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    In my text book it says that pigs are genetically modified to lack the enzyme a-1,3-transferase (,which causes pigs to lack their cell surface receptor). It also says that 'engineering of human nucleotidase enzyme into pig cells in culture reduced the activity of a number of immune cell activities involved in xenotransplantation rejection'. But then if the pigs already lack the cell surface receptors that cause the immune response, what is the point in engineering this gene into it? My teacher told me that it's to reduce an inflammatory response and sent me this link http://www.ncbi.nlm.nih.gov/m/pubmed/16021917/ but I don't understand it at all. I thought inflammatory responses were caused by chemicals released by damaged cells. I don't understand how this works :confused:
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    (Original post by celina10)
    In my text book it says that pigs are genetically modified to lack the enzyme a-1,3-transferase (,which is the enzyme which causes pigs to lack their cell surface receptor). It also says that 'engineering of human nucleotidase enzyme into pig cells in culture reduced the activity of a number of immune cell activities involved in xenotransplantation rejection'. But then if the pigs already lack the cell surface receptors that cause the immune response, what is the point in engineering this gene into it? My teacher told me that it's to reduce an inflammatory response and sent me this link http://www.ncbi.nlm.nih.gov/m/pubmed/16021917/ but I don't understand it at all. I thought inflammatory responses were causes by chemicals released by damaged cells. I don't understand how this works :confused:
    It appears to be a double safety from what I can see.
    The specific immune response is caused by the presence of non-self antigen - such as those from a pig and may result in an immune response to the transplant and so a rejection.
    The non-specific inflammatory response is explained in this animation
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    (Original post by celina10)
    In my text book it says that pigs are genetically modified to lack the enzyme a-1,3-transferase (,which is the enzyme which causes pigs to lack their cell surface receptor). It also says that 'engineering of human nucleotidase enzyme into pig cells in culture reduced the activity of a number of immune cell activities involved in xenotransplantation rejection'. But then if the pigs already lack the cell surface receptors that cause the immune response, what is the point in engineering this gene into it?

    My teacher told me that it's to reduce an inflammatory response and sent me this link http://www.ncbi.nlm.nih.gov/m/pubmed/16021917/ but I don't understand it at all. I thought inflammatory responses were causes by chemicals released by damaged cells. I don't understand how this works :confused:
    OK. There are a few things.

    1) Just because the Pig has been genetically engineered to lose the foreign enzyme a-1,3-transferase, that does not mean a human body will not recognise it as being foreign and send a immune response.

    This is because the Pig has multiple cell surface receptors and chemicals that will be alien to the human body. As soon as our body recognises these substances, it will send an immune/inflammatory response to attack it.


    2) An inflammatory response can be sent for multiple reasons. There does not need to be a damaged cells.

    For example if you have an autoimmune disease like Rheumatoid arthritis, you own body sends out inflammatory responses against itself and damages joints.

    This is similar. The Human body recognises alien Pig Tissue and sends an inflammatory response to destroy it.



    3) Now, we engineer the human nucleotidase enzyme to reduce the inflammatory response.

    The link says that human nucleotidase enzyme produces adenosine.

    Normally Adenosine is used to reduce the inflammatory response. However, in Pig Tissue, there is low human nucleotidase enzyme and therefore low Adenosine.

    So, it is made to have high human nucleotidase enzyme
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    (Original post by celina10)
    So it just makes it more likely for transplants to be successful by reducing inflammation. Does the enzyme stop histamine being released? Or deactivate or stop one of the chemicals in this process that causes inflammation?
    The explanation above is far better than the one I'll be able to give
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    (Original post by DorianGrayism)
    OK. There are a few things.

    1) Just because the Pig has been genetically engineered to lose the foreign enzyme a-1,3-transferase, that does not mean a human body will not recognise it as being foreign and send a immune response.

    This is because the Pig has multiple cell surface receptors and chemicals that will be alien to the human body. As soon as our body recognises these substances, it will send an immune/inflammatory response to attack it.


    2) An inflammatory response can be sent for multiple reasons. There does not need to be a damaged cells.

    For example if you have an autoimmune disease like Rheumatoid arthritis, you own body sends out inflammatory responses against itself and damages joints.

    This is similar. The Human body recognises alien Pig Tissue and sends an inflammatory response to destroy it.

    3) Now, we engineer the human nucleotidase enzyme to reduce the inflammatory response.

    The link says that human nucleotidase enzyme produces adenosine.

    Normally Adenosine is used to reduce the inflammatory response. However, in Pig Tissue, there is low human nucleotidase enzyme and therefore low Adenosine.

    So, it is made to have high human nucleotidase enzyme
    This makes sense! Thank you
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    (Original post by celina10)
    This makes sense! Thank you
    Excellent. IF there is any bit that you don't understand, let me know
 
 
 
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