字幕列表 影片播放
-
Measles is one of the most contagious diseases known to man.
麻疹是人類已知最具傳染性的疾病之一。
-
In fact, if someone with measles coughs in an elevator, 90% of the people who use that
實際上,如果患有麻疹的人在電梯中咳嗽,那麼在使用該電梯的人中
-
elevator after will catch the disease.
有 90% 會感染到麻疹。
-
Unless of course you've been vaccinated.
當然,除非你已經接種過了疫苗。
-
Then you'll be completely fine.
那你就不會有事。
-
This is the measles virus, it's been around for thousands of years and has been responsible
這是麻疹病毒,已經存在了數千年,並造成了
-
for the deaths of millions of people.
數百萬人的死亡。
-
Now, on the surface, measles symptoms seem fairly innocuous.
現在,從表面上看,麻疹產生的症狀似乎是無害的。
-
But the real damage, the damage that can lead to death, happens on a cellular level.
但是真正的傷害,可能導致死亡的傷害,是發生在細胞上。
-
Hi I'm Roberto Cattaneo.
嗨,我是 Roberto Cattaneo 。
-
I'm a Doctor of Philosophy and Professor of Molecular Biology at the Mayo Clinic.
我是梅奧醫學中心的博士,及分子生物學教授。
-
I'm studying the measles virus since about 35 years.
我研究麻疹病毒大約已經 35 年了。
-
Measles uses the trachea as a trampoline.
麻疹把氣管當成跳板。
-
It is in the ideal position in the body to get expelled and to get aerosolized dispersed
氣管是身體中將病毒排出體外最理想的位置,它將病毒以小分子霧狀方式
-
in the air in small particles very efficiently.
有效地散播至空氣中。
-
When someone with measles coughs or sneezes, these droplets contain the measles virus,
當患有麻疹的人咳嗽或打噴嚏時,這些飛沫中會含有麻疹病毒
-
and because measles is a respiratory disease, all someone needs to do is breathe in that
並且由於麻疹是一種呼吸系統疾病,因此人們只要吸入被病毒感染的空氣
-
infected air in order to contract measles.
就會染上麻疹。
-
Unless, of course, they've been vaccinated.
當然,除非他們已經接種了疫苗。
-
When the measles virus reaches the lungs, it is met by a type of white blood cell called a macrophage.
當麻疹病毒到達肺部時,會遇到一種叫做巨噬細胞的白血球。
-
Usually, macrophages seek out and destroy dangerous pathogens like viruses.
通常,巨噬細胞會發現並消滅,像是病毒之類的危險病原體。
-
But the measles virus tricks the macrophage into not seeing it as a danger and instead,
但是麻疹病毒,會誘使巨噬細胞誤認為它是沒有危險性的
-
safely transports the virus into the body's lymph nodes.
反而將它安全地運送至人體的淋巴結。
-
It's here that the virus begins to replicate and spread throughout the entire lymphatic system.
就在這裡,病毒開始複製並傳染至整個淋巴系統。
-
Yea, I mean the macrophages thinks to have a system in which they basically get rid of the virus
是的,我的意思是說,巨噬細胞基本上有一套機制可以消滅病毒
-
And measles can stay there.
但是麻疹病毒卻可以在那裡存活。
-
So not only it is invisible but it begins to make damage to these cells.
因此,它不僅像是隱形的,而且還開始對這些巨噬細胞造成損害。
-
The task of these cells is also to go out and fight infection,
這些細胞具有抵抗外來感染的任務
-
but instead of fighting infection, they go out with the virus and distribute it to the body.
但它們不但沒有抵抗病毒感染,反而將其傳播到身體各部位。
-
Now, as the virus starts to spread, it enters immune cells that express a protein named
現在,隨著病毒開始傳播,它侵入至免疫細胞裡稱為
-
SLAM.
SLAM 的蛋白質受體。
-
These cells are “memory” immune cells, meaning that they remember other pathogens
這些細胞是有「記憶」能力的免疫細胞,這意味著它們會記住
-
that previously infected the host.
先前感染過宿主的其他病原體。
-
Measles attacks and kills these SLAM-expressing memory cells and once those memories of past
麻疹病毒會攻擊並殺死這些記憶細胞,一旦過去感染的記憶被清除
-
infections are erased, the body will be in a much weaker position to fight off future infections
人體對於未來被感染的抵抗力就會變弱了。
-
This is why measles is so deadly.
這就是為什麼麻疹如此致命的原因。
-
But even though the virus has tricked your immune system to helping it, that doesn't
但是,即使麻疹病毒欺騙了你的免疫系統,也並不表示
-
mean your immune system has given up.
你的免疫系統已經無效。
-
Well, at some point the immune system will notice and will secrete cytokines and attract other immune cells.
在某個時候,免疫系統會反應而分泌出細胞激素,並引起其他免疫細胞的注意。
-
So at some point the enemy will be identified and taken care of.
在此同時,病毒就會被識別出來而被消滅。
-
But for the viruses in fact it is only necessary to get out of the host and find a new host.
但是實際上,對於病毒而言,它只需要脫離原宿主,去找一個新宿主就可以繼續存活。
-
So it's in fact better not to kill the host.
因此,病毒實際上最好不要殺死宿主 (它才能繼續被散播出去)。
-
That's right, it's in the best interest of the virus not to kill you, that's some other diseases job.
對的,不將你殺死,才是對這種病毒最有利的,殺死宿主是其他疾病的事。
-
The job of the measles virus is to find a new host, which brings us to another protein
麻疹病毒的任務既是尋找新的宿主,我們就必需提到該病毒入侵的
-
the virus expresses: nectin4.
另一種蛋白質受體:nectin4。
-
And we discovered nectin4 as the epithelial receptor or host exit receptor for measles virus.
我們發現 nectin4 是麻疹病毒入侵上皮細胞的受體或宿主出口受體。
-
As measles spreads throughout the body, it also enters cells that express the protein nectin4.
隨著麻疹擴散到全身,病毒也入侵細胞的 nectin 4 蛋白質受體。
-
This protein is expressed very preferentially in the trachea.
這種蛋白質在氣管中特別顯著。
-
And the more the virusit replicates in the trachea, the more cells it kills there.
病毒在氣管中複製的越多,被殺死的細胞就越多。
-
This dead cell build up actually causes the human host to cough or sneeze, helping spread
被殺死的細胞屍體不斷堆積,就會造成人類宿主咳嗽或打噴嚏,這樣就就助長
-
it into a new human host, bringing us right back to where we started.
將病毒傳播到新的人類宿主中,從而又開始一個另一個的傳染循環。
-
Now, the good news is that once you get the measles, your body learns how to defeat it
現在,好消息是,一旦你得了麻疹,你的身體學會了如何戰勝它
-
and you probably won't get it again.
那你可能就不會被再次感染了。
-
This is similar to how the vaccine works, but the difference is you're given a weaker
這與疫苗的原理是一樣的,區別在於疫苗的劑量較低
-
dose, so you can become immune without getting sick or damaging your immune cells.
因此你既可以免疫又不致生病或損壞免疫細胞。
-
So the vaccine causes the host to remain immune to measles we think for life long or almost life long time.
因此,麻疹疫苗可使人類對麻疹有終身或近乎終身的免疫功效。
-
And without measles, other diseases, the ones that actually do the killing, have gone down.
少了麻疹,其他疾病,也就是真正足以致死的疾病,都已减少了。
-
Basically the number of hospitalization has been reduced considerably sometimes to about
基本上,一些因其他傳染病而住院的人數已大大減少
-
half for several different infectious diseases.
有時甚至減少了大約一半。
-
So, if you haven't been vaccinated...
因此,如果你尚未接種疫苗...
-
Yea, the vaccine works beautifully.
沒錯,麻疹疫苗的效果很好。
-
maybe think about it?
也許你願意考慮一下?
-
Measles may be the enemy of the immune system, but researchers, including Dr Cattaneo, are
麻疹可能是免疫系統的敵人,但包括 Cattaneo 博士在內的研究人員
-
working on ways to alter the measles virus so it kills cancer cells.
正在研究用對付麻疹病毒方法,來殺死癌細胞。
-
For me, a reason to continue study measles is to make it into a friend, making an old
對我來說,繼續研究麻疹的一個原因,是想把它變為朋友
-
enemy into a new friend by modifying it genetically.
通過基因改造,把原來的敵人變成新的朋友。