CD4 Rabbit Polyclonal Antibody

Function

The T cell receptor (TCR) is a heterodimer composed of either α and β or γ and δ chains. CD3 chains and the CD4 or CD8 co-receptors are also required for efficient signal transduction through the TCR. The TCR is expressed on T helper and T cytotoxic cells that can be distinguished by their expression of CD4 and CD8; T helper cells express CD4 proteins and T cytotoxic cells display CD8. CD4 is also expressed on cortical cells, mature medullary thymocytes, microglial cells and dendritic cells. CD4 (also designated T4 and Leu 3), is a membrane glycoprotein that contains four extracellular immunoglobin-like domains. The TCR in association with CD4 can bind class II MHC molecules presented by the antigen-presenting cells. The CD4 protein functions by increasing the avidity of the interaction between the TCR and an antigen-class II MHC complex. An additional role of CD4 is to function as a receptor for HIV.

Background References

1. Ruterbusch M et al. In Vivo CD4+ T Cell Differentiation and Function: Revisiting the Th1/Th2 Paradigm. Annu Rev Immunol. 2020 Apr

2. Raphael I et al. Memory CD4+ T Cells in Immunity and Autoimmune Diseases. Cells. 2020 Feb

Tissue Specificity

Highly expressed in T-helper cells. The presence of CD4 is a hallmark of T-helper cells which are specialized in the activation and growth of cytotoxic T-cells, regulation of B cells, or activation of phagocytes. CD4 is also present in other immune cells such as macrophages, dendritic cells or NK cells.

Post-translational Modification

Palmitoylation and association with LCK contribute to the enrichment of CD4 in lipid rafts.; Phosphorylated by PKC; phosphorylation at Ser-433 plays an important role for CD4 internalization.

Subcellular Location

Cell membrane.

UNIPROT

SwissProt: P01730 Human

Synonyms