IgE BINDING PROTEINS AND USES THEREOF

1 . A VHH domain that binds IgE, comprising a complementarity determining region 1 (CDR1), a complementarity determining region 2 (CDR2), and a complementarity determining region 3 (CDR3) of a VHH that comprises the amino acid sequence of SEQ ID NO:119.

2 . The VHH domain of claim 1 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:3; the CDR2 comprises the amino acid sequence of SEQ ID NO:58; and the CDR3 comprises the amino acid sequence of SEQ ID NO:63, under the AbM definition.

3 . The VHH domain of claim 1 or 2 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:3; the CDR2 comprises the amino acid sequence of SEQ ID NO:48, 4, 49, 50, or 102; and the CDR3 comprises the amino acid sequence of SEQ ID NO:51, 5, 52, 53, or 103.

4 . The VHH domain of claim 3 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:3, the CDR2 comprises the amino acid sequence of SEQ ID NO:48, and the CDR3 comprises the amino acid sequence of SEQ ID NO:51.

5 . The VHH domain of claim 3 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:3, the CDR2 comprises the amino acid sequence of SEQ ID NO:102, and the CDR3 comprises the amino acid sequence of SEQ ID NO:103.

6 . The VHH domain of claim 1 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:54; the CDR2 comprises the amino acid sequence of SEQ ID NO:59; and the CDR3 comprises the amino acid sequence of SEQ ID NO:64, under the Chothia definition.

7 . The VHH domain of claim 6 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:54, the CDR2 comprises the amino acid sequence of SEQ ID NO:59, and the CDR3 comprises the amino acid sequence of SEQ ID NO:71.

8 . The VHH domain of claim 1 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:55; the CDR2 comprises the amino acid sequence of SEQ ID NO:60; and the CDR3 comprises the amino acid sequence of SEQ ID NO:65, under the Kabat definition.

9 . The VHH domain of claim 8 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:55, the CDR2 comprises the amino acid sequence of SEQ ID NO:68, and the CDR3 comprises the amino acid sequence of SEQ ID NO:72.

10 . The VHH domain of claim 1 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:56; the CDR2 comprises amino acid sequence of SEQ ID NO:61; and the CDR3 comprises the amino acid sequence of SEQ ID NO:66, under the Contact definition.

11 . The VHH domain of claim 10 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:56, the CDR2 comprises the amino acid sequence of SEQ ID NO:69, and the CDR3 comprises the amino acid sequence of SEQ ID NO:73.

12 . The VHH domain of claim 1 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:57; the CDR2 comprises the amino acid sequence of SEQ ID NO:62; and the CDR3 comprises the amino acid sequence of SEQ ID NO:67, under the IMGT definition.

13 . The VHH domain of claim 12 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:57, the CDR2 comprises the amino acid sequence of SEQ ID NO:70, and the CDR3 comprises the amino acid sequence of SEQ ID NO:74.

14 . A VHH domain that binds IgE, comprising a paratope comprising 1, 2, 3, 4, 5, 6, 7, or 8 of amino acids 26, 27, 32, 99, 100, 105, 106, and 110 of SEQ ID NO:42.

15 . The VHH domain of claim 14 , wherein the paratope comprises amino acids 26, 27, 32, 99, 100, 105, 106, and 110 of SEQ ID NO:42.

16 . The VHH domain of claim 15 , wherein the paratope further comprises amino acids 29, 35, 52, 97, 98, 103, 107, 111, and 112 of SEQ ID NO:42.

17 . A VHH domain that binds IgE, comprising a CDR1 that comprises the amino acid sequence of SEQ ID NO:115 and a CDR3 that comprises the amino acid sequence of SEQ ID NO:116.

18 . The VHH domain of claim 17 , wherein the CDR1 comprises the amino acid sequence of SEQ ID NO:114.

19 . The VHH domain of claim 17 or 18 , wherein the CDR3 comprises the amino acid sequence of SEQ ID NO:118.

20 . The VHH domain of claim 17 or 18 , wherein the CDR3 comprises the amino acid sequence of SEQ ID NO:117.

21 . The VHH domain of any one of claims 1-20 , comprising glutamate (E), aspartate (D), lysine (K), or arginine (R) at position 11 according to Kabat numbering.

22 . The VHH domain of any one of claims 1-21 , comprising glutamate (E), arginine (R), or aspartate (D) at position 112 according to Kabat numbering.

23 . The VHH domain of any one of claims 1-22 , comprising leucine (L) at position 108 according to Kabat numbering.

24 . The VHH domain of any one of claims 1-23 , wherein the VHH domain is humanized.

25 . The VHH domain of any one of claims 1-24 , comprising the amino acid sequence of SEQ ID NO:47.

26 . The VHH domain of any one of claims 1-25 , comprising an amino acid sequence at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical to an amino acid sequence selected from SEQ ID NOs:2, 6-46, and 101.

27 . The VHH domain of claim 26 , comprising an amino acid sequence selected from SEQ ID NOs:2, 6-46, and 101.

28 . The VHH domain of any one of claims 1-25 , comprising an amino acid sequence at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical to the amino acid sequence of SEQ ID NO:42.

29 . The VHH domain of claim 28 , comprising the amino acid sequence of SEQ ID NO:42.

30 . The VHH domain of any one of claims 1-29 , wherein the VHH domain binds human IgE, optionally wherein the human IgE comprises the amino acid sequence of SEQ ID NO:1.

31 . The VHH domain of claim 30 , wherein the VHH domain inhibits binding of IgE to FcεR1A.

32 . The VHH domain of claim 30 or 31 , wherein the VHH domain does not bind a complex of human IgE and FcεR1A.

33 . The VHH domain of any one of claims 1-32 , wherein the VHH domain does not bind cynomolgus monkey IgE.

34 . The VHH domain of any one of claims 1-33 , wherein the VHH domain does not bind IgA, IgM, or IgG2.

35 . A polypeptide comprising a first VHH domain of any one of claims 1-34 .

36 . The polypeptide of claim 35 , comprising one single VHH domain.

37 . The polypeptide of claim 35 , further comprising a second VHH domain of any one of claims 1-34 .

38 . The polypeptide of claim 37 , further comprising a third VHH domain of any one of claims 1-34 .

39 . The polypeptide of claim 37 or 38 , wherein each VHH domain comprises the same CDR1, CDR2, and CDR3 amino acid sequences.

40 . The polypeptide of claim 39 , wherein each VHH domain comprises the same VHH sequence.

41 . The polypeptide of any one of claims 35-40 , further comprising an Fc region.

42 . The polypeptide of claim 41 , wherein the Fc region is a human IgG1 Fc region.

43 . The polypeptide of claim 42 , wherein the Fc region comprises one or more substitutions selected from G236D, S267E and L328F, numbered according to the EU index as in Kabat.

44 . The polypeptide of claim 43 , wherein the Fc region comprises substitutions S267E and L328F, numbered according to the EU index as in Kabat.

45 . The polypeptide of any one of claims 41-44 , wherein the Fc region comprises the amino acid sequence of SEQ ID NO:79, 75, 76, 80, 81, or 82.

46 . The polypeptide of any one of claims 35-45 , comprising the amino acid sequence of SEQ ID NO:86, 85, 92, 93, 112, or 113.

47 . The polypeptide of any one of claims 35-36 and 41-45 , consisting of the amino acid sequence of SEQ ID NO:86, 85, 92, 93, 112, or 113.

48 . A protein comprising two or more polypeptides of any one of claims 35-47 that form a dimer under physiological conditions.

49 . The protein of claim 48 , wherein the dimer is a homodimer.

50 . The protein of claim 49 , consisting of the two polypeptides.

51 . The polypeptide or protein of any one of claims 35-50 , wherein polypeptide or protein reduces IgE production in a subject's blood to a greater extent than an isotype antibody.

52 . The polypeptide or protein of any one of claims 35-51 , wherein the polypeptide or protein inhibits degranulation of mast cells or basophils to a greater extent than an isotype antibody.

53 . The polypeptide or protein of any one of claims 35-52 , wherein the polypeptide or protein inhibits activation of mast cells or basophils to a greater extent than an isotype antibody.

54 . The polypeptide or protein of any one of claims 35-53 , wherein the polypeptide or protein does not induce antigen-independent mast cell or basophil activation.

55 . The polypeptide or protein of any one of claims 35-54 , wherein the polypeptide or protein binds IgE with a Kp of less than or equal to about 5 nM, 4 nM, 3 nM, 2 nM, or 1 nM, as measured by surface plasmon resonance (SPR) assay.

56 . An immunoconjugate comprising the polypeptide or protein of any one of claims 35-55 and a therapeutic agent.

57 . A pharmaceutical composition comprising the polypeptide or protein of any one of claims 35-55 or the immunoconjugate of claim 56 , and a pharmaceutically acceptable carrier.

58 . An isolated nucleic acid that encodes the VHH of any one of claims 1-34 or the polypeptide of any one of claims 35-47 and 51-55 .

59 . A vector comprising the nucleic acid of claim 58 .

60 . A host cell comprising the nucleic acid of claim 58 or the vector of claim 59 .

61 . A host cell that expresses the polypeptide or protein of any one of claims 35-55 .

62 . A method of producing the polypeptide or protein of any one of claims 35-55 , comprising incubating the host cell of claim 60 or 61 under conditions for expression of the polypeptide or protein.

63 . The method of claim 62 , further comprising isolating the polypeptide or protein.

64 . A method of reducing IgE levels in a subject, the method comprising administering to a subject in need thereof the polypeptide or protein of any one of claims 35-55 , the immunoconjugate of claim 56 , or the pharmaceutical composition of claim 57 .

65 . A method of treating an allergy, the method comprising administering to a subject in need thereof the polypeptide or protein of any one of claims 35-55 , the immunoconjugate of claim 56 , or the pharmaceutical composition of claim 57 .

66 . The method of claim 65 , wherein the subject has a food allergy, an environmental allergy, a companion animal allergy, and/or a venom allergy.