Also see:
Toxic Plant Estrogens
Carrageenan: A pseudo-latex allergy
Some plants have specific “pests,” such as insects, that have adapted to be resistant to that plant’s toxins, but if the plant and its predator are to survive, there has to be a balance between the plant tissue’s digestibility and its toxicity. Injury of a plant stimulates it to make increased amounts of its defensive chemicals. -Ray Peat, PhD
Science. 1972 May 5;176(4034):512-4.
Toxic substances in plants and the food habits of early man.
Leopold AC, Ardrey R.
The widespread occurrence of toxic substances in plants must have greatly restricted their usefulness as food for primitive man. The development of cooking of plant products is suggested to have been a major evolutionary advance, making a major increase in the vegetable materials palatable to man; this technical advantage apparently occurred only in the most recent 2 percent of the anthropological record.
I think far too little attention is being given to the effects of abnormal and stressful growth conditions on the plants’ natural defense systems. Plants normally synthesize some toxins and inhibitors of digestive enzymes to discourage attacks by bacteria, fungi, insects, and other predators. When a plant is injured or otherwise stressed, it produces more of the defensive substances, and very often they communicate their stress to other plants, and the resulting physiological changes can cause changes in seeds that affect the resistance of the progeny. (Agrawal, 2001). -Ray Peat, PhD in “Milk in context: allergies, ecology, and some myths”
Am Nat. 2001 May;157(5):555-69.
Transgenerational consequences of plant responses to herbivory: an adaptive maternal effect?
Agrawal AA.
Herbivory has many effects on plants, ranging from shifts in primary processes such as photosynthesis, growth, and phenology to effects on defense against subsequent herbivores and other species interactions. In this study, I investigated the effects of herbivory on seed and seedling characteristics of several families of wild radish (Raphanus raphanistrum) to test the hypothesis that herbivory may affect the quality of offspring and the resistance of offspring to plant parasites. Transgenerational effects of herbivory may represent adaptive maternal effects or factors that constrain or amplify natural selection on progeny. Caterpillar (Pieris rapae) herbivory to greenhouse-grown plants caused plants in some families to produce smaller seeds and those in other families to produce larger seeds compared with undamaged controls. Seed mass was positively associated with probability of emergence in the field. The number of setose trichomes, a putative plant defense, was higher in the progeny of damaged plants in some families and lower in the progeny of damaged plants in other families. In a field experiment, plant families varied in their resistance to several herbivores and pathogens as well as in growth rate and time to flowering. Seeds from damaged parent plants were more likely to become infested with a plant virus. Although herbivory on maternal plants did not directly affect interactions of offspring with other plant parasites, seed mass influenced plant resistance to several attackers. Thus, herbivory affected seed characters, which mediated interactions between plants and their parasites. Finally, irrespective of seed mass, herbivory on maternal plants influenced components of progeny fitness, which was dependent on plant family. Natural selection may act on plant responses to herbivory that affect seedling-parasite interactions and, ultimately, fitness.
“One of many substances produced by plants in response to injury is chitinase, an enzyme that breaks down chitin, a polysaccharide that is a structural component of fungi and insects. Chitinase, which is produced by bacteria and humans, as well as by plants and other organisms, is involved in developmental processes as well as in the innate immune system. In plants, the enzyme is induced by ethylene and salicylate, in animals by estrogen, light damage, and infections, and can be demonstrated in polyps and cancers.
The two main classes of plant allergens are the stress-induced chitinases, and seed storage proteins, such as gluten. The chitinase allergens are responsible for reactions to latex (which is secreted by rubber trees in reaction to a wound), bananas, avocados, many other fruits and vegetables, and some types of wood and other plant materials. Intensive agricultural methods are increasing the formation of the defensive chemicals, and the industrialized crops are responsible for the great majority of the new allergies that have appeared in the last 30 years.” -Ray Peat, PhD in “Milk in context: allergies, ecology, and some myths”
Kokuritsu Iyakuhin Shokuhin Eisei Kenkyusho Hokoku. 1998;(116):46-62.
[Plant defense-related proteins as latex allergens].
[Article in Japanese]
Yagami T.
Immediate-type allergic reactions to latex products made from natural rubber are called latex allergy. One of the notable features of latex-allergic people is their cross-reactivity to various vegetable foods and pollen. The structurally similar proteins which most kinds of plants potentially induce must be responsible for these cross-reactions. However, the taxonomical dissimilarity among the causative plants has kept us from concrete explanations of such cross-reactive allergens. We have speculated that plant defense-related proteins are a possible cause of the latex allergy. The well-known serologic relationships and sequence similarities of these ubiquitous plant proteins can explain the cross-reactivity without difficulty. Rubber trees cultured in plantation farms are repeatedly tapped and treated with phytohormones. These stresses would result in the significant induction of defense-related proteins. Indeed, we were able to detect defense-related enzymes in latex extracts. Moreover, three hydrolytic enzymes (beta-1,3-glucanase, chitinase/lysozyme, and carboxylesterase) that are very likely to take a defensive role were specifically recognized by the IgE antibodies of latex-allergic people and atopic patients. These experimental results strongly support our hypothesis. Because of their conserved structures, defense-related proteins should form a family of plant pan-allergens.
Clin Exp Allergy. 1999 May;29(5):673-80.
Isolation and characterization of major banana allergens: identification as fruit class I chitinases.
Sanchez-Monge R, Blanco C, Díaz-Perales A, Collada C, Carrillo T, Aragoncillo C, Salcedo G.
BACKGROUND:
Banana allergy has been associated with the latex-fruit syndrome. Several IgE-binding components, the relevant ones being proteins of 30-37-kDa, have been detected in banana fruit, but none of them have been isolated and characterized yet. Objective To purify and characterize the 30-37 kDa banana allergens.
METHODS:
Fifteen patients allergic to banana were selected on the grounds of a latex-allergic population. Prick by prick tests to this fruit were performed. Total and specific IgE to banana were determined. Banana allergens were isolated by affinity chromatography, followed by cation-exchange chromatography. Their characterization includes N-terminal sequencing, enzymatic activity assays, immunodetection with sera from allergic patients and with antichitinase antibodies, and CAP and immunoblot inhibition tests. Skin prick tests with banana extracts and with the purified allergens were also carried out.
RESULTS:
Two major IgE-binding proteins of 34 and 32 kDa, also recognized by polyclonal antibodies against chestnut chitinases, were immunodetected in crude banana extracts. Purification and characterization of both proteins have allowed their identification as class I chitinases with an hevein-like domain. Each isolated allergen reached inhibition values higher than 90% in CAP inhibition assays, and fully inhibited the IgE-binding by the crude banana extract when tested by an immunoblot inhibition method. The two purified allergens provoked positive skin prick test responses in more than 50% of the banana-allergic patients.
CONCLUSIONS:
Class I chitinases with an hevein-like domain are major allergens in banana fruit. Their presence in other fruits and nuts, such as avocado and chestnut, could explain the cross-sensitization among these foods.
J Allergy Clin Immunol. 1998 Mar;101(3):379-85.
Plant defense-related enzymes as latex antigens.
Yagami T, Sato M, Nakamura A, Komiyama T, Kitagawa K, Akasawa A, Ikezawa Z.
BACKGROUND:
Latex allergy is an increasing hazard to people who frequently come into contact with latex products. Of interest concerning this immediate-type allergy is the cross-reactivity to various vegetable foods and pollen. Despite its high prevalence, no adequate explanation has been provided for the cross-reactive antigens.
OBJECTIVE:
We have hypothesized that a series of plant defense-related proteins act as latex allergens, as well as vegetable food allergens. To evaluate this hypothesis, hydrolytic enzymes that are very likely to take on defensive roles in rubber trees were examined for their antigenicity.
METHODS:
By applying chromatographic procedures, defense-related enzymes were separated from nonammoniated latex (NAL). Their antigenicity was examined by immunoblotting and ELISA with sera containing IgE antibodies to crude latex proteins.
RESULTS:
Three kinds of hydrolytic enzymes (basic beta-1,3-glucanases [35, 36.5, and 38 kd], a basic chitinase/lysozyme [29.5 kd], and an acidic esterase [44 kd]) were separated from NAL. They were recognized by IgE antibodies from a significant number of patients allergic to latex. The basic beta-1,3-glucanases and the acidic esterase were also strongly recognized by IgE antibodies from several atopic subjects who were allergic to various vegetable foods rather than latex products.
CONCLUSION:
It was ascertained that the three defense-related enzymes separated from NAL constituted part of the latex antigens. Taking together the well-known serologic or immunologic relationships and amino acid sequence similarities of defense-related proteins coming from phylogenetically distant plant species, we can suspect their universal antigenicity and cross-reactivity.
Clin Exp Allergy. 2002 Mar;32(3):455-62.
Cloning and molecular characterization of the Hevea brasiliensis allergen Hev b 11, a class I chitinase.
O’Riordain G, Radauer C, Hoffmann-Sommergruber K, Adhami F, Peterbauer CK, Blanco C, Godnic-Cvar J, Scheiner O, Ebner C, Breiteneder H.
BACKGROUND:
In the last 10 years type-I allergy against proteins from Hevea brasiliensis latex has become an acknowledged medical issue. Fruit-allergic patients represent one risk group for developing latex allergy. Class I chitinases have been identified from chestnut, avocado and banana as relevant allergens. The chitin binding (hevein) domain from these class I chitinases has been postulated to bear the important IgE binding epitopes.
OBJECTIVE:
To clone the cDNA of an allergenic latex class I chitinase, to express the recombinant protein and to determine its IgE cross-reactivity with hevein (Hev b 6.02).
METHODS:
A full-length cDNA coding for a class I chitinase has been isolated from Hevea latex RNA by reverse transcription followed by PCR. The chitinase encoding sequence has been subcloned into the pMAL expression vector and expressed in E. coli as a fusion protein to maltose binding protein. The highly enriched recombinant protein fraction has been tested for its IgE binding capacity in immunoblots and ELISA. Furthermore, the pathogenesis-related function of the recombinant protein was tested in a fungal growth inhibition assay.
RESULTS:
The Hevea brasiliensis latex chitinase, designated Hev b 11, displays 70% identity to the endochitinase from avocado and its hevein-domain 58% to hevein (Hev b 6.02). The recombinant Hev b 11-maltose binding protein is recognized by latex- and fruit-allergic patients with IgE binding in both, ELISA and immunoblots. Pre-incubation of sera with rHev b 11-maltose binding protein showed an overall 16% inhibition of subsequent binding to rHev b 6.02-maltose binding protein on solid phase. The growth of F. oxysporum was inhibited in a dose dependent manner by addition of rHev b 11-maltose binding protein to the culture.
CONCLUSIONS:
Hev b 11, a class I chitinase, is another allergen from Hevea latex with a chitin binding domain and displays a different IgE binding capacity compared with hevein.
Biochem Soc Trans. 2002 Nov;30(Pt 6):935-40.
The latex-fruit syndrome.
Wagner S, Breiteneder H.
Approximately 30-50% of individuals who are allergic to natural rubber latex (NRL) show an associated hypersensitivity to some plant-derived foods, especially freshly consumed fruits. This association of latex allergy and allergy to plant-derived foods is called latex-fruit syndrome. An increasing number of plant sources, such as avocado, banana, chestnut, kiwi, peach, tomato, potato and bell pepper, have been associated with this syndrome. The prevailing hypothesis is that allergen cross-reactivity is due to IgE antibodies that recognize structurally similar epitopes on different proteins that are phylogenetically closely related or represent evolutionarily conserved structures. Several types of proteins have been identified to be involved in the latex-fruit syndrome. Two of these are plant defence proteins. Class I chitinases containing an N-terminal hevein-like domain cross-react with hevein (Hev b 6.02), a major IgE-binding allergen for patients allergic to NRL. A beta-1,3-glucanase was identified as an important latex allergen which shows cross-reactivity with proteins of bell pepper. Another important NRL allergen, Hev b 7, is a patatin-like protein that shows cross-reactivity with its analogous protein in potato. Furthermore, patients with allergy to plant-derived foods and associated pollinosis show a high frequency of IgE reactivity to the pan-allergen profilin, which may cause positive serum IgE determinations to NRL. Although there is much information about the plant-derived foods and some data about the allergens involved in the latex-fruit syndrome, it is not always clear whether latex sensitization precedes or follows the onset of food allergy.
Clin Exp Allergy. 2004 Nov;34(11):1739-46.
Characterization of cross-reactive bell pepper allergens involved in the latex-fruit syndrome.
Wagner S, Radauer C, Hafner C, Fuchs H, Jensen-Jarolim E, Wüthrich B, Scheiner O, Breiteneder H.
BACKGROUND:
Between 30% and 50% of individuals who are allergic to latex products are also allergic to specific plant foods, a fact that is well documented as the latex-fruit syndrome. Simultaneous sensitization to latex and bell pepper has been previously reported. Although bell pepper fruits are frequently consumed raw, cooked or as a spice, little is known about the cross-reactive allergens.
OBJECTIVE:
In this study we wished to identify bell pepper allergens involved in the latex-fruit syndrome.
METHODS:
Sera of four patients who displayed clinical symptoms to latex and bell pepper were used in immunoblot studies on protein extracts of three different cultivars of fresh bell pepper and fresh Hevea latex. Cross-reactive allergens were identified by inhibition experiments using recombinant Hev b 8 (latex profilin), and natural Hev b 2 (latex beta-1,3-glucanase) in addition to the protein extracts. A novel cross-reactive IgE-reactive 30 kDa protein was subjected to sequence analysis.
RESULTS:
Three patients displayed IgE to profilins from bell pepper fruits and latex. Two patients possessed IgE to Hev b 2, a latex beta-1,3-glucanase, and a homologous protein in bell pepper. One patient possessed IgE reactive with a protein of 30 kDa identified by N-terminal sequencing as an l-ascorbate peroxidase and another patient to a protein of 38 kDa. Additionally, IgE binding proteins in two higher molecular weight ranges showed cross-reactive capacities.
CONCLUSION:
Our findings show on the molecular level that bell pepper is part of the latex-fruit syndrome. For the first time we have identified the major latex allergen Hev b 2, a beta-1,3-glucanase, and the bell pepper l-ascorbate peroxidase as cross-reactive allergens. We were also able to show that profilins are responsible for some of the IgE cross-reactivity.
J Allergy Clin Immunol. 1999 Mar;103(3 Pt 1):507-13.
Class I chitinases as potential panallergens involved in the latex-fruit syndrome.
Blanco C, Diaz-Perales A, Collada C, Sánchez-Monge R, Aragoncillo C, Castillo R, Ortega N, Alvarez M, Carrillo T, Salcedo G.
BACKGROUND:
Latex-fruit cross-sensitization has been fully demonstrated. However, the antigens responsible for this “latex-fruit syndrome” have not been identified. We have recently shown that class I chitinases are relevant chestnut and avocado allergens.
OBJECTIVE:
We sought to evaluate the in vivo and in vitro reactions of purified chestnut and avocado chitinases in relation to the latex-fruit syndrome.
METHODS:
From a latex-allergic population, eighteen patients allergic to chestnut, avocado, or both were selected. Skin prick tests (SPTs) were performed with crude chestnut and avocado extracts, chitinase-enriched preparations, and purified class I and II chitinases from both fruits. CAP-inhibition assays with the crude extracts and purified proteins were carried out. Immunodetection with sera from patients with latex-fruit allergy and immunoblot inhibition tests with a latex extract were also performed. Eighteen subjects paired with our patients and 15 patients allergic to latex but not food were used as control groups.
RESULTS:
The chestnut class I chitinase elicited positive SPT responses in 13 of 18 patients with latex-fruit allergy (72%), and the avocado class I chitinase elicited positive responses in 12 of 18 (67%) similarly allergic patients. By contrast, class II enzymes without a hevein-like domain did not show SPT responses in the same patient group. Each isolated class I chitinase reached inhibition values higher than 85% in CAP inhibition assays against the corresponding food extract in solid phase. Immunodetection of the crude extracts and the purified class I chitinases revealed a single 32-kd band for both chestnut and avocado. Preincubation with a natural latex extract fully inhibited the IgE binding to the crude extracts, as well as to the purified chestnut and avocado class I chitinases.
CONCLUSION:
Chestnut and avocado class I chitinases with an N-terminal hevein-like domain are major allergens that cross-react with latex. Therefore they are probably the panallergens responsible for the latex-fruit syndrome.
Curr Opin Allergy Clin Immunol. 2001 Apr;1(2):177-83.
The role of plant panallergens in sensitization to natural rubber latex.
Salcedo G, Diaz-Perales A, Sanchez-Monge R.
Latex allergy represents an increasing occupational problem, mainly among healthcare workers. An association between latex allergy and hypersensitivity to some plant foods, particularly fruits (the latex-fruit syndrome), has been established. Class I chitinases with an N-terminal hevein-like domain from avocado, chestnut, banana and other foods, and latex hevein seem to be the allergens responsible for the cross-reactions involved in the latex-fruit syndrome. The potential role of other latex allergens, such as profilin, Hev b 5, Hev b 7 and beta-1,3-glucanases, in the co-sensitization to latex and plant foods is also discussed.
Curr Allergy Asthma Rep. 2003 Jan;3(1):47-53.
Latex-fruit syndrome.
Blanco C.
Natural rubber latex immunoglobulin E-mediated hypersensitivity is probably one of the most relevant challenges that has been faced in the treatment of allergies during recent years. Additionally, allergen cross-reactivity has arisen as another very important problem, in the difficulty in diagnosing it and in its clinical implications. It is clear that some latex allergens cross-react with plant-derived food allergens, the so-called latex-fruit syndrome, with evident clinical consequences. Although the foods most frequently involved are banana, avocado, kiwi, and chestnut, several others are also implicated. Investigations point to a group of defense-related plant proteins, class I chitinases, which cross-react with a major latex allergen, hevein, as the panallergens responsible for the syndrome. This review focuses on our current understanding of the latex-fruit syndrome.
J Am Diet Assoc. 2000 Nov;100(11):1381-4.
The latex and food allergy connection.
Perkin JE.
Natural rubber latex is used in the manufacture of many products in the United States. As natural rubber latex allergy becomes of increasing concern, dietitians need to have an understanding of this allergy and how it relates to workplace safety, employee health, and patient feeding and counseling. Natural rubber latex contains more than 35 proteins that may be related to Type I, Ig-E-mediated allergy in numerous segments of the population, including health care workers and patients. Many foods, especially chestnut, banana, and avocado, have the potential to cross-react with natural rubber latex. Chitinase enzymes, related to plant defense, are believed to be involved in this cross-reaction. A strong connection between food allergy and natural rubber latex allergy is recognized and described in this review.
