The HLA-DRA Knockout CAL-27 Polyclonal Cells product is a CRISPR/Cas9-mediated gene disruption pool derived from the CAL-27 human oral squamous cell carcinoma line. This polyclonal knockout cell population provides a loss-of-function model for investigating the role of the HLA-DRA gene in antigen presentation and adaptive immunity. The use of a polyclonal pool minimizes clonal selection artifacts and reflects the heterogeneous nature of gene editing outcomes, offering a more representative in vitro system for functional studies.
The CAL-27 cell line is a widely established model of oral squamous cell carcinoma isolated from a human tongue lesion. CAL-27 cells exhibit epithelial morphology and are commonly employed in cancer biology research to study tumor progression, metastasis, and therapeutic resistance. This host cell line provides a relevant tumor microenvironment context for exploring immune evasion mechanisms, as HLA-DR expression can influence anti-tumor immune responses.
HLA-DRA encodes the alpha chain of the HLA-DR heterodimer, a key component of the MHC class II complex. The alpha chain pairs with the beta chain (HLA-DRB) to form an antigen-presenting structure that binds processed peptides and presents them to CD4+ T cells through the TCR. HLA-DRA expression is tightly regulated by the class II transactivator CIITA and cytokines such as IFNG and IL4, along with RFX family transcription factors and NF-Y. Upon peptide presentation, the HLA-DR complex engages CD4 and the TCR, recruiting Lck and activating downstream signaling that culminates in T-cell activation and cytokine production. The invariant chain CD74 chaperones HLA-DR assembly and peptide loading. Consequently, knockout of HLA-DRA disrupts the MHC-II antigen presentation pathway, impairing CD4+ T-cell priming.
In oral squamous cell carcinoma, loss of HLA-DR expression is a documented immune escape mechanism, allowing tumor cells to evade CD4+ T-cell recognition. This HLA-DRA knockout CAL-27 model provides a versatile platform for dissecting how tumor cells modulate MHC class II-mediated immune surveillance. Researchers can use this system to investigate the interplay between cancer cell-intrinsic MHC-II deficiency and the tumor microenvironment and to explore strategies for restoring immune recognition in head and neck cancers. The model is also relevant for studying autoimmune and inflammatory conditions where aberrant MHC-II expression contributes to pathology.
This knockout cell pool supports diverse applications, including antigen presentation studies, cancer immunotherapy research, and autoimmune disease modeling. Representative assays include flow cytometry for confirming ablation of HLA-DR surface expression, western blotting, RT-qPCR, co-immunoprecipitation to probe residual complex formation, and functional T-cell activation or cytokine secretion analyses. The product enables rigorous investigation of tumor immune evasion and the development of immunomodulatory therapies. For further information, please contact Ascent Research.
