Celiac, Gluten and Trypsin Inhibitor

---the other 200 posts---   

Wheat

Summary

Forget the gluten.  Celiac is caused by trypsin inhibitors (ATI) that were increased in wheat fifty years ago to combat pests.  Immune response to ATI spreads to include gluten and transglutaminase that perpetuates the disease.  Celiac is an unexpected consequence of traditional plant breeding that could be fixed with GMO approaches.

Plants Protect Themselves with Antibiotics, Pesticides and Trypsin Inhibitors.

Plants respond to pathogens and pests by making themselves toxic.  Thus, plants produce natural antibiotics, phytoalexins, a.k.a. phytochemicals, polyphenolics or antioxidants, to kill bacteria and fungi.  They also produce chemical pesticides and proteins, e.g. trypsin inhibitor, that block the digestion and utilization of plant proteins by insects.  One of these trypsin inhibitors makes ground soybeans inedible until it is removed in water rinses during the production of tofu.  Another of these trypsin inhibitors, in wheat, is the cause of celiac.

Plants Target the Nerves, Immune Cells and Intestines

Plants have evolved chemicals and proteins that attack and punish plant-eating animals.  A single molecule of caster bean toxin protein, for example, can kill a human cell.  Plants produce some of the most toxic molecules on earth.  The nervous system of insects and other herbivores is typically targeted by plants.  Many recreational drugs, e.g. opioids, THC, nicotine, caffeine, etc., for example, are made by plants in self defense.  Human nerves respond to these natural pesticides and the bitter taste and the vomit reflex help us to detect and avoid toxic phytochemicals.  Gluten proteins contain polyglutamine stretches of amino acids that resist digestion and bind to intestinal cells.  Seed lectins bind to the glycoproteins on the surface of the intestines and inhibit digestion.  Wheat seeds also contain an inhibitor of starch and protein digestion, the amylase/trypsin inhibitor, ATI.  ATI binds to the receptors on immune cells that trigger general inflammatory responses to pathogens, e.g. TLR4.  It is the ATI in wheat that starts an immune response to gluten and celiac.

Wheat trypsin inhibitor causes celiac and autoimmunity

ATI Increased to Make Wheat Resistant to Pests

More than fifty years ago, plant breeders began to screen wheat varieties for resistance to pests.  Breeding ultimately resulted in enhanced pest resistance that resulted from increased production of ATI in wheat kernels.  Modern wheat flour contains modest changes in gluten and other components over the last century with the singular exception of ATI, which has increased about 50 fold.  It is also interesting that ATI is a major wheat allergen.  This suggests that celiac starts as an allergy to ATI present in wheat flour.

Celiac Results from Superfine Milling of High-ATI Wheat

Wheat has been milled more and more finely to improve the shelf-life of bread flour.  The inedible bran and the germ are first removed from the wheat kernels and then the endosperm is ground so finely that the starch granules are broken.  Even "whole wheat flour" is ground in the same way and the bran and germ are simply added back to make it “whole.”  The important point here is that superfine milling results in starch that is readily digested by amylase in the small intestines, instead of acting as soluble fiber to feed gut flora.  The result of eating bread from superfine flour is that gut flora are starved for soluble fiber and the immune system is depleted of Tregs that would otherwise suppress allergy and autoimmunity.  Superfine milling of high-ATI wheat presents ATI to an immune system that is primed for allergy.

ATI is a Good Immunogen

Allergy development requires 1) inflammation, 2) an appropriate immunogen and 3) lack of Tregs (immune system cells that develop in the lining of the intestines and block allergies and autoimmunity.)  The modern milling of wheat flour eliminates a major source of soluble fiber, starves gut flora and reduces Tregs, but allergy development still requires inflammation and an appropriate immunogen.  An immunogen is a protein that will interact with cells of the immune system to produce antibodies and activate aggressive attacks.  I have found that all proteins of food or the environment, i.e. allergens, or of the body, i.e. autoantigens, that act as immunogens to initiate allergies or autoimmunity have the same sequence of three amino acids, a "basic triplet."  ATI has a characteristic basic triplet in its protein amino acid sequence and that is why it is a good immunogen to initiate allergies.

Allergy to ATI is Aggrevated by TLR Recognition of ATI

ATI enriched, superfine flour Is a powerful initiator of allergies, because it starves gut flora to block Treg production and is a good immunogen, but the immune system will still ignore ATI in the gut, unless inflammation is also activated.  Unfortunately, ATI actively stimulates inflammation of the intestines by specifically binding to TLR4, which is the receptor that also binds/recognizes the LPS of bacteria.  Thus, ATI is a way for the wheat plant to defend its seeds by triggering excessive Intestinal inflammation.  Inflammation, immunogen and Treg insufficiency is the ATI allergy trifecta.

Wheat ATI Allergy Leads to Celiac

First exposure to ATI and development of an allergy will make subsequent expose to wheat proteins more immunologically intense.  I discussed the response of the intestinal lining to gluten in previous posts.  Wheat gluten proteins are adapted to provide nutrients for growing wheat embryos and to provide defense against pathogens and herbivores.  Gluten proteins contain long stretches of amino acid glutamine, which is poorly digested by gut enzymes.  The glutamine is also converted into glutamate by the gut enzyme, transglutaminase, tTG.  Unfortunately, during the process, the enzyme is covalently connected to the undigested gluten fragments.  The allergic ATI reaction combined with gluten/tTG conjugates, leads to presentation of the gluten/tTG to the immune system and antibody production agains both gluten and tTG.  Subsequent exposure to gluten results in the autoimmune disease of celiac.

Celiac is Self-Perpetuating

The aggressive immune attack on the intestines in response to eating gluten-containing grains, is bad in itself, but it also causes a series of related autoimmune diseases.  Attack on the intestines also disrupts the development of the lining of the intestines, which in turn disrupts the community of bacteria and fungi, gut flora, that are essential for digestion of plant polysaccharides, soluble fiber, and the development of the immune system.  Gut flora dysfunction results in vitamin deficiencies, food intolerances and autoimmunity.  Thus, celiac is self-perpetuating, because it causes inflammation, immunogen presentation and Treg deficiency.

Celiac Causes Numerous Autoimmune Diseases

Celiac is often associated with other autoimmune diseases, because it causes them.  Antibodies to tTG are diagnostic for celiac and the autoimmune attack on the intestines is mediated by anti-tTG antibodies.  But anti-tTG antibodies of celiac don’t just attack the intestines, they attack any other tissues that have tTG, such as the thyroid gland and hair follicles.  Thus, it should not be a surprise that celiacs are at high risk for autoimmune disease, e.g. Hashimoto’s thyroiditis, of the thyroid gland, including both hypothyroid and hyperthyroid diseases, depending on which region of the thyroid is attacked.  Some forms of hair loss, alopecia, are also initiated by autoimmune attack on the tTG in hair follicles.  Persistent exposure of celiacs to gluten will result in a cascade of autoimmune diseases as other body antigens are presented to the immune system and tissues with those antigens are targeted and attacked to produce arthritis, vitiligo, etc.

Pest Resistance, Plant Breeding and GMO Solutions

Genetic modification of plants occurs every time seeds are planted.  Traditional plant breeding by selecting desirable individual plants grown from crosses of selected parents is one form of genetic modification.  Specifically introducing desired genes using recombinant DNA techniques is another, more controlled method.  Traditional plant breeding has systematically destroyed the diversity of crop plants by loss of genes that are not selected, but even the traits, such as pest resistance, that provide benefit, have also brought unintended consequences.  We now have grains with many desirable features of high yield and disease resistance, but they also provide increased risk of celiac, gluten intolerance and associated autoimmune diseases.  Maybe it is time to consider GM techniques as a safer alternative to fix modern wheat and to examine milling approaches to save our gut flora.

Health Diagrams II — Curing Autoimmunity and Allergies

Cure for Celiac and Autoimmunity

Celiac and other autoimmune diseases are perpetuated by the presence of the corresponding autoantigen/allergen, in this case tTG and gluten proteins, and a deficiency of Tregs.  Oddly enough, some pathogens (Helicobacter pylori) and parasites (Helminth worms) stimulate Treg development in the lining of the intestines, in addition to normal gut flora, Clostridium spp.  It may be the relative absence of pathogens and parasites in affluent societies that reduces Tregs and enhances the incidence of allergies and autoimmunity.  Antibiotics and the antibiotic activity of pharmaceuticals in general may also contribute to Treg deficiencies by damage to gut flora.  Clearly, the repair of gut flora and reestablishment of the associated immune system will go a long way toward curing autoimmune diseases such as celiac.  Celiac, however, provides the added complexity that it damages the ability of the intestines to maintain a functional gut flora.  Thus, the cure for celiac would require simultaneous repair of both the gut and its flora, e.g. by a  fecal transplant and supportive diet containing numerous soluble fibers to which the donor flora have been previously adapted, i.e. lacking antigenic triggers.

Transglutaminase, Gluten, Celiac, Inflammation, Autoimmunity

The point of this post is that the intestines produce an enzyme, transglutaminase (TG) that normally protects the gut from toxic plant proteins, such as grain gluten, but modern food processing and antibiotics corrupt digestion of gluten to produce intestinal inflammation and a series of related autoimmune diseases including celiac, thyroiditis, diabetes, baldness and atherosclerosis. 

Transglutaminase Links Proteins Enzymatically

Transglutaminase is a ubiquitous enzyme produced in the intestines, thyroid, heart, skin, hair follicles, etc.  This enzyme attaches to a protein (TG + ProA ~~> TG-ProA) via amino groups extending from some of the protein's amino acids, e.g. lysine or glutamine, and then the enzyme replaces itself by another protein leaving the two proteins crosslinked (TG-ProA + ProB ~~> TG + ProA-ProB).  Another alternative reaction is to leave the original glutamine without its amino group to yield glutamic acid residues.

Linking Proteins Makes Connective Tissue Tough

Transglutaminase is useful to crosslink the proteins in connective tissue.  Proteins in basement membranes form a matrix by binding to the heparan sulfate sidechains of another basement protein, perlecan.  The heparin-binding domains consist of basic amino acids that TG can react with to crosslink the proteins.

Linking Pathogen Proteins

Transglutaminase is also produced to crosslink the DNA/heparin/matrix polysaccharide-binding domains of pathogenic bacteria leading to aggregation, localization and death of the bacteria.  Inflammation resulting from activation of the inflammatory transcription factor, NFkB, stimulates production of TG.

Gluten is a Plant's Way of Saying "Don't Eat Me!"

Gliadin is a protein component of gluten that contains long stretches of glutamine residues, i.e. it is a polyglutamine protein similar to the protein that causes Huntington's disease.  Gliadin is an advantage as a storage protein for grain, because it is aggregated by the TG that protects the lining of the intestines of herbivores, such as humans, makes the animal sick and thereby discourages eating the grain.  Aggregation of gliadin/gluten inhibits digestion of the grain protein and can leave TG bound to gliadin.  Conversion of the polyglutamine stretches to polyglutamic acid stretches that are negatively charged, produces proteins that will bind to the positively charged heparan sulfates that circulate along the surface of intestinal cells leading to damage and inflammation.

Basic Triplet Leads to Antibody Production

Transglutaminase is also transported into cells, because it contains a region with a triplet of basic amino acids (...EPKQKRKLVA...).  This internalization probably contributes to enhanced presentation of TG to the immune system for subsequent antibody production.

Transglutaminase is Inflammatory

Transglutaminase interaction on the surface of cells also activates, NFkB, the transcription factor responsible for inflammation. Thus, TG turns on inflammation and part of inflammation is the activation of the innate immune system that includes production of TG.  This circular activation may produce autoinflammation that is associated with various forms of inflammatory bowel diseases.

Gluten Sensitivity is Normally Controlled By Gut Flora

Gluten sensitivity expressed by most people, is the intestinal response to the toxicity of gluten as it interacts with TG and causes inflammation.  This inflammation will also result in immune presentation of both gliadin and TG, and production of antibodies to both. Antibody production will normally be controlled by regulatory T cells of the immune system, unless spreading inflammation in the gut and/or antibiotics destabilizes the gut flora and compromises regulatory T cell development in the intestines.  

Anti-Glutaminase Antibodies Attack the Gut

Celiac results from uncontrolled production of antibodies to gliadin and TG with attack by the immune system on the aggregated gliadin/TG on the surface of the intestinal epithelium.  Celiac flare ups in response to eating even small quantities of gluten lead to further inflammation of the gut and further disruption and simplification of gut flora.

Celiac Leads to Thyroiditis and Much More

Transglutaminase is also produced by the thyroid and celiac will develop into a more generalized autoimmune disease that results in Hashimoto's thyroiditis.   TG production in the skin can result in skin rashes and may contribute to rosacea.  The base of hair follicles contains TG involved in hair production, and may contribute to some forms of hair loss.  Another substantial worry about the sequelae of celiac and gluten intolerance is the presence of TG in coronary arteries.

Antibiotics are Part of the Gluten Problem

Celiac and gluten sensitivity seem to be increasing with modern processing of grains and increased use of antibiotics.  Wheat has been gradually changed by traditional breeding, but genetic engineering has not yet been developed for wheat.  So, at least in this case, GM wheat cannot be part of the problem.  Many recent studies show that antibiotics profoundly and permanently alter gut flora.  As a result, the immune system, which is dependent on gut flora diversity is compromised, and various forms of autoimmunity and allergies develop.

Super Fine Flour Damages Gut Flora

Germ and bran are removed from all wheat before it is ground.  This is true even for whole grain flours, which have some of the germ and bran added back after milling.  Modern milling may be part of the gluten problem, because the flour is ground so fine that the grains of starch are broken.  Broken starch grains are digested by pancreatic amylases in the upper intestines, whereas some of the starch from intact grains is digested by gut flora in the colon.  Thus, modern wheat flour fails to feed gut flora like soluble fiber to produce short chain fatty acids, e.g. proprionic acid that supports Treg development; modern superfine flour supports autoimmune diseases and allergies.

Cultural Practices Make Gluten Safe

Wheat has been bred to produce bread as fast as possible from superfine flour.  This rapid bread production eliminates the exposure of gluten to enzymes from both germinating wheat seed and fermenting bacteria, which are part of traditional bread making.  Coarsely milled, traditional flour responds to soaking in water by activating enzymes that partially digest gluten, since gluten is a storage form of amino acids destined for the seedling.  Sour dough starter, a mixture of bacteria that can ferment the starch and gluten into short chain fatty acids and bubbles of carbon dioxide, has been used traditionally to provide leavening and flavor to bread.  Both flour and bacterial enzymes modify the structure of gluten to render it less toxic to the intestines.  Cultural traditions insured that gluten would be systematically detoxified by enzymes during hydration and fermentation of dough prior to baking.  Modern processing leaves wheat gluten in bread unmodified and toxic.

Prevention and Cure:  Eliminate or Detoxify Wheat and Add Bacteria

Preventing and curing diseases associated with gluten and transglutaminase is simple.  Eliminating wheat would do the trick.  Unfortunately, wheat is the mainstay in many parts of the world.  Fortunately, gluten intolerance is not uniformly observed where wheat is eaten.  This indicates that there are potentially safe ways to eat wheat and bread.  I gained insight into how to eat wheat safely from two books that were recently published:  Cooked by Michael Pollan and Artisan Bread in Five Minutes a Day by Jeff Hertzberg, MD and Zoë François.

Michael Pollan has recently become interested in gut flora and his book revealed how he built up a healthy gut flora eating homemade fermented food and compromised his work with antibiotics.  The major breakthrough that I made by reading Cooked was based on his experiments in baking whole wheat bread.  He hydrated the flour first and then used sour dough starter for lengthy fermentation.  This was the same process that I had used to make great loaves of bread (photo above) using Jeff Hertzberg’s directions in Artizan Bread in Five Minutes a Day.

The answer to gluten intolerance and most autoimmune diseases amounts to eliminating wheat or treating wheat in a safe, traditional process that inactivates the toxic properties of gluten; and maintaining a healthy gut flora (probiotics are not enough) with hundreds of different species of bacteria that promote the development of the suppressive immune system mediated by regulatory T cells:

Safe Traditional Bread 

• Remove bran and discard as toxic insoluble fiber.
• Grind wheat to retain starch grain structure.
• Soak flour to hydrate and activate wheat enzymes to start digestion/detox of gluten.
• Ferment dough with bacteria (sour dough starter) to continue digestion/detox of gluten.
• Bake.

Develop Healthy Gut Flora and Suppressive Immune System

• Avoid antibiotics that kill bacteria.
• Avoid hygiene practices, e.g. antibacterial soaps, bleaching surfaces, closing toilet covers, etc. that eliminate sources of healthy bacteria.
• Kiss your loved ones and pets, and encourage everyone to garden/play in the soil (an excellent source of thousands of different species of bacteria.)
• Recruit healthy gut bacteria by eating a variety of homemade fermented vegetables. My most highly recommended source is my friends at: http://www.fermentista.us
• Remember that cooked or pasteurized foods do not contain useful bacteria.
• Remember that dairy probiotic bacteria cannot live in the human gut and can only provide a temporary help to the immune system.
• Limit the variety of foods that are consumed and gradually change with the seasons to avoid rapid changes in nutrients to which gut flora cannot adapt.  Food intolerances indicate maladapted gut flora.
• Constipation indicates dysfunctional gut flora and a compromised immune system.

Antibiotics, Gluten, Hashimoto's Thyroiditis and Baldness

My impression is that Hashimoto's is caused by a combination of an initial immune attack on the thyroid and incompetent regulatory T cells.  In most cases the immune attack on the thyroid is a secondary consequence of celiac/gluten intolerance, in which anti-transglutaminase antibodies attack transglutaminase bound to gluten in the intestines.  Transglutaminase  is an enzyme that is also produced by the thyroid (and hair follicles) and attack by celiac antibodies can enhance or inhibit thyroid hormone production (or baldness.)  Both Hashimoto's and celiac do not occur if the suppressive part of the immune system, i.e. regulatory T cells, is functioning.  

Antibiotics Compromise the Immune System

The major point here is that antibiotics disrupt normal bacterial biofilms that line the intestines and these healthy gut bacteria are required for development of regulatory T cells.  Compromise of Tregs leads to autoimmune diseases, e.g. celiac, Hashimoto’s and baldness, and also allergies.

Antigens/Allergens Have Basic Amino Acid Triplets

The antigens targeted in autoimmune diseases, e.g. tTG, anti-nuclear, TPO, and allergies form an obvious pattern.  All of these antigens and allergens have simple amino acid sequences (rare patches of three basic/positively charged amino acids) that enhance their presentation to the immune system to produce antibodies.  Nuclear proteins, for example, are frequent autoantigens and most of these proteins interact with nucleic acids (negatively charged) and have predictable patches of positively charged amino acids (arginine and lysine).  Other common autoantigens have basic amino acid (arg/lys) patches, because they interact with phospholipids (also negatively charged.)  Proteins with basic patches, e.g. HIV-TAT or heparanase, are also readily transported into cells and nuclei.  Peptides with these sequences are produced by action of stomach enzymes on proteins, e.g. milk lactoferrin, and are antimicrobial.

Allergies / Autoimmune Diseases Are a Predictable Consequence of Antibiotics

Doctors treat with antibiotics, but they fail to repair damage that they cause to gut flora.  The gut flora of most patients treated with antibiotics, especially those who are most fastidiously hygienic, never fully recover.  Constipation is a common symptom of severe dysbiosis and related immunoincompetence.  Probiotics are gut flora bandaids and do not survive as components of gut flora.

Gut bacteria are also needed for development of the aggressive part of the immune system.  Thus, autoimmune diseases can be treated with even more intense use of antibiotics, that will eliminate the rest of the immune system.  Since all vitamins are produced by gut flora as quorum sensing signals, antibiotics can also produce the exotic symptoms of vitamin deficiencies.

Antibiotics are essential to many therapeutic approaches, e.g. surgical procedures or therapy for chronic Lyme disease, but they must be used responsibly and treated patients must be subsequently tested to ensure a repaired gut flora and a functional immune system have been reestablished after antibiotics.  Long term antibiotic use needs special attention, e.g. deliberate Repair of Gut Flora or a fecal transplant.

Thus, I think that it is most likely that ever increasing antibiotic exposure and processed foods, coupled with obsessive hygiene have led to crippled gut flora (as observed in the simplified gut microbiomes of Americans), a net decline in suppressive Tregs and the observed increase of autoimmunity and allergies.  The competence of the immune system may be a major determinant in the course of infection with a pathogen that can produce chronic infections.

Genetics of Food Intolerance

Food intolerance is based on missing bacteria in the the gut rather than inadequacy of human enzymes, e.g. lactase, or altered immune system.

I make the extreme statement that food intolerance is not genetic, to emphasize that the vast majority of intolerance can be cured by changing the bacterial composition of the gut's microbiological community, the gut flora, rather than attempting to accommodate a permanent deficiency. The two common "intolerances" that are offered by my readers to invalidate my sweeping statement are lactose and gluten (celiac) intolerance.

Lactose Intolerance is Not Due to Inadequate Lactase
Everybody has the same gene for lactase, but some people have altered upstream control elements and continue to express lactase in their intestinal cells after infancy, whereas others don't. The racial pattern of adult lactase expression is an interesting note on human evolution, but is irrelevant with respect to an individual's ability to tolerate the lactose sugar in dairy products.

Lactose is the major sugar present in milk and the ability of the intestines to utilize lactose directly like glucose is a selective advantage for human evolution. Absent that ability, lactose would just pass through the gut without impact. However, bacteria in the colon also have lactose digesting enzymes. These bacteria produce hydrogen and methane gases, and these products in turn can feed other bacteria. If all of the products are consumed, then the lactose has been treated as a soluble fiber and the result is more gut bacteria and a happy gut. If some of the bacteria are missing, then the lactose acts as a laxative, e.g. lactulose, and the bowels are not so happy.

All that is needed to cure lactose intolerance, as in all food intolerances, is to provide the gut bacteria that are missing to fully metabolize the offending sugars or polysaccharides. Just continuing to eat dairy without also eating or introducing new species of bacteria into your gut, will just provide more symptoms, but eating yogurt still containing live probiotic bacteria (Read the label. Any live bacteria listed will work.) that have the enzymes to ferment lactose, will lead to a rapid cure. (See reference below.) As the fermenting bacteria grow in the gut, they transfer their genes to gut bacteria in the biofilms lining the gut and these new species of bacteria keep the lactose out of trouble.

The point is that having a food intolerance means that the aggregate of all of the genes in all of your gut microorganisms is lacking the genes/enzymes needed to completely digest a food component. In the case of lactose intolerance, the missing genes are present in typical probiotics, bacteria that grow on milk/lactose.

Celiac is not a Typical Food Intolerance
Celiac is a complex interaction between major toxic proteins in wheat (gliadin), detox gut enzyme (tissue transglutaminase, tTg) and antibodies. Gliadin is a wheat protein adapted to attack the intestines of herbivores. Herbivores, such as insects and humans, can in turn protect themselves from gliadin and other polyglutamine proteins with the enzyme transglutaminase. tTg binds to glutamines in gliadin and converts them to glutamic acids. Unfortunately, while the gliadin is bound to the tTg, inflammation can predispose the gut to present these proteins to the immune system for processing to trigger antibody production. This is the start of the autoimmune disease.

The major histocompatibility antigens (MHAs) code for the proteins that display fragments of proteins on cell surfaces for antigen presentation and immune response. There is a lot of MHA variation and evolutionary adaptation. Some MHAs favor antibody production to gliadin and tTg. This just shows that celiac and grain/gluten intolerance is not a typical food intolerance, which will be remedied by simply altering gut bacteria, even though establishing gut bacteria that metabolize gliadin or that reduce autoimmunity, may be part of the cure.


Enhancing Gut Flora is Part of the Cure for all Autoimmune Diseases
There are rare food allergies, even though the majority are misdiagnosed intolerances. The production of antibodies to food antigens is a symptom of the breakdown in communication between the gut immune system and gut flora. Particular species of bacteria are responsible for the development of both the aggressive and suppressive components of the immune system, which occurs in the lining of the gut. Loss of the suppressive cells, Tregs, can result from unhealthy diets and exposure to antibiotics, and results in autoimmune disease, in which the aggressive immune system is out of control and attacks self antigens.

Symptoms of all autoimmune diseases can be improved by reestablishing normal control of the aggressive part of the immune system via healthy gut flora. Clostridium species of bacteria normally induce healthy development of the suppressive immune system and these types of bacteria are common in soil clinging to fresh vegetables prior to extensive washing. Which of the bacteria that are eaten become established in the gut flora is unpredictable, because the bacteria interact with each other, food and cells lining the gut. The only safe and simple procedure currently available is the fecal transplant. Some experimental fecal transplants are facilitated by the use of encapsulated freeze-dried gut flora. There is great resistance to this simple, safe, cheap approach from the medical industry.

Reference:
Almeida CC, Lorena SL, Pavan CR, Akasaka HM, Mesquita MA. 2012. Beneficial Effects of Long-Term Consumption of a Probiotic Combination of Lactobacillus casei Shirota and Bifidobacterium breve Yakult May Persist After Suspension of Therapy in Lactose-Intolerant Patients. Nutr Clin Pract., 27(2):247-51.

Autoimmune Diseases, Bacteria and GALT (Gut Associated Immune System)

Celiac, Oxidative Stress, Peroxiredoxin, Alopecia

Grain/gluten intolerance, celiac is an immunological attack on the small intestines with increased risk for numerous autoimmune diseases.  Hashimoto’s thyroiditis is a common sequela of celiac and the two diseases share the same autoantigen, tissue transglutaminase (tTG).  Thus, the development of celiac and the production of antibodies to the tTG produced in the intestines, results in a subsequent immunological attack on other tissues that produce lots of tTG, e.g. the thyroid.  Gluten intolerance, because of its attack on the intestines and the proximity of a major part of the immune system (GALT), may play a major role as the foundation for autoimmune diseases.

Gluten Intolerance First Step in Autoimmune Diseases

Celiac may also lead to herpatic lesions of the skin, dermatitis herpetiformis and loss of hair, alopecia.  In these cases, the autoantigen is peroxiredoxin, an enzyme that eliminates hydrogen peroxide produced as a result of accumulation of reactive oxygen species, e.g. superoxide, associated with inflammation.  Peroxiredoxin is also implicated as an autoantigen in periodontal disease, suggesting that celiac may also contribute to dental gum inflammation.

Peroxiredoxin 5 Gene Associated with Alopecia Risk

A recent study (see ref. below) of genes associated with alopecia identified genes involved in Treg and Th-17 development, as well as peroxiredoxin 5 as contributors.  As expected, several genes involved in antigen presentation (HLA-DRA, HLA-DQA)  were also identified.  Th-17 lymphocytes are involved in immune attacks on self tissue, i.e. autoimmune diseases, such as alopecia, in which hair follicles are attacked by the immune system.  Tregs control immune attacks on self tissues.  Peroxiredoxin is an autoantigen and is produced in elevated amounts around hair follicles attacked in alopecia.

Basic Amino Acids of Peroxiredoxin as Expected for Autoantigen

I checked the amino acid sequence of human peroxiredoxin 5 and found an alternative (-nrrlkrfsmv-) to the triplet of basic amino acids that I expect for an autoantigen.  In this case there are two adjacent pairs of basic amino acids (blue rr and kr) that I think precipitate immunological presentation of peroxiredoxin.  Peroxiredoxins are produced in response to oxidative stress at sites of  inflammation and the presence of celiac compromises the gut associated immune system (GALT) that provides Tregs to restrict autoimmunity, so celiac sets the stage for peroxiredoxin presentation to the immune system and for subsequent production of anti-peroxiredoxin antibodies, autoimmunity and destruction of hair follicles, alopecia.

Anti-Inflammatory Diet Should Avoid and Treat Autoimmunity

Control of autoimmune diseases mediated by peroxiredoxin should benefit from a reduction in the conditions that spawned the diseases:

• Th-17 elevation -- celiac inflammation stimulated by grain/gluten
• Treg loss -- GALT inactivation due to inflammatory diet and inappropriate gut flora
• Autoantigen (basic amino acid concentration) presentation -- oxidative stress stimulation of peroxiredoxin

Treatment would be supported by dietary changes:

• anti-inflammatory diet to control gut inflammation and minimize celiac symptoms (vitamin D, low carb/high saturated fat, high omega-3 to -6 fatty acid ratio, no grains)
• probiotics and soluble fiber (e.g. pectin, inulin) to re-establish gut flora (cure dysbiotic constipation) and GALT function, and development of Tregs
• supplements to compensate for depletion of vitamin C and glutathione by oxidative stress, e.g. vitamin C and acetylcysteine (NAC)

Th-17 and Tregs in HIV Infections

Th-17 cells are also reduced by HIV infection, producing susceptibility to infection, but this infection should also reduce autoimmune disease.  The reduction in Th-17 also may be a consequence of problems in the GALT.  Therapy for HIV infection should also include diet considerations to increase Th-17 and also Tregs to reduce autoimmune diseases due to unbalanced Th-17.

ref.

Petukhova L, Duvic M, Hordinsky M, Norris D, Price V, Shimomura Y, Kim H, Singh P, Lee A, Chen WV, Meyer KC, Paus R, Jahoda CA, Amos CI, Gregersen PK, Christiano AM.  2010. Genome-wide association study in alopecia areata implicates both innate and adaptive immunity.  Nature. 466(7302):113-7.

Arthritis, Autoimmunity and Arginine Deimidation

Celiac and Antibody Production Against Tissue Transglutaminase as a Model

Arthritis is an autoimmune disease in which the immune system attacks and degrades the connective tissue of joints.  Antibodies against modified amino acids, arginine converted to citrulline, and proteins commonly found in joints, mediate the arthritis disease process.  The development of arthritis mimics the development of gluten intolerance, celiac, in which another enzyme, transglutaminase ( tissue transglutaminase, tTG or TG2) modifies the major gluten protein, gliadin, and antibodies are produced against both modified gliadin and TG2 autoantigen.

Arthritis of Joints Is Like Coeliac of Intestines;  Autoantibodies to Protein Modifying Enzymes

In other articles, I outlined the pathology of gluten intolerance:

• The major protein of wheat gluten, gliadin, contains long stretches of glutamines.
• An intestinal enzyme, TG2, converts the glutamines to glutamates by deamination.
• As TG2 works it binds to gliadin.
• In celiac, the TG2-gliadin complexes are internalized and fragmented to stimulate antibody production against both TG2 and gliadin.
• I think that the internalization and processing for antibody stimulation is dependent on the basic triplet found in TG2.

Arthritis Is Mediated by Autoantibodies to Peptidylarginine Deiminase and Citrullinated Proteins

Parallel to the celiac example, in some forms of arthritis, antibodies are produced against an enzyme that modifies proteins.  In arthritis, the enzyme involved, peptidylarginine deiminase (PAD) removes the terminal nitrogen from arginine (deimination) to produce citrullinated proteins.  Antibodies are produced to both PAD and citrullinated proteins.

PAD Also Has a Triplet of Basic Amino Acids for Internalization

I of course wondered if PAD had the same triplet of basic amino acids, e.g. RRK, that I had found on all other autoantigens and allergens.  Examining the sequence of human PAD in the NCBI sequence databases and comparing to other sequences, I found the basic triplet near the carboxy terminus.  The same or an alternative basic triplet was found in PADs from other mammals.

Autoantigens and Predicted Basic Triplets of Amino Acids Reveal the Cause of Arthritis

Arthritis is an inflammatory disease.  That means that without inflammation, arthritis cannot start and if inflammation is inhibited, arthritis cannot progress.  It is likely that arthritis is the result of chronic inflammation plus a precipitating event, such as joint injury or joint infection.  Alternatively, in a manner similar to Hashimoto’s thyroiditis, in which celiac produces anti-TG2 antibodies that attack the TG2 also produced in the thyroid gland, arthritis may be produced by autoantibodies stimulated in the inflammation of other tissues and spreading to the joints.  Celiac is also a risk factor for arthritis.  Trauma-based inflammation of a joint can also result in migration of Clamydia pneumonia (Cpn)-infected macrophages to the site of inflammation.  Cpn could contribute to joint inflammation and promote immunological presentation of autoantigens and autoantibody production.

reference:
Stenberg P, Roth B, Wollheim FA.  Peptidylarginine deiminases and the pathogenesis of rheumatoid arthritis: a reflection of the involvement of transglutaminase in coeliac disease.  Eur J Intern Med. 2009 Dec;20(8):749-55. Epub 2009 Sep 19.

Cytstic Fibrosis Overproduces Tissue Transglutaminase and Contributes to Celiac

Tissue transglutaminase (tTG or TG2) is produced in excess in some diseases, such as cystic fibrosis, and contributes to inflammation and disease symptoms. tTG also readily moves in and out of cells by virtue of its basic triplet and when in the cytoplasm, tTG is ubiquinated and degraded by proteosomes. I have previously pointed out that internalization and proteosome degradation are also the initial steps in processing of proteins for presentation by the immune system and antibody production, i.e. turning a cellular protein into an autoantigen involved in autoimmune disease.

Here is an image of a computational protein model of tTG I drew with Chimera. I have highlighted the basic triplet to show its exposure to facilitate transport.

Oxidative Stress Alters tTG and Triggers Inflammation

A recent article also links tTG intracellular chemical modifications (SUMOylation), which are linked to oxidative stress, to activation of NFkB and inflammation. Thus, tTG is a major player in controlling cell surface interactions with potentially toxic materials such as polyglutamine-rich gliadin, as well as triggering inflammation in response to oxidation stress.

Cystic Fibrosis Causes Overproduction of tTG

When I read that cystic fibrosis results in an increase in the production of tTG in lungs, I immediately thought of the role of tTG as an autoantigen in celiac disease and the progression of celiac into Hashimoto’s thyroiditis, which has the same autoantigen, tTG. I suspected that the overproduction of tTG and inflammation in cystic fibrosis should increase tTG autoantibody production and tTG-mediated autoimmune diseases of celiac and Hashimoto’s thyroiditis.

Extra tTG Leads to Autoimmune Celiac

A quick PubMed search of CF and celiac, revealed a study of comorbidity between CF and celiac in Norway. Just as expected, the two diseases occur together with a frequency three times higher than predicted by coincidence. CF stimulated tTG overproduction was driving the development of celiac.

references:
Luciani A, Villella VR, Vasaturo A, Giardino I, Raia V, Pettoello-Mantovani M, D'Apolito M, Guido S, Leal T, Quaratino S, Maiuri L. SUMOylation of tissue transglutaminase as link between oxidative stress and inflammation. J Immunol. 2009 Aug 15;183(4):2775-84.

Fluge G, Olesen HV, Gilljam M, Meyer P, Pressler T, Storrösten OT, Karpati F, Hjelte L. Co-morbidity of cystic fibrosis and celiac disease in Scandinavian cystic fibrosis patients. J Cyst Fibros. 2009 May;8(3):198-202.

Anti-inflammatory, Gluten-Free Diet for Celiac

Low Grain Is Good for Everyone

I don’t think that I have an intolerance for grain, i.e. a gluten sensitivity, but it is so common and the biochemistry is so obvious, that it is only prudent to avoid wheat and related grain products. A low or gluten-free diet is also similar to the other common healthy diets, e.g. low carb and anti-inflammatory.

Gluten-free diets came to my attention recently in two ways. First, I saw Food, Inc., a documentary movie about abuses by multinational food processors. After that movie, I felt like I was a goose being readied for foie gras. Second, was a newspaper article on the expense of a gluten-free diet and the challenges of avoiding gluten.

I haven’t had to worry about wheat contaminating my diet, but I am sympathetic to the celiacs that I know who have to labor with a sloppy and exploitative food industry that uses the cheapest ingredients to compose the processed foods that are consumed in modern diets -- processed foods are complex blends of many different potential allergens from innumerable sources throughout the world.

A Celiac Diet Is Good for All
Fortunately, the answer to pervasive gluten is just a modest modification of the basic anti-inflammatory diet that I recommend on this blog. Unfortunately, people who have already developed gluten intolerance, have probably had the problem for years before diagnosis and that means that their intestines have already suffered major physiological alterations and they have problems absorbing nutrients and vitamins. Celiacs also, because of their chronic inflammation and autoimmunity, tend to readily develop food allergies and other autoimmune diseases. The recommended anti-inflammatory diet will help to avoid celiac, put celiacs into remission and avoid development of subsequent allergies and autoimmune diseases.

Vitamin D Is Usually Deficient (and a source of inflammation)
The basic anti-inflammatory diet starts with a return to optimal vitamin D with the use of an initial blood test, followed by high level supplements to reach a suitable level and then maintenance with D3 supplements of usually 2,000-5,000 IU per day. Depending on the D3 supplement, vitamin A will also need to be supplemented, because it interacts with vitamin D. Remember that sunshine is only effective in producing adequate vitamin D if you do not suffer from chronic inflammation. I would assume that all celiacs tend to be vitamin D deficient.

A Low Carb Diet Is Easier for Celiacs
The next component of the basic diet is low carbohydrates, that means a minimum of high glycemic foods, which means to avoid sugar and starch, do not cook vegetables more than necessary and don’t over-chew your veggies. This is good for celiacs, because it reduces the need for common grain foods that no one should eat: bread, cereal, pasta, etc. Everyone should lower their consumption of these wheat products in solidarity for celiacs and for general good health. Cereal is a very bad idea for children!

Most Vegetable Oils Are Unhealthy
Most vegetable oils contribute substantially to world-wide inflammation and celiacs don’t need the added burden of inflammatory omega-6 vegetable oils. Only olive oil and butter should be used. Saturated fats are safer than typical polyunsaturated vegetable oils.

Eat Wild Fish or Tons of Fresh Flax
Most people eat too little omega-3 long chain fatty acids, since these are most abundant in fatty fish, such as wild salmon (farmed fish are fed corn and have reduced omega-3 and increased omega-6 fats.) Few vegetable sources are available, since the omega-3 fatty acids are unstable and present in leaves rather than seeds. Flax seeds have short chain omega-3 fatty acids and must be freshly ground and consumed by the cupful, because the conversion to the long chains, in which they are useful, is very inefficient. Most celiacs will need to use fish oil (or krill oil, if fish is not tolerated) supplements (4-8 EPA/DHA capsule per day taken in a meal rich in fats for bile uptake) to balance the ubiquitous inflammatory omega-6 in their diets.

Grassfed Meat/Eggs Are Your Friends
Celiacs should seek out grass/pasture fed meats, eggs and wild caught fish. Corn-fed animals have higher levels of omega-6 fats and these contribute to dietary inflammation. Celiacs can usually eat meat and fish and these are very healthy foods. Red meat was not shown to contribute to degenerative diseases, it was the high carbs eaten with the meat that produced the inflammation that contributed to heart disease. (Remember that statins only decrease cardiovascular disease because they inadvertently lower inflammation, not because they lower serum lipids, LDL.)

No, No’s: HFCS and trans fats
High fructose corn syrup and trans fats are inflammatory and unhealthy for anyone, and should be avoided as much as wheat gluten. Fruits should be eaten as seasoning, since their fructose is not healthy and they also contain ample sucrose.

Most People Would Be Healthier on a Celiac Diet
The anti-inflammatory diet proposed here for celiacs should be uniformly healthy, since it provides optimal vitamins (D, C, B12, etc.), low starch/sugar/carbs, an optimal omega-3 to -6 fatty acid ratio, increased meat and saturated fats, and avoids HFCS and trans fats. The only major adjustment for celiacs would be avoidance of individual food allergens, more attention to vitamin supplements to compensate for poor absorption and replacement of wheat by rice, potatoes, etc. The low carbohydrate nature of the diet makes it more approachable, since typical carbs, such as bread and cereal are avoided and replaced with meat and vegetables.

I look forward to advice and suggestions from readers who have experience with gluten-free diets.

Cause of Autoimmunity and Allergies

Inflammation-Induced Presentation by Mannose Receptor

Speculation on how innocuous proteins become the targets of our immune systems, and result in allergies, asthma, celiac, arthritis, lupus, and other inflammatory autoimmune diseases.

Inflammation

It all starts with chronic inflammation. In most cases diet is the predominant source of inflammation, but infections (bacterial, viral, fungal) may also contribute. Inflammation sets the stage for faulty processing of proteins at the focal location where lymphocytes and antigen-presenting cells are congregating.

Antigen Presentation

At this point a major mistake occurs. Cells that have been alerted to danger by inflammatory cytokines, start to internalize and process proteins in the vicinity, so that peptide fragments of the “antigens” can be displayed on their surfaces in the clutches of major histocompatibility complex proteins. The problem arises when self proteins are internalized, processed and displayed as candidate peptides.

Basic Triplets of All Allergens and Autoantigens

I have looked at dozens of allergens and autoantigens, and they all have one peptide sequence in common, a triplet of basic amino acids. The impetus for this article was finding this morning that one of the autoantigens for Hashimori’s thyroiditis is thyroglobulin, the serum carrier of thyroid hormones. I checked the sequence of thyroglobulin and it has two of the rare basic triplets.

Thyroiditis Autoantigen Is Thyroglobulin

I checked the Pubmed literature to see if thyroglobulin is naturally taken up by cells, since I have been trying to figure out the receptor for basic triplets. What I found was an article on the binding of thyroiditis autoantigens to mannose receptor. The idea of the paper was that the autoantigens in this case were heavily glycosylated and maybe the mannose receptor that is involved in antigen presentation of glycosylated antigens, would bind the selected autoantigens as well. I didn’t get much past the title of the paper.

Candidates for Allergen/Autoantigen Receptor

What I put together was the fact that antigen presenting cells use mannose receptor to internalize antigens. This places this receptor in the right place and the right time to be a receptor for basic triplets. But what would a basic triple binding protein domain look like and could mannose receptor be a candidate?

Structure of Thyroglobulin

I downloaded a structure for mannose receptor and began looking for a surface region that would bind carbohydrates, aromatics and basic amino acids. The critical amino acids in all of these cases are aromatic amino acids, phenylalanine, tyrosine and tryptophan. Tryptophan is at the heart of most carbohydrate binding proteins. Since the mannose receptor is a member of the carbohydrate-binding lectins, I expected to find tryptophans on the surface of the mannose receptor. I just looked for the tryptophan that binds the carbohydrates. It was exactly as I predicted. The mannose receptor should be able to form very stable tryptophan/arginine-like ladders with basic triplets.

I made a figure of the mannose receptor bound to a carbohydrate (red and grey). One of the exposed tryptophans (yellow) is bound to the carbohydrate. Several other tryptophans could be exposed and oriented toward a basic amino acid spread over the surface of the tryptophan in place of the carbohydrate. A similar kind of structure is used by importin to transport proteins with nuclear localization sites (NLS, basic quartets) into the nucleus. Many proteins with NLSs are also autoantigens, e.g. lupus.

I think that the peculiar circumstances that lead to allergy and autoimmunity result in the binding of self-proteins or allergens to mannose receptor and result in antibody production.

Why the Mannose Receptor?

Why does the mannose receptor make mistakes? The exposed tryptophan may also bind numerous plant products. In fact, the phytochemicals, e.g. alkaloids, flavonoids and terpenoids, are an abundant and varied group of chemicals that would bind to the exposed tryptophan of the mannose receptor and compete for binding with basic triplets. Protection offered by plant “anti-oxidants” may be due in part to this activity.

Celiac Causes Allergies and Autoimmune Diseases

Anti-Tissue Transglutaminase Can Lead to Hashimoto’s Thyroiditis

Celiac, gluten intolerance, causes intestinal inflammation and immunological presentation of the common intestinal protein, tissue transglutaminase (tTG). The result is anti-tTG autoantibodies that stimulate an immune attack on intestines and other tissues.

Heparan-Binding Proteins Involved in Autoimmunity and Allergy

Those familiar with my blog know that I am obsessed with heparin-binding protein domains. The reason that I am focused on these parts of proteins, is because most cells rapidly sweep heparan sulfate polysaccharides across their surfaces from sites of secretion to sites of internalization. During inflammation, proteins with strong heparin-binding domains, consisting of triplets of basic amino acids, e.g. KRK (lysine-arginine-lysine), are internalized along with the heparan sulfate. The result is an aberrant presentation of these internalized proteins to the immune system and production of inappropriate antibodies, e.g. autoantibodies.

Basic Triplets in Hasimoto’s Autoantigens

One of my hobbies is checking for the unusual occurrence of basic triplets in autoantigens and allergens. I have found dozens of examples. The most recent is associated with Hashimoto’s Thyroiditis. I knew that attack on the thyroid was common in celiacs, because the celiac autoantigen tTG (it has a basic triplet) is also present in the thyroid and the celiac autoantibodies to tTG also cause an attack on the thyroid. But the autoantigen for Hashimoto’s Thyroiditis is thyroid peroxidase (TPO).

I was momentarily perplexed, but then examined the TPO amino acid sequence and immediately found a couple of basic triplets (KKR and KRK).

MRALAVLSVTLVMACTEAFFPFISRGKELLWGKPEESRV
SSVLEESKRLVDTAMYATMQRNLKKRGILSPAQLLSFSK
LPEPTSGVIARAAEIMETSIQAMKRKVNLKTQQSQHPTD
ALSEDLLSIIANMSGCLPYMLPPK...


Hashimoto’ Thyroiditis Linked to Celiac

Then, I did a PubMed search for “celiac and Hashimoto’s”. As expected, there is a recent paper (see below) that shows that celiac commonly leads to Hashimoto’s Thyroiditis.

An obvious explanation is that the initial attack on the thyroid by anti-tTG autoantibodies of celiac leads to thyroid inflammation and presentation of TPO, with a second round of autoantibodies produced to TPO resulting in Hashimoto’s Thyroiditis. Celiac may be the initial autoimmune trigger for many other autoimmune diseases and allergies.

Autism has been associated with maternal autoimmunity and placental abnormalities. Guess where tTG is found in high abundance?

reference:
Bardella MT, Elli L, Matteis SD, Floriani I, Torri V, Piodi L. Autoimmune disorders in patients affected by celiac sprue and inflammatory bowel disease. Ann Med. 2009;41(2):139-43.

The Cause of Allegies and Autoimmune Diseases

Keyhole Limpet Hemocyanin (KLH): Internalized Antigen

Scanning the literature for a common protein that can be used as an experimental antigen, it becomes quickly obvious that a favorite is KLH. This would seem to be an odd choice -- why a keyhole limpet protein? But that is the wrong question.

Why is KLH such a good antigen, i.e. why is it readily presented to the host immune system? If you have been reading my posts, you might be thinking about triplets of basic amino acids and that is the answer.

As soon as I remembered the prominent use of KLH as an antigen, I checked the NCBI protein database and immediately found an unusual KKK (triple lysine) near the amino terminus of hemocyanin II ( it comes in two pieces). This triplet explains why KLH is such a good experimental antigen, because it is internalized into antigen presenting cells by its strong heparin-binding domain. Other components, adjuvants, are typically added to the KLH for injection to make sure that a strong local inflammation occurs.

Autoantigens Have Strong Heparin-Binding Triplet

I also learned that Hashimoto’s thyroiditis is an autoimmune disease mediated by the autoantigen thyroid peroxidase. A quick search reveals that thyroid peroxidase is an autoantigen, because it also has a triplet of basic amino acids that can enhance presentation under inflammatory conditions. Grave’s disease of hyperthyroidism is an autoimmune disease in which the thyroid receptor (with a basic triplet) is an autoantigen. The same kind of triplet of basic amino acids was found when I searched today for fire ant antigens and mosquito antigens.

I have also looked for the triplets in protein databases. The triplets are rare in cytoplasmic and extracellular proteins. The proteins that have triplets are usually identified as autoantigens in some disease. The triplets are common in nuclear proteins, since heparin-binding and nucleic acid-binding share the same basic amino acid domains. The nuclear internalization signal also results in rapid cellular internalization, e.g. HIV-TAT, heparanase, IGF-binding proteins. Nuclear proteins are common autoantigens in lupus.

Inflammation Plus Heparin-Binding Internalization: Allergy, Autoimmunity

Chronic inflammation can produce antibodies against proteins (foreign or self) with strong heparin-binding domains (triplets or sometimes neighboring pairs of basic amino acids, lysine or arginine). The generalization explains why particular proteins in pollens, foods, insects, pets, mites, asthma, MS, lupus, celiac, etc. produce antibody responses.

Bee Sting Allergy

Typical. I started to write an article on leukotrienes, the inflammatory derivatives of the omega-6 fatty acid, arachidonic acid, but ran across another powerful example to test my hypothesis to explain the cause of allergies. The leukotriene article will have to wait till another day.

Wikipedia is my source of choice for up-to-date summaries of biomedical information. I queried “leukotrienes” and immediately ran across the original name for these inflammatory compounds, “slow reacting substance of anaphylaxis”. I was initially distracted by the classic experimental use of snake venom and histamine to induce leukotriene production. Snake venom has the same enzyme, PLA2, as brown recluse spider venom (subject of a previous article) and honey bee venom, that releases arachidonic acid (ADA). ADA is an omega-6 fatty acid that is the starting material for inflammatory prostaglandins and leukotrienes.

The mention of honey bee venom in the Wikipedia article on anaphylaxis sent me on a quick check of the structure and sequence of the honey bee allergen. I initially found that the major allergen is a hyaluronidase. I quickly searched for a three amino acid sequence that I predicted would make it an allergen. It was just where I expected to find it. About two thirds of the way along the amino acid sequence I found, -TTSRKKVLP-. Three basic amino acids together, in this case -RKK-, argininine-lysine-lysine, form a strong heparin-binding domain, that I believe takes proteins into cells and during inflammation primes the immune system for allergic responses.

I have found the same strong heparin-binding domain associated with allergens of ragweed, dust mites and peanuts. The principal autoantigens of autoimmune diseases, such as lupus, celiac, etc. also display the same unusual sequences. In lupus, or example, nuclear proteins with the internalization signal provided by nucleic acid-binding domains (and nuclear localization signas) are autoantigens. This pattern is found with all allergens that I have examined. There are a few apparent exceptions, but in all of these cases, there is a closely related allergen from a related source that has the expected strong heparin-binding domain. It appears that in these cases, the less common allergen provides the initial exposure during the presentation phase of high inflammation, and the allergy is maintained by subsequent exposure to the more common allergen. After the establishment of the allergy, the strong heparin-binding domain is no longer needed, because antibodies bind to other parts of homologous allergenic proteins for internalization.

Just for fun, I have illustrated the honey bee allergen, hyaluronidase, to show both its strong heparin-binding domain (blue) along with its substrate hyaluronan (grey and red). Note that the substrate sugars are in the slot of the active site, which is lined with orange and yellow aromatic amino acids that provide flat, hydrophobic binding platforms for each sugar.

After this little distraction to provide further support for my explanation of the cause of allergies, I have to get back to looking at the role of leukotrienes in anaphylaxis, COPD, asthma and other inflammatory diseases.