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  • Hi. It's Mr. Andersen and welcome to the immune system podcast. In this podcast


  • I wanted to start with a little history. These are some beautiful illustrations from the


  • Florentine Codex which is thousands of pages long. It was created over about 45 years by


  • this guy, this friar. And basically what we did was he studied Aztec culture and how it


  • changed over his lifetime. So we've converted a lot of this to English and you can find


  • some if it on Wikipedia. It's just fascinating. So you could see these rituals and these chieftains.


  • And he would describe all of it. But a sad part of that is that he describes how small


  • pox came and devastated the Aztec. And it's one of the reasons why the Spanish were able


  • to conquer them. And so they didn't have a immunity to it. And that's what this is about.


  • So basically what happens with any kind of a infection, a viral infection like this,


  • is you have a virus. And that virus is essentially going to gain entry inside your cells. It's


  • going to use the machinery of your cell to make copies of itself. And more copies of

    あなたの細胞の機械を使って 自分自身のコピーを作ろうとしていますさらに多くのコピーを

  • itself. And more copies of itself. And eventually it's going to destroy the cell and it's going


  • to spread off to infect other cells. And so that seems awful. In other words when you

    他の細胞に感染するために拡散しますそれで それは恐ろしいことのように思えます言い換えれば

  • get a cold what's happening is that your cells are making viruses which are spreading to


  • more cells. And if it weren't for our immune system we would be devastated by all the viruses


  • that are around us. And so we have to have protection. And so I like the analogy of a


  • castle. A castle needs protection as well. And so if you're building a castle, you have


  • to think about a few ways to defend yourself. First of all you have to defend yourself from


  • the outside. So it's good to have a moat. It's also good to have a really large wall.


  • So it's hard for people to get over it. And this castle's great because it's got water


  • on all sides of it. You also have to have soldiers. So if anybody were to ever get close


  • to the gate you could shoot them with arrows or pour hot tar on them. But if they were

    門の前では矢で撃ったり 熱いタールをかけたりすることができましたしかし、もし彼らが

  • to breach the wall you have to be able to fight them there as well. But probably when


  • you're defending a castle a more important thing is you have to have intelligence. You


  • have to have spies that are sent out to surrounding areas to do reconnoissance and figure out


  • what's going on. To recognize invaders when then come. And so I'm going to quit talking


  • about castles and we're going to talk about the immune system. But the same thing works


  • inside us. And so the idea of a castle wall. Let's start with that. And so what protects


  • us from infection, our castle wall is going to be our skin. And so what our skin provides


  • us with is it provides us with a barrier. So there's going to be a barrier of cell,


  • dead cells, on the top. And keratin on the top. It's also going to have a really low


  • pH which makes it hard for any kind of bacteria to live there. And we're also going to have


  • chemicals on the surface of our skin that are going to disrupt certain viruses. And

    皮膚の表面にある化学物質が 特定のウイルスを破壊しますそして

  • also we're going to have bacteria that crowd out our skin. And so it makes it hard for


  • other bacteria to gain entry. We have what are called normal flora that just live on


  • our skin. And so all of this is going to provide protection against infection. But occasionally


  • you know that that get's breached. Occasionally you cut yourself or a pin prick or something


  • like that gains entry. And so that would be just like the soldiers making it over the


  • wall. And so what do we have? Well we have a call to arms. We have inflammation. So basically


  • we have chemicals that are released that cause our body to respond to that. Now you constantly


  • are being infected, especially if you are a teenager because you get acne. So what is


  • acne? Acne is essentially an infection in the pores of your skin. So it's bacteria that


  • are living and feeding inside our body. And so how do we fight that? Well we'll plug it


  • up for one thing, but we have swelling. So we're going to increase the heat. But basically


  • we're going to send soldiers in there. And those soldiers are the macrophages. Those


  • are going to be the eaters or the big eaters. And what they're going to do is they're going


  • to find anything that's not part of our body and they're going to eat it. So any invader

    私たちの体の一部ではないものを 見つけて食べようとしていますだから、どんな侵略者でも

  • is called antigen. And so basically what a macrophage will do is it will notice that


  • this is not part of our body. It will grab on to it. It will take it into the macrophage.


  • It'll secrete lysosomes and enzymes into it which break it up. It will lots of times present


  • that on its surface, but eventually gets rid of it. And so this is an actual picture of

    表面上はそうですが 最終的には取り除かれてしまいますそれでこれは実際の

  • a macrophage. And you can see it's grabbing I don't know if it's viruses or bacteria on


  • either side. And so that's great. But the one thing about it is it attacks anything


  • that's not us. In other words if you get a heart implant from someone else, or you get


  • a heart transplant, those macrophages are going to attack it as well. It's going to

    心臓移植をしていると マクロファージが攻撃してきますそれは

  • kill that. And so we also have what's called a specific immune response. Specific immune


  • response is more like the spies. And so basically here's an antigen again. An antigen is going


  • to have specific proteins on its surface. But to fight that we use what are called antibodies.

    その表面には特定のタンパク質がありますしかしそれと戦うために 抗体と呼ばれるものを使います

  • And so the name antigen means an antibody generator. In other words it generates the


  • formation of antibodies. So what are antibodies? Antibodies are going to be proteins produced


  • by our body. And basically they all look the same. They're this Y kind of a shape. So they're


  • a Y shape like this. We produce almost an infinite number and an infinite variety of


  • them. But at the top of the Y you're going to have different shapes. In other words,


  • you're going to have a shape that looks like this. But you're also going to have an equal


  • shape that might look like this. And you're going to have an equal shape that might look


  • like this. And so we're going to have all of these different shapes at the top. But

    こんな感じですこのように様々な形のものが 上部にありますしかし

  • we're only going to produce the shape for the one thing that we're infected by. So basically


  • the antibody will dock to the antigen. And when it does that basically it marks the antigens


  • so macrophages can find it. And it also makes it harder for them to do their job. Imagine


  • if I had another antibody here. And another antibody here. And another antibody here.


  • It's hard for them to do their job. And so when you gain immunity, specific immunity


  • or specific immune response what that means is you have the ability to produce these antibodies.

    または特異的な免疫反応 それが意味するのは、あなたはこれらの抗体を生成する能力を持っているということです。

  • And that's why when you have a cold you're not going to get that same cold again. And


  • so basically how do we do this? Or how does this work? Well we need what are called lymphocytes.


  • Lymphocytes are a type of white blood cells. And so basically there are two types of lymphocytes.


  • There are B lymphocytes and then there are T lymphocytes which will get to in just a


  • second. Okay. So B lymphocytes are made in the bone marrow. And they're responsible for


  • a humoral response. Now this term I'm going to show you a couple more times in this podcast.


  • Humoral means in the fluid or in the humers of your body. So that means in the blood.


  • In the lymph material. In the lymph vessels. In the interstitial fluid. And so humoral


  • response, what I want you to think about is going to be anytime there are viruses free


  • in the fluids of our body. And what the B lymphocytes do is they produce antibodies.


  • So how does that work? Basically you have a naive B cell. It's going to sense the shape


  • of the antigen. I'll tell you how that works in just a second. But basically what it's

    抗原のそれがどのように機能するかは すぐにお話ししますがしかし、基本的には

  • going to do is it's going to produce antibodies. And so what B lymphocytes do is they produce


  • all of these antibodies that are specific for the antigen. So in other words if we're


  • infected by this virus, we'll call this virus A1, then we're going to produce antibodies

    このウイルスに感染して このウイルスをA1と呼びます そして抗体を作ります

  • for that specific antigen. We're also going to produce memory B cells so that we have


  • that immunity for the rest of our life. So those are the B lymphocytes. And so you might


  • think, if they attack the viruses out inside our body then what do the T lymphocytes do?


  • Well the T lymphocytes are responsible for cell mediated response. What does that mean?


  • They're going to target and kill the cells inside our body that are already infected.


  • Okay. So what are the T lymphocytes? Where are they made? They're made in the thymus


  • gland which kind of sits on the top of our heart. Basically what they do is they create

    心臓の上に座っている 腺のようなものです基本的に彼らが何をするかというと、彼らは作成することです

  • what are called kill T cells or killer T lymphocytes. And so a killer T cell is an activated T cell.

    キルT細胞やキラーTリンパ球と 呼ばれるものですつまり キラーT細胞は 活性化されたT細胞です

  • Basically what it will do is it'll find any of the cells inside our body that are infected


  • with a virus. It'll dock next to them and it will kill our own cells. And so it's going

    ウィルスでそれは彼らの隣でドッキングして 我々の細胞を殺すだろうそして、それは

  • to kill any of the cells inside our body that are infected by the virus. Or even cancerous


  • cells, it's going to kill them. So it's made in the thymus and it produces cell death inside


  • us. And so the T lymphocytes are responsible for this cell mediated, I mean killing cells

    私たちのことですTリンパ球はこの細胞を媒介して 細胞を殺す役割を担っています

  • inside, our cells that are infected. B lymphocytes are going to be in the humers of our body.

    感染している私たちの細胞の中にBリンパ球は私たちの体の中の ハーマーの中に入ることになります

  • And so if I were to summarize this a little bit, this would be the humoral response up


  • here. So what type of cells are responsible for that? Those is going to be the B cells.


  • And here's the cell mediated down here. Those are going to be the killer T cells. And so


  • before we get to that let's look over here on the left side. So basically what's happening?


  • We have an antigen that is eaten by a macrophage. That macrophage is going to chop up that antigen.


  • It's going to present pieces of it on its surface. And so we use a chemical called MHC2.

    それはその表面に破片を 提示しようとしていますそこで我々はMHC2と呼ばれる化学物質を使います

  • It's major histocompatibility complex 2. It's going to present the shape of that antigen


  • on it's surface and now we get this cell right here which is super important. It's call the

    それが表面にあります そして今、私たちはこの細胞を手に入れました これは非常に重要なものですそれは

  • T helper cell. What the T helper cell is going to do is it's going to dock and it's going


  • to physically sense the shape of that antigen. It uses another protein called CD4. And it's


  • going to sense the shape of that antigen. The helper T cell is responsible for initiating


  • both the humoral and the cell mediated immune response. So let's see what helper T cell


  • is going to do. Helper T cell is going to tell that shape to the B cells. And so it


  • can produce more antibodies. It's going to activate macrophages. So it can kill more


  • of them inside the humers of our bodies. So it's responsible for that humoral response.


  • And the helper T cell is also going to activate the killer T cells. So they can kill the cell

    そしてヘルパーT細胞は キラーT細胞を活性化させようとしていますだから細胞を殺すことができるのです

  • mediated, or excuse me, the cell's that are infected by a virus. And so if isn't for these


  • guys, if it isn't for the helper T cells, we're out of luck. Now sadly, helper T cells


  • are the cells that are infected by HIV or people who have AIDS. And so you can see why


  • that's a really bad thing. Because without the helper T cells we can't fight normal infections.

    それは本当に悪いことです。ヘルパーT細胞がないと 通常の感染症とは戦えないからです

  • So if you have HIV you don't die of that. You're dying of normal infections that we


  • would fight off. So let me kind of do this in cartoon style. If we were to animate it


  • again. So what we've got here is our antigen. Remember that's our invader. And so basically


  • what's going to happen is it is going to be eaten by a macrophage. So the macrophage will


  • take it in. It will secrete enzymes into to it which are going to digest that antigen.


  • It will get rid of it. But it's also going to grab on to a little bit of that. It's going


  • to grab on with this major MHC. It's going to take it's shape out to its surface and


  • now we have helper T cell. What's helper T cell going to do? Helper T cell is going to


  • dock with that macrophage. And it's going to sense the shape of that antigen. It's now


  • going to become an activated helper T cell. So thinking back to that flow chart just a


  • second ago, where does it go next? Well it can activate macrophages. But more importantly


  • it's going to activate B cells. So now we've got an activated B cell. It's going to activate


  • killer T cells. And now through clonal selection it's basically, they're going to make clones


  • of themselves. We're going to have a whole bunch of activated B cells. We're going to

    自分自身の活性化されたB細胞の束を 持つことになります私たちは

  • have a whole bunch of activated killer T cells. So now, thinking about it, this on the top

    活性化されたキラーT細胞の束を持っていますだから今考えてみると これが一番上にある

  • is going to be the humoral response up here. And this down here is going to be the cell


  • mediated response. And so basically we can fight those antigens out here in the humers


  • of the body. We do that by sticking antibodies to it so macrophages can eat it, break it

    体内のマクロファージがそれを食べて壊すことができるように 抗体を付着させることで それを行います

  • down. We also inactivate them a little bit. But if you look down here, that killer T cell


  • is docked with a cell inside our own body that's already infected by an antigen. And


  • so it's going to secrete enzymes into it that are going to break that down. So it's going


  • to kill that. And so basically what we have done is we've killed them in the humers or


  • in the fluids of the body and then we've killed cells that are infected. And so this takes


  • awhile. But it's going to be your immune response. And it's specific to that antigen. Until we


  • get that specific antigen, we're not going to produce the antibodies for it. So let's

    その特定の抗原を手に入れても 抗体を作るつもりはありませんでは、それでは

  • talk about a cold, because I'm getting a cold right now. So basically what happens is you're

    風邪の話をしましょう 私は今風邪をひいているので基本的に何が起こるかというと、あなたは

  • exposed to the cold right here. The virus is going to start reproducing inside my body


  • and it's going to take me a little while for me to start building memory, excuse me, B


  • cells and killer T cells. And so there's going to be a lag time but essentially I'm going


  • to produce a whole bunch of antibodies and effector T cells. So that's going to increase


  • inside my body. And this time right here is where I actually feel like I have a cold.


  • So this is me feeling like I have a cold, but really what's happening is it's my body


  • fighting and killing off all the viruses. And so let's say I get exposed to that same


  • cold again in the future. Well in the future I'm going to get exposed to it. But since


  • I have so many antibodies I'm going to produce them so quickly. And since I have these memory


  • B cells and memory T cells that are just hanging out, I'm going to fight off and kill that


  • infection before I even realize that I have a cold. And this could be years later. Now


  • how could colds get around this, and they do get around it? Well they can have a bunch


  • of different types and colds I think have a hundred different types of rhinoviruses.


  • But they also can mutate. And if they mutate they change the shape of the antigen. And


  • now those antibodies aren't going to work anymore. And so that's the immune response.


  • If you think of it this way, it's like keeping the invaders out of the castle. You're at


  • least one step closer to understanding the immune system. And I hope that's helpful.

    免疫システムの理解に 少なくとも一歩近づきましたそして、それが役に立つことを願っています

Hi. It's Mr. Andersen and welcome to the immune system podcast. In this podcast



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B1 中級 日本語 細胞 抗原 抗体 リンパ 感染 マクロファージ


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    yenping, Hsieh に公開 2016 年 11 月 15 日