This video provides a basic overview of the body's response to a new allergen.
There is a lot of confusion surrounding the risks associated with genetically engineered products...but there are only 2 risks: 1. The new protein could be a toxin or 2. the new protein could be an allergen. It is easy to test for toxicity because all people, in general, react the same to a toxin...so the mechanism is easier to investigate. Allergic reactions, however, are specific to individuals and effect less than 1% of the population. Thus, it takes more investigation to determine if a new protein may be an allergen. Understanding the body's response to allergens can give us the background knowledge to understand testing that is done to reduce the risk of introducing new allergens through genetic engineering.
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[00:00:05.750]There's been a lot of confusion surrounding
[00:00:07.800]what the risks of genetic engineering actually are,
[00:00:11.610]and there's really two risks, that the protein
[00:00:15.010]that we introduce as a result of introducing the gene,
[00:00:17.930]it could be toxic or it could be a new allergen.
[00:00:21.410]And with toxicity, everyone in general
[00:00:24.840]responds the same way, and so it's really easy to test for.
[00:00:28.350]But with allergenicity, each response is very specific
[00:00:34.130]to the individual, and so this is harder to test for.
[00:00:37.250]And so in order to understand the testing process,
[00:00:40.610]first let's understand a little bit
[00:00:42.370]about how the body responds to an allergen.
[00:00:51.360]So first, let's learn about the main players in the game.
[00:00:54.690]And so first, you can see here
[00:00:56.360]we have this allergen protein.
[00:00:59.160]And so this is just, in our story,
[00:01:01.720]this is the new protein that the plant produces
[00:01:04.980]as a result of introducing the gene.
[00:01:07.620]And our other main player is this lymphocyte.
[00:01:11.810]This is another word for a type of white blood cell,
[00:01:15.430]and that's involved in your body's natural defense
[00:01:19.070]against proteins that it sees as potentially dangerous.
[00:01:23.170]So in the case of an allergen,
[00:01:25.740]the protein isn't actually dangerous,
[00:01:27.670]but your body perceives it as so.
[00:01:29.620]And so the way it perceives it as dangerous
[00:01:32.500]is if it fits in this receptor site here.
[00:01:36.170]And so you can see for this individual,
[00:01:38.670]this protein reacts with this receptor site,
[00:01:41.630]and so this lymphocyte, this white blood cell,
[00:01:45.080]is going to perceive this protein
[00:01:47.750]as potentially dangerous and label as an allergen,
[00:01:51.690]which is also then called an antigen.
[00:01:58.020]All right, so because it perceived it as dangerous,
[00:02:02.630]that cell, that lymphocyte morphed into now
[00:02:05.730]what we can see is this plasma cell.
[00:02:09.460]And so this plasma cell
[00:02:10.730]then makes special proteins called antibodies.
[00:02:14.820]And these recognize the allergen protein, the antigen.
[00:02:19.970]And so if the person's exposed to that same protein again,
[00:02:24.260]these antibodies will recognize it
[00:02:25.970]and cause an allergic reaction to occur.
[00:02:32.890]So the other main player in this story is a mast cell.
[00:02:36.520]And this is a special type of cell
[00:02:38.560]that it holds these little molecules called histamine.
[00:02:43.340]And this histamine is a powerful chemical that,
[00:02:46.370]when it's released from the cell into your body,
[00:02:49.210]it'll cause whatever allergic reaction.
[00:02:52.070]And so when these antibodies,
[00:02:56.640]once they've recognized an allergen,
[00:02:59.130]they come and they interact with this mast cell.
[00:03:01.560]And that causes it to then release this histamine.
[00:03:08.340]And so once this histamine is released,
[00:03:11.670]your body then reacts in your own individualized way.
[00:03:16.000]So some people, this is by getting hives.
[00:03:19.260]Some people, this is your lips swelling,
[00:03:22.010]or getting a runny nose.
[00:03:24.000]And so because you're introduced to this protein,
[00:03:26.730]your body reacts, and this is why we take anti-histamines
[00:03:31.970]to avoid allergic reactions,
[00:03:33.530]because it can block our body receiving this molecule
[00:03:37.490]and having allergic reaction.
[00:03:40.180]And so when we're doing food safety testing
[00:03:43.520]for a new genetically engineered plant,
[00:03:46.850]it's producing a new protein,
[00:03:48.730]and so we have to evaluate the risk
[00:03:51.150]of whether people could respond like this
[00:03:54.160]to this new protein,
[00:03:55.810]and so if you watch the allergy testing video,
[00:04:00.000]you'll be able to learn how that's done.
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