Detection of CD4 in Human Blood Lymphocytes by Flow Cytometry. |
Human peripheral blood lymphocytes were stained with Goat Anti-Human CD4 Alexa Fluor® 488‑conjugated Antigen Affinity-purified Polyclonal Antibody (Catalog # FAB8165G, filled histogram) or isotype control antibody (Catalog # IC108G, open histogram). View our protocol for Staining Membrane-associated Proteins.
CD4 in Human PBMCs. |
CD4 was detected in immersion fixed human peripheral blood mononuclear cells (PBMCs) using Goat Anti-Human CD4 Alexa Fluor® 488-conjugated Antigen Affinity-purified Polyclonal Antibody (Catalog # FAB8165G, green) at 10 µg/mL for 3 hours at room temperature. Cells were counterstained with DAPI (blue). Specific staining was localized to cell surfaces. View our protocol for Fluorescent ICC Staining of Non-adherent Cells.
CD4 is an approximately 55 kDa type I membrane glycoprotein that is expressed predominantly on most thymocytes and a subset of mature T lymphocytes. In humans, CD4 is also expressed to a lesser extent on monocytes and macrophage related cells. Human CD4 cDNA encodes a 458 amino acid (aa) residue precursor protein with a 25 aa residue signal peptide, a 371 aa residue extracellular region containing four immunoglobulin homology domains, a 24 aa residue transmembrane domain and a 38 aa residue cytoplasmic domain. CD4 is a coreceptor required for T cell recognition of antigens that are presented by class II major histocompatibility complexes. CD4 has been shown to be a coreceptor of HIV entry and specifically binds gp120, the external envelope glycoprotein of HIV.