Immune System

Antigen Receptor Diversity

The human organism, like all mammals, has defensive mechanisms to protect itself from all forms of attack. We are viewed as food by many carnivores, as well as by very small multicelled animals and many single-celled organisms.

The defense against larger dangers is a well developed intelligence. The defense against the smallest dangers is a complex array of mobile cells and biochemicals they produce, that recognize, identify, and mark invaders for destruction. Specialized cells then employ harsh chemicals to tear the invading cells down to atomic pieces that are then reprocessed as either nutrients or waste. The world of the cellular defenses is sophisticated and complex, truly a thing of incredible beauty.

Central to the system of cellular level defenses is the ability to use biochemicals to tell the difference between cells that make up our own various kinds of tissue, and cells of invaders. Since many of these invaders actually go inside our own cells, leaving some debris from their external coating molecules on the surface of a cell they invade, our hunter-killer cells have had to become creative, and detect the presence of invaders based on this left-behind debris.

Consider what happens when you are given a vaccination. The "stuff" injected into you is "cleaned up" by various types of immune system cells and different kinds of immune system activities. In the process of cleaning it up, the immune system learns about the physical and the electronic-charge shape of the molecules that were injected. It does this in the same manner as when a virus invades, or when bacteria start to grow and multiply. It learns the patterns of surface chemicals on the virus coat or that decorate the cell surface of the bacteria, and makes lots of copies of immune system cells that know the invader's pattern and the cells that make copies of chemicals that can fit against that pattern and stick to it, marking the cell or the piece of debris for cleanup.

It may take days for the immune system processes to complete the learning process, sometimes requiring the immune system to invent new patterns to get the best fit. But when it has a good match, the cleanup goes well. And when the cleanup is done, and there are no more pieces of matching debris, the immune system cells that won the battle go into high gear making more copies of themselves, until thay have created a "standing army" ready to recognize and repel a repeat invasion attempt before it can get a foothold

This last stage is how a vaccination can work to protect us from ever having to actually contract a disease. The standing army is created without an infection just by carefully extracting the right kinds of pieces from the cell walls or virus coats. The process is quite effective, although sometimes the standing army slowly disappears, so we are given "booster shots" to refresh the memory. Some vaccinations require multiple shots to generate a strong enough immune response. Each new injection is treated by the immune system as a re-infection that needs to be fought off more vigorously. So each new injection makes the standing army MUCH bigger than it had been.

So now ponder the events that follow from a bit of food protein being treated like evidence of an invasion. Single amino acids can't trigger the pattern recognizer immune system cells; the recognizers require at least a short chain of amino acids. Most protein we digest is taken apart down to its constitent individual amino acids. Wheat protein, however, contains some specific sequences of amino acids that prevent complete disassembly of the chain of amino acids, leaving pieces that are large enough to be treated as evidence of invasion.

If you eat wheat every day, the immune system sees this as a continuing infection, since the debris is always there. It tries to get rid of the infection and engages in a bit of "fuzzy logic" where it slowly and subtly changes the patterns it is trying out. The way this works is decribed in the link above on "Antigen Receptor Diversity." It makes new pattern after new pattern, and will keep this up until you stop eating wheat.

When you stop eating wheat, the immune system is fooled into going into high gear to produce a huge standing army of the cells that it "thought" were responsible for winning the war. And then the next time you eat wheat, it sees this as a re-infection, and boosts attacks with the full standing army. If you refrain from eating wheat again, the immune system thinks it has won another war, so it enlarges the standing army even more, just like when you get a vaccination booster shot. This happens repeatedly each time you consume more wheat.

The immune system response takes hours to mount, first recognizing the invasion, then recruiting all the other immune system cells that must accumulate where the invader has turned up and then attacking with a variety of different weapons, including cells that eat the invaders, others that blast them with strong chemicals released against a cell wall, ripping it apart chemically. Where was the invasion first noticed? In the early part of the small intestine, where the short chains of amino acids are being absorbed by the epithelial cells lining the intestinal lumen.

One result of the attack is inflammation, which apparently triggers a speeding up of the peristalsis that moves the contents of the intestine toward the exit. But when this happens, there hasn't been proper time for the mix of food and the various digestive chemicals to finish interacting, so you have partially digested food and active digestive chemicals showing up where they are not expected, and certainly not welcome.


There is even some cross confusion between IgE (allergy) related reactions and "delayed onset" reactions. In one study "Wheat allergy: diagnostic accuracy of skin prick and patch tests and specific IgE" the patch tests they used showed reactions not just to wheat, but also to barley and rye.