You might know of it as a sexually transmitted infection that causes uncomfortable warts,

你可能知道它是透過性行為傳播，而產生令人不舒服的疣，

the papilloma, but you also may have heard that it can lead to a deadly form of cancer.

也就是乳頭狀瘤，你可能也聽過它會導致致命的癌症。

Both are actually true, as is the possibility that you can have HPV and experience no symptoms whatsoever.

兩者都對，因為你患有 HPV 時可能不會出現任何症狀，

HPV isn't just one virus.

HPV 不只是一種病毒。

There are actually over 200 strains, and the different types of HPV can result in different

它實際上有 200 多種菌株，不同類型的 HPV 可能導致

outcomes (which we'll get into a little bit later).

不同的結果 (我們稍後會進一步談)。

But first, before HPV can do anything, it has to find a way into your skin.

但首先，HPV 在做任何事前，必須找到進入你皮膚的方法。

Hi, I'm Dr. Moscicki from the University of California Los Angeles, Department of Pediatrics.

嗨，我是加州大學洛杉磯分校小兒科的莫思基奇博士。

I'm chief of adolescent and young adult medicine, and I have been studying HPV for over 30 years now.

我是青少年和年輕成人醫學的主任，我研究 HPV 已經超過30年。

So when you're looking at skin, you have several layers, and you have the very basal cell layer,

你在仔細看皮膚時，其實有好幾層，有基底層，

that is, the layer that sits right on top of the basement membrane, and right under

也就是位於基底膜頂部的層，就在

that is what we call the dermis.

真皮層的正下方。

and on top of that, you have the spinous, and eventually, you get the very top cornified cell layers.

上面還有棘層，最後最上面還有角質層。

HPV first attaches itself to the basement membrane, by entering the body through a wound or micro-abrasion.

HPV 首先透過傷口或微小擦傷進入身體，將自身附著在基底膜上。

It usually does this through sexual intercourse, but there are other types of HPV that cause

它通常在性行為時做到這點，但還有其他類型的 HPV

hand and foot warts that aren't sexually transmitted.

不是透過性行為導致手疣和腳疣。

Reaching the basement layer is key because there is a receptor there that it must attach to first.

進入基底膜是關鍵，因為那裡有一個受體必須先連接到它。

It's referred to as a heparan sulfate receptor.

也就是硫酸乙醯肝素受體。

This receptor actually changes the virus so that it can then attach to the basal cells.

這種受體實際改變了病毒，使其可以附著在基底細胞上。

Once it does this, it injects its DNA into the cell's nucleus.

一旦這樣做，它就會將 DNA 注入細胞的細胞核。

As the basal cells matures, the infected cell makes its way to the very top.

等到基底細胞成熟，受感染的細胞會進入最頂端。

...it kind of hijacks the cell.

這有點像是挾持細胞。

And what it does is it makes it start proliferating a lot so that it can replicate itself.

它的作用是開始大量增殖，以便能夠複製自己。

This all happens without your body mounting a real defense against the disease, because

這一切發生在你的身體沒有真正防禦疾病的情況下，因為

HPV avoids expressing genes that would initiate an immune response until later in its lifecycle.

HPV 會避開在生命週期後期引發免疫反應的基因。

it looks like it's a mechanism that HPV has developed in order for its own survival.

這似乎是 HPV 為了生存所發展出的機制。

But, while HPV has found a clever way to avoid the immune system, the body can still get rid of the infection.

但是，雖然 HPV 已經找到一種避開免疫系統的聰明方法，但身體仍可以擺脫感染。

Like, you know, when you're taking a shower, that top layer of skin kind of comes off.

就像你洗澡時，那層頂層的皮膚會脫落。

...once it gets sloughed off, if there's no other place to invade, then that infection's

一旦它脫落，如果沒有其他地方可以入侵，那這種感染

just gonna burn out very quickly.

很快就會消失。

That it was a one-time chance that it found access to the basement membrane.

這是一次性進入基底膜的機會。

In fact, even though 80% of people in the United States are thought to contract HPV,

事實上，儘管美國有 80％ 的人普遍認為感染了 HPV，

90% of infections are cleared on their own.

有 90% 的感染都是自行清除。

So, if the infection doesn't usually last, whats t'he big deal?

所以，如果感染持續不久，那還有什麼大不了的？

Well, that's where those different types of HPV become really important, specifically

那就是不同類型的 HPV 變得非常重要的時候，特別是

the ones that can cause cancer.

會導致癌症的那些。

There's only about 13 types that we have associated with cancer, and they all fall into the alpha types.

大約只有 13 種類型與癌症相關，而它們都屬於 α 型。

The most famous ones are type 16 and 18.

最常見的是 16 和 18 型。

They're actually responsible for around 70% of cervical cancers.

它們其實主導了約 70% 的子宮頸癌。

Types 16 and 18  are totally different from the types of HPV that cause warts, which aren't

16 和 18 型與導致疣的 HPV 類型完全不同，這種疣

pleasant but fortunately do not typically become cancerous.

當然令人討厭，但幸運的是，它們通常不會形成癌症。

What we believe, the way it causes cancer, is that it infects, probably, a stem cell within the basal cell layer.

我們認為它導致癌症的方式是，它可能感染基底細胞層內的幹細胞。

Therefore, those stem cells, as it maturates, what happens is, literally, HPV hijacks the

因此，那些幹細胞，在它們成熟時，會發生的就是 HPV 會挾持

host cell machinery, says, I want you to replicate, because every time you don't stop me, I can

宿主細胞系統，然後說，我要你複製，因為每次你不阻止我，我可以

make more and more of my DNA.

製造越來越多 DNA。

While replicating in stem cells, these oncovirus types of HPV will express the genes called E6 and E7.

在複製幹細胞時，這些致癌的 HPV 會表現出 E6 和 E7 的基因。

These oncoproteins stop the body from killing and clearing out cells with damaged DNA, allowing

這些癌蛋白會阻止身體殺死和清除受損的 DNA 細胞，

the cancerous cells to continue replicating.

讓癌細胞繼續複製。

So when there's a damaged cell, it's a race.

所以，有細胞受損時，那就是一場比賽。

Their immune system is probably trying its best, but it's really pushing the system,

免疫系統可能竭盡全力，但它真的逼迫了系統，

that it's replicating way faster than the immune system can even access it.

它的複製速度比免疫系統快上許多。

Fortunately, we have ways to prevent HPV from getting to this point.

幸運的是，我們有辦法阻止 HPV 這樣做。

First, there are screenings for cervical cancer that can catch the disease when it is still pre-cancerous.

首先，宮頸癌的篩檢，在它仍是癌前期時可以發現疾病。

But there is an unfortunate lack of screening methods for the other cancers caused by HPV.

但是，現在缺乏由 HPV 引起其他癌症的篩查方法。

For people who are young enough and have not been exposed to HPV, there is also a very

對於年齡足夠且未接觸過 HPV 的人來說，

effective vaccine has been available since 2006.

從 2006 年以來，有一種非常有效的疫苗。

And while some people might think it's only given to girls because of the risk of cervical cancer,

而有人或許認為因為是子宮頸癌的風險，所以給女性施打，

It's recommended for boys as well.

也推薦給男性施打。

So the prevention here, we're talking about anal cancer, penile cancers, and oropharyngeal cancers.

所以這裡預防的是，我們現在談的肛門癌、陰莖癌和口咽癌。

So it's equally as important for boys to get this vaccine as it is for girls.

因此，男性接種這種疫苗和女性一樣重要。