和他的合作者还发现，在免疫系统攻击胰岛细胞后，GAD疫苗可以抑制自身免疫反应。在I型糖尿病已经发作的小鼠中，GAD疫苗也可以阻碍其发病的进程。其机制为：GAD疫苗活化了那些可以识别GAD的T细胞，然后T细胞转移到了胰岛，识别了生成胰岛素的细胞中的GAD蛋白，随后释放出一个抗炎的细胞因子，从而抑制那些正在杀死胰岛细胞的免疫活动。
现在II期临床已有非常乐观的结果，在发病两年后，使用GAD疫苗仍然能够保持一部分胰岛素的生成。但是这种疫苗能否投入使用，还需要看III期临床的实验结果。
原文链接：http://www.sciencedaily.com/releases/2006/09/060915160244.htm
原文：
Possible Treatment For Type 1 Diabetes With New Vaccine
A new vaccine being tested in a human clinical trial holds a great deal of promise for treating type 1 diabetes, a disease that newly afflicts 35,000 children each year. The research that established the foundation for this vaccine was conducted in UCLA research laboratories. The drug is still being tested and is not likely to be available for at least a few years.
"It's the only thing so far that really slows this disease down without adverse side effects," Allan J. Tobin, a UCLA professor emeritus of physiological science and neurology, said about the new drug. "The amazing thing about this emerging story, however, is that it started from basic research on the brain." Tobin, whose laboratory conducted critical neuroscience research in the late 1980s and 1990s, is a member and former director of UCLA's Brain Research Institute.
Type 1 diabetes -- also known as insulin-dependent diabetes or juvenile diabetes (because it usually begins in childhood or adolescence) -- afflicts more than 1 million Americans. It is characterized by a failure of the body to produce insulin because the immune system attacks and destroys the body's insulin-producing cells of the pancreas.
On Sunday, Sept. 17, at a meeting in Copenhagen of the European Association for the Study of Diabetes, Johnny Ludvigsson -- pediatrics professor at Sweden's University Hospital, Linköping University -- will present results from the phase II study conducted in eight hospitals in Sweden in collaboration with Diamyd Medical (www.diamyd.com), a life science company located in Stockholm, Sweden.
This fundamental discovery that influenced thinking about diabetes was made in the Life Sciences Division of UCLA's College of Letters and Science, said Arthur P. Arnold, UCLA professor and chair of physiological science.
"The broad insight of a basic neuroscience team eventually bore fruit in the fight against this disease," Arnold said. In the 1980s, using newly developed recombinant DNA techniques, Tobin's laboratory was studying genes involved in brain development and function. Tobin's team included graduate student Daniel Kaufman, now a UCLA professor in the department of molecular and medical pharmacology, and graduate student Mark Erlander, now executive vice president and chief scientific officer of AviaraDx, a biotechnology company in Carlsbad, Calif.
Together, Kaufman and Erlander were the first to isolate the genes encoding GAD (glutamic acid decarboxylase) which is an important enzyme because it synthesizes one of the main neurotransmitters for communication between neurons. Tobin's laboratory used these tools to study neuronal development in the brain. What no one knew at that time was that GAD was also made in the cells that made insulin in the pancreas -- cells that use the chemical transmitter made by GAD to communicate with other pancreas cells to help control glucose levels in the blood.
A year later, Kaufman's car fortuitously broke down while he was a postdoctoral scholar at the Salk Institute in San Diego, Calif. Forced to wait, he went to the library and stumbled on a report in a medical journal showing a connection between autoimmunity to an unknown protein in insulin-producing cells and diabetes. Kaufman surmised that this unknown protein was in fact GAD, the protein he had studied in Tobin's lab.
阅读本文的人还阅读：
作者:admin@医学,生命科学 2011-02-11 17:18
医学,生命科学网