Alexa Fluor® 488 Mouse Anti-Rat CD3 Antibody (S-3399)

CD3 is a multimeric protein complex that serves as a crucial T-cell co-receptor, composed of four distinct chains (CD3γ, δ, ε, ζ) that non-covalently associate with the T-cell receptor (TCR), where its cytoplasmic immunoreceptor tyrosine-based activation motifs (ITAMs) become phosphorylated upon antigen recognition to initiate downstream signaling cascades leading to T-cell activation, differentiation, and effector functions, making it an essential component of adaptive immunity and a valuable target for therapeutic interventions such as the immunosuppressive agent muromonab-CD3 and emerging bispecific antibodies in oncology.