The HLA-DRA Knockout NCI-H1975 Polyclonal Cells product consists of a heterogeneous stock of CRISPR/Cas9-edited human lung adenocarcinoma NCI-H1975 cells with targeted disruption of the HLA-DRA gene. This polyclonal knockout cell population retains the genomic background of the parental line while ensuring representation of multiple editing events, making it an appropriate choice for pooled functional studies that do not require clonal uniformity.
NCI-H1975 is a human non-small cell lung cancer (NSCLC) line derived from a female patient with adenocarcinoma. It carries activating EGFR L858R and T790M mutations, the latter conferring resistance to first-generation EGFR tyrosine kinase inhibitors. This clinically relevant model is widely employed for investigating EGFR-driven oncogenesis, drug resistance, and the development of novel immunotherapeutics in lung cancer.
The HLA-DRA gene encodes the alpha subunit of the MHC class II molecule HLA-DR, which presents extracellular antigen-derived peptides to CD4+ T cells. MHC class II assembly involves the invariant chain CD74 and beta chain (HLA-DRB), and its expression is regulated by the master transcriptional coactivator CIITA and the RFX complex (RFX5, RFXANK, RFXAP), downstream of interferon-gamma signaling. Upon peptide-MHC-II engagement, the TCR, CD4 coreceptor, CD3 chains, and kinases ZAP70 and LAT activate NF-??B and NFAT, driving T cell proliferation and effector cytokine production (e.g., IL-2, IFNG).
Disruption of HLA-DRA in NCI-H1975 cells abolishes surface MHC class II, impairing their ability to directly present exogenous antigens to CD4+ T lymphocytes. This knockout model provides a controlled system to interrogate the contribution of tumor-cell-intrinsic antigen presentation to immune recognition and evasion, especially in the pro-inflammatory milieu where NSCLC cells may upregulate MHC class II. Combined with the EGFR-mutant background, the model offers insights into the interplay between oncogenic signaling and adaptive immunity.
Typical research applications include flow cytometric verification of MHC-II loss, antigen presentation assays using T cell hybridomas, co-culture with CD4+ T cells to measure cytokine release (IL-2, IFNG), T cell proliferation, and phospho-signaling analysis of the TCR pathway. The polyclonal cells also support transcriptomic profiling (RNA-seq), drug sensitivity testing with immune checkpoint inhibitors, and functional investigations of CIITA-dependent transcriptional networks. For further details, please contact Ascent Research.
