NKG2A/CD159a/KLRC1 Overexpression Lysate

HEK293T cells in 10-cm dishes were transiently transfected with a non-lipid polymer transfection reagent specially designed and manufactured for large volume DNA transfection. Transfected cells were cultured for 48hrs before collection. The cells were lysed in modified RIPA buffer (25mM Tris-HCl pH7.6, 150mM NaCl, 1% NP-40, 1mM EDTA, 1xProteinase inhibitor cocktail mix, 1mM PMSF and 1mM Na3VO4, and then centrifuged to clarify the lysate. Protein concentration was measured by BCA protein assay kit.

NK group 2 member A (NKG2A), also known as killer lectin like receptor c1 (KLRC1) and CD159a, is a ~38 kDa type II transmembrane protein belonging to the C-type lectin superfamily and plays a role in suppression of cytotoxic CD8+ T cell activity and functions as an immune checkpoint (1,2). NKG2A belongs to a group of natural killer (NK) cell inhibitor receptors (IRs) which includes killer immunoglobulin receptors (KIRs), lymphocyte activation gene-3 (LAG-3), T cell immunoreceptor with Ig and ITIM domains (TIGIT), programmed death ligand-1 (PD-1), and T cell immunoglobulin mucin-3 (TIM-3) (1,3). NKG2A is synthesized as a protein of 233 amino acids (aa) with a theoretical molecular weight of 26.3 kDa and is expressed on CD56hi NK cells, NKT cells, and some CD8+ alphabeta T cells (2,4). Together with CD94, NKG2A forms a heterodimer and acts as a receptor for the MHC Class I molecular human leukocyte antigen (HLA)-E (1-3). The NKG2A/CD94 receptor interaction with the HLA-E ligand results in phosphorylation of NKG2A's immunoreceptor tyrosine-based inhibition motifs (ITIMs), causing suppression of activating signals from immunoreceptor tyrosine-based activation motif (ITAM)- containing T cell receptors (TCR) or other activating receptors like NKG2D, via the intracellular phosphatase SHP1 (2,3,5). Overall, cancer cells utilize the NKG2A-HLA-E interaction and signaling to evade immune surveillance by NK cells and T cells (1-3,5-6).

Similar to cytotoxic T lymphocyte associated protein 4 (CTLA-4) and PD-1, NKG2A has become a prominent target for immune checkpoint blockade and cancer immunotherapy (1-3,5-6). Monalizumab is a novel IgG4 monoclonal antibody developed for blocking NKG2A's interaction with HLA-E and has shown promising results in clinical trials (1-3,5-6). In addition to being used as a single agent, it is being studied as a possible combination therapy with other blocking antibodies such as anti-PD-L1 and anti-epidermal growth factor receptor (EGFR) (2,5,6).

References

1. Alfarra, H., Weir, J., Grieve, S., & Reiman, T. (2020). Targeting NK Cell Inhibitory Receptors for Precision Multiple Myeloma Immunotherapy. Frontiers in immunology, 11, 575609. https://doi.org/10.3389/fimmu.2020.575609

2. Creelan, B. C., & Antonia, S. J. (2019). The NKG2A immune checkpoint - a new direction in cancer immunotherapy. Nature reviews. Clinical oncology, 16(5), 277-278. https://doi.org/10.1038/s41571-019-0182-8

3. Zaghi, E., Calvi, M., Marcenaro, E., Mavilio, D., & Di Vito, C. (2019). Targeting NKG2A to elucidate natural killer cell ontogenesis and to develop novel immune-therapeutic strategies in cancer therapy. Journal of leukocyte biology, 105(6), 1243-1251. https://doi.org/10.1002/JLB.MR0718-300R

4. Uniprot (P26715)

5. Borst, L., van der Burg, S. H., & van Hall, T. (2020). The NKG2A-HLA-E Axis as a Novel Checkpoint in the Tumor Microenvironment. Clinical cancer research : an official journal of the American Association for Cancer Research, 26(21), 5549-5556. https://doi.org/10.1158/1078-0432.CCR-19-2095

6. Andre, P., Denis, C., Soulas, C., Bourbon-Caillet, C., Lopez, J., Arnoux, T., Blery, M., Bonnafous, C., Gauthier, L., Morel, A., Rossi, B., Remark, R., Breso, V., Bonnet, E., Habif, G., Guia, S., Lalanne, A. I., Hoffmann, C., Lantz, O., Fayette, J., ... Vivier, E. (2018). Anti-NKG2A mAb Is a Checkpoint Inhibitor that Promotes Anti-tumor Immunity by Unleashing Both T and NK Cells. Cell, 175(7), 1731-1743.e13. https://doi.org/10.1016/j.cell.2018.10.014

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Lysates are guaranteed for 6 months from date of receipt.

Array NBL1-12361

• NKG2A/CD159a/KLRC1 Antibodies
• NKG2A/CD159a/KLRC1 Lysates
• NKG2A/CD159a/KLRC1 Protein
• NKG2A/CD159a/KLRC1 Proteins and Enzymes