CD4 iFluor™ 488

CD4 is a 55kD type I transmembrane glycoprotein and a member of the immunoglobulin superfamily. It is a specific marker for T lymphocytes, monocytes, macrophages, and dendritic cells. Through interaction of MHC-II, CD4 facilitates cell-cell interaction, thymic differentiation, and activation of downstream signaling cascades. HIV infection of T-cells is instigated through binding of HIV to CD4. The OKT4 binds to the D3 domain of CD4 and does not inhibit HIV binding.