00:00okay so you are a four billion year old meat robot yep you heard me right in fact as you're
00:14made of 30-ish trillion cells and each of those have their own task you're a robot made of trillions
00:20of mini robots you are a mega meat bot and your mission for the past four billion years or so
00:27and for as long as you keep playing this game of life is to safeguard the code to duplicate it
00:33to pass it on the thing is you're rubbish at copying your own code every time it's copied
00:39errors crop up not good when an error makes a robot worse at surviving but sometimes a mistake helps
00:47them survive and they pass that glitch in the code on that's evolution in a nutshell right which means
00:53you're not the result of some fancy design i'm afraid you're a result of billions of years of
00:59bad copies go you another reason you're not totally awesome is because that megabot of yours often
01:06breaks down fortunately cardiologists immunologists microbiologists all the ists have spent centuries
01:12figuring out our sensors and wiring so if something does go wrong they can usually fix it where they
01:19struggle though is when the machinery turns on itself when a copying error leads a cell to start
01:24dividing uncontrollably to grow and multiply into a tumor that's cancer and sadly even with the might
01:32of our modern medicine some cancers evade treatment but this is where a new band of biologists step into
01:39the story the synthetic biologists these biohackers are mashing up science medicine and engineering to rewrite
01:47the code and fix the unfixable biohackers are going into a patient's genetic code and reprogramming
01:55their own immune system to recognize cancer cells and destroy them it's called car t cell therapy and
02:01it's awesome see you're constantly under attack by pathogens single cell bacteria viruses and fungi
02:09despite deciding back in the day to stay solo and not avengers assemble like you did those pathogens see
02:16you in all your mega meatbot glory as a fortress ripe for the plundering thankfully you've got a
02:22security team in place to battle these invaders your immune system and some of its top guards are
02:28your white blood cells they trawl the darkness that is your inner space checking the ids of any cells they
02:35pass although they're not name badges but rather protein fragments on the cell's surface called antigens
02:41there are two types of these guards t cells and b cells t cells check those antigen ids using special
02:49claws receptors that lock with a particular antigen if they find a match they attach and they release toxic
02:55chemicals that burst open the invading cells membrane their b cell workmates create antibodies loads of small
03:02proteins little claws that latch perfectly onto a particular antigen marking them for destruction
03:12these two comrades have got your back and your immune system is brilliant at spotting and fighting
03:17pathogens that invade from outside however they're not so good at spotting your own cells that have gone
03:23rogue the antigens on cancerous cells don't look weird they look a lot like your own cells and the t's and b's
03:31aren't programmed to attack them the usual way to deal with cancer is to try to cut the tumor out
03:37or turn to radiotherapy and then chemotherapy to destroy or block the growth of cancer cells
03:43but if it's a blood cancer if it's floating around your whole body you can't do that
03:50and if the blood cancer actually starts in your white blood cells those key guards in your immune
03:55system you'll really struggle to spot it that's the case with acute lymphoblastic leukemia and that's
04:02where car t-cell therapy is kicking butt the biohackers are reprogramming a patient's own immune system to
04:10recognize particular antigens those particular protein fragments on the cancer cells to do it you first need
04:19millions of a patient's t-cells then to get a t-cell to do something different you need to replace its
04:25normal code with something new something you've designed what synthetic biologists can now do with
04:31dna is super cool they use a computer to put together their own sequences of bases the chemical letters that
04:38spell out the dna then they model what that new genetic code will do on a computer and then make those
04:44sequences on a dna printer yeah that's a thing printing not with ink or with a plastic polymer
04:50like in a 3d printer but with those fundamental building blocks of life with those a's and c's and
04:56t's and g's the new code they designed for a t-cell has three key instructions one it tells it how to
05:04recognize and kill a cancer cell more specifically how to modify an antibody what the b-cells make to latch
05:10onto a target antigen the antibody is modified to make a new receptor that can detect the particular
05:16antigens on the specific cancer two it tells it to make copies of itself when it finds that cancer cell
05:25and three it tells it to survive in the patient's body to get this new code into the patient's t-cells
05:31you use a vector it's something that will easily infect the t-cell and carry that bespoke dna in with
05:38it and voila one car t-cell the name comes from a fire breathing monster from ancient greece that had
05:45a lion's head a goat's body and a serpent's tail it was called chimera a name that has now come to
05:51be used for something that contains two or more different types of tissues or cells as this newly
05:57engineered cells genetic code is part t-cell part antibody it's a chimera and it goes in search of
06:03the cancer's antigen using its new receptor before you put the multiplied up t-cells back into the
06:14patient you give them a mild dose of chemotherapy to wipe their existing t-cells then you simply
06:19reinsert the now modified t-cells the car t-cells and they follow their normal dna programming to move
06:26and search however thanks to their new butt kicking code they've changed what they're looking
06:32for they're now on a mission to find the cancerous cells and destroy them unlike conventional chemical
06:39based drugs that get used up or excreted from the body pretty quickly car t-cells are living drugs that
06:46stay in the patient's bloodstream for years that's a huge pro the flip side is that they're expensive
06:53each car t-cell treatment is bespoke to the patient and it's more difficult to get them to work with
06:58common cancers like breast or lung because you need a specific antigen on the cancer cells for the
07:03car t-cell to target and it's much easier to find that in blood cancers it's still early days though and
07:10there's an exciting future for car t-cell therapy researchers like dr martin puil and his team at ucl are
07:17working on improving the leukemia and lymphoma treatments even further and there's recently
07:22been some promising work on solid cancers thanks to car t-cell therapy the survival rate for b acute
07:28lymphoblastic leukemia has improved hugely nearly all patients go into remission which means that the
07:34leukemia cannot be detected anymore and most patients stay in remission biohacking is here and it can
07:42reprogram your own genetic code to enable your mega meatball to do things it's never been able to do before
07:52so
08:00so
08:00you
08:01you
08:01you
08:01you
08:01you
08:02you
Comments