CD3e Human

CD3e, also known as CD3 epsilon, is a crucial component of the T-cell receptor (TCR) complex. This protein plays a significant role in the immune system by participating in the activation and signal transduction of T-cells. The recombinant form of CD3e is produced using various expression systems to study its function and potential therapeutic applications.

CD3e is a single-pass type I membrane protein that contains an immunoglobulin-like (Ig-like) domain and an immunoreceptor tyrosine-based activation motif (ITAM) domain . It is part of the CD3 complex, which includes CD3 gamma, delta, and zeta chains, along with the TCR alpha/beta and gamma/delta heterodimers . This complex is essential for coupling antigen recognition to several intracellular signal-transduction pathways .

Recombinant human CD3e is typically produced in mammalian cell lines such as HEK293 cells. The extracellular domain of CD3e is fused with a polyhistidine tag at the C-terminus to facilitate purification . The recombinant protein is then purified using techniques like SDS-PAGE and HPLC to ensure high purity and low endotoxin levels .

Recombinant CD3e is used in various research applications, including:

• Studying T-cell activation: By binding to specific antibodies or ligands, recombinant CD3e can be used to investigate the mechanisms of T-cell activation and signal transduction.
• Therapeutic development: CD3e is a target for developing immunotherapies, such as bispecific antibodies that engage T-cells to attack cancer cells.
• Diagnostic tools: Recombinant CD3e can be used in diagnostic assays to detect and quantify T-cell populations in clinical samples.

Recombinant CD3e is typically lyophilized and stored at -20°C to -80°C to maintain stability . It is recommended to aliquot the protein to avoid repeated freeze-thaw cycles, which can degrade the protein’s activity .