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0:00
I'm Dr. Srinayak, scientist and immunologist, and I'm here to answer your question from Twitter.
0:03
This is Immune Support Pediatrics.
0:11
Can playing in dirt help your children's immune system?
0:14
Absolutely.
0:14
So in the field of immunology, there's this idea called the hygiene hypothesis.
0:23
We're almost hyper-clean now, and that we're over-cleaning ourselves and that microbes are in fact good for us, and they help our immune system and they strengthen our immune system.
0:21
And evidence from this comes from sort of these remarkable studies done comparing children that grow up on farms with children that grow up in city settings.
0:38
And the incidence of autoimmune diseases or diseases where the immune system has gone Haywire are much, much lower in the sort of farm kids or the rural kids than in the urban kids or the city kids.
0:55
Roger Bezani asked, in the 1950s, the tonsils were routinely taken out, even though they're a fixed part of the immune system, why were parents gullible?
0:55
Tonsils are a gland that are part of the immune system.
1:06
So they are like lymph nodes, they reside right here, and they swell up when you have an infection because that's where the immune system organizes.
1:12
So in the 50s and 60s, a large number of children had their tonsils removed when they were inflamed with this thought that tonsils were reservoirs where disease struck.
1:24
But then the medical establishment kind of moved away from that because there was very little evidence that this was helpful to remove your tonsils to prevent recurrent disease.
1:24
Folks are still undergoing tonsillitis or tonsil removal, but only in the cases where they actually have recurrent strep infection or in some cases of sleep apnea.
1:24
Monica LeBranch asks, what controls your immune system?
1:24
What organs or glands?
1:24
I'm wondering about this.
2:11
This is a great question.
2:18
So your immune system in fact develops in your bone marrow, from your bone marrow, also in glands like your thymus, your spleen, and your lymph nodes.
2:18
And these are really centers where the immune system is acting out of.
2:18
Think of them as sort of fortresses within the body that unleash immune cells to the rest of your systems as they're needed.
2:18
Zach Weiner asks, are viruses alive?
2:18
So viruses are this incredible gray area between alive and dead.
2:18
Is a rock alive?
2:18
Is this table alive?
2:18
No, because they can't replicate or make more of themselves on their own without help from another cell, another creature.
2:22
So here we have one type of this type of virus infects bacteria, and right here we have a virus that infects mammals or us.
2:32
What these creatures do is they infect cells, they hijack, they almost parasitize the resources of that cell to make more of themselves and spread.
2:39
And so we think viruses are this gray area between alive and not alive that are really sending our heads for a tailspin.
2:47
Immune System Quiz asks, how do mucous membranes work as a physical barrier to defend against disease?
2:55
The way mucus works is it essentially creates an even greater separation between our body, our physical barrier, and the microbe.
3:03
And these are particularly important for instance in the intestine, which is densely packed with microbes, and so the mucus just allows the microbes to sit in between our intestine and not even touch our body's barriers.
3:16
Reverend Jake 97 asks, what does the spleen even do?
3:19
So the spleen is this bean-shaped organ that's right here.
3:24
It does quite a few things.
3:24
So it houses immune cells and recycles iron, and it also gets rid of your red blood cells that are pretty old.
3:31
You don't need a spleen surprisingly.
3:33
If you get rid of your spleen, the liver takes over a lot of the functions of the spleen.
3:37
So again, our body is really, really adaptable.
3:39
It's a very fine-tuned machine.
3:42
The List Company asks, is chicken soup good for the immune system?
3:47
What natural remedies do you use to combat sickness?
3:51
I'm a scientist, so my answer is going to be a very scientific answer.
3:53
I don't use natural remedies to combat sickness, I use what we call empirically tested medicines.
4:00
One thing we need to think about when we think about medicines is how these medicines are developed, how they're rigorously tested.
4:06
I don't think that kind of study has been done with chicken soup yet, and so it's very hard to say, does this actually work in a medical setting?
4:14
Is it delicious?
4:14
Does it taste good?
4:16
Of course.
4:16
Pyramids R.M. the immune system consists of a group of cells, tissues and organs similar to the army, and each of them performs specific functions to attack any enemy storming the body, so how does the system work?
4:27
So first of all, I just want to congratulate Pyramids R. on a beautiful analogy, because it's exactly how it works.
4:27
The immune system is essentially our safeguard against invaders, and the second we have an invader, a pathogen, a virus, a bacteria that crosses our boundaries, the immune system can sense this pathogen, consensus disturbance and respond and try to kill it, eliminate it.
4:27
Troy Ella 5 asks, questions for #ImmunologyTwitter.
4:27
I didn't know there was a #ImmunologyTwitter.
4:27
If antibodies to #COVID-19 don't last very long in the body, how effective can a #vaccine be?
4:27
Really great question, really important question.
4:27
So yes, antibodies don't last very long because they are proteins, and proteins are not very long-lived, but what are very long-lived are cells.
4:27
And so the cells that make the antibodies, we call them memory B cells, are very long-lived and in fact live for decades sometimes following certain types of vaccinations.
4:27
So those are the powerhouses that last a long time.
4:27
And so even though your antibody tighter or the antibody levels may decline, the cells that make those antibodies are being stored and being preserved.
5:38
Tampa Bay News asks, the thymus gland, how does this little known gland help your immune system?
5:43
So the thymus is a very, very important gland in fact, because it is where a key type of immune cell develops, the T lymphocyte.
5:51
So the T lymphocyte is part of the T cell or the T lymphocyte, and I think I have a picture of this guy here, I mean stem.
5:59
It's this little cell, it's actually really an important part because it helps directly kill virally infected cells and it's also being harnessed to fight cancers.
6:07
The thymic gland is right here.
6:10
It sits right above your heart below your sternum, and this is where these T cells develop, where they form, where they learn, and then they're sent out to the body to patrol.
6:20
So Nisi asks, does anxiety and depression have an effect on your immune system?
6:28
The immune system and the nervous system are much more closely connected than we'd realize.
6:30
When you have an inflammatory reaction, your nerves activate, and in fact, there are some really interesting early studies that show that memories of immune systems are remembered in our brain, and of inflammation are remembered in our brain.
6:41
And also, there's a lot of evidence suggesting that when you're stressed, you have essentially more vulnerability to infections, you have more vulnerability to inflammation.
6:49
There is this interconnectiveness that's now starting to be unveiled.
6:54
Joe Baby Chase asks, what are lymph nodes?
6:57
Lymph nodes are the centers that are basically fortresses throughout our body.
7:03
They're glands throughout our body that aggregate the immune system.
7:07
So all of our tissues are constantly being monitored by immune cells, and these cells will flow into the lymph node when there is something bad like a pathogen going on, where they can orchestrate an immune response.
7:21
And you can think of this as sort of a border with a fortress.
7:25
There's, you know, soldiers at the border and if there's some, there's something bad that happens, sentinels go back to the fortress where they can organize a larger army and then send them out to the border to fight.
7:36
NHMAMD asks, how can people with HIV live a healthy lifestyle?
7:40
What's amazing, and again, credit to medical science, is that HIV is no longer a death sentence.
7:46
We have a number of different drugs that control the virus and in fact can keep viral numbers in the body so low, folks with this infection can go on to live a very healthy life.
7:59
Antiretroviral therapies and preventative measures like Chavedov have really helped limit the infectious effects and also the transmission of this devastating pathogen.
8:15
Nicole Hallman asked, specifically where does the waste go after a macrophage eats bacteria or virus?
8:18
Is this why people sneeze and have extra mucus?
8:20
Does it come out in urine?
8:23
Okay, good question.
8:23
So first, let's talk about what a macrophage is.
8:26
A macrophage is a cell of the innate immune system, and it's actually a cell that is essentially like the garbage collector of the body.
8:35
You find macrophages all over your body in every tissue, everywhere, and they're really good at eating dead cells, dying cells, they're really good at eating bacteria.
8:47
The macrophage is remarkable because it's not only a garbage truck, but it's also helping break apart the bacteria, kill it, disintegrate it, and get rid of it.
8:54
Andy Lindenberg asks, why do fevers always spike at night?
8:56
How do they know that it's night?
8:58
So our body has a remarkable system, it's called the circadian clock.
9:02
It's a cyclical clock that's within all our cells that kind of gives it the sense that it's day in or it's night, and the cells behave very differently.
9:10
And so one of the reasons fever spike at night is because your cortisol levels, your hormones are really, really controlled by this clock, and cortisol suppresses inflammation, suppresses immunity.
9:21
And so at night, the cortisol levels go down and your inflammatory response goes up, and so this is sort of the natural circadian clock, and so you feel fevers more at night.
9:34
Lindy2350 asks, asthma is defined as a lung disease, but is it also accurate to call it a disease of the immune system because similar allergies it's sparked by an overactive immune response slash inflammation?
9:45
That is correct, Lindy, or I guess Melinda.
9:48
Asthma is a disease that manifests in the lungs and it affects your breathing, but it's a disease that's caused by hyperactive immune cells.
10:00
These immune cells are once again cells that where the brake has been taken off their activity and they're sort of turned on and behaving in a manner as though they're trying to get rid of a pathogen or a bad guy, but in fact this time they are causing lung disease or asthma.
10:00
Carly with three eyes asks, I hate having psoriasis.
10:00
Like what the expletive even is psoriasis?
10:00
Where did it come from?
10:00
Why do I have it?
10:17
Psoriasis is in a disease or condition which manifests as sort of scaly plaques, redness, itching, swelling, and the underlying cause of this disease is a miscommunication between immune cells and your skin cells.
10:38
It means cells think they're fighting a pathogen or they're helping repair tissues when really there's no pathogen or tissue repair needed.
10:48
The Squatting Man asks, what does autoimmune even mean?
10:50
Once again, it's in the name autoimmune, so self, auto itself and immune.
10:55
So autoimmune is when your immune system now instead of activating and fighting pathogens, is recognizing your own cells, your own proteins as bad and attacking them.
11:07
So one example of this is diabetes when your immune system thinks that your cells that make insulin are bad guys and attacks and kills them, and so you're no longer producing insulin.
11:20
Certlab, question for immunologists, outside of the recognized genetic disorders, what's known about person-to-person variation in immune function?
11:24
Thinking about when people say, I have a strong immune system, I never get sick.
11:28
It's a very astute question and it goes down to this fundamental property of nature versus nurture, right?
11:34
How much of our, the way our body works is encoding in our genes, our DNA, that code that makes us and how much of it is the things we're exposed to in the world?
11:45
And turns out the immune system is one of those remarkable systems, it senses the world, it learns in the world, and so it's really in a large part its function is determined by all of these extrinsic factors in a really dramatic way.
11:58
So evidence for this comes from studies at an identical twin.
12:00
So we know that these twins have the exact same genome, exact same DNA because they're identical.
12:06
Folks have looked at the immune system in these twins and what they, they find is that there's remarkable differences in the way these immune cells function, in what types of immune cells there are.
12:16
And so what that tells us is even when your DNA is exactly the same, your experiences has a huge tremendous impact on how your immune system works.
12:24
Outflanked S, so anti-inflammatories bring down fever, but fever is part of the immune response to fight infection.
12:32
Does bringing down a fever prolong recovery?
12:34
This is an interesting question, because yes, fever is part of the immune reaction, and though the thought behind it is that pathogens are really good, they're adapted to our body temperature, so if the body increases its temperature, it's no longer hospitable to a pathogen.
12:50
And so that's one way by which the body is trying to get rid of this pathogen.
12:54
But what we have now are really remarkable antibiotics, antifungals, antivirals, and so we use those to eliminate the pathogen.
13:04
And so the fever strategy may no longer be necessary and doesn't really affect the prolonged recovery.
13:09
And finally, Dr. Carl, can you catch the same cold twice?
13:15
Yes, you can absolutely catch the same cold twice, and I want to clarify, you know, if you're vaccinated against a cold, you can still catch a cold, but what happens is your body has learned to deal with this bad pathogen, whether it's a virus, but as a bacteria, whatever, and so the second time you catch it, chances are you're going to clear it much, much faster.
13:32
And we know this, and certainly the examples with COVID have been very clear, where once they're vaccinated, the numbers of folks that were hospitalized, that were really experiencing severe disease was much, much lower because their immune system has now been educated on how to control the pathogen.
13:49
That's it, that's all the questions, and I hope you learned something.
13:53
Until next time.