CD123-binding polypeptides and uses thereof
Provided herein are VHH-containing polypeptides that bind CD123. Uses of the VHH-containing polypeptides are also provided.
1. A polypeptide comprising at least one VHH domain that binds CD123, wherein at least one VHH domain comprises a CDR1, a CDR2, and a CDR3, respectively comprising the amino acid sequences of SEQ ID NOs: 42, 43, and 44; 3, 4, and 5; 7, 8, and 9; 7, 8, and 38; 11, 12, and 13; 15, 16, and 17; 19, 20, and 21; 23, 24, and 25; or 23, 94, and 25.
2. The polypeptide of claim 1 , wherein at least one VHH domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 3; a CDR2 comprising the amino acid sequence of SEQ ID NO: 4; and a CDR3 comprising the amino acid sequence of SEQ ID NO: 5.
3. The polypeptide of claim 1 , wherein at least one VHH domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 42; a CDR2 comprising the amino acid sequence of SEQ ID NO: 43; and a CDR3 comprising the amino acid sequence of SEQ ID NO: 44.
4. The polypeptide of claim 1 , wherein at least one VHH domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 7; a CDR2 comprising the amino acid sequence of SEQ ID NO: 8; and a CDR3 comprising the amino acid sequence of SEQ ID NO: 9 or 38.
5. The polypeptide of claim 1 , wherein at least one VHH domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 15; a CDR2 comprising the amino acid sequence of SEQ ID NO: 16; and a CDR3 comprising the amino acid sequence of SEQ ID NO: 17.
6. The polypeptide of claim 1 , wherein at least one VHH domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 23; a CDR2 comprising the amino acid sequence of SEQ ID NO: 24 or 94; and a CDR3 comprising the amino acid sequence of SEQ ID NO: 25.
7. The polypeptide of claim 1 , wherein at least one VHH domain comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 19; a CDR2 comprising the amino acid sequence of SEQ ID NO: 20; and a CDR3 comprising the amino acid sequence of SEQ ID NO: 21.
8. The polypeptide of claim 1 , wherein at least one VHH domain is humanized.
9. The polypeptide of claim 1 , wherein at least one VHH domain comprises an amino acid sequence at least 85%, at least 90%, at least 95%, or at least 99% identical to the amino acid sequence of SEQ ID NO: 32, 29, 26, 27, 28, 30, 31, or 92.
10. The polypeptide of claim 1 , wherein at least one VHH domain comprises the amino acid sequence of SEQ ID NO: 32, 29, 26, 27, 28, 30, 31, or 92.
11. The polypeptide of claim 1 , wherein at least one VHH domain comprises an amino acid sequence at least 85%, at least 90%, at least 95%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 2, 6, 10, 14, 18, or 22.
12. The polypeptide of claim 1 , comprising one, two, or three VHH domains.
13. The polypeptide of claim 1 , wherein the polypeptide comprises at least one binding domain that binds an antigen other than CD123.
14. The polypeptide of claim 13 , wherein the polypeptide comprises at least one binding domain that binds CD3, T-cell receptor (TCR) α, TCRβ, CD28, CD16, CD32A, CD64, CD89, NKp46, or NKG2D.
15. The polypeptide of claim 12 , wherein each VHH domain binds CD123.
16. The polypeptide of claim 1 , wherein the polypeptide comprises an Fc region.
17. The polypeptide of claim 16 , wherein the Fc region comprises an amino acid sequence selected from SEQ ID NOs: 54-89.
18. The polypeptide of claim 16 , which forms a dimer under physiological conditions.
19. The polypeptide of claim 1 , wherein the polypeptide blocks binding of CD123 to IL-3.
20. An immunoconjugate comprising the polypeptide of claim 1 and a cytotoxic agent.
21. The immunoconjugate of claim 20 , wherein the cytotoxic agent is selected from a calicheamicin, an auristatin, a dolastatin, a tubulicin, a maytansinoid, a cryptophycin, a duocarmycin, an esperamicin, a pyrrolobenzodiazepine, and an enediyne antibiotic.
22. A pharmaceutical composition comprising the polypeptide of claim 1 , and a pharmaceutically acceptable carrier.
23. An isolated nucleic acid that encodes the polypeptide of claim 1 .
24. A vector comprising the nucleic acid of claim 23 .
25. A host cell that expresses the polypeptide of claim 1 .
26. A method of producing a polypeptide, comprising incubating the host cell of claim 25 under conditions suitable for expression of the polypeptide, and isolating the polypeptide.
27. A method of treating cancer comprising administering to a subject with cancer a pharmaceutically effective amount of the polypeptide of claim 1 .
28. The method of claim 27 , wherein the cancer is selected from lymphoma; Hodgkin's lymphoma; non-Hodgkin's lymphoma; B-cell lymphoma; low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; Waldenstrom's macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); acute myeloid leukemia (AML); Hairy cell leukemia; and chronic myeloblastic leukemia.
29. The method of claim 27 , further comprising administering an additional therapeutic agent.
30. The method of claim 29 , wherein the additional therapeutic agent is an anti-cancer agent, wherein the anti-cancer agent is selected from a chemotherapeutic agent, an anti-cancer biologic, radiation therapy, CAR-T therapy, and an oncolytic virus.