Many people think of supernatural phenomena as miracles or as divine signs. However, through his studies in biology, the immune system and DNA, Dr. Denis Alexander concludes that what is called natural is nothing less than miraculous. Dr. Alexander, a renowned molecular biologist, is constantly amazed by the extraordinariness of the human immune system. He explores the relationship between science and religion as the director of the Faraday Institute at Cambridge University. Dr. Alexander writes, lectures and broadcasts widely in the field of science and religion. Since 1992 he has been Editor of the journal Science and Christian Belief, and currently serves on the National Committee of Christians in Science and as a member of the International Society for Science and Religion.
M&B: Let’s talk a little bit about your research on the immune system and cancer. Specifically regarding regulatory T-Cells.
Actually, I’m working on the very early stages of T-cell development in the thymus. T-cells, which are the white blood cells that defend us against viruses and bacteria, all have to be “educated” in the thymus. They have this very strict program of education, and then only a very small percentage graduate, so only about 1 or 2 percent of all the T-cells will actually graduate. If you had that sort of system in our own educational system, I think we would look on it as not very successful. If 98 percent of all our undergraduates die, we wouldn’t think that was a very good system. But in the thymus it actually works very well. So what happens is your T-cells learn to only recognize foreign antigens like viruses and bacteria – things that are going to invade your body – and they won’t attack your own tissues. That’s the kind of education that the thymus gives. It’s really a wonderful, amazing system.
M&B: What is the specific role of the T-cells and how is it related to the functioning of other elements within the immune system?
Well, basically the whole immune system is highly complex, so T-cells are not the only cells around. You have B-cells, you have natural killer cells, you have whole sets of different types of cells, and they’re all doing different jobs. They all have to cooperate together.
Then you have killer cells, or K-cells. These natural killer cells are those which are involved in the immediate reaction of the immune system to antigens once they attack your body. So the body is set up so you have an immediate response system, whereby-it’s like mobilization of an army-you can mobilize small bits of your army in the first 24 hours. That’s the natural killer cells. They will give you immediate defense. You have helper T-cells that help the B-cells in order to develop and to make antibodies. B-cells give you your acquired immune system, which is the immune system that only comes into action after about 10 to 14 days. So, that’s the mobilization of the full resources of your army. Thinking of it in terms of a kind of defense system is actually quite useful. T-cells are involved in wiping out virally infected cells, and so they all coordinate together in a rather delicately controlled, complex balance, but they all have to coordinate with each other to make sure the system works properly. It’s amazing how it works; actually, I think, it’s remarkable.
M&B: The natural killer cells attack the cells which are not supposed to be there. But how can they recognize cells that are part of us, how do they define the “self.” Would you give us a parable about how the natural killer cells work?
In the natural killer cell system, there is also the idea of the missing self, which is the idea that when there’s a certain molecule which is not there, natural killer cells won’t attack. Therefore, they don’t recognize our own tissues. This is the idea of the missing self hypothesis. They will only attack things which they perceive to be foreign. It’s like the foreign thing is coming in and waving a flag which says, you know, I want to be attacked, I should be attacked. And that’s set up by a very carefully balanced system, between activating receptors and inhibiting receptors which operate together in order to bring that to pass. It’s quite a complex molecular system, in fact.
M&B: But it still doesn’t provide 100% support. Obviously we are not totally immune to disease.
Now, once the T-cells get out in the periphery, that’s to say the blood stream and the spleen and the other places, in the gut and so forth, then there are other mechanisms in place to keep them under control and to make sure that they don’t actually start attacking your own body. And of course, now and again, very sadly, that does happen. There are mistakes made, and so you get things like diabetes and rheumatoid arthritis and these sorts of auto-immune diseases, and that’s where the T-cells start attacking the tissues of your own body. It’s amazing, most of the time that doesn’t happen, and that’s all up to the thymus, since it educates the T-cells.
M&B: In what way do these cause cancer?
We’re actually working on a mouse model of the human cancer called Lymphoma. It happens when T-cells don’t stop dividing, and so if you look at all the immune cell types of cancers, they’re all very similar kinds of things. Certain cells of the immune system actually undergo errors in the early part of their development, and instead of moving on to the next stage of development they get stuck. Then, they carry on dividing and proliferating, filling up the whole of your bone marrow or your blood stream, and so you end up with white blood cell leukemia.
I could just tell you one example, the one that we’re working on. Basically, what happens is that when normal T-cells get DNA damage, they die. So as a program, when you get any kind of DNA damage, there’s a trigger that happens, and those cells will be wiped out by a process called apoptosis, which is programmed cell death. All of our cells, actually, have the ability to do that. But now and again something happens, an acrogenic change takes place, which is a change in a gene which causes cancer, and that prevents the cells from dying by apoptosis. And so, the cells that have this DNA damage are left to proliferate, and once you get DNA damage, then the chromosomes become unstable, and you get more DNA damage. It’s like a kind of downward spiral. Then all kinds of things happen that cause that cell to become a cancer cells, which will carry on dividing and dividing and eventually kill the mouse, or kill the patient. We’ve just recently identified one of the mechanisms whereby those cells that should die are kept alive, and it’s a very, very subtle mechanism, which is one particular protein, one particular stage of development to t-cells in the thymus.
M&B: We think that dying is a bad thing. But to give an example at the cellular molecular level, “not dying” is actually a bad thing.
Yes, I mean, death is built into our genomes, essentially. You know, we will die eventually because of all kinds of mechanisms, including the shortening of our chromosomes. The cells will only go through a certain number of divisions before they come to the end of their life. There’s a sort of internally clock. Now, of course, it’s possible that we can patch up all these things, we can use stem cells, we can use transplants. If someone needs a new heart or a liver, we give them a new heart or a liver. So clearly we can extend life by years, by decades, and that process is obviously already happening. In fact, I would say that the priority in that way is not to give wealthy people just a few more decades of life, but to try and help those people in lower income countries where what they need is better food and better water, a good water supply, basic medical care, and therefore their average life will then go from 35 up to 65 or 70 years old and so on. So, I slightly worry about this huge activity in the wealthy world to try and make ourselves immortal, and try to extend our life by another decade or so, when such big slices of the world’s population are still lacking even the very basic medical care that I think they should be given. We can extend life by potentially quite a lot, but to become immortal, I don’t think so. I think mortality is written into our genes.
M&B: As a scientist you study the immune system, as well as life and death. But as a person, what do you feel about them? Would you comment on the purpose behind of all these processes?
Well, I suppose that as someone who believes in God, I would see all of these processes that we describe as biologists, as scientists, as part of God’s processes, that part of His intentions is to bring about His own particular ends and purposes on this earth. And clearly, I think one of those purposes is transience. You know, if you have life and death, you have things in process, you also have transience. We’re not immortal-not in our present bodies at least-we don’t display the qualities of immortality. So therefore, I think that fits with the idea of a God who wants to bring in processes which involve life, and they also involve death, and they involve moving on. So we have dynamic systems. We’re not static, we’re not little puppets, you know, who always have the same kind of characteristics. We are in motion, we’re always changing, we’re always moving on. That’s what we see in human society as well as in the whole world of biological diversity. It’s a dynamic process of things, changing processes, which come into being and which go out again, and life and death go together. You know, you can’t have life without death.
M&B: But there is a sense of awe when you think about the tiniest T-cells getting educated. For some people, it would seem amazing and even miraculous as splitting the water with a simple rod, if you don’t mind me saying this.
It is amazing, and I’m constantly amazed and when I look at the immune system, and when I look at the way cells work, when I look at the way, indeed, biochemical signaling pathways operate together. I think that fact is quite remarkable, actually, and should arouse our awe and our wonder, and indeed many people look to God as a natural overall explanation. Not in the sense of replacing God in the gaps of our knowledge, but as our knowledge increases, then our understanding of God’s power and wisdom in creation increases along with that, and to me is real natural theology. Natural theology is not looking for the gaps in our knowledge, but as our knowledge increases coming to a greater appreciation of what God can do. It’s interesting. Actually, just a couple of days ago, I was listening to the account of a Chinese student in Cambridge in the UK, where I come from, and she was telling us about how she had come to have faith in God. What she said was that she was in her biochemistry lectures in the university, and the lecture was about how DNA in each cell, if you stretch it all out, it actually comes to two meters long. You know, if you take the DNA from any one cell, the packing of the DNA is so amazing that when you pull it out, it is two yards long. And she was so amazed by that, she suddenly thought, in the middle of the lecture, there’s got to be a God. There must be a God. It’s so wonderful, you know, she was amazed by this wonderful thing, and she’s moved to belief in God, and I thought that was really quite interesting.
M&B: Do you think arriving to this conclusion has to do with having an open mind, in many ways?
Yes, I think it does. I think the problem is that people brought up in a scientific culture can so often think that the scientific story is the only one that matters. They’re like people reading a book, but they see it and they only look at the black ink on the page, but when they look at the structure of the words they miss the whole message. And I think that’s always a danger in the reductionist approach. Now I’m a reductionist in the methods I use in analyzing the immune system or looking at cancer mechanisms, and that sort of reductionism is very important for us as a methodology we use in our science. But, of course, we shouldn’t then move from that into thinking that reductionism gives us the final story. It just gives us one slice of the story, one little layer of the overall story. I think we then have to take a step backwards and start looking at the message as a whole. That’s terribly important, and it’s always a temptation for people who are deeply imbedded in the scientific community or living in a scientific culture of some kind just to think the scientific story is the only one that matters, but clearly that’s not the case.
M&B: You talked about a sense of awe that surpasses the mind. But when we attribute unexplained things to God, some people tend to think that God is the God of mystery. God is the God of miracles, God of the unknown and the God of the gaps. Would you please comment on this idea?
I think the idea of the God of the gaps is a very unfortunate idea; that has a very long history. Actually, it goes back many centuries. I’m not quite sure when the idea first began. But I think it’s always been tempting as science got going, especially in the nineteenth century when science was less developed than it was now.. It was a temptation for people to try and locate their God within the present gaps of the scientific knowledge. So obviously, as the gaps are closed, so one’s understanding of God will shrink. God is then located in smaller and smaller mysteries.
Now, I think that’s very unfortunate from a theological point of view, because certainly as a Christian I believe in a God who is the author of creation, and who is the author of everything that exists. Therefore, the author writes everything, the author writes the whole book. And it would be very odd if you were looking in the book, if you went to chapter 9 and you went to the second paragraph and you said, “Ah-ha! Now I’ve located the mystery of the author in the second paragraph in chapter 9.” That would be a silly kind of argument. And I think that’s the same kind of argument that the God of the gaps people use. They try and locate bits of the book, forgetting that either the book has an author, or it doesn’t. There’s either someone who is writing the text or there isn’t. So, I think God is in charge of all the processes of the world, upholding and sustaining the whole of the book of creation, if you’d like to use that analogy. So whether we have current gaps in our knowledge now has no theological significance as far as I’m concerned. It doesn’t matter. It’s of no particular interest, so theology has no hidden investments in gaps in our knowledge. It really doesn’t matter. It simply says we’re ignorant about many things. Which is good, because otherwise I would be out of a job.
Interview conducted by Mustafa Tabanli for Ebru TV for the Emmy Award winning television series Matter and Beyond. For more information and the full episodes visit http://www.ebru.tv