CD28 Antibody (61109) [CoraFluor™ 1]

7920) and CoraFluor™ 2, amine reactive (Catalog # 7950) are terbium-based probes that have been developed for use as TR-FRET donors. They emit wavelengths compatible with commonly used fluorescent acceptor dyes such as BODIPY® (or BDY) and Janelia Fluor® dyes, FITC (Catalog # 5440), TMR and Cyanine 5 (Catalog # 5436). CoraFluor™ fluorescence is brighter and more stable in biological media than existing TR-FRET donors, leading to enhanced sensitivity and improved data generation. CoraFluor™ 1 exhibits excitation upon exposure to a 337 nm UV laser." > 7920) and CoraFluor™ 2, amine reactive (Catalog # 7950) are terbium-based probes that have been developed for use as TR-FRET donors. They emit wavelengths compatible with commonly used fluorescent acceptor dyes such as BODIPY® (or BDY) and Janelia Fluor® dyes, FITC (Catalog # 5440), TMR and Cyanine 5 (Catalog # 5436). CoraFluor™ fluorescence is brighter and more stable in biological media than existing TR-FRET donors, leading to enhanced sensitivity and improved data generation. CoraFluor™ 1 exhibits excitation upon exposure to a 337 nm UV laser." title="CoraFluor™ 1, amine reactive (Catalog:7920) and CoraFluor™ 2, amine reactive (Catalog # 7950) are terbium-based probes that have been developed for use as TR-FRET donors. They emit wavelengths compatible with commonly used fluorescent acceptor dyes such as BODIPY® (or BDY) and Janelia Fluor® dyes, FITC (Catalog # 5440), TMR and Cyanine 5 (Catalog # 5436). CoraFluor™ fluorescence is brighter and more stable in biological media than existing TR-FRET donors, leading to enhanced sensitivity and improved data generation. CoraFluor™ 1 exhibits excitation upon exposure to a 337 nm UV laser." />

CoraFluor™ 1, amine reactive (Catalog:<a class=

• Reactivity: Mu
• Applications: WB
• Clone: 61109
• Clonality: Monoclonal
• Host: Rat
• Conjugate: CoraFluor 1

CD28 Antibody (61109) [CoraFluor™ 1] Summary

• Description: This conjugate is made on demand and is not held in inventory. Each order represents a unique lot. All conjugates are generated using validated conjugation protocols and meet strict degree of labeling (F/P) specifications; additional information is available upon request. The antibody concentration is provided on the individual product label.
  
  For specialized conjugation needs, like large quantities, specific concentrations, and defined F/P ratios, bulk and custom antibody conjugation services are available.
• Immunogen: S. frugiperda insect ovarian cell line Sf 21-derived recombinant mouse CD28
  Lys21-Lys149
  Accession # P31041
• Specificity: Detects mouse CD28 in direct ELISAs and Western blots. Does not cross-react with recombinant human CD28, recombinant mouse (rm) CTLA-4, rmICOS, or rmPD-1.
• Isotype: IgG2c
• Clonality: Monoclonal
• Host: Rat
• Gene: CD28
• Purity: Protein A or G purified from hybridoma culture supernatant

Applications/Dilutions

• Dilutions:
  • Western Blot
• Application Notes: Recommended applications are based on validated applications from the unconjugated base product MAB4831. This conjugated antibody is not kept in inventory and is made to order using validated conjugation protocols.

Packaging, Storage & Formulations

• Storage: Store at 4C in the dark. Do not freeze.
• Buffer: PBS
• Preservative: No Preservative
• Purity: Protein A or G purified from hybridoma culture supernatant

Notes

CoraFluor (TM) is a trademark of Bio-Techne Corp. Sold for research purposes only under agreement from Massachusetts General Hospital. US patent 2022/0025254

Alternate Names for CD28 Antibody (61109) [CoraFluor™ 1]

• CD28 antigen (Tp44)
• CD28 antigen
• CD28 molecule
• CD28
• MGC138290
• T-cell-specific surface glycoprotein CD28
• Tp44

Background

CD28 (cluster differentiation 28) is a 44 kDa disulfide linked homodimeric T cell specific surface glycoprotein with a role in providing co-stimulatory signals required for T cell activation and survival (1). The CD28 family of receptors, including PD-1, CTLA-4, and ICOS, share several common features including paired V-set immunoglobulin superfamily (IgSF) domains attached to a single transmembrane domain and cytoplasmic domains containing critical signaling motifs (2). Additionally, CD28 and CTLA-4 are very similar in genomic organization. The corresponding genes co-map on human chromosome 2q33 and mouse chromosome 1 (3). Human CD28 isoform 1 is synthesized as a protein of 220 amino acids (aa) in length with a calculated molecular weight of 25 kDa (3).

CD28 is the prototypical and best-characterized costimulatory molecule on T cells (4). Its signals are critical for optimal naive T cell activation, cytokine production, proliferation, and survival (4). In order to sustain T cell activation, CD28 will consolidate immunological synapse formation, increase cell cycle progression through upregulated D-cyclin expression, and aid in T cell survival by in inducing the expression of the anti-apoptotic protein Bcl-XL (5). CD28 is constitutively expressed on naive and central memory CD4+ and CD8+ cells (5). CD28 deficiency has a large impact on T cell responses including activation, proliferation, immunoglobulin (Ig) class-switching, and germinal center (GC) formation (6). CD28 is a critical regulator of autoimmune diseases and tolerance to solid organ transplants in human patients (6). The CD28 pathway plays a central role in immune responses against pathogens, autoimmune diseases, and graft rejection (7). CD28 engagement via antibodies augments the proliferation of T cells in response to immobilized anti-CD3 antibodies (8). Additionally, antibody engagement of CD28 can supply costimulation to T cells encountering APCs deficient in costimulatory ligands, such as CD80 and CD86, and prevents the resultant anergic state that otherwise occurs in the absence of costimulatory signaling (8).

References

1. Esensten, J. H., Helou, Y. A., Chopra, G., Weiss, A., & Bluestone, J. A. (2016). CD28 Costimulation: From Mechanism to Therapy. Immunity, 44(5), 973-988. https://doi.org/10.1016/j.immuni.2016.04.020

2. Carreno, B. M., & Collins, M. (2002). The B7 family of ligands and its receptors: new pathways for costimulation and inhibition of immune responses. Annual review of immunology, 20, 29-53. https://doi.org/10.1146/annurev.immunol.20.091101.091806

3. Ward S. G. (1996). CD28: a signaling perspective. The Biochemical journal, 318 (Pt 2), 361-377. https://doi.org/10.1042/bj3180361

4. Zhang, R., Huynh, A., Whitcher, G., Chang, J., Maltzman, J. S., & Turka, L. A. (2013). An obligate cell-intrinsic function for CD28 in Tregs. The Journal of clinical investigation, 123(2), 580-593. https://doi.org/10.1172/JCI65013

5. Evans, E. J., Esnouf, R. M., Manso-Sancho, R., Gilbert, R. J., James, J. R., Yu, C., Fennelly, J. A., Vowles, C., Hanke, T., Walse, B., Hunig, T., Sorensen, P., Stuart, D. I., & Davis, S. J. (2005). Crystal structure of a soluble CD28-Fab complex. Nature immunology, 6(3), 271-279. https://doi.org/10.1038/ni1170

6. Bour-Jordan, H., & Blueston, J. A. (2002). CD28 function: a balance of costimulatory and regulatory signals. Journal of clinical immunology, 22(1), 1-7. https://doi.org/10.1023/a:1014256417651

7. Krummel, M. F., & Allison, J. P. (1995). CD28 and CTLA-4 have opposing effects on the response of T cells to stimulation. The Journal of experimental medicine, 182(2), 459-465. https://doi.org/10.1084/jem.182.2.459

8. Luhder, F., Huang, Y., Dennehy, K. M., Guntermann, C., Muller, I., Winkler, E., Kerkau, T., Ikemizu, S., Davis, S. J., Hanke, T., & Hunig, T. (2003). Topological requirements and signaling properties of T cell-activating, anti-CD28 antibody superagonists. The Journal of experimental medicine, 197(8), 955-966. https://doi.org/10.1084/jem.20021024

Limitations

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.

Bioinformatics

• Gene Symbol: CD28