Anti-B7-H6 antibody, fusion proteins, and methods of using the same
Antibodies, chimeric antigen receptors, and bispecific T-cell engagers having specificity for B7-H6 and methods for using the same in the diagnosis and treatment of disorders associated with B7-H6 expression are provided.
1. A chimeric antigen receptor comprising:
(a) an antigen binding fragment of an antibody that specifically binds to B7 homolog 6 (B7-H6),
(b) a transmembrane region, and
(c) an intracellular T-cell receptor signaling domain.
2. The chimeric antigen receptor of claim 1 , wherein the transmembrane region and intracellular T-cell receptor signaling domain are from CD3-zeta.
3. The chimeric antigen receptor of claim 1 , comprising an intracellular signaling domain of a costimulatory protein receptor.
4. An isolated recombinant T cell comprising the chimeric antigen receptor of claim 1 .
5. The chimeric antigen receptor of claim 1 , wherein the antigen binding fragment of an antibody which specifically binds to B7-H6 comprises:
(a) a heavy chain variable region comprising:
(i) a CDR1 of SEQ ID NO: 5,
(ii) a CDR2 of SEQ ID NO: 6, and
(iii) a CDR3 of SEQ ID NO: 7; and
(b) a light chain variable region comprising:
(i) a CDR1 of SEQ ID NO: 8,
(ii) a CDR2 of SEQ ID NO: 9, and
(iii) a CDR3 of SEQ ID NO: 10.
6. The chimeric antigen receptor of claim 3 , wherein the costimulatory protein receptor is selected from the group consisting of CD28, 41BB, and ICOS.
7. The chimeric antigen receptor of claim 1 , wherein the antigen binding fragment of an antibody which specifically binds to B7-H6 comprises:
(a) a heavy chain variable region of SEQ ID NO: 3; and
(b) a light chain variable region of SEQ ID NO: 4.
8. The chimeric antigen receptor of claim 7 , wherein the antigen binding fragment of an antibody which specifically binds to B7-H6 comprises a single chain variable fragment (scFv) comprising SEQ ID NOS: 3 and 4.
9. The chimeric antigen receptor of claim 8 , wherein the antigen binding fragment of an antibody which specifically binds to B7-H6 further comprises a peptide linker between SEQ ID NOS: 3 and 4.
10. The chimeric antigen receptor of claim 9 , wherein the peptide linker comprises SEQ ID NO: 14.
11. The chimeric antigen receptor of claim 1 , wherein the chimeric antigen receptor comprises a human CD28 hinge-transmembrane-cytoplasmic domain of SEQ ID NO: 12.
12. The chimeric antigen receptor of claim 1 , wherein the chimeric antigen receptor comprises a human CD3-zeta cytoplasmic domain of SEQ ID NO: 11.
13. The chimeric antigen receptor of claim 1 , wherein the chimeric antigen receptor comprises:
(a) a single chain variable fragment (scFv) comprising SEQ ID NOS: 3 and 4;
(b) a human CD28 hinge-transmembrane-cytoplasmic domain of SEQ ID NO: 12; and
(c) a human CD3-zeta cytoplasmic domain of SEQ ID NO: 11.
14. The chimeric antigen receptor of claim 1 , wherein the chimeric antigen receptor further comprises a truncated human CD19 fragment of SEQ ID NO: 13.
15. The chimeric antigen receptor of claim 13 , wherein the chimeric antigen receptor further comprises a truncated human CD19 fragment of SEQ ID NO: 13.
16. The isolated recombinant T cell of claim 4 which is a primary human T cell.
17. The chimeric antigen receptor of claim 1 , further comprising a hinge region or spacer region.