Bivalent IL-2 fusion toxins
IL-2 fusion toxins, e.g., bivalent-IL2 fusion toxins, and methods of use thereof.
1. A bivalent IL-2 fusion toxin comprising:
a first part comprising a cytotoxic protein, and
a second part comprising at least two Interleukin 2 (IL-2) sequences comprising amino acids 21-153 of SEQ ID NO:1, wherein the cytotoxic protein comprises diphtheria toxin, Pseudomonas exotoxin , or cytotoxic portions or variants thereof.
2. The fusion toxin of claim 1 , wherein the cytotoxic protein comprises diphtheria toxin, or cytotoxic portions or variants thereof.
3. The fusion toxin of claim 1 , further comprising a linker between the first and second parts.
4. The fusion toxin of claim 1 , wherein fusion toxin comprises a linker between the two IL-2 sequences.
5. A codon-optimized nucleic acid molecule optimized for expression in a methylotropic yeast encoding the fusion toxin of claim 1 .
6. A nucleic acid encoding the fusion toxin of claim 1 .
7. A vector comprising the nucleic acid molecule of claim 6 .
8. A host cell expressing the nucleic acid molecule of claim 5 .
9. The host cell of claim 8 , wherein the host cell is a methylotropic yeast.
10. The host cell of claim 8 , wherein the host cell is a cell of the species Pichia Pastoris.
11. A pharmaceutical composition comprising the fusion toxin of claim 1 , and a physiologically acceptable carrier.
12. A method of treating a subject who has a cancer, the method comprising administering to the subject a therapeutically effective amount of the fusion toxin of claim 1 .
13. The method of claim 12 , wherein the cancer comprises cancer cells that express CD25.
14. The method of claim 12 , further comprising administering an immunotherapy to the subject.
15. The method of claim 14 , wherein the immunotherapy comprises administration of one or more of: dendritic cells or peptides with adjuvant; DNA-based vaccines; cytokines; cyclophosphamide; anti-interleukin-2R immunotoxins; antibodies; virus-based vaccines ; formulations of Toll-like Receptor or RIG-I-like receptor ligands; or adoptive T cell therapy or other cell therapy.
16. The method of claim 12 , wherein the cancer is selected from the group consisting of B-cell neoplasms, acute nonlymphocytic leukemias, neuroblastomas, tumor infiltrating lymphocytes, and cutaneous T cell lymphoma.
17. A method of depleting CD25-expressing regulatory T cells in a subject, the method comprising administering to the subject an effective amount of the fusion toxin of claim 1 .
18. The method of claim 17 , wherein the subject has cancer, or is an experimental model of autoimmune disease or transplant rejection.
19. A method of producing a bivalent IL-2 fusion toxin, the method comprising:
expressing a codon-optimized nucleic acid molecule encoding the fusion toxin of claim 1 in a methylotropic yeast; and
substantially purifying the fusion toxin,
thereby producing the the fusion toxin.
20. The method of claim 19 , wherein the methylotropic yeast is of the species Pichia Pastoris.