CD8 Antibody (C8/468 + C8/144B)

Immunohistochemistry-Paraffin: CD8 Antibody (C8/468 + C8/144B) [NBP2-34318] - Formalin-fixed paraffin-embedded human tonsil stained with CD8 Monoclonal Antibody (C8/468+C8/144)

Immunohistochemistry-Paraffin: CD8 Antibody (C8/468 + C8/144B) [NBP2-34318] - Formalin-fixed paraffin-embedded human tonsil stained with CD8 Monoclonal Antibody (C8/468+C8/144)

• Reactivity: Hu
• Applications: IHC
• Clone: C8/468 + C8/144B
• Clonality: Monoclonal
• Host: Mouse
• Conjugate: Unconjugated
• Concentration: 0.2 mg/ml

CD8 Antibody (C8/468 + C8/144B) Summary

• Description: 200ug/ml of antibody purified from Bioreactor Concentrate by Protein A or G. Prepared in 10 mM PBS with 0.05% BSA & 0.05% azide. Also available WITHOUT BSA & azide at 1.0 mg/ml. (NBP2-34590)
  
  Antibody with azide - store at 2 to 8C. Antibody without azide - store at -20 to -80C.
• Immunogen: Human CD8 recombinant protein (C8/468); A 13 amino acid synthetic peptide from the C-terminal cytoplasmic domain of alpha chain of human CD8 molecule (C8/144B) (Uniprot: P01732)
• Localization: Cell surface
• Marker: Cytotoxic- & Suppressor T-Cell Marker
• Isotype: IgG1 Kappa/IgG1 Kappa
• Clonality: Monoclonal
• Host: Mouse
• Gene: CD8A
• Purity: Protein A or G purified

Applications/Dilutions

• Dilutions:
  • Immunohistochemistry
  • Immunohistochemistry-Paraffin 1-2 ug/ml
• Application Notes: Immunohistochemistry (Formalin-fixed): 1-2ug/ml for 30 minutes at RT. Staining of formalin-fixed tissues requires heating tissue sections in 10mM Tris with 1mM EDTA, pH 9.0, for 45 min at 95C followed by cooling at RT for 20 minutes.
  Optimal dilution for a specific application should be determined.
• Theoretical MW: 32 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.

Packaging, Storage & Formulations

• Storage: Store at 4C.
• Buffer: 10 mM PBS with 0.05% BSA
• Preservative: 0.05% Sodium Azide
• Concentration: 0.2 mg/ml
• Purity: Protein A or G purified

Alternate Names for CD8 Antibody (C8/468 + C8/144B)

• CD_antigen: CD8a
• CD8 antigen, alpha polypeptide (p32)
• CD8
• 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
• T-lymphocyte differentiation antigen T8/Leu-2

Background

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

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.

Publications for CD8 Antibody (NBP2-34318)(1)

Publication using NBP2-34318

• Ma J, Guillot A, Yang Z et al. Distinct histopathological phenotypes of severe alcoholic hepatitis suggest different mechanisms driving liver injury and failure The Journal of clinical investigation 2022-07-15 [PMID: 35838051] (IHC-P, Human)

FAQs for CD8 Antibody (NBP2-34318). (Showing 1 - 1 of 1 FAQ).

1. Is NBP2-34318 a mixture of two monoclonal Abs? Why do this? To double the signal?  ..show answer..
   • The product is a mixture of two individual antibodies: NBP2-32952 (CD8 alpha Antibody-C8/468) + NBP2-32836 (CD8 alpha Antibody-C8/144B). Among many reasons, "doubling the signals" is one. Our databases show that NBP2-32952 was raised against the purified human CD8 alpha recombinant protein, whereas NBP2-32836 was a 13 amino acid peptide from C-terminal cytoplasmic domain of alpha chain of human CD8 molecule (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC495002/pdf/jclinpath00426-0044.pdf). Since we don't map any epitope (10 - 15 a.a.) of our antibodies, we don't know where NBP2-32952 exactly binds to; but we anticipate that the epitope should be away from that of NBP2-32836. Hence by mixing two clones together would increase the possibility of detecting CD8 in vivo. 

Bioinformatics

• Gene Symbol: CD8A
• Uniprot:
  • P01732(Human)