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CD8 Recombinant Protein Antigen

Novus Biologicals, part of Bio-Techne | Catalog # NBP2-36743PEP

Novus Biologicals, part of Bio-Techne
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NBP2-36743PEP

Key Product Details

Source

E. coli

Conjugate

Unconjugated

Applications

Antibody Competition

Product Specifications

Description

A recombinant protein antigen with a N-terminal His6-ABP tag corresponding to human CD8A.

Source: E. coli

Amino Acid Sequence: AASPTFLLYLSQNKPKAAEGLDTQRFSGKRLGDTFVLTLSDFRRENEGYYFCSALSNSIMYFSHFVPVFLPAKPTTTPAPRPPT

Fusion Tag: N-terminal His6ABP (ABP = Albumin Binding Protein derived from Streptococcal Protein G)

This product is intended to be used as a blocking antigen for antibody competition assays. Any other use of this antigen is done at the risk of the user. The use of this product for commercial production is strictly prohibited. Please contact technical support if you have any questions.

Purity

>80% by SDS-PAGE and Coomassie blue staining

Predicted Molecular Mass

27 kDa.
Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.

Applications

Antibody Competition (10-100 molar excess)

Application Notes

This recombinant antigen is only intended to be used as a blocking agent to confirm antibody specificity with the corresponding antibody, catalog number NBP2-36743.

It is purified by IMAC chromatography, and the expected concentration is greater than 0.5 mg/ml.

For current lot information, including availability, please contact our technical support team click nb-technical@bio-techne.com

Protein / Peptide Type

Recombinant Protein Antigen

Formulation, Preparation and Storage

NBP2-36743PEP
Formulation PBS and 1M Urea, pH 7.4.
Preservative No Preservative
Concentration Please see the vial label for concentration. If unlisted please contact technical services.
Shipping The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage Store at -20C. Avoid freeze-thaw cycles.

Background: CD8

CD8, also known as Leu-2 or T8 in human and Lyt2 or Lyt3 in mouse, is a cell surface glycoprotein belonging to the immunoglobulin supergene family (1, 2). CD8 is expressed on cytotoxic T-lymphocytes (T-cells), most thymocytes, between 35-45% of peripheral blood lymphocytes, and a population of natural killer (NK) cells (1, 2). The CD8 molecule consists of disulfide-linked alpha (alpha) and beta (beta) chains that present on T-cells as either CD8alphaalpha homodimers or CD8alphabeta heterodimers (1, 3). Both alpha and beta chains consist of a signaling sequence, an extracellular Ig-like domain, a membrane proximal stalk region, a transmembrane domain, and a cytoplasmic tail (3). Human CD8alpha is processed as 235 amino acids (aa) in length with a theoretical molecular weight of ~26 kDa, while mouse CD8alpha is 247 aa and has a theoretical molecular weight of 27.5 kDa (4, 5). Functionally, CD8 acts as an antigen coreceptor on cytotoxic T-cells and interacts with the major histocompatibility complex (MHC) class I molecules on antigen presenting cells (APCs), mediating cell-cell interactions within the immune system. Conversely, CD4 molecules interact with antigens presented on MHC class II molecules and are activated to become helper T-cells (TH) (1,2). Interestingly, thymocytes can transiently express both CD4 and CD8 during the maturation process (2). Furthermore, the cytoplasmic tail of CD8 has a Lck (lymphocyte-specific protein tyrosine kinase) binding domain where Lck interacts with CD8, initiating a phosphorylation cascade that activates transcription factors and promotes T-cell activation (6). More specifically, CD8alphabeta functions as a T-cell co-receptor, while CD8alphaalpha promotes T-cell survival and differentiation (7).

Given its role in the immune system, CD8-deficiency in T-cells is a hallmark of many diseases and pathologies (8-10). Specifically, CD8+ T-cell deficiency is prevalent in chronic autoimmune diseases including multiple sclerosis, rheumatoid arthritis, ulcerative colitis, Crohn's disease, type 1 diabetes mellitus, and Graves' disease (8). Furthermore, cancers or chronic infection can lead to CD8 T-cell exhaustion as the continual antigen presentation and inflammatory signals eventually cause the CD8+ T-cells to lose functionality (9, 10). However, animal models and clinical studies have suggested that T-cells are capable of being reinvigorated using inhibitory receptor blockade resulting in better disease outcomes and these exhausted T-cells may be a potential therapeutic target (9, 10).

Alternative names for CD8 includes CD antigen: CD8a, CD8 antigen, alpha polypeptide (p32), CD8a molecule, CD8A, Leu2 T-lymphocyte antigen, LEU2, MAL, OKT8 T-cell antigen, p32, T cell co-receptor, T8 T-cell antigen, T-cell antigen Leu2, T-cell surface glycoprotein CD8 alpha chain, and T-lymphocyte differentiation antigen T8/Leu-2.

References

1. Littman D. R. (1987). The structure of the CD4 and CD8 genes. Annual review of immunology. https://doi.org/10.1146/annurev.iy.05.040187.003021

2. Naeim F. (2008). Chapter 2- Principles of Immunophenotyping. Hematopathology. https://doi.org/10.1016/B978-0-12-370607-2.00002-8.

3. Gao, G. F., & Jakobsen, B. K. (2000). Molecular interactions of coreceptor CD8 and MHC class I: the molecular basis for functional coordination with the T-cell receptor. Immunology today. https://doi.org/10.1016/s0167-5699(00)01750-3

4. UniProt (P01732)

5. UniProt (P01731)

6. Kappes D. J. (2007). CD4 and CD8: hogging all the Lck. Immunity. https://doi.org/10.1016/j.immuni.2007.11.002

7. Gangadharan, D., & Cheroutre, H. (2004). The CD8 isoform CD8alphaalpha is not a functional homologue of the TCR co-receptor CD8alphabeta. Current opinion in immunology. https://doi.org/10.1016/j.coi.2004.03.015

8. Pender M. P. (2012). CD8+ T-Cell Deficiency, Epstein-Barr Virus Infection, Vitamin D Deficiency, and Steps to Autoimmunity: A Unifying Hypothesis. Autoimmune diseases. https://doi.org/10.1155/2012/189096

9. Kurachi M. (2019). CD8+ T cell exhaustion. Seminars in immunopathology. https://doi.org/10.1007/s00281-019-00744-5

10. Hashimoto, M., Kamphorst, A. O., Im, S. J., Kissick, H. T., Pillai, R. N., Ramalingam, S. S., Araki, K., & Ahmed, R. (2018). CD8 T Cell Exhaustion in Chronic Infection and Cancer: Opportunities for Interventions. Annual review of medicine. https://doi.org/10.1146/annurev-med-012017-043208

Alternate Names

CD8, CD8A

Gene Symbol

CD8A

Additional CD8 Products

Product Documents for CD8 Recombinant Protein Antigen

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Product Specific Notices for CD8 Recombinant Protein Antigen

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

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