IMMUNITY, VAMPIRES, AND THE APOCALYPSE!
In which order should we take them? In reverse? Alright, the apocalypse first! Is it happening? Nope. Different folks have different beliefs about the coming destruction, of which they are all certain. Mine? An asteroid. It has happened before. A two-mile wide asteroid [1998, OR2] just passed by! Remember the dinosaurs? They caught one, maybe 20 times as large [Chicxulub Crater, Mexico].
A viral pandemic then? Nope. That has also happened before, and we survived. Even if now, we are in a pandemic and our normal is altered. This is not an apocalypse.
Vampires? No. Stop it! They don’t exist. But I do wonder what they would want in our blood. More later.
What about zombies? No to them, too. They are not real. Although it is remarkable how close some people come with their “normal” behavior. Know some?
That leaves immunology. And that subject is very real. Maybe that is what vampires would seek to study in our blood!
Blood. It is more than just red. It carries more than just the logjam of fibers to bind over wounds. It carries an army, unknown to you, that is fighting battles, constantly driving out alien invaders, and killing others. And, unless you spike a fever, or your bowels move excessively, or your head swells up like a baleen whale’s blowhole, you’d never know.
It is an ancient war, begun a long time ago. Let us look at some of those bloodstream warriors. These are some cellular components of blood and what they do:
Monocytes [the largest of the white blood cells]; macrophages [immune cells involved in phagocytosis, digesting things that are not you, or not normally so]; neutrophils [from bone marrow stem cells, polymorphonuclear granulocytes];basophils [inflammation, allergies, granulocytes]; mast cells [allergies, histamines]; eosinophils [asthma, allergies, parasites]; T-lymphocytes [cell-mediated immunity, thymus gland, “killer” and “helper” cells,” autoimmune disease]; B-lymphocytes [antigen reacting, antibody forming, acquired immunity]; and erythrocytes [red blood cells, hemoglobin].
And don’t forget those cytokine foot soldiers [small protein facilitators of your immune responses] and the antibodies themselves [large Y-shaped proteins marking the invaders for destruction].
No wonder vampires would want to drink our blood. A treasure chest of evolution. A cocktail of opportunity. Just kidding. There are no vampires or zombies, beyond their entertainment value.
How, then, do these things work? [White blood cells, not zombies]. It seems they are constantly generated for constant warfare. Especially in times of viral onslaught, when our immune system may be all we’ve got.
After millions of years of multi-cellular evolution, humans sit atop a smorgasbord of complex cellular life forms upon which we feed. And, as such, we are a table set, and a meal to be had, by all those other organisms that evolved feeding on us.
Let’s ignore, for now, the bigger ones, saber-toothed tigers and grizzly bears. We have gotten rid of most of them [think Pleistocene megafauna], leaving only ourselves, of the larger beings, to be scared of. But it is really the smaller ones we should fear.
They are smart, and they are everywhere. Natural selection gives them our ticket, and they regularly punch it. And they want to get inside us to feed and reproduce in abundance. Bacteria, fungi, viruses, and protozoans. Gross! Those are the ones our immunological warriors are bred to destroy [does that include prions and those nasty wriggling worms?]. Humans have a lot of parasites, some undoubtedly now living in us right now!
But we consider ourselves so clean, so pure. We shower every day, wash our hands, floss our teeth. The French even constructed a more personal cleaning machine, the bidet. Why, we even splash on a bit of perfume to signal to others our newfound freshness.
No such luck. Your dog will still smell you way before you cross your threshold. Bacterial skin gases and other things. And if we get sick, we think it is easy. We take a dose of antibiotic and clean ourselves again.
Wrong! Simple thinking of simple hygiene. The fact is that your body is constantly at war, though some of those creatures living with us are allies, and not foes. Think of this.
It is estimated that the number of foreign invaders on, in, and about your body ranges from 1.3 to 10 times the number of your cells. You do the math. You have about 37 trillion cells that agree to your personality.
The foreign invaders are found all over your skin, inside your elbow, behind your ear, in the mucal lining of your nose and throat. Populating your colon like a subsidized apartment, and growing anywhere else they can get inside, or penetrate the lining that defines you. Bacteria, fungi, viruses, and little protozoan animals. Worms. You are their playground, home, kitchen, and lavatory.
These things are everywhere! Nope, not true. Not inside you, if your immune system has anything to do about it. Your bigger body helps, too, in general ways. The low pH in your stomach and on your skin kills these things. But the real “Department of War,” that you don’t even know you command, has every bit the sophistication of weapons, armor, and infantry that exist in our National Defense. And most of them are based in our blood. Here is a small snapshot of our defense system’s action.
The name of our system comes from Latin [to sound significant]. “Immunis,” meaning “exempt.” Exempt from attack, I suppose. From those not invited.
Our immune system starts with stem cells in our bone marrow, and works through our thymus gland, and then through our spleen and lymphatic system. That is why your doctor checks your lymph glands below your jaw lines for signs of infection. But it is through your bloodstream that your body rapidly moves around its warriors.
Two general systems, one innate [meaning general, attacking anything that is not yourself], and the other acquired [specific weapons adapted for specific pathogens previously encountered]. Innate systems alter pH, raise temperature, deprive pathogens of necessary nutrients. They release cell-destroying chemicals and enzymes. Some of your white blood cells [macrophages] will even ingest and digest an invader whole [phagocytosis]. And some store small proteins [one is called “defensin”] in cellular granules that are released outside to damage a bacteria’s membrane. There are even lymphocytes [white blood cells] called NKT [natural killer T-cells]. You can imagine what they do to defective body cells infected by viruses or runaway tumors.
The infected area swells, as more blood is let in, heating up the tissue, causing redness and pain. The attack by macrophages, and the release of enzymes and chemicals, will build up in the tissue, and may be released as “pus.”
Acquired immunity is more specialized, and quite a bit trickier. It involves cells that have “memory” of previous invasions of specific foreign pathogens, such as bacteria, viruses, and protozoans. They are recognized by the body’s systems as”antigens,” for which B-Lymphocytes [produced in bone marrow] produce antibodies. T-Lymphocytes [produced in the thymus gland] respond with “helper” and “killer” cells. Both can produce small proteins called “cytokines,” to act as chemical coordinators.
Well, that is a bitter dish of scientific terminology. But all the worse for the invading antigens. Unless the system is somehow broken and turns on its “self” as an “autoimmune disease” [e.g. Rheumatoid arthritis, Multiple Sclerosis].
Just remember that you are more than you think. You are more complex. More beautiful. Rejoice in that fact.
Your immunological system allows you to stride forward toward your future, covered with creatures. And your well-honed systems are ready to fight off any invasions, even if some, like now, are new, or have just been found!
John WilpersMay 15, 2020 at 7:07 pm
Great job describing a complex subject, and with humor as usual! Thanks!