HLA-E Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human lung adenocarcinoma cell line NCI-H1975. This product contains a heterogeneous pool of cells with targeted disruption of the HLA-E gene, achieved via CRISPR/Cas9-mediated genome editing, resulting in abrogation of HLA-E protein expression. The polyclonal format avoids clonal artifacts and better mimics the genetic diversity of a tumor population. It serves as a loss-of-function model for studying HLA-E-mediated immune modulation.
The NCI-H1975 parental line is an EGFR-mutant (L858R/T790M) non-small cell lung cancer (NSCLC) epithelial model. These cells harbor activating mutations that drive oncogenic signaling and resistance to first-generation tyrosine kinase inhibitors. Widely employed in cancer biology, NCI-H1975 recapitulates key features of lung adenocarcinoma, including immune evasion. Introducing an HLA-E knockout into this background enables dissection of immune checkpoint function in a clinically relevant, mutation-defined NSCLC context.
HLA-E is a non-classical MHC class I molecule that forms complexes with beta-2 microglobulin (B2M) and presents peptides, often derived from classical HLA class I leader sequences, to the CD94/NKG2A inhibitory receptor on natural killer (NK) cells and CD8+ T cells. This interaction suppresses NK cell cytotoxicity and cytokine production, facilitating immune escape. HLA-E expression is transcriptionally regulated by IFN-?? and TNF-?? via STAT1 and NF-??B. Downstream, loss of HLA-E disrupts the NKG2A-mediated inhibitory signal, thereby enhancing NK cell activation; additionally, it may affect peptide presentation to CD8+ T cells. Key interacting partners include CD94, NKG2A, NKG2C, and B2M.
In EGFR-mutant NSCLC, upregulation of HLA-E contributes to immune evasion within the tumor microenvironment. Knockout of HLA-E in NCI-H1975 abrogates the inhibitory NKG2A axis, potentially sensitizing these cancer cells to NK cell-mediated lysis. This model thus enables investigation of how a single immune checkpoint alteration modifies tumor immunogenicity in the context of oncogenic EGFR signaling. It provides a defined system for studying the interplay between targeted therapy resistance mechanisms and innate immune surveillance, and for evaluating combination strategies that target both driver mutations and immune checkpoints.
Research applications include NK cell cytotoxicity assays using flow cytometry or LDH release, co-culture experiments with primary NK cells, and cytokine profiling (e.g., IFN-??, granzyme B) to quantify enhanced antitumor responses. The knockout cells are also suitable for western blot, RT-qPCR, and immunofluorescence to confirm loss of HLA-E and downstream signaling effects. They can be used in drug screening for immunomodulatory compounds, tumor microenvironment modeling, and mechanistic studies of the NKG2A/HLA-E checkpoint. Typical assays include flow cytometry for receptor expression, co-culture survival assays, and cytokine release measurements. For further information, please contact Ascent Research.
