High affinity antibody antagonists of interleukin-13 receptor alpha 1

An isolated antibody that binds to human interleukin 13 receptor alpha 1 comprising

• (a) a heavy chain variable region having an amino acid sequence selected from the group consisting of SEQ ID NO:45, SEQ ID NO:51, SEQ ID NO:
• 55, SEQ ID NO:59, SEQ ID NO:63 and SEQ ID NO:67;
• (b) a light chain variable region having an amino acids sequence selected from the group consisting of SEQ ID NO:49, SEQ ID NO:71, SEQ ID NO:75 and SEQ ID NO:79;
• or
• (c) a combination of (a) and (b).

An isolated antibody that exhibits an equilibrium dissociation constant (KD) of less than 200 pM with human interleukin 13 receptor alpha 1 and antagonizes human interleukin 13 receptor alpha 1-mediated activity, wherein

• (a) the heavy chain variable region of said antibody comprises an amino acid sequence as set forth in SEQ ID NO:63 or a sequence at least 90% homologous to the sequence set forth in SEQ ID NO:63;
• and
• (b) a light chain variable region of said antibody comprises an amino acid sequence as set forth in SEQ ID NO:
• 71 or a sequence at least 90% homologous to the sequence set forth in SEQ ID NO:71.

An isolated nucleic acid which encodes a variable region of an antibody that binds to human interleukin 13 receptor alpha 1, wherein the variable region comprises

• a) a heavy chain variable region having an amino acid sequence selected from the group consisting of SEQ ID NO:
• 45, SEQ ID NO:
• 51, SEQ ID NO:
• 55, SEQ ID NO:
• 59, SEQ ID NO:
• 63 and SEQ ID NO:
• 67;
• or
• b) a light chain variable region having an amino acid sequence selected from the group consisting of SEQ ID NO:
• 49, SEQ ID NO:
• 71, SEQ ID NO:
• 75 and SEQ ID NO:
• 79.