basic immunology question

[ohsmurfyea]

If our body detects a foreign substance and starts making antibodies how will long those antibodies stick around for? They only exist for a transient period right?? I know re exposure will lead to a 2ndary response and more AB production. Is it correct to say that after the first response if you are unexposed to the foreign substance you should technically not have the antibody present? Thanks.

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[engineeredout]

From what I understand, the antibody drops to a very low level, but you'll have cloned B cells which contain the B cell receptors (basically antibodies attached to a B cell) that are idential to the ones that picked up the infection the first go around.

I'd think you'd still have some antibodies left though right? Someone else wanna confirm?

 

[Ari1584]

From what I understand, the antibody drops to a very low level, but you'll have cloned B cells which contain the B cell receptors (basically antibodies attached to a B cell) that are idential to the ones that picked up the infection the first go around.

I'd think you'd still have some antibodies left though right? Someone else wanna confirm?

I'm not 100% sure on this but i think i remember seeing a question like this in TBR homework. I think the antibodies are always present once you have been exposed to the antigen, they are just at very low levels like you said. Don't quote me on that though ...anyone else?

 

[Marjan Islam]

The memory B cells stick around. I don't think the antibodies THEMSELVES stick around. The memory B cells do, and will proliferate into antibodies upon a second attack much quicker than in the primary attack.

 

[Caesar]

If our body detects a foreign substance and starts making antibodies how will long those antibodies stick around for? They only exist for a transient period right?? I know re exposure will lead to a 2ndary response and more AB production. Is it correct to say that after the first response if you are unexposed to the foreign substance you should technically not have the antibody present? Thanks.

Eventually Ab are eliminated by other antibodies. Memory cells stay in the system for ~60-80 years per my immuno class. You would still have some Ab present for awhile as it takes a bit of time to get it all, but I am not sure that the levels would really be high enough to notice.

Edit: Given what an antibody is (a polypeptide) it is unlikely it would stay indefinitely because biochemically it would fail to survive. Polypeptides are regularly broken down, esp those of the lymphatic and circulatory systems. This is just me thinking out loud and not looking things up. Who knows maybe I will fail that Immuno test tomorrow after all...

 

[Bacchus]

Caesar's right, Abs don't stick around the entire time. Currently accepted schema indicate the removal of the antibodies in a step-wise fashion. The exact method is still debatable, but include passive cell death theory, active cell death theory, and the antibody network theory where a series of three different Abs are produced to remove the Abs.

 

[VanBrown]

it depends on the isotype...

most humoral immune responses produce IgG which can stay for about 2-3 months. The other isotypes have lower half-lifes.

IgG - 1/2T = 3 weeks
IgA - 4-6days
IgM - 5-6 days
igD - 2days
IgE - 1-2 days

these half-lives are important ontogenetically since the newborn has little ability to mount a humoral response...