WEBVTT NOTE This file was generated by Descript 00:00:04.290 --> 00:00:06.545 When it comes to treating diseases like cancer. 00:00:07.260 --> 00:00:12.300 Modern medicine has an impressive arsenal, and one of its most versatile 00:00:12.300 --> 00:00:16.890 weapons are y shaped proteins called monoclonal antibodies. 00:00:18.420 --> 00:00:21.509 Our immune systems already produce their own antibodies. 00:00:22.680 --> 00:00:24.930 They come in billions of variations. 00:00:25.759 --> 00:00:32.720 Each matching a specific target, such as a particular toxin, bacteria, or virus. 00:00:35.720 --> 00:00:38.420 When they bind to their target, they send a signal. 00:00:39.440 --> 00:00:42.470 This bacterium is now marked for destruction. 00:00:44.150 --> 00:00:47.660 These naturally produced antibodies are pretty effective, but in 00:00:47.660 --> 00:00:51.915 the 1970s, scientists figured out how to mass produce them. 00:00:52.875 --> 00:00:56.625 They can take any specifically targeted antibody and make huge 00:00:56.625 --> 00:00:57.825 numbers of identical clones. 00:00:58.920 --> 00:01:03.600 Which means you can produce monoclonal antibodies for almost any disease you can 00:01:03.600 --> 00:01:07.110 think of, which brings us on to cancer. 00:01:09.210 --> 00:01:15.420 Mutated cells that start growing outta control can be deadly, but the body's 00:01:15.420 --> 00:01:18.930 immune system isn't defenseless meat. 00:01:19.020 --> 00:01:25.289 The CTL, it's a type of white blood cell that can detect infected or mutated cells. 00:01:26.940 --> 00:01:31.140 And when it finds one, it secretes toxic molecules that initiate a 00:01:31.140 --> 00:01:37.380 self-destruct sequence, but the CTLs do sometimes need to be reigned in. 00:01:37.680 --> 00:01:42.300 If they get over enthusiastic, the immune system can start causing collateral 00:01:42.300 --> 00:01:44.820 damage, attacking healthy cells. 00:01:46.125 --> 00:01:52.025 Fortunately, the CTLs can be turned off by activating a molecule called PD-1. 00:01:52.725 --> 00:01:57.524 The trouble with having an off switch is that cancer cells can exploit it. 00:01:58.365 --> 00:02:03.225 Many cancer cells protect themselves with a counter receptor called PD-L1. 00:02:04.785 --> 00:02:07.140 This is where monoclonal antibodies come in. 00:02:07.920 --> 00:02:10.320 Scientists can use one of two types. 00:02:10.889 --> 00:02:17.029 One that binds the PD-1 molecule or another that goes for PD-L1. 00:02:17.760 --> 00:02:22.050 Thanks to the monoclonal antibodies, all of the CTLs are fully activated 00:02:22.140 --> 00:02:23.790 and can blast away the cancer. 00:02:26.430 --> 00:02:29.909 This is just one way that monoclonal antibodies can be used. 00:02:30.450 --> 00:02:33.719 They've already proven effective against a whole range of cancers. 00:02:33.960 --> 00:02:37.830 And yet more are still being developed with their ability to 00:02:37.830 --> 00:02:40.020 be targeted at specific diseases. 00:02:40.530 --> 00:02:45.390 Monoclonal antibodies are turning out to be a game changer and one 00:02:45.390 --> 00:02:48.780 of our most effective weapons in the fight against cancer.