Microbial delivery system

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.

1 - 33 . (canceled) 
     
     
         34 . A pharmaceutical composition comprising
 dead  E. coli  comprising at least one modified peanut allergen whose amino acid sequence differs from that of a wild-type peanut allergen that occurs in nature such that the modified peanut allergen has a reduced ability to bind to or cross-link IgE as compared with the wild-type peanut allergen, wherein the wild-type peanut allergen is an Ara h 1, Ara h 2 or Ara h 3 protein with an amino acid sequence that is encoded by the nucleotide sequence of SEQ ID NO:1, SEQ ID NO:2, or SEQ ID NO:3, and wherein the modified peanut allergen has an amino acid sequence substantially identical to that of its corresponding wild type peanut allergen except that at least one IgE epitope has been mutated in the modified peanut allergen such that the modified peanut allergen has the reduced ability to bind or to crosslink IgE, and further wherein the modified peanut allergen is encapsulated inside the dead  E. coli ; and   a pharmaceutically acceptable carrier.   
     
     
         35 . The pharmaceutical composition of  claim 34 , wherein the wild-type peanut allergen is an Ara h 1 protein with an amino acid sequence that is encoded by the nucleotide sequence of SEQ ID NO:1. 
     
     
         36 . The pharmaceutical composition of  claim 34 , wherein the wild-type peanut allergen is an Ara h 2 protein with an amino acid sequence that is encoded by the nucleotide sequence of SEQ ID NO:2. 
     
     
         37 . The pharmaceutical composition of  claim 34 , wherein the wild-type peanut allergen is an Ara h 3 protein with an amino acid sequence that is encoded by the nucleotide sequence of SEQ ID NO:3. 
     
     
         38 . The pharmaceutical composition of  claim 34 , wherein the sequence of the modified peanut allergen differs from the sequence of the wild-type peanut allergen by one or more amino acid deletions, substitutions or additions within an IgE binding site of the wild-type peanut allergen. 
     
     
         39 . The pharmaceutical composition of  claim 38 , wherein the sequence of the modified peanut allergen lacks a portion of the wild-type peanut allergen sequence, and wherein said portion includes an IgE binding site. 
     
     
         40 . The pharmaceutical composition of  claim 34 , wherein the modified peanut allergen is located in the cytoplasm of the dead  E. coli.    
     
     
         41 . The pharmaceutical composition of  claim 34 , wherein the modified peanut allergen is located in the periplasm of the dead  E. coli.    
     
     
         42 . The pharmaceutical composition of  claim 34 , wherein the modified peanut allergen cannot be detected by antibody binding without disrupting the dead  E. coli.    
     
     
         43 . The pharmaceutical composition of  claim 34 , wherein the dead  E. coli  was heat-killed. 
     
     
         44 . The pharmaceutical composition of  claim 34 , wherein the dead  E. coli  was killed by chemical treatment. 
     
     
         45 . The pharmaceutical composition of  claim 44 , wherein the dead  E. coli  was killed using a chemical selected from the group consisting of iodine, bleach, ozone, and alcohol.