Some interesting things from the crazy world of immunology (and summer classes)

close-up-of-antibodyI just finished a four-week summer course in immunology, as part of my biology degree. Summer classes are INTENSE. Material that is usually spread out over an entire term is squished into four little weeks, and you have class four days a week, two and a half hours a day. And overall, you cover a huge, huge amount of material over a really short amount of time. There is lots of reading. It’s intense.

To make it worse, Immunology is a 400-level biology class, meaning mostly seniors take it, who’ve had several years of bio already. I’ve had one. There are also two recommended pre-req classes to take beforehand: cell biology and microbiology. Since all I’ve had is the first year (called “Principles” at my school), I haven’t taken either. So, I knew I was getting into something a bit over my head. It was just, I really liked the immune system part of Principles, and I like a challenge and it sounded kind of badass to do something that difficult in a short amount of time, making it that much more difficult. And it just sounded soooo interesting. When I was first thinking about it, I asked my Principles prof if I would be crazy to try it. She said to me, “All our summer courses are intense but I think if someone could do it, it’s you.” And that felt really good. But I still thought it might be half-crazy to try. Anyway, the class was full. For awhile I checked, day after day, to see if there were any openings and when there weren’t, I kinda gave up.

And then one night, less than a week before the start of summer session, I got drunk for the first time in months and was talking to a friend and realized that spaces were opening up in summer classes, and felt newly inspired and drunkenly decided to sign up for the class. It’s just, I was signed up for what probably would have been a cupcake class, but the thought of taking immunology just got me excited and sometimes you gotta live your passions. So I drunkenly decided to sign up.

The last four weeks were a total whirlwind. And I learned some interesting things that I want to share on here, now that it’s all over.

But let’s start with the basics. I told someone yesterday what class I was taking and she paused for a minute and said, “Okay, what does that even mean?” So, basically what we learned about is how the immune system works and what happens when it doesn’t. A lot of it would probably be boring to most people. There’s a lot of really detailed learning about what different types of cells do, and there are SO many different kinds of cells in the immune system and sometimes what they do overlaps. We also learned about antibodies, and how our bodies make them to be specific for different foreign invaders, and about inflammation and later allergic reactions, and about how each different type of cell matures, and how it activates (which are long sequences of this protein in the cell does this to the next protein, which does this to the next protein, which splits the next protein and on and on until you get the turning on or off of genes). And then we learned about the little chemicals each type of cell puts out and had to learn what each of these things, oh and what’s on the surface of all the different cell types and how that helps it act, and autoimmune disorders and the complement system (for anyone who is familiar with this type of thing, on my final today we had to draw the complete classical pathway of complement activated by IgG against a red blood cell, up through lysis of that rbc, which I had some fun with).

It would be hard to overstate the sheer amount of information we had to learn. There were so many charts and tables we pretty much had to memorize – antibody classes, cell surface molecules, complement molecules, cytokine molecules, all those steps of activation – where and how they’re made, what they effect and how they do it. It was a whirlwind of information. There were probably close to 300 pages of lecture notes, not to mention the reading in the book, and all my own handwritten notes from lecture, with all the added things the prof talked about in addition to what was just on his formal notes. INTENSE INTENSE INTENSE. But I kinda loved it.

My favorite part, and I don’t know why I am SO fascinated by this, maybe because it comes up a lot on things like Mystery Diagnosis (a TV show that’s like House but with real patients), is autoimmune disorders. I just find it so fascinating. There were only two questions about it on our final, two incredibly easy questions, which disappointed me because being so fascinated by it, I really knew that stuff fairly well. ANYWAY, here are some interesting things about autoimmune diseases:

Women are far, far more likely to get them than men, in most cases. In a lot, it’s 2 or 3 to 1, but in some, it’s as much as 10 or 20x more common in women! I mean, that is wild. Why the heck is that? Some are thinking it is related to estrogen or other female hormones. And that makes me wonder about all of the hormone-treated food we eat, and birth control pills and other types of contraception related to hormones, or hormone therapy during menopause. Women are also likely to get autoimmune conditions earlier than men. A really good example of that is myasthenia gravis, which will hit women in their 20s or 30s and men in their 50s or 60s or 70s.

Another thing our professor told us, more than once during the course of the class, was that autoimmune diseases are important because basically it will be very unlikely that anyone nowadays will make it to old age without getting one. A sobering thought, for sure. And a lot of things that I never even thought of as autoimmune conditions are, like diabetes type 1, chron’s disease, inflammatory bowel syndrome, MS, celiac (which my doc thought I might have but thankfully, I do not). And then there were some I knew were, like lupus and rheumatoid arthritis, and there were plenty I’d never heard of. I mean, ankylosing spondulitis (no idea if that’s even spelled right) – that doesn’t even sound like a real thing.

It does seem like these conditions are getting more common over time, and I think part of it is that testing is getting better, but still the thought that everyone’s bound to end up with at least one is sobering.

Some have a high genetic correlation, like ankylosing (one of the highest, related to HLA-B27 gene), and some it’s more iffy, like MS. And in MS, they’re not even totally sure of what happens. Neurons get demyelinated (removal of the protective coating) but they’re still not sure if it’s by antibodies, or killer T cells, or some combination, or an upregulation of this thing called FAS which leads to cell death, or even how the invading antibodies and T cells cross the blood-brain barrier.

And some are related to infections. The two we learned about are an association between a certain (rare) strain of strep with later development of rheumatic fever, and kids who get coxsackie virus have a higher tendency to get diabetes type 1, and to a lesser extent, some autoimmune conditions, including MS, have been linked with infections of Epstein-Barr. And there are also types of drug-induced autoimmunities, including a form of lupus. It makes me wonder if there are any autoimmune conditions linked with vaccinations, b/c they cause the body to make antibodies and mount an immune response. It would be interesting to know more about that.

Maybe it’s a bit twisted because some of these are really, really horrible conditions, but I am so fascinated!

We also learned about all types of allergies (known as hypersensitivities in the world of immunology) and boy did we speed through that part of the course, and how there are four different types and all the different pathologies that result. And we went a little bit into some immune deficiencies, such as hereditary angioedema, which apparently is fairly common.

An interesting thing about allergies is that the first type (the more immediate type) is thought to have evolved as a way to fight off parasitic infections because that particular system is very efficient at dealing with that, and it is possible that we have increases in allergies of this type because in the western world, we don’t really encounter many parasites. Apparently there is a correlation between people who’ve had some low-grade helminthic parasite infection and a decrease in allergies.

We talked about the different blood types and how even if you’ve never been exposed to another type, your body still makes antibodies to it (scientists don’t know why b/c usually you need to have exposure for antibody production to be activated in any significant way). And we talked about Rh (Rhesis) factor and how that affects moms and babies, which had some personal relevance because it affected my brother and sister both.

The parts we did not get into were more detailed looks at immune deficiencies, transplant rejections, tumor immunology and vaccination. Kinda thinking of reading some of it on my own b/c it all sounds interesting.

But a lot of it, yeah, would probably be dreadfully boring, chapters and chapters of cellular stuff, to anyone who’s not really into it so I will try not to bore anyone any more than I already have. It’s just hard to stop myself because I really love it. And the crazy thing is, in this class, as intense as it was, we really only scratched the surface. There would be so much more to learn and understand.

Sometimes I have these thoughts like, the immune system is so exquisitely put together, so detailed and nuanced and intricate, and so many different mechanisms have come about to deal with so many different things, it’s amazing. And b/c it’s so intricate, it’s sometimes surprises me that more doesn’t go wrong more often, that people live as long as they do.

Just today, my friend Wren posted this article on her facebook, about if birth control pills affect womens taste in men and it is all based on the MHC complex, which was a huge topic of the course.

MHC, or HLA in humans, is a set of genes that determine what molecules are expressed on (almost) all of our cells. It is how cells of the immune system recognize cells as self or non-self. It is why our bodies try to attack transplanted tissue. In the article it suggests that women can smell a man’s MHC/HLA type (this was mentioned briefly in my textbook for Principles as well – crazy!) and seek out ones that are different than their own. It makes perfect sense in terms of evolution because if you mate with someone whose HLA is different than your own, your kid would theoretically have a better chance of survival and avoiding the genetic susceptibilities to diseases and autoimmune conditions. It’s kind of like how pure-bred dogs are often at higher risk for diseases than mixes.

It was even suggested in our Principles book that people can smell whether people themselves are homozygous (got the same copy of the gene from both parents, aka themselves have less genetic diversity) or heterozygous (got different copies of the genes from each parents so have more genetic diversity themselves) and tend towards the latter.

Anyway, it’s an interesting article!

All in all, I think I did pretty well in the class. We had two exams, and I did exceedingly well on the first one, a complete perfect score, but the final was a lot harder, covered a lot more, and more complex material and it was comprehensive, so, it was tough. I need to somehow stop myself from ever changing my answers, lol. I still felt okay, but man that exam was brutal! One of the hardest I have ever taken.

Regardless, it’s over and I enjoyed it and learned a lot. I was mentally engaged and interested. But it is a relief to be done. And just when I think I’ll have some big reprieve from all that work, on Monday I start genetics, which I honestly think, in comparison, will be a lot easier. There aren’t any prerequisites beyond what I’ve already taken and it won’t be so over my head, I hope, and I’ll have people I know in my class. So, looking forward to that. And then, after those four weeks, I will have a real summer vacation.

Currently listening:
“Catalyst” – Anna Nalick – been on a Grey’s music kick – especially Season Five, which I loved, but I’m actually not entirely sure which season/episode this song is from, oh well.

Catalyst

L.A. lights never shine quite as bright as in the movies
Still wanna go?
‘Cause something here
In the way, in the way that we’re constantly moving
Reminds you of home

So you’re taking these pills
For to fill up your soul
And you’re drinking them down with cheap alcohol
And I’d be inclined to be yours for the taking
And part of this terrible mess that you’re making
But me, I’m the catalyst

When you say love is a simple chemical reaction
Can’t say I agree
‘Cause my chemical, yeah, left me a beautiful disaster
Still love’s all I see

So I’m taking these pills for to fill up my soul
And I’m drinking them down with cheap alcohol
And you’d be inclined to be mine for the taking
And part of this terrible mess that I’m making
But you, you’re the catalyst

You’ll be the vein
You’ll be the pain
You’ll be the scar
You’ll be the road, rolling below
The wheels of a car
And all of the thoughts, on God
Don’t know if I’m strong enough now
You’ll be the vein
You’ll be the pain
You’ll be the
Catalyst

These L.A. lights, no no,
They don’t shine quite as bright as back in Frisco
Do you wanna go?
Still wanna go

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2 thoughts on “Some interesting things from the crazy world of immunology (and summer classes)

  1. Wow, some fascinating tidbits here. I've always been fascinated with autoimmune diseases, my family's loaded with them — lupus, RA, even ankylosing spondylitis. Thanks for posting about some of the biology behind these conditions, especially the possible estrogen connection.Props for taking a tough class. Did you do well? And now, time to relax… peace, Linda

  2. LOL Linda you are the one person I thought of that might actually be interested enough in those kinds of topics to read the post, LOL.RA is one of those ones that is waaaay more in women than men, and is also really common. Lupus we didn't talk too much about, but basically the body makes antibodies against double-stranded DNA = not good. And there may be some connection with this thing that some immune cells have called Toll-Like Receptors, b/c a certain one, TLR-9 is specific for recognizing double-stranded DNA. It's supposed to be a defense against dsDNA viruses but I guess it can end up going kinda haywire. We didn't go too deep into that one though. But that's why it's often systemic. And apparently it can be drug (as in pharmaceuticals, not like, crack) induced but I don't know much about how or why that happens. It is pretty scary though.And I have to ask this, what IS ankylosing spondylitis? It wasn't in the book at all, just an aside our prof mentioned b/c of the high genetic correlation (and it was on the final). He gave us this chart with different ones and the relative risk (though not quite sure how this was mathematically calculated) and most were in the single digits, and this one was 87. I think a lot of families are loaded with them. It's rough. Another area we touched on was treatment. There are all kinds of newfangled things being tried that make a lot of (at least theoretical) sense. Same with allergies. So maybe there is some relief in the future.Oh another thing I forgot to put in the original post is that often times these conditions can be passed to the fetus, temporarily, while in utero. So a developing baby will get transient myasthenia gravis, as an example, because the mother's IgG antibodies (of most subclasses) cross the placenta. And luckily it is really short-lived.

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