The interference of circulating factors of the immune system was evaluated by spiking these proteins at physiologically relevant concentrations into a human CTLA-4 positive serum. There was no crossreactivity detected.
Standard Curve Range
0.16 - 10.0 ng/mL
CV% < 10.40%
CV% < 4.80%
ELISA Kit (Colorimetric)
Read 1 Review rated 5 using NBP1-91268 in the following application:
ligand and transmembrane spliced cytotoxic T lymphocyte associated antigen 4
Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4), also known as CD152, is a cell surface glycoprotein belonging to the immunoglobulin family with a role in regulation of T cell activation (1). Human CTLA-4 is a 223 amino acid (aa) protein with a theoretical molecular weight of 24.6 kDa containing a leader peptide, a IgV-like domain, a transmembrane domain, and a cytoplasmic tail (1,2). CTLA-4 is both structurally and functionally related with another member of the immunoglobulin-related receptor family, CD28 (1-3). CTLA-4 and CD28 receptors are both expressed by CD4+ and CD8+ T cells and share two common ligands, CD80 (B7.1) and CD86 (B7.2), expressed on the surface of antigen presenting cells (APCs) (2,3). While CD28 is present on the plasma membrane of T cells, CTLA-4 is predominantly expressed intracellularly on vesicles in FoxP3+ regulatory T (Treg) cells and activated T cells due to endocytosis (3). While they share ligands, the two receptors have opposing functions in T cell activation; CD28 is involved in activation of T cells, while CTLA-4 functions as a negative regulator of T cell response (2,3). One of the primary functions of CTLA-4 is preventing autoimmunity (1-4).
Similar to programmed cell death protein 1 (PD-1), CTLA-4 is an inhibitory immune checkpoint protein (3,5). Checkpoint blockade immunotherapy using drugs or antibodies to target CTLA-4 is one of the main approaches for cancer treatment (5). A number of drugs targeting CTLA-4, or a combination of CTLA-4/PD-1, have been approved for treatment of various cancers like melanoma, renal cell carcinoma, and colorectal cancer (5). While blocking CTLA-4 in the tumor microenvironment is a promising cancer therapeutic, the absence of CTLA-4 under normal conditions can have deleterious effects. Studies have found that patients with CTLA-4 deficiency or mutations have clinical features associated with autoimmunity and immune dysregulation (4). Treatment options for CTLA-4 deficiency includes immunoglobulin-replacement therapy, corticosteroids, CTLA-4-immunoglobulin (Ig) fusion protein, and, in life-threatening cases, hematopoietic stem cell transplantation (4,6). Additionally, engaging CD80/CD86 with CTLA-4-Ig is a common immunosuppressive treatment for rheumatoid arthritis and kidney transplant recipients (6).
1. Romo-Tena, J., Gomez-Martin, D., & Alcocer-Varela, J. (2013). CTLA-4 and autoimmunity: new insights into the dual regulator of tolerance. Autoimmunity reviews, 12(12), 1171-1176. https://doi.org/10.1016/j.autrev.2013.07.002
2. Hosseini, A., Gharibi, T., Marofi, F., Babaloo, Z., & Baradaran, B. (2020). CTLA-4: From mechanism to autoimmune therapy. International immunopharmacology, 80, 106221. https://doi.org/10.1016/j.intimp.2020.106221
3. Rowshanravan, B., Halliday, N., & Sansom, D. M. (2018). CTLA-4: a moving target in immunotherapy. Blood, 131(1), 58-67. https://doi.org/10.1182/blood-2017-06-741033
4. Verma, N., Burns, S. O., Walker, L., & Sansom, D. M. (2017). Immune deficiency and autoimmunity in patients with CTLA-4 (CD152) mutations. Clinical and experimental immunology, 190(1), 1-7. https://doi.org/10.1111/cei.12997
5. Rotte A. (2019). Combination of CTLA-4 and PD-1 blockers for treatment of cancer. Journal of experimental & clinical cancer research : CR, 38(1), 255. https://doi.org/10.1186/s13046-019-1259-z
6. Bluestone, J. A., St Clair, E. W., & Turka, L. A. (2006). CTLA4Ig: bridging the basic immunology with clinical application. Immunity, 24(3), 233-238. https://doi.org/10.1016/j.immuni.2006.03.001
This product is for research use only and is not approved for use in humans or in clinical diagnosis. ELISA Kits are guaranteed for 6 months from date of receipt.
The exact protocol provided by Novus for this antibody kit was followed. No blocking details.
We did not have to dilute our samples for ELISA. We only normalized the total protein to 20 ug.
The plate was read at 450 nm using the Biotek Synergy 4 plate reader.
ELISA Plate Details
The kit contained a plate pre-coated with sCTLA-4 antibody
400 uL of the provided wash buffer was used to wash wells. We would let it sit for 10 s before aspiration. Washed 4-5X.
Make sure to read the protocol at least once all the way through before starting the ELISA. It only takes about 4-5 hours total time. Also, our standard curve did not correlate well with the standard curve provided in the protocol book (Yes, a 40 page book that is very detailed), so don't be surprised if you standard curve is off too. Our standard curve provided an r squared value > 0.98, so everything turned out great. Really liked the kit and will use it again in the future.
Product General Protocols
Find general support by application which include: protocols, troubleshooting, illustrated assays, videos and webinars.
FAQs for CTLA-4 ELISA Kit (NBP1-91268). (Showing 1 - 1 of 1 FAQs).
Does this kit work with CTLA4Ig fusion protein? CTLA4Ig contains the extracellular domain of human CTLA4 and human IgG1 Fc. Do you know if any customers use this kit to check CTLA4Ig? sCTLA4 and CTLA4Ig have the same extracellular domain. If the two antibodies used in the ELISA kit are against the extracellular domain, it could be used to detect CTLA4Ig. Could you please tell me the epitopes of the two antibodies?
The standard protein in our human CTLA-4 is a soluble fusion protein consisting of the extracellular domain of human CTLA-4, fused to mouse IgG2a Fc. This means that our kit will detect your CTLA4Ig.
CD86 - I work in tandem with CD80 CD86 belongs to the immunoglobulin superfamily of proteins that drive innate and adaptive immune responses. It is an 80kD co-stimulatory molecule for the priming and activation of naive and memory T-cells, respectively. CD86 is expressed on activated ... Read full blog post.