anti-CD3 Fab fragments

Anti-CD3 Fab fragments are monovalent antibody fragments designed to bind the CD3 complex on T cells. Unlike bivalent anti-CD3 antibodies, which can cause systemic T cell activation and cytokine release, these Fab fragments are used to co-potentiate T cell responses. They induce a specific conformational change in the CD3 complex (CD3Δc), exposing a conserved proline-rich sequence (PRS) in the CD3ε cytoplasmic tail. This exposure allows for the recruitment of cytoplasmic adaptor proteins like Nck, which participate in the CD3 signaling cascade. By mimicking the conformational change required for productive signaling, anti-CD3 Fabs lower the threshold for T cell activation when the T cell receptor (TCR) engages weak or poorly immunogenic antigens. Research has demonstrated their potential as immunotherapeutic agents in oncology, specifically showing efficacy in reducing melanoma burden in preclinical mouse models.

Other names

anti-CD3 Fabsanti-CD-3 Fabsanti-CD 3 Fabsanti-mouse CD3 Fabs