SELL (L-selectin, CD62L) is a cell adhesion molecule belonging to the selectin family, primarily expressed on leukocytes, including lymphocytes, neutrophils, and monocytes. It plays a critical role in mediating the initial tethering and rolling of leukocytes along vascular endothelium during inflammatory responses and lymphocyte homing to secondary lymphoid organs. SELL interacts with carbohydrate ligands such as GlyCAM-1. CD34. and MadCAM-1 on endothelial cells, facilitating leukocyte recruitment to sites of infection or injury.
SELL antibodies are tools developed to target this glycoprotein for research or therapeutic purposes. In research, they are widely used to study leukocyte trafficking dynamics, immune cell subset identification (e.g., distinguishing naïve and memory T-cells based on SELL expression levels), and inflammatory mechanisms. Therapeutically, SELL-blocking antibodies have been explored to modulate immune responses in conditions like autoimmune diseases, sepsis, or transplant rejection by inhibiting leukocyte infiltration. Conversely, agonistic antibodies may enhance immune surveillance in cancer immunotherapy.
Notably, SELL shedding from the cell surface via proteolytic cleavage (e.g., by ADAM17) during leukocyte activation serves as a regulatory mechanism, making SELL antibodies valuable in tracking cellular activation states. Recent studies also investigate SELL's role in cancer metastasis, as tumor cells may exploit SELL-mediated pathways for dissemination. Challenges remain in balancing therapeutic efficacy with potential immunosuppressive side effects. Ongoing research continues to refine SELL-targeting strategies using monoclonal antibodies, antibody fragments, or bispecific constructs.