CD68, also known as macrosialin, is a glycoprotein encoded by the CD68 gene on chromosome 17p13.1. It contains 354 amino acids and has a molecular weight of around 37–40 kDa. CD68 is an intracellular protein found within the endosomal/lysosomal compartment of cells, although it can also be present on the cell surface under certain conditions. The protein undergoes post-translational modifications such as glycosylation and phosphorylation, contributing to its function and localization. The main function of CD68 is to serve as a marker for lysosomal/endosomal compartments and to participate in phagocytosis and endocytosis. It also plays a crucial role in the degradation of foreign particles, cellular debris, and apoptotic cells within these phagocytic cells, contributing to the maintenance of tissue homeostasis and immune responses.
CD68 is predominantly expressed in cells of the monocyte/macrophage lineage, including macrophages, monocytes, and dendritic cells. Various factors, including inflammatory cytokines, growth factors, and cellular differentiation signals, regulate the expression of CD68. Moreover, protein expression levels can be upregulated in response to infection, inflammation, or tissue injury, reflecting the activation state of macrophages and monocytes. CD68 expression can also be modulated during cellular differentiation processes, such as monocyte-to-macrophage differentiation. Dysregulated expression of CD68 has been associated with various pathological conditions, including inflammation, atherosclerosis, neurodegenerative diseases, and cancer.
In inflammatory diseases, increased CD68 expression is often observed in affected tissues, reflecting the infiltration of activated macrophages and monocytes.
CD68 expression can be identified using immunohistochemistry (IHC) or flow cytometry. In cancer, the expression levels of this protein can be used as a diagnostic tool, aiding in the identification and quantification of tumor-associated macrophages (TAMs) within the tumor microenvironment. High CD68 levels may suggest increased TAM infiltration, impacting tumor progression, invasion, and metastasis. Similarly, in inflammatory and infectious diseases, CD68 expression helps pinpoint activated macrophages or monocyte-derived cells, assisting in disease diagnosis and severity assessment.
Concerning prognostic value, CD68-positive TAMs within the tumor microenvironment have been linked to various cancer outcomes. While increased TAM infiltration may correlate with poorer prognosis in some cases, indicating aggressive tumor behavior, it can conversely signify better prognosis and improved survival rates in others, reflecting a favorable immune response.
NeoBiotechnologies offers a variety of antibodies against CD68 that have been validated for ELISA, flow cytometry, immunofluorescence, immunohistochemistry, and Western blotting, as well as HuProt-validated options. Additionally, we hold exclusive rights to CD68 antibodies available for licensing or collaboration [https://www.neobiotechnologies.com/gene-name/cd68/].
Synonyms
Macrosialin, Gp110, GP110, LAMP4, Microsialin, Macrosialin, SCARD1, Scavenger Receptor Class D Member-1
Research Areas
Immunology, Hematopoietic Stem Cells
