STARTER's Featured Product Recommendation: Immune Checkpoint Target CTLA-4
CTLA-4, also known as CD152, is a transmembrane protein encoded by the CTLA-4 gene. It is expressed on activated CD4+ and CD8+ T cells and shares high homology with the co-stimulatory molecule receptor CD28 on the T cell surface.
Both CTLA-4 and CD28 belong to the immunoglobulin superfamily and bind to the same ligands, CD86 (B7-2) and CD80 (B7-1). The key immunoregulatory function of CTLA-4 lies in its control of CD4+FoxP3-, CD8+ T cells, and regulatory T cells (Tregs). CTLA-4 can terminate the response of activated T cells and mediate the suppressive function of Tregs. Current research indicates that CTLA-4 inhibits T cell responses primarily through two mechanisms:
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Competitive Binding and Phosphatase Recruitment: CTLA-4 competitively binds to B7 or recruits phosphatases to its intracellular domain, thereby attenuating signals from the T cell receptor (TCR) and CD28.
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Downregulation of CD80/CD86 Expression: CTLA-4 reduces the expression levels of CD80 and CD86 on antigen-presenting cells (APCs) or removes them from APCs through transendocytosis, thereby limiting CD28-mediated T cell activation. Additionally, CTLA-4 mediates dendritic cell binding to CD80/CD86 and induces the expression of the tryptophan-degrading enzyme IDO, leading to TCR inhibition. CTLA-4 antibodies bind to CTLA-4 to reduce Treg activity and activate TCR signaling.
The only CTLA-4 antibody currently approved for clinical use is Ipilimumab (trade name Yervoy), developed by Bristol-Myers Squibb (BMS). It received FDA approval in 2011 for the treatment of melanoma. Tremelimumab, initially developed by Pfizer and now under investigation by MedImmune, has not been approved for any cancer treatment due to suboptimal clinical performance.
Product Recommendation
Data Presentation
WB result of Invivo CTLA-4 (CD152) Mouse mAb
Primary antibody: Invivo CTLA-4 (CD152) Mouse mAb at 1/1000 dilution
Lane 1: reduced purified mouse CTLA-4 with histidine tag at C-terminus 1 µg
Lane 2: reduced purified mouse CTLA-4 with histidine tag at C-terminus 0.5 µg
Secondary antibody: Goat Anti-Mouse IgG, (H+L), HRP conjugated at 1/10000 dilution
Predicted MW: 25~30 kDa
Observed MW: 20~30 kDa
