[QUOTE=Guy in the Corner]
That isn’t the problem here because the baby is able to produce normal levels of IgM almost immediately which are able to respond to an antigenic insult.
[/QUOTE]
I do not understand what your point is.
[QUOTE=Guy in the Corner]
The maternal antibodies are still there. They take about six months to totally degrade. Maternal antibodies don’t “suck” the antigen. The antibodies can bind to the antigen presented by the vaccination. The antibodies act as opsonins making it easier for macrophages to phagocytose the antigen. These can then be displayed on MHC molecules allowing a response to develop eventually leading to the formation of memory cells. In essence, maternal antibodies make it easier for the baby’s immune system to handle the insult.
[/QUOTE]
I believe you are incorrect. Here is the relevant passage in my immunology textbook.
[quote="Immunology 5th edition, Goldsby, P418]
…passively aquired maternal antibodies bind to epitopes on the DPT vaccine and block adequate activation of the immune system; therefore, this vaccine must be given several times after the maternal antibodies have been cleared from an infant’s circulation in order to achieve adequate immunity.
[/quote]
It would seem to me that macrophages digesting antigens in a baby with maternal antibodies would present antigen epitopes bound to antibodies. As opposed to plain epitopes. This would explain the lowered immune response. WhyNot
Thanks. Thats alot clearer.
It would seem to me that macrophages digesting antigens in a baby with maternal antibodies would present antigen epitopes bound to antibodies. As opposed to plain epitopes. This would explain the lowered immune response.
[/QUOTE]
I don’t believe that matters because as the macrophages engulf the bound epitopes it will all be degraded by cathepsins leaving just an array of small peptides to be presented. The antibody binding has no bearing on the degradation it just increases the ability to get engulfed.
I misread one of your previous comments and thought that what I wrote was correcting something in there. The IgM comment is true, but has no bearing. Sorry about that.
I’m going to look for some more information on early vaccinations. I don’t want to say that I don’t trust Kuby/Goldsby, but I have found numerous errors in the book in the past.
[QUOTE=Guy in the Corner]
I don’t believe that matters because as the macrophages engulf the bound epitopes it will all be degraded by cathepsins leaving just an array of small peptides to be presented. The antibody binding has no bearing on the degradation it just increases the ability to get engulfed.
[/QUOTE]
I believe the important thing about those small peptides is their 3d structure. Specifically the 3d structure on the surface of whatever the antigen itself is. If bound by an antibody then degraded I would imagine the 3d structure would still be changed. Seeing as how the immune system is exquisitely specific I think it would matter.
[QUOTE=Harmonix]
I believe the important thing about those small peptides is their 3d structure. Specifically the 3d structure on the surface of whatever the antigen itself is. If bound by an antibody then degraded I would imagine the 3d structure would still be changed. Seeing as how the immune system is exquisitely specific I think it would matter.
[/QUOTE]
The MHC’s display peptide fragments ranging from 8-14 amino acids long. There is really going to be negligible 3d structure there. Additionally, the antibody binding is not mediated by covalent bonds but rather the weak forces (hydrogen bonding, hydrophobic forces, etc). The antibody will separate from the antigen in endosomes from both the acidity as well as the enzymes.
I’m sorry. You are correct. The above was speculation and I was shooting from the hip. It’s been along time since I took immunology.
I however still thought 3d structure must be relavant. Sequence alone can not possibly be specific enough to reliably distinguish self from non-self. In brushing up I found this figure on Wikipedia. A similar one can be found in my textbook. It explains to me how 3D structure is taken into account without it being present in the short oligos left after degradation.
Also, would you agree that maternal antibodies would interfere with the process in the picture? (antigen mediated activation of B cells) That should affect memory cell generation and therefore immunity.
[QUOTE=Chief Pedant]
For this reason, vaccination programs are hard to drive when the diseases they are preventing are already rare in that population, and it is for this reason that vaccination is required by law.
We have been living in the lap of disease-free luxury so long that we have forgotten the extent to which mass vaccination programs have created a fat and healthy citizenry.
[/QUOTE]
I knew one of the last Spaniards to survive polio. She got it at age 15 and spent decades blind and bedridden. You’ll never hear me complain about giving the polio vaccine to a kid of mine (“of mine” in any degree). A description of her and offering to give her surviving sister’s address to whomever is saying there’s no need for it anymore usually ends the discussion.
Illnesses which were all but gone 10 years ago are now becoming common again. About one in three subsaharian immigrants to Spain picked up by the Red Cross upon arrival testes positive for hepatitis; tuberculosis is relatively frequent - not just a positive for the test, but people who actually have the illness. While most of Spain is positive for TB antibodies, actually seeing it developed was extremely rare. There’s been outbreaks in at least two schools in the last year - for an illness that used to be something Madame Bovary had.
3D structure does matter (I did a presentation on protein folding and 3D structure as part of my MS, several of the examples were from antibody literature because medical stuff is good for calling and keeping people’s attention).
[QUOTE=Velma]
I have no medical training, but I am doing more reading about this right now as I am pregnant. The books that I have (I can look for specific sites if you want) all do recommend that a newborn child not be exposed to public places for at least the first 6 weeks or so. Taking a newborn to the grocery store, or to a nursery or daycare is cautioned against, and the reason always seems to be that their immune systems are not fully functioning yet. I don’t have a book that goes into much detail about that though, but that seems to be the paranoia new parents have about sanitizing everything for a new baby.
[/QUOTE]
I haven’t heard this! We were encouraged to take the baby out, but cautioned about too much contact with people who had colds or flu - Butterbaby was born in November so there were plenty of those germs about. One decision we did make was that we would not sterilise anything. All her stuff has always just been washed in the sink like ours (no dishwasher…). We also al
I haven’t heard this! We were encouraged to take the baby out, but cautioned about too much contact with people who had colds or flu - Butterbaby was born in November so there were plenty of those germs about, and told these people should at least wash their hands before holdong her
One decision we did make was that we would not sterilise anything. All her stuff has always just been washed in the sink like ours (no dishwasher…). If her toys drop on the floor we just give them back - as long as they didn’t land in a puddle!
I have no cites as this is a personal observation but all my friends with children have their oldest one who is troubled with allergies, and the younger ones not. I am sure, as are they, that by the second one the sterilising and cleanliness worries are watered down and the younger siblings are in contact with a lot more ‘germs’.
Butterbaby has had all her jabs, bar the chicken-pox as she’s had the virus. She has MMR to go and will have it close to her first birthday. Small pox has been virtually erradicated thanks to immunisation programmes. I think it’s important, but again that’s a personal opinion.
Sorry about the double post, the baby was playing with the mouse and posted the first one, then I took too long writing the rest and went over my five minute edit window… Never try and post when you should have had a cup of tea…
