question about antigens (immune system vs. blood)

[theonlytycrane]

I was confused between the distinction because in the immune system antigens are any foreign molecule that can initiate an immune system response. After exposure, lymphocytes will have antigen specific receptors for an immune response.

In blood cells antigens are surface proteins that classify blood type. In the case of blood type A, A antigens are exposed on the surface of blood cells but B antibodies are produced.

Am I understanding this correctly?

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[clathrin413]

Consider the alternate case: if your body did make antibodies for the antigens on your red blood cells, your immune system would mount an immune response against your own blood. This would be considered an autoimmune disorder.

So yes, you are correct: a person with Type A blood has A-glycoproteins cell surface markers on their erythrocytes. They do have B antibodies, but not A antibodies. If this person needed a blood transfusion, they should receive O or A blood, but not B or AB blood, as these would activate a response from the B antibodies.

 

[NextStepTutor_2]

I was confused between the distinction because in the immune system antigens are any foreign molecule that can initiate an immune system response. After exposure, lymphocytes will have antigen specific receptors for an immune response.

In blood cells antigens are surface proteins that classify blood type. In the case of blood type A, A antigens are exposed on the surface of blood cells but B antibodies are produced.

Am I understanding this correctly?

Just remember that an antigen is simply a name for a surface molecule (usually a protein) which your body can use to identify cell types. Just because you have an antigen does not mean the body will generate an immune cell to attack it. You immune system spend your early years learning and being exposed to your own cells so that it will recognize friend from foe. Blood antigen recognition is part of this process.

Hope this helps, good luck!

 

[JoeCaputo]

I was confused between the distinction because in the immune system antigens are any foreign molecule that can initiate an immune system response. After exposure, lymphocytes will have antigen specific receptors for an immune response.

In blood cells antigens are surface proteins that classify blood type. In the case of blood type A, A antigens are exposed on the surface of blood cells but B antibodies are produced.

Am I understanding this correctly?

B antibodies are produced in the presence of B, not all the time, I think thats what you meant anyways though.

It helped me to look at it from the biochem view. In regular bio, we learned to repeat the definition as you said it, but in biochem/orgo we looked at the molecular structure. Type O blood contains 3 modified sugars hanging off. Type A and B have these same 3 modified sugars, with the same placement, but they each have a fourth modified sugar connected to one of the other 3. This fourth sugar is the "difference" sugar. So "O" will not be recognized as non-self cells by type O,A, and B, but going the other way, they need to have the same blood type, or be a universal acceptor. When the body recognizes non-self it initiates an immune response. I left out Rh as well, we haven't gotten there yet.

 

[theonlytycrane]

B antibodies are produced in the presence of B, not all the time, I think thats what you meant anyways though.

It helped me to look at it from the biochem view. In regular bio, we learned to repeat the definition as you said it, but in biochem/orgo we looked at the molecular structure. Type O blood contains 3 modified sugars hanging off. Type A and B have these same 3 modified sugars, with the same placement, but they each have a fourth modified sugar connected to one of the other 3. This fourth sugar is the "difference" sugar. So "O" will not be recognized as non-self cells by type O,A, and B, but going the other way, they need to have the same blood type, or be a universal acceptor. When the body recognizes non-self it initiates an immune response. I left out Rh as well, we haven't gotten there yet.

Nope. I'm talking about blood type. Blood cells type B have B antigens, but anti-body anti-B are not produced. You might be trying to talk about the adaptive immune system.

 

[aldol16]

B antibodies are produced in the presence of B, not all the time, I think thats what you meant anyways though.

If you have B and produce anti-B antibodies, then let's say you're screwed.

 

[JoeCaputo]

If you have B and produce anti-B antibodies, then let's say you're screwed.

I was referring to a person with A blood type. Will they produce anti-b without the introduction of B?

 

[aldol16]

I was referring to a person with A blood type. Will they produce anti-b without the introduction of B?

Yes. This is one of the more interesting questions one could ask. That is, let me reframe your question. Why would a person with A blood type be able to produce anti-B if they've never been exposed to B before? Well, the prevailing view is that it has to do with gut microflora that produce similar proteins that look like the B antigen.