Mouse Lymphocyte Antigen 9 (LY9) Protein

Background

Lymphocyte antigen 9 (LY9), also known as SLAMF3 (Signaling Lymphocytic Activation Molecule Family Member 3), is a transmembrane glycoprotein and member of the immunoglobulin (Ig) superfamily. This molecule is part of the broader SLAM family, a set of proteins primarily expressed on immune cells. LY9, like other SLAM family members, plays a key role in immune cell signaling, cell-to-cell interactions, and immunoregulation, specifically in adaptive immunity. This protein is highly expressed on lymphocytes, particularly T cells and natural killer (NK) cells, and it is involved in mediating various immune responses by interacting with other immune cells. LY9 participates in homotypic interactions, meaning it binds to another LY9 molecule on adjacent cells, facilitating immune cell communication and signaling. Its expression is primarily associated with lymphoid tissues, but it is also present on other immune cells, where it regulates responses by activating intracellular signaling cascades. Studies show that LY9 contributes to immune regulation by affecting processes such as cytokine secretion, cytotoxicity, and immune cell differentiation. Given its involvement in immune signaling, LY9 is being investigated as a therapeutic target in conditions where immune regulation is disrupted, including autoimmune diseases, cancers, and immunodeficiencies.