Tiny Bombs in your Blood - The Complement System Winzige Bomben im Blut - Das Komplementsystem Pequeñas bombas en la sangre - El sistema del complemento 血液中の小さな爆弾 - 補完システム Maleńkie bomby we krwi - układ dopełniacza Pequenas bombas no sangue - O sistema do complemento Крошечные бомбы в вашей крови - система комплемента Kanınızdaki Minik Bombalar - Tamamlayıcı Sistem Крихітні бомби у вашій крові - система комплементу 血液中的小炸弹——补体系统 血液中的小炸彈——補體系統

Every living being needs to fight off other living beings that want to feast on them.​ Todo ser vivo necesita luchar contra otros seres vivos que quieren darse un festín con él. Todo ser vivo precisa lutar contra outros seres vivos que querem se banquetear com eles. Каждое живое существо должно бороться с другими живыми существами, которые хотят полакомиться им.

So as multicellular life evolved over billions of years, it came up with ways to defend itself.​ Así que, a medida que la vida multicelular evolucionó durante miles de millones de años, ideó formas de defenderse. Então, à medida que a vida multicelular evoluiu ao longo de bilhões de anos, surgiu maneiras de se defender. По мере того как многоклеточная жизнь развивалась на протяжении миллиардов лет, она придумывала способы самозащиты.

Today humans have a sophisticated defense network,​ Die Menschen verfügen heute über ein ausgeklügeltes Verteidigungsnetz. Hoy en día, los humanos disponen de una sofisticada red de defensa.

like physical barriers, defense cells, and weapons factories.​

But one of the most important defenses of our body is largely unknown:​

The Complement System​

It evolved over 700 million years ago and is an army of over 30 different proteins​

that work together in a complex and elegant dance to stop intruders.​ die in einem komplexen und eleganten Tanz zusammenarbeiten, um Eindringlinge aufzuhalten.

All in all, about 15 quintillion of them are saturating every fluid in your body right now.​ Alles in allem sind etwa 15 Quintillionen von ihnen in jeder Flüssigkeit in Ihrem Körper. Ao todo, cerca de 15 quintilhões deles estão saturando todos os fluidos do seu corpo agora. В общей сложности около 15 квинтиллионов из них насыщают сейчас все жидкости в вашем организме.

Guided by nothing but chemistry,​ these proteins are one of the most effective weapons we have against invaders.​ Guiadas únicamente por la química, estas proteínas son una de las armas más eficaces que tenemos contra los invasores. Many other parts of the immune system are just tools to activate the Complement System.​

But it's also really dangerous.​

Imagine having trillions of little bombs inside your blood that could go off at any moment.​ Imagine ter trilhões de pequenas bombas dentro do seu sangue que podem explodir a qualquer momento. Представьте себе, что в вашей крови находятся триллионы маленьких бомб, которые могут взорваться в любой момент.

So our cells use numerous mechanisms to prevent​ ​complement from accidentally attacking ​ ​ them​ .​ Unsere Zellen nutzen also zahlreiche Mechanismen, um zu verhindern, dass Komplementärstoffe sie versehentlich angreifen. Por ello, nuestras células utilizan numerosos mecanismos para evitar que el complemento las ataque accidentalmente .

Okay, what exactly does it do and what makes it so dangerous?​ Bien, ¿qué hace exactamente y qué lo hace tan peligroso?

In a nutshell, The Complement System does three things:​ In a nutshell, The Complement System does three things:​

it cripples enemies, it activates the immune system, and it rips holes in things until they die.​ Es verkrüppelt Feinde, es aktiviert das Immunsystem, und es reißt Löcher in Dinge, bis sie sterben. paraliza a los enemigos, activa el sistema inmunológico y agujerea las cosas hasta que mueren. ele paralisa os inimigos, ativa o sistema imunológico e abre buracos nas coisas até que elas morram. он калечит врагов, активирует иммунную систему и проделывает дыры в предметах, пока они не умрут.

But, how?​

After all, these are mindless proteins randomly drifting around without will or direction.​ Schließlich handelt es sich um geistlose Proteine, die willen- und ziellos umherschwirren. Al fin y al cabo, se trata de proteínas sin sentido que vagan aleatoriamente sin voluntad ni dirección. Afinal, essas são proteínas irracionais vagando aleatoriamente sem vontade ou direção.

Well, this is actually part of the strategy.​ Bueno, esto es en realidad parte de la estrategia.

Complement proteins float around in a sort-of passive mode.​ Komplementproteine bewegen sich in einer Art passivem Modus.

They do nothing, until they get activated and change their shape.​

In the world of proteins, your shape determines what you can and cannot do.​ En el mundo de las proteínas, tu forma determina lo que puedes y no puedes hacer.

Because shape determines what you can interact with and in what way.​

For example, in your passive shape you might do nothing.​

In your active shape, however, you might, for example, change the shape of other proteins​

activating them so they can activate others.​

Mechanisms like this one can start cascades that spread very quickly.​ Mecanismos como este podem iniciar cascatas que se espalham muito rapidamente.

Imagine the complement proteins as being like millions of matches very close together.​ Stellen Sie sich die Komplementproteine wie Millionen von Streichhölzern vor, die dicht beieinander liegen. Imagine as proteínas do complemento como milhões de fósforos muito próximos uns dos outros. Представьте, что белки комплемента похожи на миллионы спичек, расположенных очень близко друг к другу.

Once one catches fire, it ignites the ones around it.​ Cuando uno se incendia, prende fuego a los que le rodean. Uma vez que um pega fogo, incendeia os que estão ao seu redor.

They ignite more and suddenly you have a big fire.​ Eles acendem mais e de repente você tem um grande incêndio.

To show the actual mechanisms of The Complement System is a tad complicated and overwhelming.​ Die tatsächlichen Mechanismen des Komplementsystems darzustellen, ist ein wenig kompliziert und überwältigend. Mostrar los mecanismos reales del Sistema Complementario es un poco complicado y abrumador. Mostrar os mecanismos reais do Sistema Complemento é um pouco complicado e esmagador. Показать реальные механизмы работы The Complement System довольно сложно и накладно.

So, we'll simplify here.​

Now, let's imagine you cut yourself and a bunch of bacteria enter the wound​ Agora, vamos imaginar que você se corta e um monte de bactérias entra na ferida

and make it into the surrounding tissue.​ y llegar al tejido circundante. e torná-lo no tecido circundante.

Our complement attack begins with C3.​

C3 is the first match, the initial spark that will start our fire.​ C3 es la primera cerilla, la chispa inicial que encenderá nuestro fuego. C3 é a primeira partida, a faísca inicial que iniciará nosso fogo.

And to do that, C3 needs to switch from passive to active.​

How this happens is complex, but let's just say it can happen randomly​

through other complement proteins that bind to enemies or through antibodies.​ a través de otras proteínas del complemento que se unen a los enemigos o a través de anticuerpos. através de outras proteínas do complemento que se ligam a inimigos ou através de anticorpos.

All you really need to know is that C3 breaks into two smaller proteins,​

C3a and C3b, that are now activated.​ C3a y C3b, que ahora están activados.

One of these parts, the C3b protein, is like a seeker missile specialized in bacteria, fungi, and viruses.​ Uma dessas partes, a proteína C3b, é como um míssil de busca especializado em bactérias, fungos e vírus.

It has a fraction of a second to find a victim or it will be neutralized by water molecules.​ Tiene una fracción de segundo para encontrar una víctima o será neutralizado por las moléculas de agua.

If C3b does find a target, it anchors itself very tightly to its surface and doesn't let go.​ Si el C3b encuentra una diana, se ancla muy fuertemente a su superficie y no la suelta.

By doing so, the protein changes its shape again.​

In its new shape, it's now able to grab other proteins and start a small cascade,​

changing its shape multiple times, adding other complement proteins to itself.​ cambiando su forma varias veces, añadiéndose a sí misma otras proteínas del complemento.

Finally, it transforms itself into a recruiting platform known as C3 Convertase.​ Ten slotte transformeert het zichzelf in een rekruteringsplatform dat bekend staat als C3 Convertase. Por fim, transforma-se em uma plataforma de recrutamento conhecida como C3 Convertase.​

This platform is an expert at activating more C3 proteins that start the whole cycle anew.​ Esta plataforma es experta en activar más proteínas C3 que inician de nuevo todo el ciclo.

An amplification loop begins.​ Comienza un bucle de amplificación.

Soon, thousands of proteins cover the bacteria.​

For the bacteria, this is very bad.​

It can cripple the bacteria and make them helpless, or slow them down.​ Puede paralizar las bacterias y dejarlas indefensas, o ralentizarlas. Pode paralisar as bactérias e torná-las indefesas ou retardá-las.

Imagine being covered by thousands of flies.​ Imagina que te cubren miles de moscas.

But, there's more.​

Do you remember the other part of C3—the C3a protein?​

C3a is like a distress beacon.​ C3a ist wie ein Notsignal. El C3a es como una baliza de socorro. C3a é como um farol de socorro.

Thousands of them flood away from the site of battle screaming for attention.​ Miles de ellos se alejan del lugar de la batalla gritando para llamar la atención. Milhares deles saem do local da batalha gritando por atenção.

Passive immune cells notice the C3a proteins,​

and awaken from their slumber to follow the protein tracks to the site of infection.​ e despertam de seu sono para seguir os rastros de proteínas até o local da infecção.

The more alarm proteins they encounter, the more aggressive they get.​

This way, complement guides reinforcements exactly to the place where they're needed the most.​ De este modo, el complemento guía los refuerzos exactamente al lugar donde más se necesitan. Desta forma, o complemento orienta os reforços exatamente para o local onde são mais necessários.

So far, the complement has slowed down the invaders and called for help.​

Now, it's beginning to actively help to kill the enemy.​

The first immune cells to arrive at the battlefield are ​ ​ phagocytes​ .​ De eerste immuuncellen die op het slagveld arriveren, zijn fagocyten.

Which means, cells that swallow you whole, trap you in a tiny prison, and then kill you with acid.​ Es decir, celdas que te tragan entero, te atrapan en una diminuta prisión y luego te matan con ácido. O que significa que células que engolem você inteiro, prendem você em uma pequena prisão e depois o matam com ácido. Это означает, что клетки, которые проглатывают вас целиком, заключают в крошечную тюрьму, а затем убивают кислотой.

But, to swallow an enemy, they need to grab it first.​

Which is not easy because bacteria prefer not to be grabbed and are sort-of slippery.​ Lo cual no es fácil porque las bacterias prefieren que no las agarren y son algo escurridizas.

But now, the complement that has anchored itself to the bacteria​ Pero ahora, el complemento que se ha anclado a la bacteria

acts as a sort-of glue that makes it easy for the immune cells to catch their victims.​

But it gets even better.​ Pero aún hay más.

Imagine being covered in flies again.​ Now, imagine them turning into wasps.​ Imagina que vuelves a estar cubierto de moscas. Ahora, imagina que se convierten en avispas. Another cascade is about to begin.​

On the surface of a bacteria, the C3 recruitment platform changes its shape again​

and begins to recruit new proteins.​

Together, they begin the construction of a bigger structure: a Membrane Attack Complex.​

Piece-by-piece, new proteins shaped like long spears anchor themselves deep into the bacteria's membranes,​ Peça por peça, novas proteínas em forma de lanças longas ancoram-se profundamente nas membranas das bactérias,

until they rip a hole into them that can't be closed again.​ até que eles abrem um buraco neles que não pode ser fechado novamente.

Fluids rush into the bacteria and their insides spill out.​ Los fluidos se precipitan dentro de las bacterias y sus entrañas se derraman. Os fluidos correm para as bactérias e seu interior se espalha. Жидкости устремляются к бактериям, и их внутренности выплескиваются наружу.

They bleed to death.​ Se desangran hasta morir.

The remaining bacteria are maimed and distracted by the complement,​ Las bacterias restantes son mutiladas y distraídas por el complemento.

and quickly taken care of by the arriving immune cells.​ y rápidamente se encargan las células inmunitarias que llegan. e rapidamente atendidos pelas células imunes que chegam. и быстро лечится прибывающими иммунными клетками.

The invasion has been nipped in the bud before it had the opportunity to become dangerous.​ La invasión ha sido cortada de raíz antes de que tuviera la oportunidad de volverse peligrosa. A invasão foi cortada pela raiz antes de ter a oportunidade de se tornar perigosa. Вторжение было пресечено в зародыше, прежде чем оно успело стать опасным.

You probably didn't even notice it.​ Probablemente ni siquiera te diste cuenta.

But while bacteria are not happy about complement,​ Но пока бактерии не радуются дополнению.

the enemies it might be the most useful against are actually viruses.​ los enemigos contra los que podría ser más útil son en realidad los virus. Враги, против которых он может быть наиболее полезен, на самом деле являются вирусами.

Viruses have one problem: they need to travel from cell to cell.​ Los virus tienen un problema: necesitan viajar de célula a célula.

Outside of cells, they're basically hoping to randomly bump against a cell to infect by pure chance.​ Fora das células, eles basicamente esperam colidir aleatoriamente com uma célula para infectar por puro acaso.

Here, they're completely defenseless.​

And here, complement is able to intercept and cripple them,​ E aqui, o complemento é capaz de interceptá-los e inutilizá-los,​

so they become harmless and guide the immune system to devour them.​

Without complement, virus infections would be a lot more deadly.​ Sin el complemento, las infecciones víricas serían mucho más mortales.

But wait, if we have such an effective weapon, why do we ever get sick?​ Pero, si disponemos de un arma tan eficaz, ¿por qué enfermamos?

The problem is that in a war, both sides adapt.​ El problema es que en una guerra, ambos bandos se adaptan.

For example, when the ​ ​ vaccinia virus​ infects a cell,​ Por ejemplo, cuando el virus vaccinia infecta una célula. Als het vacciniavirus bijvoorbeeld een cel infecteert, Por exemplo, quando o vírus vaccinia infecta uma célula,

it forces it to produce a protein that shuts complement activation down.​ le obliga a producir una proteína que cierra la activación del complemento. força-o a produzir uma proteína que desliga a ativação do complemento. он заставляет его вырабатывать белок, который блокирует активацию комплемента.

This way, the virus creates safe zones around the cells it infects.​ De este modo, el virus crea zonas seguras alrededor de las células que infecta.

When it kills them, and tries to infect more, it has a higher chance of being successful.​

Or some bacteria, for example, can grab certain molecules from the blood that keep the complement system calm​ O algunas bacterias, por ejemplo, pueden captar ciertas moléculas de la sangre que mantienen en calma el sistema del complemento

and make themselves invisible.​

So the complement system, while being extremely important,​

is only one player in the complex and beautiful organization that is our immune system.​

A beautiful example of how many mindless things can do smart things together.​ Un bello ejemplo de cómo muchas cosas sin sentido pueden hacer cosas inteligentes juntas. Um belo exemplo de quantas coisas irracionais podem fazer coisas inteligentes juntas.

This video was sponsored by ​ ​ you​ .​

Without your direct support, this channel would not exist.​

And it's hard to overstate how grateful we are for that.​ Y es difícil exagerar lo agradecidos que estamos por ello. E é difícil exagerar o quanto somos gratos por isso.

In 2019, an average kurzgesagt video took at least 1200 hours to produce.​

We need months to research and write our scripts, clear them with experts,​ Necesitamos meses para investigar y escribir nuestros guiones, aclararlos con expertos.

illustrate and animate every scene from scratch, and to compose original music.​ ilustrar y animar cada escena desde cero, y componer música original.

This is only possible through a combination of sponsorships,​

your support on Patreon, and selling merch​

like this poster and postcards we made about The Complement System.​

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The purpose of kurzgesagt is to make the best videos we can​

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Thank you so much for making this possible.​

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