Anti-CD276 polypeptides, proteins, and chimeric antigen receptors

#Incorporated by reference in its entirety herein is a computer-readable nucleotide/amino acid sequence listing submitted concurrently herewith and identified as follows: one 207 KB ASCII (Text) file named “0389259_ST25.txt”, dated Sep. 14, 2015.

#Cancer is a public health concern. Despite advances in treatments such as chemotherapy, the prognosis for many cancers, including solid tumors, may be poor. It is estimated that about 559,650 Americans will die from cancer, corresponding to 1,500 deaths per day (Jemal et al., CA Cancer J. Clin., 57:43-66 (2007)). Accordingly, there exists an unmet need for additional treatments for cancer, particularly solid tumors.

#An embodiment of the invention provides a polypeptide comprising (i) SEQ ID NOs: 1-6, (ii) SEQ ID NOs: 11-16, or (iii) SEQ ID NOs: 20-25.

#FIG. 1 is a graph showing percent lysis of target 51Cr labeled CHO or CHO-276 cells by effector human T cells transduced with a nucleotide sequence encoding a CAR comprising SEQ ID NO: 42 (CD276.1 second generation, version 1) or a CAR comprising SEQ ID NO: 45 (CD276.17 second generation, version 1) at various effector to target ratio (E:T) ratios. Open squares represent percent lysis of target CHO cells co-cultured with cells expressing SEQ ID NO: 42 (CD276.1 second generation, version 1), closed squares represent percent lysis of target CHO-276 cells co-cultured with cells expressing SEQ ID NO: 42 (CD276.1 second generation, version 1), open circles represent percent lysis of target CHO cells co-cultured with cells expressing SEQ ID NO: 45 (CD276.17 second generation, version 1), and closed circles represent percent lysis of target CHO-276 cells co-cultured with cells expressing SEQ ID NO: 45 (CD276.17 second generation, version 1) at the indicated effector to target ratio (E:T) ratios.

#FIG. 2 is a graph showing percent lysis of target cells CHO K1 (open squares), 5838 (closed circles), CHO 276 (closed squares), or K562 (diamonds) by effector human cells transduced with a nucleotide sequence encoding a CAR comprising SEQ ID NO: 42 (CD276.1 second generation, version 1) at the indicated effector to target ratios.

#FIG. 3 is a graph showing percent lysis of target cells CHO K1 (open squares), 5838 (closed circles), CHO 276 (closed squares), K562 (diamonds), or TC71 (triangles) by effector human cells transduced with a nucleotide sequence encoding a CAR comprising SEQ ID NO: 39 (CD276.6 second generation, version 1) at the indicated effector to target ratios.

#An embodiment of the invention provides polypeptides and proteins comprising an antigen binding domain of an anti-CD276 antibody. The polypeptides and proteins advantageously specifically recognize and bind to CD276 (also known as B7-H3). CD276 is expressed or overexpressed on a variety of human tumors, including pediatric solid tumors and adult carcinomas. Examples of cancers that express or overexpress CD276 include, but are not limited to, neuroblastoma, Ewing's sarcoma, rhabdomyosarcoma, and prostate, ovarian, colorectal, and lung cancers. Without being bound to a particular theory or mechanism, it is believed that by specifically recognizing and binding to CD276, the inventive polypeptides and proteins may, advantageously, target CD276-expressing cancer cells. In an embodiment of the invention, the inventive polypeptides and proteins may elicit an antigen-specific response against CD276. Accordingly, without being bound to a particular theory or mechanism, it is believed that by eliciting an antigen-specific response against CD276, the inventive proteins and polypeptides may provide for one or more of the following: targeting and destroying CD276-expressing cancer cells, reducing or eliminating cancer cells, facilitating infiltration of immune cells and/or effector molecules to tumor site(s), and enhancing/extending anti-cancer responses.

#The term “polypeptide” as used herein includes oligopeptides and refers to a single chain of amino acids connected by one or more peptide bonds. The polypeptide may comprise one or more variable regions (e.g., two variable regions) of an antigen binding domain of an anti-CD276 antibody, each variable region comprising a complementarity determining region (CDR) 1, a CDR2, and a CDR3. Preferably, a first variable region comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 1, 11, or 20 (CDR1 of first variable region), a CDR2 comprising the amino acid sequence of SEQ ID NO: 2, 12, or 21 (CDR2 of first variable region), and a CDR3 comprising the amino acid sequence of SEQ ID NO: 3, 13, or 22 (CDR3 of first variable region), and the second variable region comprises a CDR1 comprising the amino acid sequence of SEQ ID NO: 4, 14, or 23 (CDR1 of second variable region), a CDR2 comprising the amino acid sequence of SEQ ID NO: 5, 15, or 24 (CDR2 of second variable region), and a CDR3 comprising the amino acid sequence of SEQ ID NO: 6, 16, or 25 (CDR3 of second variable region). In this regard, the inventive polypeptide can comprise SEQ ID NOs: 1-3, 4-6, 11-13, 14-16, 20-22, 23-25, 1-6, 11-16, or 20-25. Accordingly, an embodiment of the invention provides a polypeptide comprising (i) SEQ ID NOs: 1-6, (ii) SEQ ID NOs: 11-16, or (iii) SEQ ID NOs: 20-25. Preferably, the polypeptide comprises the amino acid sequences of SEQ ID NOs: 20-25.

#In an embodiment, the polypeptides each comprise one or more variable regions (e.g., first and second variable regions) of an antigen binding domain of an anti-CD276 antibody, each comprising the CDRs as described above. The first variable region may comprise SEQ ID NO: 8, 18, or 27. The second variable region may comprise SEQ ID NO: 7, 17, or 26. Accordingly, in an embodiment of the invention, the polypeptide comprises SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NOs: 7 and 8, SEQ ID NOs: 17 and 18, or SEQ ID NOs: 26 and 27. Preferably, the polypeptide comprises SEQ ID NOs: 26 and 27.