Abstract: The present invention provides methods and compositions for treating or preventing allergic responses, particularly anaphylactic allergic responses, in subjects who are allergic to allergens or susceptible to allergies. Methods of the present invention utilize administration of microorganisms to subjects, where the microorganisms produce allergens and protect the subjects from exposure to the allergens until phagocytosed by antigen-presenting cells. Particularly preferred microorganisms are gram-negative bacteria, gram-positive bacteria, and yeast. Particularly preferred allergens are proteins found in foods, venoms, drugs and latex that elicit allergic reactions and anaphylactic allergic reactions in individuals who are allergic to the proteins or are susceptible to allergies to the proteins. The proteins may also be modified to reduce the ability of the proteins to bind and crosslink IgE antibodies and thereby reduce the risk of eliciting anaphylaxis without affecting T-cell mediated Th1-type immunity.

Abstract: The present invention provides methods and compositions for treating or preventing allergic responses, particularly anaphylactic allergic responses, in subjects who are allergic to allergens or susceptible to allergies. Methods of the present invention utilize administration of microorganisms to subjects, where the microorganisms produce allergens and protect the subjects from exposure to the allergens until phagocytosed by antigen-presenting cells. Particularly preferred microorganisms are gram-negative bacteria, gram-positive bacteria, and yeast. Particularly preferred allergens are proteins found in foods, venoms, drugs and latex that elicit allergic reactions and anaphylactic allergic reactions in individuals who are allergic to the proteins or are susceptible to allergies to the proteins. The proteins may also be modified to reduce the ability of the proteins to bind and crosslink IgE antibodies and thereby reduce the risk of eliciting anaphylaxis without affecting T-cell mediated Th1-type immunity.

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 altering as little as a single amino acid within the protein, preferably a hydrophobic residue towards the center of the IgE epitope, to eliminate IgE binding. Additionally or alternatively a modified allergen with reduced IgE binding may be prepared by disrupting one or more of the disulfide bonds that are present in the natural allergen. The disulfide bonds may be disrupted chemically, e.g., by reduction and alkylation or by mutating one or more cysteine residues present in the primary amino acid sequence of the natural allergen. In certain embodiments, modified allergens are prepared by both altering one or more linear IgE epitopes and disrupting one or more disulfide bonds of the natural allergen.

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.

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.

Abstract: One of the major peanut allergens, Ara h I, was selected from cDNA expression library clones using Ara h I specific oligo-nucleotides and polymerase chain reaction technology. The Ara h I clone identified a 2.3 kb mRNA species on a Northern blot containing peanut poly A+RNA. DNA sequence analysis of the cloned inserts revealed that the Ara h I allergen has significant homology with the vicilin seed storage protein family found in most higher plants. The isolation of the Ara h I clones allowed the synthesis of this protein in E. coli cells and subsequent recognition of this. recombinant protein in immunoblot analysis using serum IgE from patients with peanut hypersensitivity.

Abstract: Peanuts are a common cause of food hypersensitivity reactions. The sera of 10 patients who had atopic dermatitis and a positive double-blind placebo-controlled food challenge to peanut were used to investigate the major allergens of peanut. Crude Florunner extracts were fractionated by anion-exchange chromatography using a step gradient (limit buffer, 0.05M BisTris/1.5M NaCl). A protein peak (OD 280) which eluted at 10% NaCl and demonstrated intense IgE-binding was further analyzed by two-dimensional SDS-PAGE/immunoblot analysis. The majority of this fraction is a protein which has a molecular weight of 17 kD and a pI of 5.2. Sequencing data from the N-terminus revealed the following initial 9 amino acids: (*)-Q-Q-(*)-E-L-Q-D-L. Based on IgE-binding activity and no known amino acid sequence identity to other allergens, this allergen is designated Ara h II. Ara h II may be used to detect and quantify peanut allergens in foodstuffs.

Abstract: Peanuts are a common cause of food hypersensitivity reactions. The sera of 10 patients who had atopic dermatitis and a positive double-blind placebo-controlled food challenge to peanut were used to investigate the major allergens of peanut. Crude Florunner extracts were fractionated by anion-exchange chromatography using a step gradient (limit buffer, 0.05M BisTris/1.5M NaCl). One hundred microliters of each 2.0 ml fraction was dot-blotted onto nitrocellulose paper and IgE-binding activity assessed using the serum pool to select allergen-containing fractions. A protein peak (OD 280) which eluted at 10% NaCl and demonstrated intense IgE-binding was further analyzed by two-dimensional SDS-PAGE/immunoblot analysis. The majority of this fraction is a protein which has a molecular weight of 17 kD and a pI of 5.2. Sequencing data from the N-terminus revealed the following initial 9 amino acids: (*)-Q-Q-(*)-E-L-Q-D-L.

Abstract: Peanuts are a common cause of food hypersensitivity reactions. The sera of 10 patients who had atopic dermatitis and a positive double-blind placebo-controlled food challenge to peanut were used to investigate the major allergens of peanut. Crude Florunner extracts were fractionated by anion-exchange chromatography using a step gradient (limit buffer, 0.05M BisTris/1.5M NaCl). One hundred microliters of each 2.0 ml fraction was dot-blotted onto nitrocellulose paper and IgE-binding activity assessed using the serum pool to select allergen-containing fractions. A protein peak (OD 280) which eluted at 10% NaCl and demonstrated intense IgE-binding was further analyzed by two-dimensional SDS-PAGE/immunoblot analysis. The majority of this fraction is a protein which has a molecular weight of 17 kD and a pI of 5.2. Sequencing data from the N-terminus revealed the following initial 9 amino acids: (*)-Q-Q-(*)-E-L-Q-D-L.

Abstract: Peanut allergen Ara h II was identified using the sera of patients who had atopic dermatitis and a positive food challenge to peanut. The Ara h II allergen, having a molecular weight of 17 kD and a pI of 5.2, was isolated by anion exchange chromatography. Ara h II may be used to detect and quantify peanut allergens in foodstuffs.