Macrosialin (CD68) (CD68)

Macrosialin, also known as CD68, is a heavily glycosylated type I transmembrane protein that belongs to the lysosome-associated membrane protein (LAMP) family and the scavenger receptor class D (SCARD1) (UniProt P34810). It is primarily expressed in the late endosomes and lysosomes of monocytes and macrophages, though it can rapidly shuttle to the cell surface upon activation (PubMed: 2803980, UniProt P34810). Macrosialin plays a critical role in phagocytic activities, including the clearance of apoptotic cells and the binding of oxidized low-density lipoprotein (oxLDL), which contributes to foam cell formation in atherosclerosis (PubMed: 7684403, nih.gov). In oncology, it serves as the gold-standard immunohistochemical marker for identifying tumor-associated macrophages (TAMs), with its expression levels often serving as a prognostic indicator for various solid tumors (PubMed: 2654191, nih.gov). While it is extensively used as a diagnostic biomarker, Macrosialin is also being investigated as a therapeutic target for modulating immune responses in inflammatory and autoimmune diseases (nih.gov). Current research focuses on neutralizing its signaling pathways to dampen overactive macrophage responses or to reprogram the tumor microenvironment to enhance the efficacy of immunotherapies (nih.gov). Although specific approved therapies targeting the CD68 protein are currently lacking, its role in mediating macrophage-driven pathology makes it a subject of significant interest in drug discovery (nih.gov). Its interaction with tissue-specific lectins and selectins further facilitates the homing of macrophage subsets to sites of inflammation or malignancy (UniProt P34810).

Other names

CD68Gp110LAMP4SCARD1Scavenger receptor class D member 1

Neutralization of CD68 signaling to reduce macrophage activation; inhibition of scavenger receptor activity to prevent foam cell formation; modulation of phagocytosis in the tumor microenvironment (nih.gov).