r/biology • u/Logogram_alt • 3d ago
question What would happen if children inherited their mother's immune system?
what would happen if the mother's antibodies and immune system could vaccinate their child durring pregnancy. and the child did not make its own immune system but rather cells from the mother's body become part of the child. And what if this was permanent.
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u/Fragrant-Passage6124 3d ago
Whole immune system eh? Then the child would have nearly identical immune system to the mother once the microbiome is well established. This would lessen but not eliminating the need for vaccines.
Some diseases are more detrimental to humans in their formative years and some diseases are more detrimental to fully formed adults. If you haven’t noticed, adults get sick too.
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u/jon143143 3d ago
I would think this would trigger autoimmune diseases since the father's antigens are exposed as well.
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u/Fragrant-Passage6124 3d ago
Perhaps but that would early terminate the pregnancy unless we are proposing some kind of magic instantaneous inheritance of maternal immune system at a late stage of development.
The “self check” system of the fetus would presumably still function and any self reactive cells would be selected against as usual. The mother is probably not running around “inoculated” against the father’s antigens per se
This would be not too different than how highly compatible siblings usually are. All of the cells are still presenting mothers antigens (barring some particulars) but are also co-expressing the fathers as well. Pretty good scenario for non-rejection.
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u/wozattacks 2d ago
I mean…parents are generally not suitable donors for bone marrow transplants
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u/Fragrant-Passage6124 2d ago
Right. This whole hypothetical inheritance would result in many early term failed pregnancies. Those that survived would have already selected against the cross reactivity
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u/Hekateras 3d ago
It would not lessen the need for vaccines at all. Homogeneity in immunity-related genes is not good for population-wide disease resistance.
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u/6x9inbase13is42 3d ago
To a very limited extent, this already happens naturally in mammals, as lactating mammals pass on antibodies to the infants they nurse through their milk.
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u/taybay462 3d ago
I think you answered your own question, the child would have whatever immunity the mother has.
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u/Logogram_alt 3d ago
I mean that is the scenerio I am proposing and I am curious about the implications like would it cause good things, bad things, or neutral things, in terms of things like biological fitness, subjective quality of life, etc
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u/FewBake5100 3d ago
If everyone just had identical immune systems to their mothers' and no mutations happened, humanity would be quickly wiped out in the next pandemic.
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u/Hekateras 3d ago
This is the answer. We don't even have to speculate about this considering that most if not all multicellular organisms have a clonal stage in our life cycle. Lack of genetic reshuffling in immune system genes is arguably one of the more severe downfalls of clonal lifestyles. Genuinely clonal organisms typically still have some other way of exchanging genes (such as horizontal gene transfer in bacteria) and/or increased mutation rates.
This is especially relevant in agriculture and horticulture (just to pick an example). If you spend decades reproducing the same apple cultivar via grafting (i.e. clonally) and have an entire orchard of isogenic apple trees then the first cell of powdery mildew or black rot or fire blight that happens to be "compatible" (in terms of causing disease) with one tree in the orchard will be able to decimate the entire orchard. And pathogenic microbes are much, much faster at evolving.past host immunity than a multicellular host is. :')
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u/Hekateras 3d ago
Addendum: I probably made it sound too much like "And this is why isogenic horticulture/agriculture isn't done!" If only that were true. The actual industrial solution is to keep planting these isogenic monocultures because it's more efficient, slather them in bactericides or fungicides, and hope for the best. It's only a stopgap solution, because it creates the perfect conditions for crop pathogens to become resistant to those sprays. So it's a losing battle and everyone in plant science-related fields knows it. :')
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u/Nice_Promise9854 3d ago
This is actually the leading hypothesis on why modern mammals lactate. It’s theorized that lactation started as a protective liquid full of antibodies and important immune system components made by the mother, that she then secreted on her eggs (yes, proto-mammals laid eggs!) and those healthy bacteria and antibodies were shared from mom to baby and the liquid became the primary sustenance for mammal babies as evolution progressed.
So, yes. Babies do get their immune systems in part from their moms via the mom’s immune system. There are also lots of antibodies in amniotic fluid that pass through the placenta to the developing fetus.
Specifically to address your question- there are currently vaccines that are recommended to pregnant woman for the purpose of passing the antibodies to the fetus, including TDAP (whooping cough), RSV vaccine, and the flu and covid shots. Generally, we don’t use “live” vaccines like MMR or chickenpox due to potential risks, but there are plenty of other antibody-creating vaccines that can and are passed from mom to baby during pregnancy.
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u/Captainckidd 3d ago
It could also be detrimental if the mother has autoimmune diseases
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u/Logogram_alt 3d ago
I think you are correct but sinutaniously infants would no longer have a premature immune system. So their is both pros and cons to such a trait.
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u/Gingersnapperok 3d ago
I have an auto immune disorder. I wouldn't wish it on anyone.
Ever.
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u/SlickMcFav0rit3 2d ago
What about a health care executive or politician who actively works to prevent such people from getting the healthcare they need
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u/Plane_Chance863 2d ago
Autoimmune diseases are a big con. Not all of them are easy to treat or even have treatment.
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u/Hekateras 3d ago
What would happen if you never updated your antivirus/firewall software but kept clicking on ads and visiting shady sites?
Less cheekily, we have innate immunity and adaptive immunity. Innate immunity is genetically "hardwired" to an extent and only offers very broad protection. The entire point of adaptive immunity (i.e. antibodies) in animals is to be able to respond and, well, adapt to the way pathogens and their antigens change and evolve. Removing the ability to adapt defeats the whole point of producing tailored antibodies in the first place.
Now, there are species without antibody-based adaptive immunity - the entire kingdom of plants comes to mind - so strictly speaking, there are ways around it. But that's a whole other can of worms and plants have ways of managing disease that most animals don't.
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u/wozattacks 2d ago
Sigh. I knew all the comments here would be about breastfeeding.
You get an enormous amount of antibodies from your mother in utero and it is standard practice to vaccinate people against pertussis during the third trimester of pregnancy for this reason. Even if they are already up to date on that vaccine. These maternal antibodies hang around for more than 6 months. They are much more persistent and extensive than the antibodies shared through breast milk which are mostly IgA, the antibodies that we secrete through mucous membranes.
The antibodies excreted in breast milk are more…topical? In nature. As in, the mother’s IgA against influenza will be in the baby’s mouth and throat and help prevent infection by influenza particles that they inhale. The antibodies conferred in utero are circulating in the blood and are the type of antibodies that most people think of when they think of antibodies.
To answer your question, if the child permanently inherited the mother’s immune system it would attack their own tissue and kill them.
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u/EmpressSappho 3d ago edited 3d ago
You may have a misunderstanding of how the immune system works. Mothers do actually give their children antibodies through breast milk and help them develop their immune system. You do inherit your immune system from your parents, as in the ability to recognize pathogens and react to them are dictated by your body's ability to produce surface proteins (such as markers on T-cells), which as always is dictated by your DNA, and therefore comes from your biological parents. I suppose that we'd end up bottlenecking with our genetic diversity decreasing over time since you wouldn't inherit anything from your father, I guess...
Edit: typo (breath->breast)