Cytotoxic T-lymphocyte-associated protein 4 (canine) (CTLA-4)

Canine Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a transmembrane receptor expressed on the surface of activated T-cells and regulatory T-cells in dogs. It serves as a critical negative regulator of the immune system by outcompeting the costimulatory receptor CD28 for binding to B7 ligands on antigen-presenting cells, effectively dampening T-cell activation and proliferation (UniProt Q9GLL6). In veterinary oncology, CTLA-4 is a major target for cancer immunotherapy because many canine tumors exploit this pathway to suppress the host's anti-tumor immune response. By utilizing monoclonal antibodies like gilvetmab to block CTLA-4, clinicians can restore the ability of the canine immune system to identify and eliminate malignant cells (PubMed: 35121735). This target is particularly significant in the treatment of aggressive canine cancers such as oral melanoma and osteosarcoma, where traditional therapies often fail. However, modulating this pathway carries the risk of inducing immune-related adverse events due to the loss of peripheral tolerance.

Other names

CD152Cytotoxic T-lymphocyte protein 4Canine CTLA-4

Immune checkpoint inhibition; the drug binds to canine CTLA-4 on T-cells, preventing its interaction with B7-1 (CD80) and B7-2 (CD86) on antigen-presenting cells, thereby removing the inhibitory signal and enhancing anti-tumor T-cell activity.