How to create a world where no one dies waiting for a transplant | Luhan Yang

112,443 views ・ 2018-10-05

TED


Please double-click on the English subtitles below to play the video.

00:12
Hi everyone.
0
12840
1216
00:14
I would like to introduce you to Laika.
1
14080
2480
00:17
To most of us, Laika is simply a very cute pig.
2
17680
4200
00:22
However, to hundreds of thousands of patients in need of a lifesaving organ
3
22800
6536
00:29
Laika is a symbol of hope.
4
29360
2280
00:32
You see, ever since the 1970s,
5
32960
3096
00:36
when organ transplants became a real option
6
36080
3296
00:39
for patients with kidney failure and other organ diseases,
7
39400
4216
00:43
organ supply has been an issue.
8
43640
2600
00:46
Over the last few decades,
9
46920
1896
00:48
the issue only worsened as organ demand has exponentially increased.
10
48840
5040
00:55
Currently in the US,
11
55400
2296
00:57
there are close to 115,000 patients
12
57720
4176
01:01
in need of a lifesaving organ transplant.
13
61920
2760
01:05
By the end of my talk,
14
65520
1816
01:07
one more patient will be added to this list.
15
67360
3760
01:12
Today, about 100 people will get a new organ,
16
72120
4375
01:16
a chance to start their life anew,
17
76519
2817
01:19
and yet by the end of today,
18
79360
2976
01:22
20 others will die waiting.
19
82360
2480
01:26
The situation is heartbreaking
20
86240
2496
01:28
for patients, for their families
21
88760
2896
01:31
and for the doctors who want to do more.
22
91680
3000
01:36
In some parts of the world,
23
96000
1936
01:37
the situation also becomes a disturbing social issue.
24
97960
3600
01:42
In Asia, for example,
25
102120
1976
01:44
media outlets reported that desperate patients
26
104120
4056
01:48
are obtaining organs from the cruel black market.
27
108200
3920
01:53
It is clear that a solution is needed to this crisis.
28
113600
5416
01:59
Human lives are at stake.
29
119040
2560
02:03
As a biologist and a geneticist,
30
123160
3056
02:06
it has become my mission to help solve this problem.
31
126240
3680
02:10
Today, I am optimistic to say that we are on our way there,
32
130760
5016
02:15
thanks to Laika.
33
135800
1200
02:17
Using gene editing technology,
34
137600
2336
02:19
it's now possible to exquisitely create a human-transplantable organ
35
139960
5856
02:25
that can be safely grown in pigs.
36
145840
2560
02:29
Before we jump into the incredible science that makes it happen,
37
149920
4256
02:34
let's have a better understanding what xenotransplantation is.
38
154200
4400
02:39
It's a process of transplanting animal organs into humans.
39
159120
4480
02:44
You may want to ask, why pig organs?
40
164480
3016
02:47
Because some pigs carry organs with similar size and physiology
41
167520
4816
02:52
to human organs.
42
172360
1200
02:54
Over the last half a century,
43
174280
2416
02:56
pioneers of transplantation have tried hard to make it happen,
44
176720
4856
03:01
but with limited to no success.
45
181600
2880
03:05
Why is that?
46
185080
1200
03:06
Two fundamental hurdles stood in the way.
47
186880
2760
03:10
First is a problem of rejection.
48
190240
3176
03:13
When our immune system sees a new organ as foreign,
49
193440
3816
03:17
it will reject it.
50
197280
1240
03:19
Second, and this one is specific to the organs from the pig,
51
199400
4320
03:24
every pig carries a virus that is benign to the pig,
52
204760
4416
03:29
but can be transmitted into humans.
53
209200
2656
03:31
It is called the porcine endogenous retrovirus (PERV),
54
211880
5496
03:37
and this virus has the potential to cause a viral epidemic similar to HIV.
55
217400
6000
03:44
Without an effective way to address these issues,
56
224280
4776
03:49
the field of xenotransplantation has been on hold for more than one decade.
57
229080
5600
03:55
Little progress has been made, until now.
58
235600
4080
04:01
Let me share with you how I got here today with Laika.
59
241480
3680
04:06
My journey started from Emei Mountain in China.
60
246280
4016
04:10
That is the place well described in a lot of legendary stories,
61
250320
4416
04:14
like the "Crouching Tiger, Hidden Dragon."
62
254760
2640
04:17
That is the place I call home.
63
257840
2320
04:20
Growing up in the mountain,
64
260920
1736
04:22
I started to have a strong connection with nature.
65
262680
3080
04:26
This is me when I was seven years old
66
266680
3056
04:29
standing in front of an ancient Buddhist temple
67
269760
3416
04:33
with a monkey on my shoulder.
68
273200
2016
04:35
I still vividly remember how my friends and I
69
275240
3576
04:38
would toss peanuts around to distract the monkeys
70
278840
3176
04:42
so that we could cross to hike through the valley.
71
282040
2680
04:45
I love nature.
72
285840
1496
04:47
When it was time to choose a field of study,
73
287360
2856
04:50
I chose to study biology at Peking University in Beijing.
74
290240
4000
04:55
However, the more I learned,
75
295760
2496
04:58
the more questions I had.
76
298280
1320
05:00
How could our genetic makeup be so similar to animals
77
300520
4536
05:05
and yet we look so different?
78
305080
1920
05:07
How is our immune system capable of fighting off so many pathogens
79
307920
4856
05:12
but smart enough not to attack ourselves.
80
312800
2720
05:16
Questions like this tormented me.
81
316280
2520
05:19
I know it sounds nerdy, but you know I'm a scientist.
82
319880
2840
05:24
After college, I decided I didn't want to just ask the questions,
83
324000
5256
05:29
I wanted to answer them, so I did.
84
329280
3160
05:33
In 2008, I was lucky enough to be accepted
85
333560
4056
05:37
into the PhD program at Harvard University
86
337640
3536
05:41
and worked with Dr. George Church.
87
341200
2080
05:43
While working in Church's lab,
88
343920
1736
05:45
I started to learn and experiment with the genetic makeup of mammals.
89
345680
4680
05:51
Among all the experiments,
90
351200
2256
05:53
one particular one took me closer to Laika.
91
353480
3200
05:57
In 2013, my colleagues and I made changes in a human cell
92
357520
5936
06:03
using a tool you may have heard about
93
363480
2456
06:05
called CRISPR.
94
365960
1536
06:07
We were one of the first two groups
95
367520
3216
06:10
to report the successful use of such a tool in changing our DNA.
96
370760
5376
06:16
It was an exciting moment in scientific discovery.
97
376160
3520
06:20
The gene-editing tool CRISPR has two components.
98
380800
4336
06:25
It has a scissor called the enzyme CRISPR
99
385160
3496
06:28
and what is called a guide RNA.
100
388680
2680
06:31
Think about it as genetic scissors with a microscope.
101
391920
4136
06:36
The microscope is a guide RNA,
102
396080
3096
06:39
which brings the scissors to the place we want to cut
103
399200
4016
06:43
and says, "Here it is,"
104
403240
2016
06:45
and the enzyme CRISPR just cuts and repairs the DNA in the way we want.
105
405280
5240
06:51
Shortly after we reported our study,
106
411720
3216
06:54
physicians at Mass General Hospital were intrigued by the medical applications
107
414960
5936
07:00
of our research.
108
420920
1576
07:02
They reached out to us,
109
422520
1496
07:04
and together, we began to see the potential to use CRISPR
110
424040
4096
07:08
to solve the organ shortage crisis.
111
428160
2600
07:11
How do we do it?
112
431840
1616
07:13
It is simple, yet very complex.
113
433480
3120
07:18
We started by making changes in a pig's cell to make it virus-free
114
438080
6016
07:24
and human-immune-compatible.
115
444120
2776
07:26
The nucleus of that cell is then implanted into a pig egg
116
446920
4776
07:31
and allowed to divide into an embryo.
117
451720
2896
07:34
The resulting embryo is then placed into the uterus of a surrogate mother
118
454640
5296
07:39
and allowed to divide into a pig.
119
459960
2040
07:42
Basically, it's a process of cloning.
120
462680
2360
07:45
The piglet then carries organs whose genetic makeup
121
465760
3856
07:49
hopefully wouldn't be rejected by the human immune system.
122
469640
3600
07:54
In 2015, our team decided to tackle the viral transmission problem first.
123
474960
6416
08:01
We wanted to take out all 62 copies of the PERV virus
124
481400
6176
08:07
from the pig genome,
125
487600
1400
08:10
but at the time, it was nearly mission impossible.
126
490200
4136
08:14
Even with CRISPR,
127
494360
1416
08:15
we could only do one or two modifications within a cell.
128
495800
4816
08:20
The record for number of modifications we can do in a particular cell was five.
129
500640
6536
08:27
We had to increase the throughput by more than tenfold to achieve that.
130
507200
5240
08:33
With very careful design and hundreds of trials,
131
513400
3656
08:37
we successfully took out all the virus,
132
517080
3216
08:40
broke the record.
133
520320
1576
08:41
More importantly, our studies showed
134
521920
2456
08:44
that we could eliminate the possibility of this dangerous virus
135
524400
5056
08:49
being transmitted into humans.
136
529480
2319
08:53
Last year, with a modified cell and cloning technology,
137
533080
4376
08:57
our startup, eGenesis, produced Laika,
138
537480
3840
09:02
the first pig of its kind born without PERV.
139
542160
4480
09:07
(Applause)
140
547480
3736
09:11
Laika represents the first critical step
141
551240
3976
09:15
in establishing safe xenotransplantation.
142
555240
3736
09:19
It is also a platform
143
559000
1896
09:20
that we can do further genetic modification on
144
560920
2976
09:23
to solve the immunology problem.
145
563920
2200
09:26
Since then, we have created more than 30 pigs without PERV,
146
566760
5096
09:31
and they may be the most advanced geno-modified animal living on earth.
147
571880
5600
09:38
We named Laika after the Soviet dog
148
578400
3296
09:41
who was the first animal to orbit the earth.
149
581720
3320
09:45
We hope Laika and her siblings
150
585600
2976
09:48
can lead us into a new frontier of science and medicine.
151
588600
4800
09:55
Imagine a world where patients who suffer from liver failure
152
595360
5136
10:00
can be saved with a new liver
153
600520
2656
10:03
without having to wait for a donation
154
603200
3056
10:06
or another human to die.
155
606280
1800
10:09
Imagine a world where people with diabetes
156
609600
4096
10:13
do not have to rely on insulin after every meal
157
613720
3736
10:17
because we can provide them with good pancreatic cells
158
617480
4096
10:21
that can produce insulin on their own.
159
621600
2280
10:24
And imagine a world where patients with kidney failure
160
624600
4976
10:29
do not have to face the burden of dialysis.
161
629600
3680
10:34
We are striving to create that world,
162
634320
3736
10:38
a world without organ shortage.
163
638080
2800
10:41
We finally have the tool to tackle the problem
164
641720
3736
10:45
we could never tackle before,
165
645480
2136
10:47
and Laika is just the beginning of our journey.
166
647640
3280
10:52
We have to be very humble in front of nature,
167
652040
3536
10:55
because there are more issues to be addressed,
168
655600
2616
10:58
including immunology
169
658240
1616
10:59
and things we couldn't even anticipate at this point.
170
659880
3960
11:04
However, it is our responsibility to translate the cutting-edge science
171
664760
6136
11:10
into medicine to save the lives of all the patients who are waiting.
172
670920
5320
11:17
Thank you very much.
173
677480
1256
11:18
(Applause)
174
678760
4840
11:29
Chris Anderson: I mean, Luhan, this is extraordinary work here.
175
689800
3496
11:33
Come forward.
176
693320
1200
11:35
So what's the next steps here? You've got rid of the virus.
177
695640
4416
11:40
The next steps involve trying to get to the point
178
700080
2336
11:42
where a human body won't reject a transplant.
179
702440
3776
11:46
What's involved in solving that?
180
706240
1800
11:49
Luhan Yang: It's a very complicated process.
181
709160
2256
11:51
So we need to take out the antigen of the pigs.
182
711440
4456
11:55
In addition, we can learn a lot from cancer.
183
715920
3416
11:59
How can cancer invade or circumvent our immune system
184
719360
4176
12:03
so that we can utilize the trick of cancer
185
723560
4456
12:08
and implement that on the pig organ
186
728040
2336
12:10
to fool our immune system to not attack the organ.
187
730400
3080
12:15
CA: When would you estimate, when do you hope
188
735680
3376
12:19
that the first successful transplant would happen?
189
739080
3320
12:23
LY: It would be irresponsible for me to give you any number.
190
743360
3880
12:28
CA: We're at TED. We're always irresponsible.
191
748200
2120
12:30
LY: But we are working day and night
192
750760
1736
12:32
trying to make this happen for the patients.
193
752520
2080
12:35
CA: So not even, you won't say that you think it could happen
194
755440
2896
12:38
within a decade or within five years or something?
195
758360
2376
12:40
LY: For sure we hope it happens within one decade.
196
760760
2400
12:44
(Laughter)
197
764080
1936
12:46
CA: So there's a lot of people here who would be very, very excited at that,
198
766040
3616
12:49
the potential is extraordinary.
199
769680
1496
12:51
There will be some other people here who are going,
200
771200
2416
12:53
"That pig is too cute.
201
773640
1256
12:54
Humans shouldn't be exploiting something so cute for our benefit."
202
774920
4576
12:59
Do you have any response to that?
203
779520
2440
13:03
LY: Yeah, sure.
204
783120
1256
13:04
So imagine one pig can save eight people's lives.
205
784400
4896
13:09
In addition, similar to human donation,
206
789320
3096
13:12
if we only harvest one kidney from the pig,
207
792440
2736
13:15
the pig can still be alive,
208
795200
1896
13:17
so we are very mindful about the issues,
209
797120
4056
13:21
but I think our goal is just to address the unmet medical need
210
801200
4376
13:25
for those patients and their families.
211
805600
2696
13:28
CA: Plus, no one can say that to you if they eat bacon, right?
212
808320
3280
13:32
LY: That's a good point.
213
812440
1216
13:33
(Laughter)
214
813680
1456
13:35
CA: Luhan, thank you so much. LY: Thank you so much.
215
815160
2456
13:37
(Applause)
216
817640
2240
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7