Anti-Human CD4 (Clone SK3) - Purified (PhenoCycler-Fusion (CODEX)® Ready) (C3355-50ug)

CD4 is a type I transmembrane glycoprotein with four domains and is a member of the Ig superfamily1,2. CD4 functions primarily as a coreceptor for the MHC class II molecule-peptide complex3. CD4 initiates the early phase of T-cell activation via its association with the T-cell receptor complex and protein tyrosine kinase Lck. In addition, CD4 functions as a mediator of direct neuronal damage in infectious and immune-mediated diseases of the central nervous system. Furthermore, HIV displays tropism for CD4+ T cells4 and CD4 acts as the primary receptor for HIV viral entry via binding of its extracellular domain with the HIV-1 gp120 surface glycoprotein2,3. SK3 can be used as a reference standard in quantitative flow cytometry5,6 and to study HIV viral entry4. SK3 does not compete for binding with Tregalizumab7. Since the binding site of Tregalizumab is in close proximity to a disulfide bond in domain 2 of CD4, SK3 binds elsewhere in the CD4 protein. Lisco et al give domain 3 as the binding site8.