Friday, November 4, 2011

Creatures Medicine 101: Antigens and Antibodies

Antibodies fight antigens. Right? Every chemical list says so. Even the hoverdoc's cure glossary says so.

Well... as much sense as that makes, I'm having an impossible time proving that true. I can't find any chemical reaction genes that indicate as such, and if I inject a norn with an antibody and follow it up with an antigen injection, it doesn't seem to decay any faster than if no antibodies were present.

No.. the way the reaction equation works is something like this: Antigen X = Antibody X + side effect X
For example, the CFE bruin genome states that 2 antigen 0 = 12 Antibody 0 + 1 histamine B

Antibodies don't seem to actually fight antigens. Antibodies are what the immune system turns antibodies into; essentially, they are a by-product of the body's attempt to fight the infection. In this second graph, I manually lowered the concentration of antibody 0 several times (hence the jagged blue line) and the concentration had absolutely no effect on the rate of decay of the antigen; it follows the same steady curve.

So if antibodies don't fight antigens, what are you supposed to give an ill creature? It is a bit daunting to suddenly find that those antibody-filled lemons aren't doing a thing for a creature's immunity.

What a creature really needs to fight antigens is Vitamin C; this chemical speeds up the reaction rate of the antigen-to-antibody conversion. As a disclaimer though, you want to be very careful using vitamin C to cure antigen 5 (we'll get to exactly why in a minute). Sadly, the only source of Vitamin C I am aware of is found in the vitamin potion from the potion machine on the C3 bridge, meaning DS-standalone worlds will have to find a non-native way to get this vitamin.

But not only does Vitamin C speed up the antigen conversion, it also speeds up the clock rate of the bones organ, which is responsible for the creation of Prostaglandin, the chemical used to heal the organs injured by the antigens. Vitamin C really is quite the healer! Just be sure the creature is eating enough fat and protein, as those are broken down into the chemicals necessary for Prostaglandin synthesis.

But let's step back a bit to talk a little more about antigens themselves. As mentioned earlier, the immune system breaks antigens down into antibodies and a "side effect" chemical. The side effects are as follows:

- Antigen 0 -- Histamine B
- Antigen 1 -- Histamine A
- Antigen 2 -- Coldness
- Antigen 3 -- Coldness
- Antigen 4 -- Hotness
- Antigen 5 -- Wounded
- Antigen 6 -- Hotness
- Antigen 7 -- Pain

Most of these side effects are rather harmless, and act more as symptoms of the infection than anything. But antigen 5's side effect is quite the opposite, in fact; it is deadlier than the antigen itself. Woundedness is a chemical that will instantly kill the creature if it gets too high.

As mentioned before, Vitamin C accelerates the breakdown of antigens to antibodies. This also means it accelerates the creation of the side-effect chemical. This graph shows the reaction resulting from injecting a creature with antigen 5 less than a half dose of vitamin C. The antigen breaks down faster, and both the antibody and the wounded chemical (chemical 90 in this graph) spike, creating a very dangerous situation. For antigen 5, it may be best to have the creature rest and recover naturally.

There is more to know about antigens, particularly which organs they attack. In the next installment (which I haven't actually started writing yet, and still have some research to do, so it'll likely be a while) I plan to detail the functions of each organ so you can have some context as to what exactly is at stake when dealing with antigens.


  1. I love these entries! I'm hoping to do a little study on the toxins and antigens in C1 shortly: They're much more straightforward than those in C3/DS, but the whole antibody/antigen reaction is still present. Some might agree, but it's almost like creatures don't have a real immune system. The antigens create the antibodies that are supposed to fight them off.

    Have you viewed the graph of a creature who is actually infected with an antigen? If memory serves me correctly, the antigen has a steady "spiking" pattern. I've got a few of these graphs filed under Biochemistry.

    Antigen 5 certainly is dangerous! Vitamin C does seem to be the cure, although I never thought of it before. That is, except in the case of antigen 5.

    Excellent discussion, as always! I learn something new from your entries all the time, and I usually get the urge to jump into the scientific side of the game. I'm sure this will be helpful to others, and perhaps it will help save some Norns, Ettins, and Grendels!

  2. Sorry for the multiple comments: I just found a very interesting page from The Norn Underground, which talks about creating more realistic antibody/antigen reactions. Very interesting concept that might be worth checking out! Seems to me like the genes have been altered to make antibodies actually fight off the antigens... Sounds more like a real immune system!

    Granted, these are for the C1 genetics, but I think the idea might apply to this discussion. It's always bothered me that creatures don't have anything resembling a real immune system. I'm tempted to try out some genetic engineering as recommended on the page!

  3. Vitamins C and E have a half life of 255, the same as such vital chemicals as ATP, energy, muscle tissue, etc. Could feeding your norns something with vitamin C in it regularly cause the vitamin to build up in their system, leading to shorter illnesses in general? (assuming antigen 5 is out of the picture...)

  4. Wow, that's quite remarkable. Jessica is quite right that Norns, Grendels and Ettins don't have anything that closely resembles an immune system. But these findings are quite remarkable.

    I currently have a Norn who isn't able to produce Antibody4, and theoretically should have a hard time getting over Antigen4.

    Previously I had a similar Norn with the missing Antibody, however she managed to recover from her related Antigen without issue.

    I'll definitely be doing some tests on my current Norn to see what I can find out.

  5. As far as antibodies fighting antigens go, I believe that it's not the creature itself that uses antibodies to fight off antigens. What I think happens is that as soon as a certain antibody gets high enough/stays in the system long enough, the game engine itself kills the antigen and prevents it from re-infecting the creature.

    I'm not 100% sure that's what happens, though - I haven't read it anywhere. Rather, it's an educated guess I've made from personal observation.

  6. Does prostaglandin also speed up the conversion of antigens to antibodies?

    The hotness associated with antigens 6 and 4 should be mentioned, as it is in the previous post, as a possible cause of death by dehydration, if the antigen to antibody reaction proceeds too quickly.

  7. The antibodies don't do anything to the antigens themselves but they do fight bacteria. If I remember correctly, the bacteria.cos file has code that makes the bacteria more likely to die or detach if they're infecting a creature with high antibodies. Of course, you can just use the antibacterial spray to remove the bacteria. Feeding antibodies to norns is still helpful to minimize their exposure to bacteria when you're not watching though.