CXC-chemokine antagonists isolated from

1. An isolated polypeptide comprising:

a)SEQ ID NO: 5 (Evasin-3);

b)SEQ ID NO: 6 (mature Evasin-3);

c)SEQ ID NO: 17 (Evasin-3-HIS);

d)SEQ ID NO: 18 (mature Evasin-3-HIS);

e)SEQ ID NO: 26 (Met-Evasin-3); or

f)SEQ ID NO: 5 in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

2. The isolated polypeptide according to claim 1 , wherein said polypeptide comprises SEQ ID NO: 5 (Evasin-3).

3. The isolated polypeptide according to claim 1 , wherein said polypeptide comprises SEQ ID NO: 6 (mature Evasin-3).

4. The isolated polvpeptide according to claim 1 , wherein said polypeptide comprises SEQ ID NO: 17 (Evasin-3-HIS).

5. The isolated polypeptide according to claim 1 , wherein said polypeptide comprises SEQ ID NO: 18 (mature Evasin-3-HIS).

6. The isolated polypeptide according to claim 1 , wherein said polypeptide comprises SEQ ID NO: 26 (Met-Evasin-3).

7. The isolated polypeptide according to claim 1 , wherein said polypeptide comprises SEQ ID NO: 5 (Evasin-3) and in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

8. The isolated polypeptide according to claim 1 wherein said polypeptide further comprises one or more amino acid sequences chosen from the following: an extracellular domain of a membrane-bound protein, an immunoglobulin constant region, a multimerization domain, a heterodimeric protein hormone, a signal peptide, an export signal or a tag sequence operably linked to said polypeptide.

9. A composition comprising a pharmaceutically acceptable carrier and a polypeptide comprising;

a) SEQ ID NO: 5 (Evasin-3);

b) SEQ ID NO:6 (mature Evasin -3);

c) SEQ ID NO: 17 (Evasin-3-HIS);

d) SEQ ID NO: 18 (mature Evasin-3-HIS);

e) SEQ ID NO: 26 (Met-Evasin-3); or

f) SEQ ID NO: 5 in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

10. The composition according to claim 9 , wherein said polypeptide comprises SEQ ID NO: 5 (Evasin-3).

11. The composition according to claim 9 , wherein said polypeptide comprises SEQ ID NO: 6 (mature Evasin-3).

12. The composition according to claim 9 , wherein said polypeptide comprises SEQ ID NO: 17 (Evasin-3-HIS)

13. The composition according to claim 9 , wherein said polypeptide comprises SEQ ID NO): 18 (mature Evasin-3-HIS).

14. The composition according to claim 9 , wherein said polypeptide comprises SEQ ID NO: 26 (Met-Evasin-3).

15. The composition according to claim 9 , wherein said polypeptide comprises SEQ ID NO: 5 (Evasin-3) and in which a evsteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

16. The composition according to claim 9 , wherein said polypeptide further comprises one or more amino acid sequences chosen from the following: an extracellular domain of a membrane-bound protein, an immunoglobulin constant region, a multimerization domain, a heterodimeric protein hormone, a signal peptide, an export signal or a tag sequence operably linked to said polypeptide.

17. An isolated nucleic acid encoding a polypeptide comprising:

a) SEQ ID NO:5 (Evasin-31);

b) SEQ ID NO:6 (mature Evasin-3);

c) SEQ ID NO: 17 (Evasin-3-HIS);

d) SEQ ID NO: 18 (mature Evasin-3HIS);

e) SEQ ID NO: 26 (Met-Evasin-3); or

f) SEQ ID NO: 5 in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

18. An isolated cloning or expression vector comprising a nuclcic acid encoding a polypeptide comprising; a) SEQ ID NO: 5 (Evasin-3); b) SEQ ID NO: 6 (mature Evasin-3); c) SEQ ID NO: 17 (Evasin-3-HIS); d) SEQ ID NO: 18 (mature Evasin-3-HIS); e) SEQ ID NO: 26 (Met-Evasin-3); or f) SEQ ID NO: 5 in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

19. An isolated host cell comprising an expression vector comprising a nucleic acid encoding a polypeptide comprising: a) SEQ ID NO: 5 (Evasin-3); b) SEQ ID NO: 6 (mature Evasin-3); c) SEQ ID NO: 17 (Evasin-3-HIS); d) SEQ ID NO: 18 (mature Evasin-3-HIS); e) SEQ ID NO: 26 (Met-Evasin-3); or f) SEQ ID NO: 5 in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

20. A method for producing a polypeptide comprising culturing a host cell under conditions allowing or promoting expression of said polypeptide, wherein said host cell comprising an expression vector comprising: a nucleic acid encoding a polypeptide comprising: a) SEQ ID NO: 5 (Evasin-3); b) SEQ ID NO: 6 (mature Evasin-3); c) SEQ ID NO: 17 (Evasin-3-HIS); d) SEQ ID NO: 18 (mature Evasin-3-HIS); e) SEQ ID NO: 26 (Met-Evasin-3); or f) SEQ ID NO:5 in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.

21. The method according to claim 20 , further comprising purifying the polypeptide.

22. The method according to claim 21 , further comprising formulating the polypeptide with a pharmaceutically acceptable carrier.

23. A method for immunizing an animal against a blood-feeding ectoparasite comprising administering to said animal a polypeptide comprising: comprising a nucleic acid encoding a polypeptide comprising: a) SEQ ID NO: 5 (Evasin-3); b) SEQ ID NO: 6 (mature Evasin-3) c) SEQ ID NO: 17 (Evasin-3-HIS); d) SEQ ID NO: 18 (mature Evasin-3-HIS); e) SEQ ID NO: 26 (Met-Evasin-3); or f) SEQ ID NO: 5 in which a cysteine residue in the position corresponding to residues 48, 52, 59, 63, 65 or 76 or the asparagine at position 51 or 82 has been substituted.