CA2319437C - Methods and reagents for decreasing allergic reactions - Google Patents

Abstract

It has been determined that allergens, which are characterized by both humoral (IgE) and cellular (T cell) binding sites, can be modified to be less allergenic by modifying the IgE binding sites. The IgE
binding sites can be converted to non-IgE binding sites by masking the site with a compound that prevents IgE binding or by altering as little as a single amino acid within the protein, most typically a hydrophobic residue towards the center of the IgE-binding epitope, to eliminate IgE binding. The method allows the protein to be altered as minimally as possible, other than within the IgE-binding sites, while retaining the ability of the protein to activate T cells, and, in some embodiments by not significantly altering or decreasing IgG binding capacity. The examples use peanut allergens to demonstrate alteration of IgE binding sites. The critical amino acids within each of the IgE binding epitopes of the peanut protein that are important to immunoglobulin binding have been determined. Substitution of even a single amino acid within each of the epitopes led to loss of IgE
binding. Although the epitopes shared no common amino acid sequence motif, the hydrophobic residues located in the center of the epitope appeared to be most critical to IgE binding.

Description

METHODS AND REAGENTS FOR DECREASING ALLERGIC REACTIONS
Background of the Invention The United States government has rights in this invention by virtue of grants from the National Institute of Health RO1-AI33596.
Allergic disease is a common health problem affecting humans and companion animals (mainly dogs and cats) alike. Allergies exist to foods, molds, grasses, trees, insects, pets, fleas, ticks and other substances present in the environment. It is estimated that up to 8% of young children and 2%
of adults have allergic reactions just to foods alone. Some allergic reactions (especially those to foods and insects) can be so severe as to be life threatening. Problems in animals tend to be less severe, but very common.
For example, many dogs and cats have allergies to flea saliva proteins, grasses, and other common substances present in the environment.
Allergy is manifested by the release of histamines and other mediators of inflammation by mast cells which are triggered into action when IgE antibodies bound to their receptors on the mast cell surface are cross linked by antigen. Other than avoidance, and drugs (e.g.
antihistamines, decongestants, and steroids) that only treat symptoms and can have unfortunate side effects and often only provide temporary relief, the only currently medically accepted treatment for allergies is immunotherapy.
Immunotherapy involves the repeated injection of allergen extracts, over a period of years, to desensitize a patient to the allergen. Unfortunately, traditional immunotherapy is time consuming, usually involving years of treatment, and often fails to achieve its goal of desensitizing the patient to the allergen. Furthermore, it is not the recommended treatment for food allergies, such as peanut allergies, due to the risk of anaphylaxis.
Noon (Noon, Lancet 1911; 1:1572-73) first introduced allergen injection immunotherapy in 1911, a practice based primarily on empiricism with non-standardized extracts of variable quality. More recently the introduction of standardized extracts has made it possible to increase the efficacy of immunotherapy, and double-blind placebo-controlled trials have demonstrated the efficacy of this form of therapy in allergic rhinitis, asthma and bee-sting hypersensitivity (BSAC Working Party, Clin. Exp. Allergy 1993; 23:1-44). However, increased risk of anaphylactic reactions has accompanied this increased efficacy. For example, initial trials of immunotherapy to food allergens has demonstrated an unacceptable safety:efficacy ratio (Oppenheimer et al. JAllergy Clfn. Immun. 1992;
90:256-62; Sampson, J. Allergy Clin. Immun. 1992; 90:151-52; Nelson et al.
J. Allergy Clin. Immun. 1996; 99:744-751). Results like these have prompted investigators to seek alternative forms of immunotherapy as well as to seek other forms of treatment.
Initial trials with allergen-non-specific anti-IgE antibodies to deplete the patient of allergen-specific IgE antibodies have shown early promise (Boulet, et al. 1997; 155:1835-1840; Fahy, et al. American JRespir. Crit.
Care Med. 1997; 155:1828-1834; Demoly P. and Bousquet J. American J
Resp. Crit. Care Med. 1997; 155:1825-1827). On the other hand, trials utilizing immunogenic peptides (representing T cell epitopes) have been disappointing (Norman, et al. J. Aller. Clin. Immunol. 1997; 99:S127).
Another form of allergen-specific immunotherapy which utilizes injection of plasmid DNA (Raz et al. Proc. Nat. Acad. Sci. USA 1994; 91:9519-9523; Hz et al. Int. Immunol. 1996; 8:1405-1411) remains unproven.
There remains a need for a safe and efficacious therapy for allergies, especially those where traditional immunotherapy is ill advised due to risk to the patient or lack of efficacy. There is also a need for altematives to therapies, for example, by creating foods, materials or substances that do not include the allergens that are most problematic, or which contain modified allergens which do not elicit the same reaction. While the technology to make genetically engineered plants and animals is at this point well established, useful modifications would require understanding how allergens can be modified so that they retain the essential functions for the plants' and animals' nutritional value, taste characteristics, etc., but no longer elicit as severe an allergic response.
It is therefore an object of the present invention to provide a method for decreasing the allergenicity of allergens either by modifying the allergen itself or by producing a compound that would mask the epitope and thus prevent binding of IgE.
It is a further object of the present invention to provide allergens that elicit fewer IgE mediated responses.
It is still another object of the present invention to provide a method to make genetically engineered plants and animals that elicit less of an allergic response than the naturally occurring organisms.
Summary of the Invention It has been determined that allergens, which are characterized by both humoral (IgG and IgE) and cellular (T cell) binding sites, can be made less allergenic by modifying the IgE binding sites. The IgE binding sites can be eliminated by masking the site with a compound that would prevent IgE
binding or by altering as little as a single amino acid within the protein to eliminate IgE binding. The method allows the protein to be altered as minimally as possible, (i.e. only within the IgE-binding sites) while retaining the ability of the protein to activate T cells and, optionally, to bind IgG.
Binding sites are identified using known techniques, such as by binding with antibodies in pooled sera obtained from individuals known to be immunoreactive with the allergen to be modified. Proteins that are modified to alter IgE binding are screened for binding with IgG and/or activation of T
cells.
Peanut allergens (Ara h 1, Ara h 2, and Ara h 3) have been used in the examples to demonstrate alteration of IgE binding sites while retaining binding to IgG and activation of T cells. The critical amino acids within each of the IgE binding epitopes of the peanut protein that are important to immunoglobulin binding were determined. Substitution of even a single amino acid within each of the epitopes led to loss of IgE binding. Although the epitopes shared no common amino acid sequence motif, the hydrophobic residues located in the center of the epitope appeared to be most critical to IgE binding.

Standard techniques such as a skin test for wheal and flare formation can be used to assess decreased allergenicity of modified proteins, created as described in the examples. The modified allergens can also be tested for binding to IgG and proliferation of T cells, and modified allergens selected for optimal stimulation of T cells and binding IgG.
The immunotherapeutics can be delivered by standard techniques, using injection, by aerosol, sublingually, topically (including to a mucosal surface), and by gene therapy (for example, by injection of the gene encoding the immunotherapeutic into muscle or skin where it is transiently expressed for a time sufficient to induce tolerance).
This method and the criteria for identifying and altering allergens can be used to design useful proteins (including nucleotide molecules encoding the proteins) for use in immunotherapy, to make a vaccine and to genetically engineer organisms such as plants and animals which then produce proteins with less likelihood of eliciting an IgE response. Techniques for engineering plants and animals are well known. Based on the information obtained using the method described in the examples, one can engineer plants or animals to cause either site specific mutations in the gene encoding the protein(s) of interest, or to knock out the gene and then insert the gene encoding the modified protein.
Brief Description of the Drawings Figure 1 shows an example of how IgE binding epitopes were mapped to a specific amino acid sequence on the Ara h 1 allergen.
Figure 2 shows how IgE binding epitopes were mapped to a specific amino acid sequence on the Ara h 2 allergen.
Figure 3 shows how IgE binding epitopes were mapped to a specific amino acid sequence on the Ara h 3 allergen.
Figure 4 is a graph of the %IgE binding relative to wild type Ara h2 of modified Ara h 2 allergens.
Figure 5 shows the results of T-cell proliferation assays using the native and recombinant wild-type and modified Ara h 2 protein, compared to crude peanut as a control.
Detailed Description of the Invention I?efinitions The following definitions are used herein.
An antigen is a molecule that elicits production of antibody (a humoral response) or an antigen-specific reaction with T cells (a cellular response).
An allergen is a subset of antigens which elicits IgE production in addition to other isotypes of antibodies.
An allergic reaction is one that is IgE mediated with clinical symptoms primarily involving the cutaneous (uticaria, angiodema, pruritus), respiratory (wheezing, coughing, laryngeal edema, rhinorrhea, watery/itching eyes), gastrointestinal (vomiting, abdominal pain, diarrhea), and cardiovascular (if a systemic reaction occurs) systems.
An epitope is a binding site including an amino acid motif of between approximately six and fifteen amino acids which can be bound by either an immunoglobulin or recognized by a T cell receptor when presented by an antigen presenting cell in conjunction with the major histocompatibility complex (MHC). A linear epitope is one where the amino acids are recognized in the context of a simple linear sequence. A conformational epitope is one where the amino acids are recognized in the context of a particular three dimensional structure.
An immunodominant epitope is one which is bound by antibody in a large percentage of the sensitized population or where the titer of the antibody is high, relative to the percentage or titer of antibody reaction to other epitopes present in the same protein.
A decreased allergic reaction is characterized by a decrease in clinical symptoms following treatment of symptoms associated with exposure to an allergen, which can involve respiratory, gastrointestinal, skin, eyes, ears and mucosal surfaces in general.

An antigen presenting cell (an APC) is a cell which processes and presents peptides to T cells to elicit an antigen-specific response.
Immunostimulatory sequences are oligodeoxynucleotides of bacterial, viral or invertebrate origin that are taken-up by APCs and activate them to express certain membrane receptors (e.g., B7-1 and B7-2) and secrete various cytokines (e.g., IL-1, IL-6, IL-12, TNF). These oligodeoxynucleotides containing unmethylated CpG motifs cause brisk activation and when injected into animals in conjunction with antigen, appear to skew the immune response to a Thl -type response. See, for example, Yamamoto, et al., Microbiol. Immunol. 36,983 (1992); Krieg, et al., Nature 374, 546-548 (1995); Pisetsky, Immunity 5, 303 (1996); and Zimmerman, et al., J. Immunol. 160, 3627-3630 (1998).
I. Diagnostic and Therapeutic Reagents.
The first step in making the modified allergen is to identify IgE
binding sites and/or immunodominant IgE binding sites. The second step is to mutate one or more of the IgE binding sites, preferably including at a minimum one of the immunodominant sites, or to react the allergen with a compound that selectively blocks binding to one or more of the IgE binding sites. The third step is to make sufficient amounts of the modified allergen for administration to persons or animals in need of tolerance to the allergen, where the modified allergen is administered in a dosage and for a time to induce tolerance, or for diagnostic purposes. The modified allergen can be administered by injection, or in some cases, by ingestion or inhalation.
A. Allergens.
Many allergens are known that elicit allergic responses, which may range in severity from mildly irritating to life-threatening. Food allergies are mediated through the interaction of IgE to specific proteins contained within the food. Examples of common food allergens include proteins from peanuts, milk, grains such as wheat and barley, soybeans, eggs, fish, crustaceans, and mollusks. These account for greater than 90% of the food allergies (Taylor, Food Techn. 39, 146-152 (1992). The IgE binding epitopes from the major allergens of cow milk (Ball, et al. (1994) Clin. Exp.
Allergy, 24, 758-764), egg (Cooke, S.K. and Sampson, H.R. (1997) J.
Immunol., 159, 2026-2032), codfish (Aas, K., and Elsayed, S. (1975) Dev.
Biol. Stand. 29, 90-98), hazel nut (Elsayed, et al. (1989) Int. Arch. Allergy Appl. Immunol. 89, 410-415), peanut (Burks et al., (1997) Eur. J.
Biochemistry, 245:334-339; Stanley et al., (1997) Archives of Biochemistry and Biophysics, 342:244-253), soybean (Herein, et al. (1990) Int. Arch.
AllergyAppl. Immunol. 92, 193-198) and shrimp (Shanty, et al. (1993) J
Immunol. 151, 5354-5363) have all been elucidated, as have others. Other allergens include proteins from insects such as flea, tick, mite, fire ant, cockroach, and bee as well as molds, dust, grasses, trees, weeds, and proteins from mammals including horses, dogs, cats, etc.
The majority of allergens discussed above elicit a reaction when ingested, inhaled, or injected. Allergens can also elicit a reaction based solely on contact with the skin. Latex is a well known example. Latex products are manufactured from a milky fluid derived from the rubber tree, Hevea brasiliensis and other processing chemicals. A number of the proteins in latex can cause a range of allergic reactions. Many products contain latex, such as medical supplies and personal protective equipment. Three types of reactions can occur in persons sensitive to latex: irritant contact dermatitis, and immediate systemic hypersensitivity. Additionally, the proteins responsible for the allergic reactions can fasten to the powder of latex gloves.
This powder can be inhaled, causing exposure through the lungs. Proteins found in latex that interact with IgE antibodies were characterized by two-dimensional electrophoresis. Protein fractions of 56, 45, 30, 20, 14, and less than 6.5 kd were detected (Posch A. et al., (1997) J. Allergy Clin. Immunol.
99(3), 385-395 ). Acidic proteins in the 8-14 kd and 22 - 24 kd range that reacted with IgE antibodies were also identified (Posch A. et al., (1997) J.
Allergy Clin. Immunol. 99(3), 385-395. The proteins prohevein and hevein, from hevea brasiliensis, are known to be major latex allergens and to interact with IgE (Alenius, H., et al., Clin. Exp. Allergy 25(7), 659-665; Chen Z., et al., (1997) J. Allergy Clin. Immunol. 99(3), 402-409). Most of the IgE
binding domains have been shown to be in the hevein domain rather than the domain specific for prohevein (Chen Z., et al., (1997) J. Allergy Clin.
Immunol. 99(3), 402-409). The main IgE-binding epitope of prohevein is thought to be in the N-terminal, 43 amino acid fragment (Alenius H., et al., (1996) J. Immunol. 156(4), 1618-1625). The hevein lectin family of proteins has been shown to have homology with potato lectin and snake venom disintegrins (platelet aggregation inhibitors) (Kielisqewski, M.L., et al., (1994) Plant J. 5(6), 849-861).
B. Identification of IgE Bindi g Sites.
Allergens typically have both IgE and IgG binding sites and are recognized by T cells. The binding sites can be determined either by using phage display libraries to identify conformational epitopes (Eichler and Houghten, (1995) Molecular Medicine Today 1, 174-180; Jensen-Jarolim et al., (1997) J. Appl. Clin. Immunol. 101, 5153a) or by using defined peptides derived from the known amino acid sequence of an allergen (see examples below), or by binding of whole protein or protein fragments to antibodies, typically antibodies obtained from a pooled patient population known to be allergic to the allergen. It is desirable to modify allergens to diminish binding to IgE while retaining their ability to activate T cells and in some embodiments by not significantly altering or decreasing IgG binding capacity. This requires modification of one or more IgE binding sites in the allergen.

A preferred modified allergen is one that can be used with a majority of patients having a particular allergy. Use of pooled sera from allergic patients allows detenmination of one or more immunodominant epitopes in the allergen. Once some or all of the IgE binding sites are known, it is possible to modify the gene encoding the allergen, using site directed mutagenesis by any of a number of techniques, to produce a modified allergen as described below, and thereby express modified allergens. It is also possible to react the allergen with a compound that achieves the same result as the selective mutation, by making the IgE binding sites inaccessible, but not preventing the modified allergen from activating T cells, and, in some embodiments, by not significantly altering or decreasing IgG binding.
Assays to assess an immunologic change after the administration of the modified allergen are known to those skilled in the art. Conventional assays include RAST (Sampson and Albergo, 1984), ELISAs (Burks, et al.
1986) immunoblotting (Burks, et al. 1988), and in vivo skin tests (Sampson and Albergo 1984). Objective clinical symptoms can be monitored before and after the administration of the modified allergen to determine any change in the clinical symptoms.
It may be of value to identify IgEs which interact with conformational rather than linear epitopes. Due to the complexity and heterogeneity of patient serum, it may be difficult to employ a standard immobilized allergen affinity-based approach to directly isolate these IgEs in quantities sufficient to permit their characterization. These problems can be avoided by isolating some or all of the IgEs which interact with conformational epitopes from a combinatorial IgE phage display library.
1o Steinberger et al. (Steinberger, P., Kraft D. and Valenta R. (1996) "Construction of a combinatorial IgE library from an allergic patient:
Isolation and characterization of human IgE Fabs with specificity for the major Timothy Grass pollen antigen," Phl p. 5 J. Biol. Chem. 271, 10967-10972) prepared a combinatorial IgE phage display library from mRNA
isolated from the peripheral blood mononuclear cells of a grass allergic patient. Allergen-specific IgEs were selected by panning filamentous phage expressing IgE Fabs on their surfaces against allergen immobilized on the wells of 96 well microtiter plates. The cDNAs were than isolated from allergen-binding phage and transformed into E coli for the production of large quantities of monoclonal, recombinant, allergen-specific IgE Fabs.
If native allergen or full length recombinant allergen is used in the panning step to isolate phage, then Fabs corresponding to IgEs specific for conformational epitopes should be included among the allergen-specific clones identified. By screening the individual recombinant IgE Fabs against denatured antigen or against the relevant linear epitopes identified for a given antigen, the subset of conformation-specific clones which do not bind to linear epitopes can be defined.
To determine whether the library screening has yielded a complete inventory of the allergen-specific IgEs present in patient serum, an immunocompetition assay can be performed. Pooled recombinant Fabs would be preincubated with immobilized allergen. After washing to remove unbound Fab, the immobilized allergen would then be incubated with patient serum. After washing to remove unbound serum proteins, an incubation with a reporter-coupled secondary antibody specific for IgE Fc domain would be performed. Detection of bound reporter would allow quantitation of the extent to which serum IgE was prevented from binding to allergen by recombinant Fab. Maximal, uncompeted serum IgE binding would be determined using allergen which had not been preincubated with Fab or had been incubated with nonsense Fab. If IgE binding persists in the face of competition from the complete set of allergen-specific IgE Fab clones, this experiment can be repeated using denatured antigen to determine whether the epitopes not represented among the cloned Fabs are linear or conformational.
Production of Recombinant or Modified Allergens A modified allergen will typically be made using recombinant techniques. Expression in a procaryotic or eucaryotic host including bacteria, yeast, and baculovirus-insect cell systems are typically used to produce large (mg) quantities of the modified allergen. It is also possible to make the allergen synthetically, if the allergen is not too large, for example, less than about 25-40 amino acids in length.
Production o~'ransgenic Plants and Animals Transgenic plants or animals expressing the modified allergens have two purposes. First, they can be used as a source of modified allergen for use in immunotherapy and second, appropriately modified plants or animals can be substituted for the original plant or animal, making immunotherapy unnecessary. Furthenmore, it is possible that eating modified peanuts or cod fish, for example, could have either or both of two effects: (1) not imparting an allergic response on their own and (2) conferring protection from the unmodified source by acting as an immunotherapeutic agent for the unmodified source. Methods for engineering of plants and animals are well known and have been for a decade. For example, for plants see Day, (1996) Crit. Rev. Food Sci. & Nut. 36(S), 549-567, the teachings of which are incorporated herein. See also Fuchs and Astwood (1996) Food Tech. 83-88. Methods for making recombinant animals are also well established. See, for example, Colman, A" Production of therapeutic proteins in the milk of transgenic livestock" (1998) Biochem. Soc. Symp. 63, 141-147; Espanion and Niemann, (1996) DTWDtxch Tierarztl Wochenschr 103(8-9), 320-328; and Colman, Am. J. Clin. Nutr. 63(4), 639S-645S. One can also induce site specific changes using homologous recombination and/or triplex forming oligomers. See, for example, Rooney and Moore, (1995) Proc. Natl. Acad. Sci. USA 92, 2141-2149; Agrawal, et al., Bio World Today, vol. 9, no. 41, p. 1"Chimeriplasty -Gene Surgery, Not Gene Therapy - Fixes Flawed Genomic Sequences"
David N. Leff.

Production and Screening of Compounds blocking IgE Binding Sites Once the IgE binding sites have been identified, it is also possible to block or limit binding to one or more of these sites by reacting the allergen with a compound that does not prevent the allergen from activating T cells, and in some embodiinents does not significantly alter or decrease IgG
binding capacity, resulting in a modified allergen similar in functionality to that produced by mutation. There are two principal ways to obtain compounds which block IgE binding sites: combinatorial libraries and combinatorial chemistry.
Identification of Compounds That Mask IgE Binding Sites through Application of Combinatorial Chemistry In some cases it may be preferable to utilize non-peptide compounds to block binding of IgE to the allergen by masking tiie IgE binding epitope.
This can be accomplished by using molecules that are selected from a complex mixture of random niolecules in what has been referred to as "i vitro genetics" or combinatorial cliemistry (Szostak, TIBS 19:89, 1992). In this approach a large pool of random and defined sequences is synthesized and then subjected to a selection and enrichnlent process. The selection and enrichntent process involves the binding of the IgE binding epitopes to a solid support, followed by interaction with the products of various combinatorial libraries. 1'llose molecules wilich do not bind these tnolecules at all are removed iminediately by elution with a suitable solvent. Those moleculcs which bind to the epitopcs will remain bOUnd to t11C solid SllppOrt, ~vhcrcas, imbound compounds will bc rcmovcd front ttic colLulln. Thosc ConlpOunds bound to the Cohinln C1n bC rcnlOved, far exanlhle, by compctitive binding. 1'ollownng renlOval o( thcsc conll)Ounds, thc tl compounds which have bound can be identified, using methodology well known to those of skill in the art, to isolate and characterize those compounds which bind to or interact with IgE binding epitopes. The relative binding affinities of these compounds can be compared and optimum compounds identified using competitive binding studies which are well known to those of skill in the art.
Identification of Compounds That Interact with IgE, Binding Sites through Application of Combinatorial Phage DiaLay Libraries Recombinant, monoclonal Fabs directed against confonmational epitopes, identified as described above, can be used as reagents to assist in the definition of the biochemical nature of these epitopes. Cross-linking studies employing derivatized Fabs can be employed to label amino acid residues in the vicinity of the epitopes. Similarly, the Fabs can be used in protease protection studies to identify those domains of the allergen protein which are shielded from protease degradation by pre-binding of a specific Fab. Experiments employing recombinant monoclonal Fabs as reagents to label or protect from labeling should permit at least partial elucidation of the structures of conformational epitopes.
"Humanized" recombinant Fabs should bind to allergens if injected into a patient and thus prevent the binding of these allergens to native IgE.
Since the Fabs cannot interact with the FcE receptor, the binding of the IgE
Fabs to allergen would not be expected to elicit mast cell degranulation.
Allergen should be neutralized as it is by protective IgGs.
Anti-idiotype antibodies directed against the conformational epitope-specific Fabs should resemble the conformation epitopes themselves.
Injection of these anti-idiotype antibodies should induce the production of anti-anti-idiotype IgGs which would recognize, bind to and inactivate the conformational epitopes. The method through which the anti-idiotype antibodies would be produced (i.e. animal immunization, "in vitro"
immunization or recombinant phage display library) would have to be determined. Similarly, the possibility that the anti-idiotype antibodies (which resemble the conformational epitopes) would be recognized by patient IgEs and induce mast cell degranulation needs to be considered.

II. Diagnostic and Therapeutic Procedures Using Modified Allergens.
It is important to administer the modified allergen to an individual (human or animal) to decrease the clinical symptoms of allergic disease by using a method, dosage, and carrier which are effective. Allergen will typically be administered in an appropriate carrier, such as saline or a phosphate saline buffer. Allergen can be administered by injection subcutaneously, intramuscularly, or intraperitoneally (most humans would be treated by subcutaneous injection), by aerosol, inhaled powder, or by ingestion.
Therapy or desensitization with the modified allergens can be used in combination with other therapies, such as allergen-non-specific anti-IgE
antibodies to deplete the patient of allergen-specific IgE antibodies (Boulet, et al. (1997) 155:1835-1840; Fahy, et al. (1997) American JRespir. Crit.
Care Med. 155:1828-1834; Demoly, P. and Bousquet (1997) JAm JResp.
Crit. Care Med. 155:1825-1827), or by the pan specific anti-allergy therapy described in U. S. Serial No. 08/090,375 filed June 4, 1998, by M. Caplan and H. Sosin. Therapy with the modified allergen can also be administered in combination with an adjuvant such as IL 12, IL 16, IL 18, Ifn-~.

The nucleotide molecule encoding the modified allergen can also be administered directly to the patient, for example, in a suitable expression vector such as a plasmid, which is injected directly into the muscle or dermis, or through administration of genetically engineered cells.
In general, effective dosages will be in the picogram to milligram range, more typically microgram to milligram. Treatment will typically be between twice/weekly and once a month, continuing for up to three to five years, although this is highly dependent on the individual patient response.
The modified allergen can also be used as a diagnostic to characterize the patient's allergies, using techniques such as those described in the examples.
EXAMPLES
Peanut allergy is one of the most common and serious of the immediate hypersensitivity reactions to foods in terms of persistence and severity of reaction. Unlike the clinical symptoms of many other food allergies, the reactions to peanuts are rarely outgrown, therefore, most diagnosed children will have the disease for a lifetime (Sampson, H.A., and Burks, A.W. (1996) Annu. Rev. Nutr. 16, 161-77; Bock, S.A. (1985) J.
Pediatr. 107, 676-680). The majority of cases of fatal food-induced anaphylaxis involve ingestion of peanuts (Sampson et al., (1992) NEJM 327, 380-384; Kaminogawa, S. (1996) Biosci. Biotech. Biochem. 60, 1749-1756).
The only effective therapeutic option currently available for the prevention of a peanut hypersensitivity reaction is food avoidance. Unfortunately, for a ubiquitous food such as a peanut, the possibility of an inadvertent ingestion is great.
The examples described below demonstrate identification, modification, and assessment of allergenicity of the major peanut allergens, Ara h 1, Ara h 2, and Ara h 3. Detailed experimental procedures are included for Exarnple 1. These same procedures were used for Examples 2-5. The nucleotide sequences of Ara h 1, Ara h 2, and Ara h 3, are shown in SEQ ID NOs. 1, 3, and 5, respectively. The amino acid sequences of Ara h 1, Ara h 2, and Ara h 3 are shown in SEQ ID NOs. 2, 4, and 6 respectively.
Example 1: Identification of linear IgE binding epitopes.
Due to the significance of the allergic reaction and the widening use of peanuts as protein extenders in processed foods, there is increasing interest in defining the allergenic proteins and exploring ways to decrease the risk to the peanut-sensitive individual. Various studies over the last several years have identified the major allergens in peanuts as belonging to different families of seed storage proteins (Burks, et al. (1997) Eur. J. Biochem. 245, 334-339; Stanley, et al. (1997) Arch. Biochem. Biophys. 342, 244-253). The major peanut allergens Ara h 1, Ara h 2, and Ara h 3 belong to the vicilin, conglutin and glycinin families of seed storage proteins, respectively. These allergens are abundant proteins found in peanuts and are recognized by serum IgE from greater than 95% of peanut sensitive individuals, indicating that they are the major allergens involved in the clinical etiology of this disease (Burks, et al. (1995) J. Clinical Invest., 96, 1715-1721). The genes encoding Ara h 1(SEQ ID NO. 1), Ara h 2 (SEQ ID NO. 3), and Ara h 3 (SEQ ID NO. 5) and the proteins encoded by these genes (SEQ ID NO. 2, 4, 6) have been isolated and characterized. The following studies were conducted to identify the IgE epitopes of these allergens recognized by a population of peanut hypersensitive patients and a means for modifying their affinity for IgE.
Experimental Procedures Serum IgE. Serum from 15 patients with documented peanut hypersensitivity reactions (mean age, 25 yrs) was used to determine relative binding affinities between wild type and mutant Ara h 1 synthesized epitopes. The patients had either a positive double-blind, placebo-controlled, food challenge or a convincing history of peanut anaphylaxis (laryngeal edema, severe wheezing, and/or hypotension; Burks, et al. (1988) J. Pediatr.
113, 447-451). At least 5 ml of venous blood was drawn from each patient, allowed to clot, and serum was collected. A serum pool from 12 to 15 patients was made by.mixing equal aliquots of serum IgE from each patient.
The pools were then used in immunoblot analysis.
Peptide synthesis. Individual peptides were synthesized on a derivatized cellulose membrane using 9-fluorenyllmethoxycarbonyl (Fmoc) amino acid active esters according to the manufacturer's instructions (Genosys Biotechnologies, Woodlands, Texas; Fields, G.B. and Noble, R.L.
(1990) Int. J. Peptide Protein Res. 35, 161-214). Fmoc-amino acids (N-terminal blocked) with protected side chains were coupled in the presence of 1-methyl-2-pyrrolidone to a derivatized cellulose membrane. Following washing with dimethylformamide (DMF), unreacted terminal amino groups were blocked from further reactions by acetylation with acetic anhydride.
The N-terminal Fmoc blocking group was then removed by reaction with 20% piperidine and 80% DMF, v/v. The membrane was washed in DMF
followed by methanol, the next reactive Fmoc-amino acid was then coupled as before, and the sequence of reactions was repeated with the next amino acid. When peptide synthesis was complete, the side chains were deprotected with a mixture of dichloromethane (DCM), triflouroacetic acid, and triisobutylsilane (1.0:1.0:0.5), followed by successive washes in DCM, DMF, and methanol. Peptides synthesis reactions were monitored by bromophenol blue color reactions during certain steps of synthesis.
Cellulose derivitised membranes and Fmoc-amino acids were supplied by Genosys Biotechnologies. All other chemical were purchased from Aldrich Chemical Company, Inc. (Milwaukee, WI) or Fluka (Buchs, Switzerland).
Membranes were either probed immediately or stored at -20 C until needed.
IgE bii:ding assays. Cellulose membranes containing synthesized peptides were washed 3 times in Tris-buffered saline (TBS; 136 mM NaCI, 2.7 mM KCI, and 50 mM trizma base pH 8.0) for 10 min at room temperature (RT) and then incubated overnight in blocking buffer: [TBS, 0.05% TweenTM 20; concentrated membrane blocking buffer supplied by Genosys; and sucrose (0.0:1.0:0.5)]. The membrane was then incubated in pooled sera diluted in 1:5 in 20 mM Tris-Cl pH7.5, 150 mM NaCI, and 1%
bovine serum albumin ovemight at 4 C. Primary antibody was detected with iz5I-labeled equine atlti-human IgE (Kallestad, Chaska, MN).
Quantitatiaii of IgE biudiug. Relative amounts of IgE binding to individual peptides were determined by a Bio-RadTM (Hercules, CA) model GS-700 imaging laser densitometer and quantitated with Bio-Rad inolecular analyst software. A background area was scanned and subtracted from thc obtained values. Following quantitation, wild type intensities were notnlalized to a value of one and the mutants were calculated as percentages relative to the wild type.
Syntliesis ai:d purification of recombinant Ara h 2 protein. cDNA
encoding Ara h 2 was placed in the pET-24b expression vector. The pET-24 expression vector places a 6 x histidine tag at the carboxyl end of the inserted protein. The histidine tag allows the recombinant protein to be purified by afGnity purification on a nickcl column (HisBind resin). Rccombinant Ara li 2 was expressed and purified according to the instructions of the pET svsteni inanual. Briefly, expression of the recombinant Ara h 2Nvas induced in 200 nil cultures of strain BL21(DE3) E. coii with i niM 1PTG at mid log phase.
Cultures were allowcd to continue for an additional 3 hout-s at 36"C. Cells were han-ested by centrifugation at 2000 x g for 15 minutes and then lysed in denaturini; bindin`, buffer (6 M urea, 5 niM imidazole, 0.5 M NaCI, 20 mM
'I,ris-I1C1, hli 7.())_ l_vsatcs Nvcrc cleared by centrifugation at 39,000 xtur lb 20 minutes followed by filtration though 0.45 micron filters. The cleared lysate was applied to a 10 ml column of HisBind resin, washed with imidazole wash buffer (20 mM imidazole, 6 M urea, 0.5 M NaCI, 20 mM
Tris-HCI, pH 7.9). The recombinant Ara h 2 was then released from the colunm using elution buffer (1 M imidazole, 0.5 M NaCI, 20 mM Tris-HCI, pH 7.9). The elution buffer was replaced with phosphate buffered saline by dialysis. The purification of recombinant Ara h 2 was followed by SDS
PAGE and immunoblots. Peanut specific serum IgE was used as a primary antibody.
Skin prick tests. The ability of purified native and recombinant Ara h 2 to elicit the IgE mediated degranulation of mast cells was evaluated using prick skin tests in a peanut allergic individual. An individual meeting the criteria for peanut allergy (convincing history or positive double blind placebo controlled food challenge) and a non-allergic control were selected for the testing. Purified native and recombinant Ara h 2 and whole peanut extract (Greer Laboratories, Lenoir, N.C.) were tested. Twenty microliters of the test solution were applied to the forearm of the volunteer and the skin beneath pricked with a sterile needle. Testing was started at the lowest concentration (less than or equal to 1 mg/ml) and increased ten fold each round to the highest concentration or until a positive reaction was observed.
Mean diameters of the wheal and erythema were measured and compared to the negative saline control. A positive reaction was defined as a wheal 3mm larger then the negative control. Histamine was used as the positive control.
Results Identification of the linear IgE-binding epitopes of Ara h 1, Ara h 2 and Ara h 3 allergens. Epitope mapping was performed on the Ara h 1, Ara h 2 and Ara h 3 allergens by synthesizing each of these proteins in 15 amino acid long overlapping peptides that were offset from each other by 8 amino acids. The peptides were then probed with a pool of serum IgE from 15 patients with documented peanut hypersensitivity. This analysis resulted in multiple IgE binding regions being identified for each allergen. The exact position of each IgE binding epitope was then determined by re-synthesizing these IgE reactive regions as 10 or 15 amino acid long peptides that were offset from each other by two amino acids. These peptides were probed with the same pool of serum IgE from peanut sensitive patients as used before.
An example of this procedure for each of the peanut allergens is shown in Figures 1-3. Figure 1 shows amino acid residues 82-133 of Ara h 1, containing peptides 4, 5, 6, and 7, as identified in Table 1. Figure 2 shows amino acid residues 55-76 of Ara h 2, containing peptides 6 and 7, as shown in Table 2. Figure 3 shows amino acid residues 299-321 of Ara h 3, containing peptide 4 as identified in Table 3. This analysis revealed that there were 23 linear IgE binding epitopes on Ara h 1, 10 epitopes on Ara h 2, and 4 epitopes on Ara h 3.
In an effort to determine which, if any, of the epitopes were recognized by the majority of patients with peanut hypersensitivity, each set of epitopes identified for the peanut allergens were synthesized and then probed individually with serum IgE from 10 different patients. All of the patient sera tested recognized multiple epitopes.
Table 1 shows the amino acid sequence and position of each epitope within the Ara h 1 protein of all 23 IgE binding epitopes mapped to this molecule. Table 2 shows the amino acid sequence and position of each epitope within the Ara h 2 protein of all 10 IgE binding epitopes mapped to this molecule. Table 3 shows the amino acid sequence and position of each epitope within the Ara h 3 protein of al14 IgE binding epitopes mapped to this molecule.
Four epitopes of the Ara h 1 allergen (peptides 1, 3, 4, 17 of Table 1), three epitopes of the Ara h 2 allergen (peptides 3, 6, 7 of Table 2), and 1 epitope of the Ara h 3 allergen (peptide 2 of Table 3) were immunodominant.

Table 1. Ara h I IgE Binding Epitopes EPITOPE AA SEQUENCE POSITION
1 AKSSPI'QKKT 25-34 7 REREED-)Y$QP 123-132 TPfQEEDFFP 294-303 T1rTFGKLFEVK 409-418 16 GTQNT,RT,yAV 461-470 18 ET ,HT .T .GFGTN 525-534 23 PEK,ESPF_.KFD 597-606 The underlined portions of each peptide are the smallest IgE binding sequences as determined by this analysis. All of these sequences can be found in SEQ ID NO 2.
Table 2. Ara h 2 IgE Binding Epitopes EPITOPE AA SEQUENCE POSITION

6 YE$DL)MSQ 57-66 9 R$ F.I.RNi.PQQ 127-136 The underlined portions of each peptide are the smallest IgE binding sequences as determined by this analysis. All of these sequences can be found in SEQ ID NO 4.

Table 3. Ara h 3 IgE Binding Epitopes EPITOPE AA SEQUENCE POSITION

The underlined portions of each peptide are the smallest IgE binding sequences as determined by this analysis. All of these sequences can be found in SEQ ID NO 6.

Example 2: Modification of peanut allergens to decrease allergenicity.
The major linear IgE binding epitopes of the peanut allergens were mapped using overlapping peptides synthesized on an activated cellulose membrane and pooled serum IgE from 15 peanut sensitive patients, as described in Example 1. The size of the epitopes ranged from six to fifteen amino acids in length. The amino acids essential to IgE binding in each of the epitopes were determined by synthesizing duplicate peptides with single amino acid changes at each position. These peptides were then probed with pooled serum IgE from 15 patients with peanut hypersensitivity to determine if the changes affected peanut-specific IgE binding. For example, epitope 9 in Table 1 was synthesized with an alanine or methionine residue substituted for one of the amino acids and probed. The following amino acids were substituted (first letter is the one-letter amino acid code for the residue normally at the position, the residue number, followed by the amino acid that was substituted for this residue; the numbers indicate the position of each residue in the Ara h 1 protein, SEQ ID NO. 2): Q143A, P144A; R145A;
K146A; I147A; R148A; P149A; E 150A; G 151 A; R152A; Q143M; P144M;
R145M; K146M; I147M; R148M; P149M; E150M; G151M; R152M. The immunoblot strip containing the wild-type and mutated peptides of epitope 9 showed that binding of pooled serum IgE to individual peptides was dramatically reduced when either alanine or methionine was substituted for each of the amino acids at positions 144, 145, and 147-150 of Ara h 1 shown in SEQ ID NO. 2. Changes at positions 144, 145, 147, and 148 of Ara h I
shown in SEQ ID NO. 2 had the most dramatic effect when methionine was substituted for the wild-type amino acid, resulting in less than 1% of peanut specific IgE binding to these peptides. In contrast, the substitution of an alanine for arginine at position 152 of Ara h 1 shown in SEQ ID NO. 2 resulted in increased IgE binding. The remaining Ara h 1 epitopes, and the Ara h 2 and Ara h 3 epitopes, were tested in the same manner and the intensity of IgE binding to each spot was determined as a percentage of IgE
binding to the wild-type peptide. Any amino acid substitution that resulted in less than 1% of IgE binding when compared to the wild type peptide was noted and is indicated in Tables 4-6. Table 4 shows the amino acids that were determined to be critical to IgE binding in each of the Ara h 1 epitopes.
Table 5 shows the amino acids that were determined to be critical to IgE
binding in each of the Ara h 2 epitopes. Table 6 shows the amino acids that were determined to be critical to IgE binding in each of the Ara h 3 epitopes.
This analysis indicated that each epitope could be mutated to a non-IgE binding-peptide by the substitution of a single amino acid residue.
The results discussed above for Ara h 1, Ara h 2, and Ara h 3 demonstrate that once an IgE binding site has been identified, it is possible to reduce IgE binding to this site by altering a single amino acid of the epitope.
The observation that alteration of a single amino acid leads to the loss of IgE
binding in a population of peanut-sensitive individuals is significant because it suggests that while each patient may display a polyclonal IgE reaction to a particular allergen, IgE from different patients that recognize the same epitope must interact with that epitope in a similar fashion. Besides finding that many epitopes contained more than one residue critical for IgE binding, it was also determined that more than one residue type (ala or met) could be substituted at certain positions in an epitope with similar results. This allows for the design of a hypoallergenic protein that would be effective at blunting allergic reactions for a population of peanut sensitive individuals.
Furthermore, the creation of a plant producing a peanut where the IgE
binding epitopes of the major allergens have been removed should prevent the development of peanut hypersensitivity in individuals genetically predisposed to this food allergy.

Table 4: Amino Acids Critical to IgE Binding of Ara h 1 EPITOPE AA SEQUENCE POSITION

2 QEPDj2LKQKA 48-57 4 GE$TRGROPG 89-98 6 PRREE!GGRWG 107-116 8 EDW$RpSHQQ 134-143 9 Qg$Kj$PEGR 143-152 11 Syj1QEESRNT 311-320 14 DITLYpMRE 393-402 17 $$yTARLKEG 498-507 19 HRIFLAGDjKD 539-548 IDQIEKQAKp 551-560 Note. The Ara h 1 IgE binding epitopes are indicated as the single letter amino acid code. The position of each peptide with respect to the Ara h 1 protein is indicated in the right hand column. The amino acids that, when altered, lead to loss of IgE binding are shown as the bold, underlined residues. Epitopes 16 and 23 were not included in this study because they were recognized by a single patient who was no longer available to the study. All of these sequences can be found in SEQ ID NO 2.

Table 5. Amino Acids Critical to IgE Binding of Ara h 2 EPITOPE AA SEQUENCE POSITION
1 HASARQQ 'EL 15-24 2 Q-WEj1QSaDRRC 21-30 3 DBRCQSQLE$ 27-36 4 LRpCEQ,IiLMQ 39-48 6 YERppXSPSQ 57-66 9 K.RELRNLPQQ 127-136 QRCUDy,ESG 143-152 Note. The Ara h 2 IgE binding epitopes are indicated as the single letter amino acid code. The position of each peptide with respect to the Ara h 2 protein is indicated in the right hand column. The amino acids that, when altered, lead to loss of IgE binding are shown as the bold, underlined residues. All of these sequences can be found in SEQ ID NO 4.

Table 6. Amino Acids Critical to IgE-Binding of Ara h 3.
EPITOPE AA SEQUENCE POSITION
1 IETWNpr[NQEFECAG 33-47 3 VTVRGGLRjLSpDRK 279-293 4 DEDEYEYDEEp$RRG 303-317 Note. The Ara h 3 IgE binding epitopes are indicated as the single letter amino acid code. The position of each peptide with respect to the Ara h 3 protein is indicated in the right hand column. The amino acids that, when altered, lead to loss of IgE binding are shown as the bold, underlined All of these sequences can be found in SEQ ID NO 6.

Example 3: A Modified Ara h 2 Protein Binds less IgE But Similar Amounts of IgG.
In order to determine the effect of changes to multiple epitopes within the context of the intact allergen, four epitopes (including the three immunodominant epitopes) of the Ara h 2 allergen were mutagenized and the protein produced recombinantly. The amino acids at position 20, 31, 60, and 67 of the Ara h 2 protein (shown in SEQ ID NO. 4) were changed to alanine by mutagenizing the gene encoding this protein by standard techniques.
These residues are located in epitopes 1, 3, 6, and 7 and represent amino acids critical to IgE binding that were determined in Example 2. The modified and wild-type versions of this protein were produced and immunoblot analysis performed using serum from peanut sensitive patients.
These results showed that the modified version of this allergen bound significantly less IgE than the wild type version of these recombinant proteins (Figure 4) but bound similar amounts of IgG.
Example 4: A modified Ara b 2 protein retains the ability to stimulate T-cells to proliferate.
The modified recombinant Ara h 2 protein described in Example 3 was used in T-cell proliferation assays to determine if it retained the ability to activate T cells from peanut sensitive individuals. Proliferation assays were performed on T-cell lines grown in short-term culture developed from six peanut sensitive patients. T-cells lines were stimulated with either 50 g of crude peanut extract, 10 g of native Ara h 2, 10 g of recombinant wild-type Ara h2, or 10 g of modified recombinant Ara h 2 protein and the amount of 3H-thymidine determined for each cell line. Results were expressed as the average stimulation index (SI) which reflected the fold increase in 3H-thymidine incorporation exhibited by cells challenged with allergen when compared with media treated controls (Figure 5).

Example 5: A Modified Ara h 2 Protein Elicits a Smaller Wheal and Flare in Skin Prick Tests of a Peanut Sensitive Individual.
The modified recombinant Ara h 2 protein described in Example 3 and the wild type version of this recombinant protein were used in a skin prick test of a peanut sensitive individual. Ten micrograms of these proteins were applied separately to the forearm of a peanut sensitive individual, the skin pricked with a sterile needle, and 10 minutes later any wheal and flare that developed was measured. The wheal and flare produced by the wild-type Ara h 2 protein (8 mm X 7 mm) was approximately twice as large as that produced by the modified Ara h 2 protein (4 mm X 3mm). A control subject (no peanut hypersensitivity) tested with the same proteins had no visible wheal and flare but, as expected, gave positive results when challenged with histamine. In addition, the test subject gave no positive results when tested with PBS alone. These results indicate that an allergen with only 40% of its IgE binding epitopes modified (4/10) can.give measurable reduction in reactivity in an in vivo test of a peanut sensitive patient.
These same techniques can be used with the other known peanut allergens, Ara h 1(SEQ ID NO 1 and 2), Ara h 3 (SEQ ID NO. 5 and 6), or any other allergen.

SEQUENCE LISTING

<110> University of Arkansas Mt. Sinai School of Medicine of the City University of New York Sosin, Howard <120> Methods and Reagents for Decreasing Clinical Reaction to Allergy <130> HS102 <140>
<141>
<150> 09/141220 <151> 1998-08-27 <150> 60/074590 <151> 1998-02-13 <150> 60/074624 <151> 1998-02-13 <150> 60/074633 <151> 1998-02-13 <150> 60/073283 <151> 1998-01-29 <160> 6 <170> PatentIn Ver. 2.0 <210> 1 <211> 1930 <212> DNA
<213> Peanut <400> 1 aataatcata tatattcatc aatcatctat ataagtagta gcaggagcaa tgagagggag 60 ggtttctcca ctgatgctgt tgctagggat ccttgtcctg gcttcagttt ctgcaacgca 120 tgccaagtca tcaccttacc agaagaaaac agagaacccc tgcgcccaga ggtgcctcca 180 gagttgtcaa caggaaccgg atgacttgaa gcaaaaggca tgcgagtctc gctgcaccaa 240 gctcgagtat gatcctcgtt gtgtctatga tcctcgagga cacactggca ccaccaacca 300 acgttcccct ccaggggagc ggacacgtgg ccgccaaccc ggagactacg atgatgaccg 360 ccgtcaaccc cgaagagagg aaggaggccg atggggacca gctggaccga gggagcgtga 420 aagagaagaa gactggagac aaccaagaga agattggagg cgaccaagtc atcagcagcc 480 acggaaaata aggcccgaag gaagagaagg agaacaagag tggggaacac caggtagcca 540 tgtgagggaa gaaacatctc ggaacaaccc tttctacttc ccgtcaaggc ggtttagcac 600 ccgctacggg aaccaaaacg gtaggatccg ggtcctgcag aggtttgacc aaaggtcaag 660 gcagtttcag aatctccaga atcaccgtat tgtgcagatc gaggccaaac ctaacactct 720 tgttcttccc aagcacgctg atgctgataa catccttgtt atccagcaag ggcaagccac 780 cgtgaccgta gcaaatggca ataacagaaa gagctttaat cttgacgagg gccatgcact 840 cagaatccca tccggtttca tttcctacat cttgaaccgc catgacaacc agaacctcag 900 agtagctaaa atctccatgc ccgttaacac acccggccag tttgaggatt tcttcccggc 960 gagcagccga gaccaatcat cctacttgca gggcttcagc aggaatacgt tggaggccgc 1020 cttcaatgcg gaattcaatg agatacggag ggtgctgtta gaagagaatg caggaggtga 1080 gcaagaggag agagggcaga ggcgatggag tactcggagt agtgagaaca atgaaggagt 1140 gatagtcaaa gtgtcaaagg agcacgttga agaacttact aagcacgcta aatccgtctc 1200 aaagaaaggc tccgaagaag agggagatat caccaaccca atcaacttga gagaaggcga 1260 gcccgatctt tctaacaact ttgggaagtt atttgaggtg aagccagaca agaagaaccc 1320 ccagcttcag gacctggaca tgatgctcac ctgtgtagag atcaaagaag gagctttgat 1380 gctcccacac ttcaactcaa aggccatggt tatcgtcgtc gtcaacaaag gaactggaaa 1440 ccttgaactc gtggctgtaa gaaaagagca acaacagagg ggacggcggg aagaagagga 1500 ggacgaagac gaagaagagg agggaagtaa cagagaggtg cgtaggtaca cagcgaggtt 1560 gaaggaaggc gatgtgttca tcatgccagc agctcatcca gtagccatca acgcttcctc 1620 cgaactccat ctgcttggct tcggtatcaa cgctgaaaac aaccacagaa tcttccttgc 1680 aggtgataag gacaatgtga tagaccagat agagaagcaa gcgaaggatt tagcattccc 1740 tgggtcgggt gaacaagttg agaagctcat caaaaaccag aaggaatctc actttgtgag 1800 tgctcgtcct caatctcaat ctcaatctcc gtcgtctcct gagaaagagt ctcctgagaa 1860 agaggatcaa gaggaggaaa accaaggagg gaagggtcca ctcctttcaa ttttgaaggc 1920 ttttaactga 1930 <210> 2 <211> 626 <212> PRT
<213> Peanut <220>
<221> PEPTIDE
<222> (25)..(34) <223> peptide 1 <220>
<221> PEPTIDE
<222> (48) .. (57) <223> peptide 2 <220>
<221> PEPTIDE
<222> (65)..(74) <223> peptide 3 <220>
<221> PEPTIDE
<222> (89)..(98) <223> peptide 4 <220>
<221> PEPTIDE
<222> (97)..(106) <223> peptide 5 <220>
<221> PEPTIDE
<222> (107)..(116) <223> peptide 6 <220>
<221> PEPTIDE
<222> (123)..(132) <223> peptide 7 <220>
<221> PEPTIDE
<222> (134)..(143) <223> peptide 8 <220>
<221> PEPTIDE
<222> (143)..(152) <223> peptide 9 <220>
<221> PEPTIDE
<222> (294)..(303) <223> peptide 10 <220>
<221> PEPTIDE
<222> (311)..(320) <223> peptide 11 <220>
<221> PEPTIDE
<222> (325)..(334) <223> peptide 12 <220>
<221> PEPTIDE
<222> (344)..(353) <223> peptide 13 <220>
<221> PEPTIDE
<222> (393)..(402) <223> peptide 14 <220>
<221> PEPTIDE
<222> (409)..(418) <223> peptide 15 <220>
<221> PEPTIDE
<222> (461)..(470) <223> peptide 16 <220>
<221> PEPTIDE
<222> (498)..(507) <223> peptide 17 <220>
<221> PEPTIDE
<222> (525)..(534) <223> peptide 18 <220>
<221> PEPTIDE
<222> (539)..(548) <223> peptide 19 <220>
<221> PEPTIDE
<222> (551) .. (560) <223> peptide 20 <220>
<221> PEPTIDE
<222> (559)..(568) <223> peptide 21 <220>
<221> PEPTIDE
<222> (578)..(587) <223> peptide 22 <220>
<221> PEPTIDE
<222> (597)..(606) <223> peptide 23 <400> 2 Met Arg Gly Arg Val Ser Pro Leu Met Leu Leu Leu Gly Ile Leu Val Leu Ala Ser Val Ser Ala Thr His Ala Lys Ser Ser Pro Tyr Gln Lys Lys Thr Glu Asn Pro Cys Ala Gln Arg Cys Leu Gln Ser Cys Gln Gln Glu Pro Asp Asp Leu Lys Gln Lys Ala Cys Glu Ser Arg Cys Thr Lys Leu Glu Tyr Asp Pro Arg Cys Val Tyr Asp Pro Arg Gly His Thr Gly Thr Thr Asn Gln Arg Ser Pro Pro Gly Glu Arg Thr Arg Gly Arg Gln Pro Gly Asp Tyr Asp Asp Asp Arg Arg Gln Pro Arg Arg Glu Glu Gly Gly Arg Trp Gly Pro Ala Gly Pro Arg Glu Arg Glu Arg Glu Glu Asp Trp Arg Gln Pro Arg Glu Asp Trp Arg Arg Pro Ser His Gin Gln Pro Arg Lys Ile Arg Pro Glu Gly Arg Glu Gly Glu Gln Glu Trp Gly Thr Pro Gly Ser His Val Arg Glu Glu Thr Ser Arg Asn Asn Pro Phe Tyr Phe Pro Ser Arg Arg Phe Ser Thr Arg Tyr Gly Asn Gln Asn Gly Arg Ile Arg Val Leu Gln Arg Phe Asp Gln Arg Ser Arg Gln Phe Gln Asn Leu Gln Asn His Arg Ile Val Gln Ile Glu Ala Lys Pro Asn Thr Leu Val Leu Pro Lys His Ala Asp Ala Asp Asn Ile Leu Val Ile Gln Gln Gly Gln Ala Thr Val Thr Val Ala Asn Gly Asn Asn Arg Lys Ser Phe Asn Leu Asp Glu Gly His Ala Leu Arg Ile Pro Ser Gly Phe Ile Ser Tyr Ile Leu Asn Arg His Asp Asn Gln Asn Leu Arg Val Ala Lys Ile Ser Met Pro Val Asn Thr Pro Gly Gln Phe Glu Asp Phe Phe Pro Ala Ser Ser Arg Asp Gln Ser Ser Tyr Leu Gln Gly Phe Ser Arg Asn Thr Leu Glu Ala Ala Phe Asn Ala Glu Phe Asn Glu Ile Arg Arg Val Leu Leu Glu Glu Asn Ala Gly Gly Glu Gln Glu Glu Arq Gly Gln Arg Arg Trp Ser Thr Arg Ser Ser Glu Asn Asn Glu Gly Val Ile Val Lys Val Ser Lys Glu His Val Glu Glu Leu Thr Lys His Ala Lys Ser Val Ser Lys Lys Gly Ser Glu Glu Glu Gly Asp Ile Thr Asn Pro Ile Asn Leu Arg Glu Gly Glu Pro Asp Leu Ser Asn Asn Phe Gly Lys Leu Phe Glu Val Lys Pro Asp Lys Lys Asn Pro Gln Leu Gln Asp Leu Asp Met Met Leu Thr Cys Val Glu Ile Lys Glu Gly Ala Leu Met Leu Pro His Phe Asn Ser Lys Ala Met Val Ile Val Val Val Asn Lys Gly Thr Gly Asn Leu Glu Leu Val Ala Val Arg Lys Glu Gln Gln Gln Arg Gly Arg Arg Glu Glu Glu Glu Asp Glu Asp Glu Glu Glu Glu Gly Ser Asn Arg Glu Val Arg Arg Tyr Thr Ala Arg Leu Lys Glu Gly Asp Val Phe Ile Met Pro Ala Ala His Pro Val Ala Ile Asn Ala Ser Ser Glu Leu His Leu Leu Gly Phe Gly Ile Asn Ala Glu Asn Asn His Arg Ile Phe Leu Ala Gly Asp Lys Asp Asn Val Ile Asp Gln Ile Glu Lys Gln Ala Lys Asp Leu Ala Phe Pro Gly Ser Gly Glu Gln Val Glu Lys Leu Ile Lys Asn Gln Lys Glu Ser His Phe Val Ser Ala Arg Pro Gln Ser Gln Ser Gln Ser Pro Ser Ser Pro Glu Lys Glu Ser Pro Glu Lys Glu Asp Gln Glu Glu Glu Asn Gln Gly Gly Lys Gly Pro Leu Leu Ser Ile Leu Lys Ala Phe Asn <210> 3 <211> 474 <212> DNA
<213> Peanut <400> 3 ctcaccatac tagtagccct cgcccttttc ctcctcgctg cccacgcatc tgcgaggcag 60 cagtgggaac tccaaggaga cagaagatgc cagagccagc tcgagagggc gaacctgagg 120 ccctgcgagc aacatctcat gcagaagatc caacgtgacg aggattcata tgaacgggac 180 ccgtacagcc ctagtcagga tccgtacagc cctagtccat atgatcggag aggcgctgga 240 tcctctcagc accaagagag gtgttgcaat gagctgaacg agtttgagaa caaccaaagg 300 tgcatgtgcg aggcattgca acagatcatg gagaaccaga gcgataggtt gcaggggagg 360 caacaggagc aacagttcaa gagggagctc aggaacttgc ctcaacagtg cggccttagg 420 gcaccacagc gttgcgactt ggacgtcgaa agtggcggca gagacagata ctaa 474 <210> 4 <211> 157 <212> PRT
<213> Peanut <220>
<221> PEPTIDE
<222> (15)..(24) <223> peptide 1 <220>
<221> PEPTIDE
<222> (21)..(30) <223> peptide 2 <220>
<221> PEPTIDE
<222> (27)..(36) <223> peptide 3 <220>
<221> PEPTIDE
<222> (39)..(48) <223> peptide 4 <220>
<221> PEPTIDE
<222> (49)..(58) <223> peptide 5 <220>
<221> PEPTIDE
<222> (57)..(66) <223> peptide 6 <220>

<221> PEPTIDE
<222> (65)..(74) <223> peptide 7 <220>
<221> PEPTIDE
<222> (115)..(124) <223> peptide 8 <220>
<221> PEPTIDE
<222> (127)..(136) <223> peptide 9 <220>
<221> PEPTIDE
<222> (143)..(152) <223> peptide 10 <400> 4 Leu Thr Ile Leu Val Ala Leu Ala Leu Phe Leu Leu Ala Ala His Ala Ser Ala Arg Gln Gln Trp Glu Leu Gln Gly Asp Arg Arg Cys Gln Ser Gln Leu Glu Arg Ala Asn Leu Arg Pro Cys Glu Gln His Leu Met Gln Lys Ile Gln Arg Asp Glu Asp Ser Tyr Glu Arg Asp Pro Tyr Ser Pro Ser Gln Asp Pro Tyr Ser Pro Ser Pro Tyr Asp Arg Arg Gly Ala Gly Ser Ser Gln His Gln Glu Arg Cys Cys Asn Glu Leu Asn Glu Phe Glu Asn Asn Gln Arg Cys Met Cys Glu Ala Leu Gln Gln Ile Met Glu Asn Gln Ser Asp Arg Leu Gln Gly Arg Gin Gln Glu Gln Gln Phe Lys Arg Glu Leu Arg Asn Leu Pro Gln Gln Cys Gly Leu Arg Ala Pro Gln Arg Cys Asp Leu Asp Val Glu Ser Gly Gly Arg Asp Arg Tyr 14.5 150 155 <210> 5 <211> 1524 <212> DNA
<213> Peanut <400> 5 cggcagcaac cggaggagaa cgcgtgccag ttccagcgcc tcaatgcgca gagacctgac 60 aatcgcattg aatcagaggg cggttacatt gagacttgga accccaacaa ccaggagttc 120 gaatgcgccg gcgtcgccct ctctcgctta gtcctccgcc gcaacgccct tcgtaggcct 180 ttctactcca atgctcccca ggagatcttc atccagcaag gaaggggata ctttgggttg 240 atattccctg gttgtcctag acactatgaa gagcctcaca cacaaggtcg tcgatctcag 300 tcccaaagac caccaagacg tctccaagga gaagaccaaa gccaacagca acgagatagt 360 caccagaagg tgcaccgttt cgatgagggt gatctcattg cagttcccac cggtgttgct 420 ttctggctct acaacgacca cgacactgat gttgttgctg tttctcttac tgacaccaac 480 aacaacgaca accagcttga tcagttcccc aggagattca atttggctgg gaacacggag 540 caagagttct taaggtacca gcaacaaagc agacaaagca gacgaagaag cttaccatat 600 agcccataca gcccgcaaag tcagcctaga caagaagagc gtgaatttag ccctcgagga 660 cagcacagcc gcagagaacg agcaggacaa gaagaagaaa acgaaggtgg aaacatcttc 720 agcggcttca cgccggagtt cctggaacaa gccttccagg ttgacgacag acagatagtg 780 caaaacctaa gaggcgagac cgagagtgaa gaagagggag ccattgtgac agtgagggga 840 ggcctcagaa tcttgagccc agatagaaag agacgtgccg acgaagaaga ggaatacgat 900 gaagatgaat atgaatacga tgaagaggat agaaggcgtg gcaggggaag cagaggcagg 960 gggaatggta ttgaagagac gatctgcacc gcaagtgcta aaaagaacat tggtagaaac 1020 agatcccctg acatctacaa ccctcaagct ggttcactca aaactgccaa cgatctcaac 1080 cttctaatac ttaggtggct tggacctagt gctgaatatg gaaatctcta caggaatgca 1140 ttgtttgtcg ctcactacaa caccaacgca cacagcatca tatatcgatt gaggggacgg 1200 gctcacgtgc aagtcgtgga cagcaacggc aacagagtgt acgacgagga gcttcaagag 1260 ggtcacgtgc ttgtggtgcc acagaacttc gccgtcgctg gaaagtccca gagcgagaac 1320 ttcgaatacg tggcattcaa gacagactca aggcccagca tagccaacct cgccggtgaa 1380 aactccgtca tagataacct gccggaggag gtggttgcaa attcatatgg cctccaaagg 1440 gagcaggcaa ggcagcttaa gaacaacaac cccttcaagt tcttcgttcc accgtctcag 1500 cagtctccga gggctgtggc ttaa 1524 <210> 6 <211> 510 <212> PRT
<213> Peanut <220>
<221> PEPTIDE
<222> (33)..(47) <223> peptide 1 <220>
<221> PEPTIDE
<222> (240)..(254) <223> peptide 2 <220>
<221> PEPTIDE
<222> (279)..(293) <223> peptide 3 <220>
<221> PEPTIDE
<222> (303)..(317) <223> peptide 4 <4Q0> 6 Ile Ser Phe Arg Gln Gln Pro Glu Glu Asn Ala Cys Gln Phe Gln Arg Leu Asn Ala Gin Arg Pro Asp Asn Arg Ile Glu Ser Glu Gly Gly Tyr Ile Glu Thr Trp Asn Pro Asn Asn Gln Glu Phe Glu Cys Ala Gly Val Ala Leu Ser Arg Leu Val Leu Arg Arg Asn Ala Leu Arg Arg Pro Phe Tyr Ser Asn Ala Pro Gln Glu Ile Phe Ile Gln Gln Gly Arg Gly Tyr Phe Gly Leu Ile Phe Pro Gly Cys Pro Arg His Tyr Glu Glu Pro His Thr Gln Gly Arg Arg Ser Gln Ser Gln Arg Pro Pro Arg Arg Leu Gln Gly Glu Asp Gln Ser Gln Gln Gln Arg Asp Ser His Gin Lys Val His Arg Phe Asp Glu Gly Asp Leu Ile Ala Val Pro Thr Gly Val Ala Phe Trp Leu Tyr Asn Asp His Asp Thr Asp Val Val Ala Val Ser Leu Thr Asp Thr Asn Asn Asn Asp Asn Gln Leu Asp Gln Phe Pro Arg Arg Phe Asn Leu Ala Gly Asn Thr Glu Gln Glu Phe Leu Arg Tyr Gln Gln Gln Ser Arg Gln Ser Arg Arg Arg Ser Leu Pro Tyr Ser Pro Tyr Ser Pro Gln Ser Gln Pro Arg Gln Glu Glu Arg Glu Phe Ser Pro Arg Gly Gln His Ser Arg Arg Glu Arg Ala Gly Gln Glu Glu Glu Asn Glu Gly Gly Asn Ile Phe Ser Gly Phe Thr Pro Glu Phe Leu Glu Gln Ala Phe Gln Val Asp Asp Arg Gln Ile Val Gln Asn Leu Arg Gly Glu Thr Glu Ser Glu Glu Glu Gly Ala Ile Val Thr Val Arg Gly Gly Leu Arg Ile Leu Ser Pro Asp Arg Lys Arg Arg Ala Asp Glu Glu Glu Glu Tyr Asp Glu Asp Glu Tyr Glu Tyr Asp Glu Glu Asp Arg Arg Arg Gly Arg Gly Ser Ar.g Gly Arg Gly Asn Gly Ile Glu Glu Thr Ile Cys Thr Ala Ser Ala Lys Lys Asn Ile Gly Arg Asn Arg Ser Pro Asp Ile Tyr Asn Pro Gln Ala Gly Ser Leu Lys Thr Ala Asn Asp Leu Asn Leu Leu Ile Leu Arg Trp Leu Gly Leu Ser Ala Glu Tyr Gly Asn Leu Tyr Arg Asn Ala Leu Phe Val Ala His Tyr Asn Thr Asn Ala His Ser Ile Ile Tyr Arg Leu Arg Gly Arg Ala His Val Gln Val Val Asp Ser Asn Gly Asn Arg Val Tyr Asp Glu Glu Leu Gln Glu Gly His Val Leu Val Val Pro Gln Asn Phe Ala Val Ala Gly Lys Ser Gln Ser Glu Asn Phe Glu Tyr Val Ala Phe Lys Thr Asp Ser Arg Pro Ser Ile Ala Asn Leu Ala Gly Glu Asn Ser Val Ile Asp Asn Leu Pro Glu Glu Val Val Ala Asn Ser Tyr Gly Leu Gln Arg Glu Gln Ala Arg Gln Leu Lys Asn Asn Asn Pro Phe Lys Phe Phe Val Pro Pro Ser Gln Gln Ser Pro Arg Ala Val Ala

Claims (20)

We claim:

1. A modified protein allergen whose amino acid sequence is substantially identical to that of an unmodified protein allergen except that at least one amino acid has been modified in one or more IgE epitopes so that pooled serum IgE binding to the modified protein allergen is reduced as compared with pooled serum IgE binding to the unmodified protein allergen, and wherein the modified protein allergen activates T cells in substantially the same way as the unmodified protein allergen, wherein the unmodified protein allergen is a peanut allergen selected from the group consisting of Ara h 1, Ara h 2, and Ara h 3.

2. The modified protein allergen of claim 1 wherein at least one amino acid has been modified in all the IgE epitopes of the unmodified protein allergen.

3. The modified protein allergen of claim 1 wherein at least one modified amino acid is located in the center of the one or more IgE epitopes of the unmodified protein allergen.

4. The modified protein allergen of claim 1 wherein at least one amino acid in the one or more IgE epitopes of the unmodified protein allergen has been modified by substitution.

5. The modified protein allergen of claim 1 wherein at least one hydrophobic amino acid in the one or more IgE epitopes of the unmodified protein allergen has been substituted by a neutral or hydrophilic amino acid.

6. The modified protein allergen of claim 1 wherein the modified protein allergen retains the ability to activate T cells that have been cultured from at least one individual that is allergic to the unmodified protein allergen.

7. The modified protein allergen of claim 1 wherein the modified protein allergen retains the ability to bind IgG.

8. The modified protein allergen of claim 1 wherein the modified protein allergen retains the ability to initiate a Th1-type response.

9. The modified protein allergen of claim 1 wherein the modified protein allergen is made in a transgenic plant or animal.

10. The modified protein allergen of claim 1 expressed in a recombinant host selected from the group consisting of plants and animals.

11. The modified protein allergen of claim 1 expressed in a recombinant host selected from the group consisting of bacteria, yeast, fungi, and insect cells.

12. The modified protein allergen of any one of the claims 1-11 wherein the modified protein allergen has an amino acid sequence that is substantially identical to that of the unmodified protein allergen except that at least one amino acid has been modified in at least one linear IgE epitope.

13. The modified protein allergen according to any one of claims 1 to 11 wherein the unmodified protein is Ara h 1.

14. The modified protein allergen according to any one of claims 1 to 11 wherein the unmodified protein is Ara h 2.

15. The modified protein allergen according to any one of claims 1 to 11 wherein the unmodified protein is Ara h 3.

16. A composition comprising the modified protein allergen of any one of claims 1 to 15 and an adjuvant selected from the group consisting of IL-12, IL-16, IL-18, IFN.gamma., and immune stimulatory oligodeoxynucleotide sequences containing unmethylated CpG motifs which cause brisk activation and skew the immune response to a Th1-type response.

17. A nucleotide molecule encoding the modified protein allergen as defined by any one of claims 1 to 15.

18. The nucleotide molecule of claim 17 in a vector for expression in a recombinant host.

19. Use of the modified protein allergen as defined by any of claims 1-15 in an individual to reduce the clinical response to a protein allergen, in an amount and for a time sufficient to reduce the allergic reaction to the protein allergen.

20. A transgenic plant cell expressing the modified protein allergen according to any one of claims 1 to 15.