CD6 Antibodies

Background

CD6 is a transmembrane glycoprotein mainly expressed on the surface of T lymphocytes. As a member of the immunoglobulin superfamily, its structure contains three scavenger receptor cysteine-rich domains. The protein encoded by this gene plays a key role in the formation of immune synapses by mediating the interaction between antigen-presenting cells and T cells, and also participates in the regulation of T cell activation and differentiation as a costimulatory molecule. Research has found that CD6 gene polymorphisms are associated with susceptibility to autoimmune diseases, including multiple sclerosis and rheumatoid arthritis. Due to its significant role in immune regulation, CD6 has become a key research target for the treatment of autoimmune diseases. The development of related monoclonal antibody drugs has entered the clinical trial stage, providing a new direction for precise immunotherapy.

Structure Function Application Advantage Our Products

Structure of CD6

CD6 is a transmembrane glycoprotein with a molecular weight of approximately 105-130 kDa, and its differences mainly stem from the varying degrees of glycosylation modification.

Species	Human	Mouse	Rat
Molecular Weight (kDa)	105-130	110-135	108-132
Primary Structural Differences	Contains three SRCR domain structure	Highly homologous to human CD6	Extracellular region structure highly conservative

The CD6 protein is composed of 668 amino acids, and its extracellular region contains three highly conserved scavenger receptor cysteine-enriched (SRCR) domains, forming an extended rod-like structure. This protein is linked to multiple phosphorylation sites in the intracellular segment through the transmembrane region. Among them, serine at position 629 is the main site for PKC-mediated phosphorylation and directly regulates T cell activation signal transduction. The third SRCR domain is a key region for binding to the ligand CD166/ALCAM, and this specific interaction is an important molecular basis for the formation of immune synapses.

Fig. 1:Schematic representation of endogenous CD6 ligands. Fig. 1 Schematic representation of endogenous CD6 ligands.¹

Key structural properties of CD6:

Extracellular region contains three cysteine enrichment of scavenger receptor (SRCR) domain structure
Transmembrane regions anchor proteins to cell membranes
Intracellular section contains conservative phosphorylation sites, but the signal transduction of T cell activation

Functions of CD6

The main function of CD6 is to act as a T-cell co-stimulatory receptor to participate in the regulation of immune responses, and it is also involved in pathophysiological processes such as immune tolerance and inflammatory responses.

Function	Description
Immune synaptic formation	By binding to the ligand CD166 through the extracellular SRCR domain, it promotes stable contact between T cells and antigen-presenting cells.
Regulation of T cell activation	Transmit co-stimulatory signals, coordinate with TCR signals to regulate T cell proliferation and differentiation, and determine the intensity of immune response.
Maintenance of immune tolerance	Participate in thymus negative selection, affect the clearance of autoreactive T cells, and prevent the occurrence of autoimmune diseases.
Regulation of inflammatory response	Mediates the migration and retention of lymphocytes at the site of inflammation and regulates the degree of local immune cell infiltration.
Therapeutic targets for diseases	As potential therapeutic targets for autoimmune diseases such as multiple sclerosis and psoriasis, related antibody drugs have entered clinical research.

The binding of CD6 to the ligand CD166 shows moderate affinity, and its signal output intensity is dynamically regulated by the phosphorylation state of intracellular serine segments. This characteristic enables it to precisely control the activation threshold of immune responses and avoid excessive immune reactions.

Applications of CD6 and CD6 Antibody in Literature

1. Gurrea-Rubio, Mikel, David A. Fox, and Javier S. Castresana. "CD6 in Human Disease." Cells 14.4 (2025): 272. https://doi.org/10.3390/cells14040272

The article indicates that CD6 is a surface protein expressed on lymphocytes such as T cells, and it participates in the processes of lymphocyte activation, proliferation and adhesion through its interaction with its ligands. It is related to the pathogenesis of autoimmune diseases and is a potential target for cancer immunotherapy.

2. Aragón-Serrano, Lucía, et al. "CD6 and its interacting partners: newcomers to the block of Cancer immunotherapies." International Journal of Molecular Sciences 24.24 (2023): 17510. https://doi.org/10.3390/ijms242417510

The article indicates that CD6 is a signal transduction receptor mainly expressed in T cells, and its ligands are highly expressed in various cancer cells. This makes it an emerging therapeutic target for hematological malignancies and solid tumors. This review summarizes a variety of anti-cancer immune strategies targeting CD6, including monoclonal antibodies, soluble bait receptors, and CAR-T cell therapy.

3. Gonçalves, Carine M., et al. "CD6, a rheostat-type signalosome that tunes T cell activation." Frontiers in immunology 9 (2018): 2994. https://doi.org/10.3389/fimmu.2018.02994

The article indicates that CD6 is an important glycoprotein on the surface of T cells and is involved in T cell activation and immune response. Its intracellular tail can recruit various signal-effector molecules, which have a regulatory effect on TCR signal transduction. Compared with the inhibitory receptor CD5 of the same family, the specific function (inhibition or antagonism) of CD6 in T cell signal transduction remains controversial and is currently the focus of research.

4. Santos, Rita F., et al. "The CD6 interactome orchestrates ligand-independent T cell inhibitory signaling." Cell Communication and Signaling 22.1 (2024): 286. https://doi.org/10.1186/s12964-024-01658-y

The article indicates that CD6 is a new type of "switch" scaffold receptor, and its function is dual. On the one hand, it exerts constitutive inhibitory effects through intracellular regions, setting the threshold for T cell activation; On the other hand, the binding of its extracellular region to CD166 can enhance the adhesion of T cells to APCs, but this LIGAND-dependent regulation is independent of TCR signaling.

5. Gurrea-Rubio, Mikel, et al. "Ligands of CD6: Roles in the pathogenesis and treatment of cancer." Frontiers in immunology 15 (2025): 1528478. https://doi.org/10.3389/fimmu.2024.1528478

The article indicates that CD6 is an important regulatory molecule of T cells, participating in intercellular interactions by binding to CD166, CD318 and the possible new ligand CD44. These ligands are highly expressed on various cancer cells and are associated with poor prognosis and metastasis, making CD6 and its ligands a new focus in cancer research and immunotherapy.

Creative Biolabs: CD6 Antibodies for Research

Creative Biolabs specializes in the production of high-quality CD6 antibodies for research and industrial applications. Our portfolio includes monoclonal antibodies tailored for ELISA, Flow Cytometry, Western blot, immunohistochemistry, and other diagnostic methodologies.

Custom CD6 Antibody Development: Tailor-made solutions to meet specific research requirements.
Bulk Production: Large-scale antibody manufacturing for industry partners.
Technical Support: Expert consultation for protocol optimization and troubleshooting.
Aliquoting Services: Conveniently sized aliquots for long-term storage and consistent experimental outcomes.

For more details on our CD6 antibodies, custom preparations, or technical support, contact us at email.

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