Anti-CD4 Antibody, clone SK3

T-cell surface glycoprotein CD4 (UniProt: P01730; also known as T-cell surface antigen T4/Leu-3, CD4) is encoded by the CD4 gene (Gene ID: 920) in human. CD4 is a single-pass type I membrane glycoprotein that is highly expressed in T-helper cells and is also found in macrophages, dendritic cells, and NK cells. CD4 is synthesized with a signal peptide (a 1-25), which is subsequently cleaved off to generate the mature form that has an extracellular domain (aa 26-396), a transmembrane domain (aa 397-418), and a cytoplasmic domain (aa 419-458). It has three Ig-like C2-type and one Ig-like V-type domain. CD4 plays an essential role in the immune response and serves multiple functions in response against both external and internal offenses. In T-cells, it functions primarily as a coreceptor for MHC class II molecule:peptide complex. It interacts simultaneously with the T-cell receptor (TCR) and the MHC class II presented by antigen presenting cells and recruits the Src kinase LCK to the vicinity of the TCR-CD3 complex. The LCK can then initiate different intracellular signaling events by phosphorylating various substrates, which lead to lymphokine production, motility, adhesion and activation of T-helper cells. CD4 is also reported to participates in the development of T-helper cells in the thymus and trigger the differentiation of monocytes into functional mature macrophages. CD4 also serves a primary receptor for human immunodeficiency virus-1 (HIV-1). It is removed from plasma membrane by Nef protein of HIV-1, which increases clathrin-dependent endocytosis and lysosomal degradation of CD4.

Human peripheral blood T lymphocytes.

Quality Control Testing

Evaluated by Flow Cytometry in human peripheral blood mononuclear cells (PBMC).

Flow Cytometry Analysis: 1.0 µg from a representative lot detected CD4/Leu3 in human peripheral blood mononuclear cells (PBMC).

Tested Applications

Immunohistochemistry Applications: A representative lot detected CD4 in Immunohistochemistry applications (Tjin, E.P.M., et al. (2014). Cancer Immunol Res. 2(6):538-46).

Flow Cytometry Analysis: A representative lot detected CD4 in Flow Cytometry applications (Evans, R.L., et al. (1981). Proc Natl Acad Sci USA. 78(1):544-8; Mold, J.E., et al. (2021). Cell Rep. 35(8):109174).

Note: Actual optimal working dilutions must be determined by end user as specimens, and experimental conditions may vary with the end user.

Clone SK3 is a mouse recombinant monoclonal antibody that detects CD4. It targets an epitope from the extracellular domain.

Purified mouse monoclonal antibody IgG1 in buffer containing 0.1 M Tris-Glycine (pH 7.4), 150 mM NaCl with 0.05% sodium azide.

0.5 mg/mL. Please refer to guidance on suggested starting dilutions and/or titers per application and sample type.

Recommended storage: +2°C to +8°C.

Concentration: Please refer to the Certificate of Analysis for the lot-specific concentration.

Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.