Anti-CD158e/k (KIR3DL1/DL2) Antibody, clone 5.133

Killer cell immunoglobulin-like receptor 3DL1/Killer cell immunoglobulin-like receptor 3DL2 (UniProt: P43629 (KIR3DL1) /P43630 (KIR3DL2) also known as CD158e/CD158k is encoded by the KIR3DL1/KIR3DL2 gene (Gene ID: 3811 (KIR3DL1) / 3812 (KIR3DL2)) in human. CD158e and CD158k are members of the KIR family expressed on natural killer (NK) cells and subsets of T cells. Killer cell immunoglobulin-like receptors (KIRs) are a family of surface glycoproteins expressed primarily on natural killer (NK) cells and subsets of T cells. They interact with human leukocyte antigen (HLA) class I molecules and play a pivotal role in the regulation of immune responses, particularly in distinguishing healthy cells from infected, transformed, or HLA class I-deficient cells. Structurally, KIRs consist of immunoglobulin-like extracellular domains that recognize specific motifs within HLA class I molecules. Functionally, they are categorized into inhibitory and activating receptors. The inhibitory KIRs, which contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs), mediate tolerance by suppressing cytotoxic activity upon engagement with HLA class I molecules. In contrast, activating KIRs, which possess immunoreceptor tyrosine-based activation motifs (ITAMs), promote immune responses, particularly against cells lacking HLA class I expression. CD158e has been implicated in the immune evasion mechanisms of certain diseases, including cancer and chronic viral infections. Elevated expression of CD158e has been observed in NK cells from patients with lung cancer, which correlates with impaired NK cell function due to the sustained expression of HLA class I molecules by tumor cells. Similarly, in chronic hepatitis C (CHC), high levels of CD158e expression on NK cells are associated with altered immune responses and poor treatment outcomes. CD158k acts as a co-inhibitory receptor, modulating immune responses and increasing the resistance of cells to activation-induced cell death (apoptosis). This receptor is important in immune surveillance, particularly in differentiating malignant cells from normal ones. CD158k is of particular clinical relevance in Sézary syndrome (SS), a leukemic form of cutaneous T-cell lymphoma. It is consistently expressed on Sézary cells, making it a reliable diagnostic marker for SS. Anti-CD158e/k (KIR3DL1/DL2), clone 5.133 recognizes both CD158e and CD158k KIRs. (Ref.: Campbell, K.S., et al., (2011), Immunology, 132(3), 315-325)

Recombinant extracellular domain of NKAT4-human IgG1 fusion protein.

Quality Control Testing

Isotype testing: Identity Confirmation by Isotyping Test.

Isotyping Analysis: The identity of this monoclonal antibody is confirmed by isotyping test to be mouse IgG1 .

Flow Cytometry Analysis: 1.0 µg from a representative lot detected CD158e/k (KIR3DL1/DL2) in one million COS cells transiently transfected with human KIR3DL1/DL2.

Immunoprecipitation Analysis: A representative lot detected CD158e/k (KIR3DL1/DL2) in Immunoprecipitation applications (Dohring, C., et al. (1996). J Immunol. 156(9):3098-101).

Inhibition Assay: A representative lot inhibited NK-cell mediated cytotoxicity (Dohring, C., et al. (1996). J Immunol. 156(9):3098-101).

Flow Cytometry Analysis: A representative lot detected CD158e/k (KIR3DL1/DL2) in Flow Cytometry applications (Dohring, C., et al. (1996). J Immunol. 156(9):3098-101).

Note: Actual optimal working dilutions must be determined by end user as specimens, and experimental conditions may vary with the end user.

Clone 5.133 is a mouse monoclonal antibody that detects CD158e/k (KIR3DL1/DL2). It targets an epitope from the extracellular domain.

Purified mouse monoclonal antibody IgG1 in PBS without preservatives.

1.0 mg/mL. Please refer to guidance on suggested starting dilutions and/or titers per application and sample type.

Store at -10°C to -25°C. Handling Recommendations: Upon receipt and prior to removing the cap, centrifuge the vial and gently mix the solution. Aliquot into microcentrifuge tubes and store at -20°C. Avoid repeated freeze/thaw cycles, which may damage IgG and affect product performance.

Concentration: Please refer to the Certificate of Analysis for the lot-specific concentration.

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