The CD4 protein, encoded by the CD4 gene, is a transmembrane glycoprotein that plays a crucial role in the immune system. The CD4 gene is located on chromosome 12q13 and encodes a protein comprising 458 amino acids, resulting in a molecular weight of around 55 kDa. CD4 undergoes various post-translational modifications, including phosphorylation and glycosylation, which are essential for its function. As a membrane protein, CD4 is primarily expressed on the surface of helper T-cells, where it acts as a co-receptor for the T-cell receptor (TCR) and interacts with major histocompatibility complex class II (MHC-II) molecules on antigen-presenting cells. This interaction facilitates T-cell activation and the initiation of immune responses against pathogens. CD4 expression is also observed in other immune cells, such as macrophages and dendritic cells, albeit at lower levels. The expression of CD4 is tightly regulated during T-cell development and activation, with its levels influenced by various factors, including cytokines and antigen presentation.
Dysregulation of CD4 expression or mutations in the CD4 gene can lead to immune system dysfunction and are associated with diseases such as HIV/AIDS, where the virus targets and destroys CD4-positive T-cells, compromising the immune response. Numerous examples of targeting CD4 protein with monoclonal antibodies (mAbs) for therapeutic applications exist. For example, Ibalizumab is a humanized monoclonal antibody that targets the CD4 receptor on the surface of T cells. By binding to CD4, Ibalizumab blocks the interaction between CD4 and the HIV envelope glycoprotein gp120, thereby preventing viral entry into CD4-positive T cells. Additionally, CD4-targeted therapies have been explored in autoimmune diseases, where modulating CD4-positive T-cell responses can help alleviate symptoms and reduce disease progression.
Furthermore, CD4 expression has been used as a marker of T-cell activation and differentiation in various disease states, providing valuable diagnostic and prognostic information in conditions such as autoimmune diseases and infectious diseases. In HIV/AIDS, monitoring CD4 T-cell counts is crucial for assessing disease progression and immune function, with lower CD4 counts indicating increased susceptibility to opportunistic infections and poorer prognosis. Additionally, in autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus, alterations in CD4 T-cell subsets and CD4/CD8 ratios serve as biomarkers for disease activity and severity, aiding in diagnosis and treatment decisions. In certain cancers like lymphomas and leukemias, aberrant CD4 expression patterns have also been associated with disease aggressiveness and treatment response, offering prognostic insights and potential therapeutic targets.
NeoBiotechnologies offers a variety of antibodies against CD4 that have been validated for ELISA, flow cytometry, immunofluorescence, immunohistochemistry, and Western blotting, as well as HuProt-validated options. Additionally, we hold exclusive rights to CD4 antibodies available for licensing or collaboration [https://www.neobiotechnologies.com/gene-name/cd4/].
Synonyms
T-cell surface glycoprotein CD4, T-cell surface antigen T4/Leu-3, L3T4; Leu3; Ly-4; Lymphocyte antigen CD4; p55; T cell antigen T4/LEU3; T cell differentiation antigen L3T4; T-cell surface antigen T4/Leu-3; T-cell surface glycoprotein CD4
Research Areas
Cardiovascular, Immunology, AKT Signaling, Cytokine Signaling, Hematopoietic Stem Cells, Infectious Disease