So, now you have a single molecule, very large molecule, with not just two binding sites but with ten binding sites.
所以如果你体内有一个细胞,一个体积很大的细胞,细胞表面不只有两个抗原结合位点,而有十个抗原结合位点
When they do that they can actually engulf the bacteria in a process called phagocytosis and break them down into antigens.
免疫细胞确实是将细菌整个吞进了肚内,这一过程称为吞噬作用,并将细菌分解成小抗原
They just wait, they wait for their time, they wait until you are in danger from a particular antigen.
它们时刻准备着,在等待着那一刻,等待你被某种特别的抗原威胁的时刻
We looked at the kinetics of this response, what happens in your body after you're exposed to an antigen.
我们曾学习过这种应答的效应,当人体遇到抗原后会发生怎样的变化
So, the antigen we're thinking about is a vaccine particularly designed to elicit immune response against a pathogen.
我们现在考虑的这种抗原,是一种特别设计的疫苗,它能够诱发免疫效应以消灭病原体
They might ingest extracellular antigen, presented pieces of it on their cell surface in the context of MHC-2.
它们可以吞噬胞外抗原,根据细胞表面的,主要组织相容性抗原-2
Usually it's done by taking all or part of the infectious agent, and showing them to your immune system in some way.
通常它会带着全部或部分抗原介质,并以某种方式呈递给你的免疫系统
Memory cells are long lasting cells that remember this exposure and can respond very quickly on second exposure.
记忆细胞可以长时间记忆与抗原的接触,并在再次免疫中迅速做出应答
The way that they appear in your body tells the immune system something about where they came from.
抗原在体内出现的方式,向免疫系统表明了抗原的来源
One is there's no lag period, notice that antibody levels start rising right away after the second exposure.
第一是没有迟滞期,请注意,抗体浓度迅速上升,在第二次接触抗原时
The advantage of this is that now you have four binding sites for antigen instead of just two.
这样的好处是一个抗体上,有四个抗原结合位点而不仅仅是两个
So a vaccine is designed in order to engage that biology, in order to provide antigens that will stimulate specifically your immune system.
所以疫苗的作用就是参与这个生理活动,提供抗原 来刺激你的免疫系统
They're just antigens that belong to you and so you don't normally mount an immune response to antigens that are part of you.
它们是你的自身抗原,但通常对自身抗原不会产生免疫反应
So, I have a bacteria infection, stimulates my immune system, I start making antibodies that bind to an antigen specific to that bacteria.
所以 如果我被细菌感染了,我的免疫系统被激活,开始制造抗体,这些抗体结合到细菌特异性的抗原上
Now, just--what this diagram also shows you is that that response is specific to that particular antigen.
看,就像这幅图表展示的一样,免疫应答是针对特定的抗原
So, these are better at binding to antigen because they have more binding sites on them.
连接抗体是对付抗原的有效方法,因为抗体表面将会有更多的抗原结合位点
One of the things that happens is that certain cells within your body process the vaccine or the antigen and we talked about that.
在人体内,发生的反应之一是,特定的细胞对疫苗或者抗原做出反应,之前我们讨论过这个
It's not just that your whole immune system gets revved up and it's going to respond more rapidly to any antigen it's exposed to.
并不是整个免疫系统都得以加强,免疫应答会对,以前接触过的抗原做出的应答更加迅速
There's a region up here called the antigen binding region and those-- and there's two copies of that region and it's responsible for antigen binding.
在图片上部有个区域,被称作抗原结合区,而这些,而这里有两个抗原结合区,主要负责与抗原结合
Then, your muscle cells would start producing Hepatitis B surface antigen and your immune system recognizing that's a foreign protein would start responding to it.
于是,肌肉细胞将会,开始制造乙肝表面抗原,然后免疫系统就会识别出,那是外来蛋白质并且产生免疫应答
Again, these are antibodies that are specific to that antigen or vaccine that we introduced.
我再说一次,这些抗体针对于,我们所接种的抗原或疫苗特异产生
When you get exposed to that particular antigen they say, 'I'm on, it's my time'.
等到你暴露在特定的抗原中,它们说,该我了,到我大显身手的时候了
The response to the second exposure in antigen is different in a couple of ways.
第二次接触相同抗原,免疫系统的应答,在以下几个方面是不同的
We're going to use this special word "Antigen," and antigen has a very particular meaning.
我们将用到抗原这个特别的词,抗原有其独特意义
So, every time you're exposed to a new vaccine or a new antigen you go through this primary response before you have the secondary response.
所以,每当你接触到新疫苗或是新抗原,在再次免疫之前,机体将会经历这样的初次免疫过程
Make a lot of the virus, it has all of its antigenic epitopes on it, but we'll just kill it so that it can't replicate.
先增殖出大量的病毒,病毒表面有特定的抗原决定簇,然后杀死病毒使其无法复制
We're thinking about the particular antibody that binds to this antigen that you're exposed to.
现在,我们考虑一种特殊的,与你所接触的抗原相结合的抗体
From a technological perspective, antibodies are incredible tools because antibodies are molecules that are specifically designed to bind to a particular antigen or a particular chemical.
从技术角度上来说,抗体是一种令人难以置信的分子,它们被设计来,特异性地结合抗原,或者某种化学物质
These are cells that recognize a particular antigen, they're ready to differentiate into antibody.
这些记忆细胞可识别相应的抗原,它们已经准备好分化产生抗体
Any molecule can be an antigen; the food that you eat is full of antigens, microbes that try to live in your body are full of antigens.
任何分子都可以成为抗原,你吃的食物中富含抗原,试图栖息在你身体中的微生物充满抗原
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