• Question: could we take cells of animals and transfer them to ill or sick people

    Asked by brownarc to Jen, Jill, Mel, Phil, Stef on 6 Mar 2013.
    • Photo: Stefan Piatek

      Stefan Piatek answered on 6 Mar 2013:

      Ah that’s a really good question. There’s lots of different things that you have to think about, but to keep it simple I’m going to use an example of parts of an animal.

      Let’s say someone has a heart that isn’t working well and they need a new valve, they have a couple of options: They can have a plastic one put in, have one from a pig or possibly get an organ donation from a human. The plastic one needs replacement because it doesn’t last long though.

      Your body recognises things that aren’t a part of you and attacks them, so when you have a valve from a pig or a heart from a human, your fighter cells start attacking them. Patients who do take the donation have to take drugs to make your immune system (fighter cells) calm down which means that they’re more likely to get infection.

      There’s also a lot of differences between humans and other animals (we don’t have hooves!), even at the cellular level so at the moment a lot of work is going to the idea of making organs or tissues from your own cells rather than transferring them from animals.

    • Photo: Phil Rice

      Phil Rice answered on 6 Mar 2013:

      We could but the body is likely to recognise them as foreign and kick them out. Trouble is the reaction could be very damaging dependoing on which part of the body was involved. The first blood transfusion to a human being, believe it or not, was from a sheep and the person survived?!!

    • Photo: Jennifer Paxton

      Jennifer Paxton answered on 6 Mar 2013:

      Ah, this is right up my street! The simple answer is no because your body will try to attack and get rid of anything it doesn’t recognise as its own, so if you transplanted animal cells directly into a human they would all be killed off (or harm the human!). You can take medicine to stop this bad reaction from happening, but it has bad side effects and it means that the patient could get ill from another infection – all because the cells that would normally fight off anything nasty or that it doesn’t recognise have been made to stop fighting!

      BUT! The reason you get this happening is because you have little markers on the outside of the cells that tell the body it is not the same as everything else or “foreign”. So, some scientists are trying to find ways to cover up these markers to allow the donor cells into the body.

      Also, instead of just using cells you could use tissues instead. A tissue is made up of cells within a matrix, which is like a goo that gives the cells somewhere to live. (If you imagine a chocolate chip cookie, the cells are chocolate chips and the matrix is the biscuit part!). It is easier to take tissue from an animal and transplant it into a human if you don’t have the cells there, so scientists are trying to remove all the cells from tissues so the just have the matrix left (so the biscuit, without all the chocolate chips!). This is called decellularisation and animals like pigs can be used because their organs (heart, lungs, liver etc.) and tissues are about the same size as humans. You could also do this with tissues from another human. The ideal plan would be for the sick person to have their own cells grown inside a decellularised tissue or organ and for that to be transplanted. This means that the chance of it being rejected by the body is much less and the patient would be made well again!

    • Photo: Melissa Brereton

      Melissa Brereton answered on 10 Mar 2013:

      Our body is designed to live in harmony and reject anything that it does not recognise as its own whether it be cells of an animal or another human! Our immune system is the body’s CCTV system that patrols around and alerts us to anything unusual or foreign. When it recognises something that shouldn’t be there, it does everything in its power to try and get rid of this object which can sometimes make us very sick. This is what happens when we pick up a virus or bacterial infection and we get poorly- the symptoms are our immune system reacting to the virus or bacteria in our blood!

      So to answer your question, no, our body would not like it if we took cells from an animal and transferred them into people. However, we have some really powerful drugs which can reduce the power of our immune system and this is what is given to patients when they are given a new heart or kidney. These drugs could be used during transfer of animal cells.

      There are a few examples of where animal cells are used to treat ill people. For many years, insulin was removed from pigs and given to patients with diabetes to use in their injections and it was very effective! However, as technology improved, it became possible for us to grow human insulin in huge tanks and this was a lot cheaper and better tolerated by the patients.

      I think in the future, we will start using our own cells- growing them in a dish and transplanting them into patients. This is what the area of “stem cells” is all about and it is very exciting!

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