Il-17a/f heterologous polypeptides and therapeutic uses thereof

(canceled)

3:

• The method of claim 1, wherein said one or more antibodies, or antigen-binding fragments thereof, are an antibody that specifically binds to IL-17A, or an antigen-binding fragment thereof, and an antibody that specifically binds to IL-17F, or an antigen-binding fragment thereof.

4-7. (canceled)

8:

• The method of claim 1, wherein said one or more antibodies, or antigen-binding fragments thereof, are one or more cross-reactive antibodies, or antigen-binding fragments thereof, that bind to both IL-17A (SEQ ID NO:
• 3) and IL-17F.

9:

• The method of claim 1, wherein said one or more antibodies, or antigen-binding fragments thereof, are one or more bispecific antibodies, or antigen-binding fragments thereof, having IL-17A and IL-17F specificity.

10:

• The method of claim 1, wherein said one or more antibodies, or antigen-binding fragments thereof, are one or more monoclonal antibodies, or antigen-binding fragments thereof.

11:

• The method of claim 10 wherein said one or more monoclonal antibodies, or antigen-binding fragments thereof, are chimeric, humanized or human antibodies.

12-13. (canceled)

14:

• A method of treating multiple sclerosis (MS) or rheumatoid arthritis (RA) in a human subject in need thereof comprising simultaneous targeting of IL-17A and IL-17F in said human subject wherein said method comprises administration to said human subject of a therapeutically effective amount of a cross-reactive antibody, or an antigen-binding fragment thereof, wherein said antibody, or antigen-binding fragment thereof, specifically binds to both IL-17A, a polypeptide having the amino acid sequence of SEQ ID NO:
• 3 without an associated leader peptide, and IL-17F, a polypeptide having the amino acid sequence of SEQ ID NO:
• 4 without an associated leader peptide.

15-16. (canceled)

17:

• A method of treating multiple sclerosis (MS) or rheumatoid arthritis (RA) in a human subject in need thereof comprising simultaneous targeting of IL-17A and IL-17F in said human subject wherein said method comprises administration to said human subject of a therapeutically effective amount of a bi-specific antibody, or antigen-binding fragment thereof, wherein said antibody, or antigen-binding fragment thereof, consists of two arms wherein one arm of said antibody recognizes IL-17A and the other arm of said antibody recognizes IL-17F.

18-19. (canceled)

20:

• A method of treating multiple sclerosis (MS) or rheumatoid arthritis (RA) in a human subject in need thereof comprising simultaneous targeting of IL-17A and IL-17F in said human subject wherein said method comprises administration to said human subject of a therapeutically effective amount of a bi-specific antibody, or an antigen-binding fragment thereof, wherein said antibody, or antigen-binding fragment thereof, consists of a heavy chain which recognizes IL-17A and a light chain which recognizes IL-17F.

21-22. (canceled)

23:

• A method of treating multiple sclerosis (MS) or rheumatoid arthritis (RA) in a human subject in need thereof comprising simultaneous targeting of IL-17A and IL-17F in said human subject wherein said method comprises administration to said human subject of a therapeutically effective amount of a bi-specific antibody, or antigen-binding fragment thereof, wherein said antibody, or antigen-binding fragment thereof, consists of a heavy chain which recognizes IL-17F and a light chain which recognizes IL-17A.

24-25. (canceled)