Method of treating or preventing a disease or condition mediated by pathogenic IgG antibodies

1. A method of treating or preventing a disease or condition mediated by pathogenic IgG antibodies in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of an Immunoglobulin G-degrading enzyme of S. pyogenes (IdeS) polypeptide, or a polynucleotide encoding an IdeS polypeptide, wherein said polynucleotide is incorporated in an expression vector.

2. The method according to claim 1 , wherein said IdeS polypeptide comprises:

(a) the amino acid sequence of SEQ ID NO: 1;

(b) a variant thereof having at least 50% identity to the amino acid sequence of SEQ ID NO: 1 and having IgG cysteine protease activity; or

(c) a fragment of either thereof having IgG cysteine protease activity.

3. The method according to claim 2 , wherein said polypeptide consists of the sequence shown in SEQ ID NO: 1.

4. The method according to claim 1 , wherein said polynucleotide comprises:

(a) SEQ ID NO: 3;

(b) a sequence having one or more degenerate substitutions relative to the sequence as defined in (a);

(c) a sequence having at least 60% identity to a sequence as defined in (a) or (b) and which encodes a polypeptide having IgG cysteine protease activity; or

(d) a fragment of any one of the sequences as defined in (a), (b) or (c) which encodes a polypeptide having IgG cysteine protease activity.

5. The method according to claim 4 , wherein said polynucleotide consists of the nucleic acid sequence shown in SEQ ID NO: 3.

6. The method of claim 1 , wherein the disease or condition mediated by pathogenic IgG antibodies is an autoimmune disease, transplant rejection or acquired haemophilia.

7. The method of claim 6 , wherein said autoimmune disease is Addison's disease, alopecia areata, ankylosing spondilitis, antiphospholipid syndrome, aplastic anaemia, autoimmune gastritis, autoimmune hearing loss, autoimmune haemolytic anaemias, autoimmune hepatitis, autoimmune hypoparathyroidism, autoimmune hypophysitis, autoimmune inner ear disease, autoimmune lymphoproliferative syndrome, autoimmune myocarditis, autoimmune oophoritis, autoimmune orchitis, autoimmune polyendocrinopathy, Beçhet's disease, bullous pemphigoid, cardiomyopathy, chronic inflammatory demyelinating polyneuropathy, Churg-Strauss syndrome, coeliac disease, Crohn's disease, CREST syndrome, Degos disease, epidermolysis bullosa acquisita, essential mixed cryoglobulinaemia, giant cells arteritis, glomerulonephritis, Goodpasture's syndrome, Graves' disease, Guillan-Barre syndrome, Hashimoto's thyroiditis, idiopathic thrombocytopenic purpura, inflammatory bowel disease, Kawasaki's disease, Meniere's syndrome, mixed connective tissue disease, Mooren's ulcer, multiple sclerosis, myasthenia gravis, pemphigus foliaceous, pemphigus vulgaris, pernicious anaemia, polyarteritis nodosa, polyglandular autoimmune syndrome type 1 (PAS-1), polyglandular autoimmune syndrome type 2 (PAS-2), polyglandular autoimmune syndrome type 3 (PAS-3), polymyositis/dermatomyositis, primary biliary cirrhosis, psoriasis, psoriatic arthritis, Raynaud's syndrome, Reiter's syndrome, rheumatoid arthritis, sarcoidosis, scleroderma, Sjögren's syndrome, subacute thyroiditis, sympathetic opthalmia, systemic lupus erythematosus, Takayasu's arteritis, type 1 diabetes mellitus, vitiligo, Vogt-Koyanagi-Harada disease or Wegener's granulomatosis.

8. The method according to claim 7 , wherein said autoimmune disease is rheumatoid arthritis.

9. The method according to claim 7 , wherein said autoimmune disease is systemic lupus erythematosus.

10. The method according to claim 7 , wherein said transplant rejection is allograft or xenograft rejection.

11. A method of treating, ex vivo, blood taken from a patient suffering from a disease or condition mediated by pathogenic IgG antibodies, comprising contacting the blood with an IdeS polypeptide.

12. The method according to claim 8 , wherein the blood is returned to the patient after contacting it with said IdeS polypeptide.

13. The method according to claim 8 , wherein the disease or condition is transplant rejection mediated by pathogenic IgG antibodies.