The CD3e protein, encoded by the CD3E gene, is a crucial component of the T-cell receptor (TCR) complex involved in immune responses. The CD3E gene is on chromosome 11q23. CD3e has 207 amino acids with a molecular weight of around 20 kDa. This protein undergoes post-translational modifications, including phosphorylation, which play essential roles in its function. CD3e is a membrane protein integral to T-cell development, activation, and signaling. It forms a heterodimeric complex with other CD3 subunits to compose the TCR complex, which recognizes antigens presented by antigen-presenting cells. Upon antigen recognition, CD3e initiates downstream signaling cascades, leading to T-cell activation, proliferation, and effector functions essential for immune responses against pathogens and tumors.
CD3e is a well-known T-cell marker, and its levels are tightly regulated during T-cell development and activation. Various factors, including cytokines and TCR engagement, influence CD3e expression. Dysregulation of CD3e expression or mutations in the CD3E gene can impair T-cell function, leading to immunodeficiencies and autoimmune diseases.
CD3e expression is clinically significant for immune-related disorders and cancers. In autoimmune diseases like rheumatoid arthritis and multiple sclerosis, increased infiltration of CD3e-positive T-cells into affected tissues aids in diagnosis and disease monitoring. Conversely, in colorectal, melanoma, and ovarian cancers, high levels of CD3e-positive T-cell infiltration within the tumor microenvironment correlate with improved patient outcomes and enhanced response to immunotherapy. CD3e expression is also a predictive biomarker for response to immunotherapies and has been used as a diagnostic marker for T-cell malignancies and autoimmune diseases, providing valuable information for disease classification and prognosis.
Furthermore, there are examples of targeting CD3e with therapeutic monoclonal antibodies (mAbs) for immunotherapy. One notable example of a therapeutic CD3e-targeting monoclonal antibody is Teplizumab, a humanized monoclonal antibody that specifically binds to CD3e on the surface of T-cells. By targeting CD3e, Teplizumab modulates T-cell activation and function, making it a promising candidate for treating autoimmune diseases, particularly type 1 diabetes mellitus (T1DM). Clinical trials investigating Teplizumab have shown promising results in delaying the onset and progression of T1DM in individuals at high risk of developing the disease. Additionally, Catumaxomab, a bispecific monoclonal antibody that targets CD3e on T-cells and epithelial cell adhesion molecule (EpCAM) on tumor cells, was developed to target malignant ascites associated with EpCAM-positive tumors, such as ovarian and gastric cancers. By engaging T-cells via CD3e and tumor cells via EpCAM, Catumaxomab facilitates T-cell-mediated cytotoxicity against tumor cells, leading to improved control of malignant ascites and potentially extending survival in patients with advanced cancer.
NeoBiotechnologies offers a variety of antibodies against CD3e that have been validated for ELISA, flow cytometry, immunofluorescence, immunohistochemistry, and Western blotting. Additionally, we hold exclusive rights to CD3e antibodies available for licensing or collaboration [https://www.neobiotechnologies.com/shop/?s=CD3E].
Synonyms
T-cell surface glycoprotein CD3 epsilon chain, T-cell surface antigen T3/Leu-4 epsilon chain, CD3 epsilon; CD3 TCR complex; T cell antigen receptor complex epsilon subunit of T3; T-cell surface antigen T3/Leu-4 epsilon chain; T-cell surface glycoprotein CD3 epsilon chain; T3E; TCRE; TiT3 complex
Research Areas
Cardiovascular, Immunology, Hematopoietic Stem Cells, PD-1 blockade immunotherapy
