Isolated human mesenchymal stem cell expressing a bispecific antibody that binds CD33 and CD3 and method of using to treat cancer
The invention concerns pluri- or multipotent stem cells (SCs), e.g. human pluri- or multipotent stem cells (hSCs) engineered to express a multispecific antibody and which further express, on their surface, a human immune cell co-stimulatory ligand or an active fragment thereof.
1. An isolated human mesenchymal stem cell (MSC) comprising a nucleic acid sequence encoding a bispecific antibody that specifically binds CD33 and CD3, said antibody comprising:
a) a first antigen-binding domain that specifically binds to CD33 comprising a variable light (V L ) chain and a variable heavy (V H ) chain, and
b) a second antigen-binding domain that specifically binds to CD3 comprising a V L chain and a V H chain,
wherein said MSC expresses and secretes said bispecific antibody.
2. The isolated human MSC of claim 1 , wherein said bispecific antibody is a single chain bispecific antibody.
3. The isolated human MSC of claim 1 , wherein said bispecific antibody comprises a linker comprising the amino acid sequence GGGGS (SEQ ID NO:33).
4. The isolated human MSC of claim 1 , wherein said bispecific antibody comprises a linker consisting of the amino acid sequence of SEQ ID NO:34.
5. The isolated human MSC of claim 1 , wherein:
i) said V H chain of the first antigen-binding domain that specifically binds to CD33 comprises:
a) a V H complementarity determining region 1 (V H CDR1) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 9, 10, 11, and 12,
b) a V H complementarity determining region 2 (V H CDR2) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 13, 14, 15, and 16, and
c) a V H complementarity determining region 3 (V H CDR3) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 5, 17, 18, 19, and 20; and wherein
ii) said V L chain of the first antigen-binding domain that specifically binds to CD33 comprises:
a) a V L CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 21, 22, 23, and 24,
b) a V L CDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 7, 25, 26, 27, and 28, and
c) a V L CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 8, 29, 30, 31, and 32.
6. The isolated human MSC of claim 5 , wherein:
i) said V H chain of the first antigen-binding domain that specifically binds to CD33 comprises:
a) a V H CDR1 comprising the amino acid sequence of SEQ ID NO: 3,
b) a V H CDR2 comprising the amino acid sequence of SEQ ID NO: 4, and
c) a V H CDR3 comprising the amino acid sequence of SEQ ID NO: 5; and
ii) said V L chain of the first antigen-binding domain that specifically binds to CD33 comprises:
a) a V L CDR1 comprising the amino acid sequence of SEQ ID NO: 6,
b) a V L CDR2 comprising the amino acid sequence of SEQ ID NO: 7, and
c) a V L CDR3 comprising the amino acid sequence of SEQ ID NO: 8.
7. The isolated human MSC of claim 1 , further comprising a nucleic acid sequence encoding 4-1 BB ligand, B7-1, or B7-2,
wherein said MSC functionally expresses said 4-1 BB ligand, B7-1, or B7-2.
8. A composition comprising the isolated human MSC of claim 1 , and a pharmaceutically acceptable carrier.
9. The isolated human MSC of claim 6 , wherein said bispecific antibody is a humanized bispecific antibody.
10. A method of preventing acute myeloid leukemia in a human, the method comprising administering a therapeutically effective amount of isolated human MSCs into the human in an amount effective to prevent acute myeloid leukemia, wherein the MSCs comprise:
i) a nucleic acid sequence encoding a bispecific antibody comprising:
a) a first antigen-binding domain that specifically binds to CD33 comprising a variable light (V L ) chain and a variable heavy (V H ) chain, and
b) a second antigen-binding domain that specifically binds to CD3 comprising a V L chain and a V H chain; and
ii) a nucleic acid sequence encoding 4-1 BB ligand, B7-1, or B7-2,
wherein said MSC expresses and secretes said bispecific antibody and functionally expresses said 4-1BB ligand, B7-1, or B7-2.
11. The method of claim 10 , wherein the bispecific antibody is a single chain antibody.
12. The method of claim 10 , wherein:
i) said CD33 V H comprises:
a) a V H CDR1 comprising the amino acid sequence of SEQ ID NO:3,
b) a V H CDR2 comprising the amino acid sequence of SEQ ID NO:4, and
c) a V H CDR3 comprising the amino acid sequence of SEQ ID NO:5; and
ii) said CD33 V L comprises:
a) a V L CDR1 comprising the amino acid sequence of SEQ ID NO:6,
b) a V L CDR2 comprising the amino acid sequence of SEQ ID NO:7, and
c) a V L CDR3 comprising the amino acid sequence of SEQ ID NO:8.
13. The method of claim 12 , wherein said bispecific antibody is a humanized bispecific antibody.