Treatment for IgE-mediated disease

1. A method of treating a disease or condition mediated by pathogenic IgE antibodies in a subject, the method comprising:

(a) selecting a subject having a disease or condition characterized by one or more of (i) undesirable IgE production, (ii) excessive, harmful or unwanted IgE-mediated basophil activation, and (iii) excessive, harmful or unwanted IgE-mediated mast cell activation, wherein the disease or condition is selected from a hyper-IgE syndrome, an atopic disorder, an allergic reaction, and a hypersensitivity reaction characterized by having an abnormally increased amount of IgE specific for one or more allergens; and

(b) administering to the subject a therapeutically effective amount of an EndoS polypeptide to reduce interactions between the pathogenic IgE antibodies and FcεR on FcεR bearing cells in the subject, relative to said interactions prior to said step of administering, and thereby treating the disease or condition mediated by pathogenic IgE antibodies,

wherein the EndoS polypeptide comprises:

(i) the amino acid sequence of SEQ ID NO: 1,

(ii) a fragment of (i) having IgE endoglycosidase activity which hydrolyzes at least one IgE Cε asparagine-linked glycan between two core N-acetylglucosamine residues of the glycan,

(iii) a variant of (i) having at least 97% identity to the amino acid sequence of SEQ ID NO: 1 and having IgE endoglycosidase activity which hydrolyzes at least one IgE Cε asparagine-linked glycan between two core N-acetylglucosamine residues of the glycan; or

(iv) a variant of (ii) having at least 97% identity to a corresponding portion of the amino acid sequence of SEQ ID NO: 1 and having IgE endoglycosidase activity which hydrolyzes at least one IgE Cε asparagine-linked glycan between two core N-acetylglucosamine residues of the glycan.

2. The method of claim 1 wherein said EndoS polypeptide consists of the amino acid sequence of SEQ ID NO: 1.

3. The method of claim 1 , wherein said disease or condition is characterized by presence of at least one symptom selected from atopic dermatitis, allergic rhinitis, allergic conjunctivitis and allergic asthma.

4. The method of claim 1 , wherein said atopic disorder or allergic or hypersensitivity reaction is characterized by an immune response to a plant allergen, an animal dander allergen, a mold or fungal allergen, a dust allergen, a dust mite allergen, a stinging insect venom, an environmental allergen, a food allergen or a therapeutic agent.

5. The method of claim 4 wherein said immune response is a response to at least one of: cat dander protein Fel d1; House dust mite proteins Der P1, Der P2 and Der P7; Ragweed protein amb a 1.1, a 1.2, a1.3 or a1.4; Rye grass proteins lo1 p1and lo1 p5; Timothy grass proteins phl p1 and phl p5; Bermuda grass protein Cyn d 5; Alternaria alternate proteins Alt a 1, Alt a 2 and Enolase (Alt a 6); Birch protein Bet v1and P14; German Cockroach proteins Bla g 1, Bla g 2, Bla g 3, Bla g 4, Bla g 5 and Bla g 6; Mugwort protein Art v 1; Russian thistle protein Sal k 1 and Sal k 2; peanut protein Ara hl, Ara h2, Ara h3, Ara h4, Ara H5, Ara h6, a plant profilin; a lipid transfer protein; an antibiotic; and an anti-cancer agent.

6. The method of claim 4 wherein the plant allergen is a grass allergen.