Lysosomal-associated membrane protein 1 (LAMP-1) (CD107a)

Lysosomal-associated membrane protein 1 (LAMP-1), commonly known as CD107a, is a highly glycosylated Type I transmembrane protein that constitutes a significant portion of the lysosomal membrane. Its primary physiological roles include maintaining lysosomal structural integrity, regulating pH, and facilitating the trafficking of cytotoxic proteins like perforin within immune cells. In the context of immunology, CD107a is the gold-standard biomarker for the degranulation of Natural Killer (NK) cells and cytotoxic T lymphocytes (CTLs), as it is translocated to the cell surface during the release of lytic granules. Beyond its role as a marker, surface-expressed CD107a protects these effector cells from self-destruction by reducing perforin binding to their own membranes. In oncology, CD107a is often overexpressed on the surface of highly metastatic and chemoresistant tumor cells, making it an emerging target for therapeutic antibodies and a indicator of poor prognosis. While not yet a target for widely approved direct inhibitors, it is extensively used to monitor the efficacy of immunotherapies such as bispecific T-cell engagers (BiTEs) and CAR-T cell therapies.

Other names

LAMP1LAMPALGP120Cluster of Differentiation 107aLysosome-associated membrane glycoprotein 1

CD107a is primarily utilized as a functional biomarker to measure the degranulation and cytotoxic activity of immune cells; however, it is also being investigated as a therapeutic target in colorectal cancer where its inhibition or depletion increases reactive oxygen species (ROS) production and restores chemosensitivity.