CD4 Recombinant Rabbit Monoclonal Antibody [JE56-36]

Function

Integral membrane glycoprotein that plays an essential role in the immune response and serves multiple functions in responses against both external and internal offenses. In T-cells, functions primarily as a coreceptor for MHC class II molecule:peptide complex. The antigens presented by class II peptides are derived from extracellular proteins while class I peptides are derived from cytosolic proteins. Interacts simultaneously with the T-cell receptor (TCR) and the MHC class II presented by antigen presenting cells (APCs). In turn, recruits the Src kinase LCK to the vicinity of the TCR-CD3 complex. LCK then initiates different intracellular signaling pathways by phosphorylating various substrates ultimately leading to lymphokine production, motility, adhesion and activation of T-helper cells. In other cells such as macrophages or NK cells, plays a role in differentiation/activation, cytokine expression and cell migration in a TCR/LCK-independent pathway. Participates in the development of T-helper cells in the thymus and triggers the differentiation of monocytes into functional mature macrophages. (Microbial infection) Primary receptor for human immunodeficiency virus-1 (HIV-1). Acts as a receptor for Human Herpes virus 7/HHV-7.

Background References

1. Sanchez-Martinez A. et. al. Cytotoxic CD4+ T-cells during HIV infection: Targets or weapons? J Clin Virol. 2019 Oct;119:17-23.

2. Tompa A. et. al. Subsets of CD4+, CD8+, and CD25hi Lymphocytes Are in General Not Influenced by Isolation and Long-Term Cryopreservation. J Immunol. 2018 Sep 15;201(6):1799-1809.

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