ULBP1 (UL16-binding protein 1), also known as RAET1I, is a cell surface glycoprotein belonging to the human NKG2D ligand family. It interacts with the NKG2D receptor expressed on natural killer (NK) cells, γδ T cells, and CD8+ αβ T cells, playing a critical role in immune surveillance against infected or transformed cells. ULBP1 is typically absent in healthy tissues but is upregulated under cellular stress, viral infection, or DNA damage, marking compromised cells for immune destruction.
Antibodies targeting ULBP1 are essential tools for studying its expression, function, and interaction with NKG2D in immunological responses. They are widely used in flow cytometry, immunohistochemistry, and functional assays to investigate ULBP1's role in cancer immunology, autoimmune diseases, and viral infections. Therapeutic applications are also explored, including blocking antibodies to suppress autoimmune reactions or agonist antibodies to enhance NK cell-mediated cytotoxicity in cancer. Challenges include understanding ULBP1's regulation and tissue-specific roles, as its aberrant expression is linked to both tumor immune evasion and autoimmune pathology. Commercial ULBP1 antibodies (monoclonal/polyclonal) are validated for research, with ongoing studies optimizing their clinical potential in immunotherapy.