The B2M Knockout NCI-H1703 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population generated from the NCI-H1703 human lung squamous cell carcinoma line. This model introduces targeted disruption of the B2M gene, which encodes beta-2-microglobulin, a critical subunit of major histocompatibility complex class I (MHC-I) molecules. The polyclonal format preserves a heterogeneous mutation pool within the edited population, enabling researchers to study loss-of-function effects without single-cell clonal selection. The product is supplied as a ready-to-use proliferative cell population for downstream immunological and oncological applications.
The parental NCI-H1703 cell line was established from a 54-year-old male patient with stage 4 metastatic lung squamous cell carcinoma. This line harbors well-characterized mutations in TP53 and CDKN2A, rendering it a clinically relevant model for studying advanced lung cancer biology. As a squamous cell carcinoma line, NCI-H1703 recapitulates key features of non-small cell lung cancer, including altered growth factor signaling and immune microenvironment interactions. The presence of these tumor suppressor mutations makes it particularly valuable for investigating how immune evasion mechanisms cooperate with intrinsic oncogenic pathways.
B2M encodes beta-2-microglobulin, an essential MHC-I subunit. MHC-I assembly requires endoplasmic reticulum chaperones such as calnexin, calreticulin, and tapasin, and peptide transporters TAP1/TAP2. B2M expression is transcriptionally activated by interferon-gamma (IFNG) via STAT1-IRF1 and by NF-kappaB. Surface MHC-I triggers CD8+ T cell activation, while MHC-I loss enhances NK cell cytotoxicity through missing-self recognition. In NCI-H1703, B2M knockout eliminates MHC-I surface expression, impairing CD8+ T cell responses and potentially increasing NK cell susceptibility.
In the NCI-H1703 background, B2M disruption provides a powerful tool to dissect tumor-immune interactions in lung squamous cell carcinoma. The loss of beta-2-microglobulin recapitulates a clinically observed immune evasion strategy, as tumors often downregulate MHC-I to escape T cell recognition. Combined with the host line’s TP53 and CDKN2A mutations, this model allows investigation of how genomic instability and defective antigen presentation synergize to promote immune escape and metastasis. Moreover, the polyclonal knockout population enables the study of heterogeneous editing outcomes, mimicking the subclonal MHC-I loss often seen in patient tumors.
Typical research applications include flow cytometric assessment of MHC-I surface downregulation, western blot confirmation of B2M protein loss, and functional assays such as CD8+ T cell-mediated cytotoxicity and NK cell-mediated killing assays. This model is also suitable for RNA sequencing to profile immune-related gene expression changes, checkpoint inhibitor response studies, and high-content screening for modulators of antigen presentation. Researchers investigating bare lymphocyte syndrome mechanisms or autoimmune-related pathways may also employ this line. For additional details and customization options, please contact Ascent Research.
