CD3 is a member of the immunoglobulin superfamily and acts as a mediator of signal transduction. It is a multimeric protein composed of four distinct polypeptide chains (ε, γ, δ, ζ). Each of these chains contain immunoreceptor tyrosine activation motifs (ITAMS) which are required for initiation of signaling cascades, as they recruit protein tyrosine kinases, signaling intermediates and adapter molecules. CD3 is expressed by a high-percentage of circulating peripheral T cells forming a complex with the T cell receptor (TCR). As CD3 is present at all stages of T cell development, it is a highly effective T cell marker. Read our CD3 mini-review for detailed information on CD3 including its structure alongside that of the TCR, the genes involved in its expression, its function and the signal transduction pathways mediated by the CD3 complex.
For more information about T cells refer to the following resources available:
Here we look at anti-CD3 clones and their recommended applications.
CD3 antibodies are also available for dog, pig, chicken and Rhesus monkey.
Anti-mouse CD3 V CD4
Fig. 1. RPE conjugated rat anti-mouse CD4 (MCA4635PE) and APC conjugated rat IgG2a isotype control.
Fig 3. Staining of a formalin fixed paraffin embedded human tonsil with rat anti-human CD3 antibody, clone CD3-12 (MCA1477) following heat mediated antigen retrieval.