Canine monoclonal antibodies against canine cytotoxic T lymphocyte associated protein 4 (CTLA-4)

An antibody or antigen-binding fragment thereof comprising an antigen-binding domain that specifically binds to an epitope of canine cytotoxic T lymphocyte-associated protein 4 (CTLA-4), wherein the antigen-binding domain comprises:

• (i) a heavy chain variable region comprising an amino acid sequence having at least 80% identity to the amino acid sequence of the heavy chain variable region set forth in SEQ ID NO:
• 6;
• and
• (ii) a light chain variable region comprising an amino acid sequence having at least 80% identity to the amino acid sequence set forth in SEQ ID NO:
• 8;
• wherein the heavy chain variable region comprises three heavy chain complementarity determining regions (HCDRs), wherein HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:
• 1, HCDR2 comprises the amino acid sequence set forth in SEQ ID NO:
• 2, and HCDR3 comprises the amino acid sequence set forth in of SEQ ID NO:
• 3;
• and
• wherein the light chain variable region comprises three light chain complementarity determining regions (LCDRs), wherein LCDR1 comprises the amino acid sequence set forth in SEQ ID NO:
• 4, LCDR2 comprises the amino acid sequence of VDG, and LCDR3 comprises the amino acid sequence set forth in SEQ ID NO:
• 5.