The HLA-DRA Knockout Ca Ski Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the human Ca Ski epithelial cell line. This model features targeted disruption of the HLA-DRA gene, which encodes the alpha chain of the HLA-DR MHC class II heterodimer. Loss of HLA-DRA expression eliminates functional HLA-DR surface presentation, providing a robust tool for studying MHC class II-dependent immune mechanisms. The polyclonal format preserves genetic variability while ablating the target gene, enabling unbiased functional analyses.
The Ca Ski host cell line was established from a cervical epidermoid carcinoma metastasis and contains integrated HPV-16 genomes. As HPV-16-positive epithelial cells, they express viral oncoproteins E6 and E7, leading to p53 inactivation and pRb degradation, and are widely used as a model for HPV-driven cervical carcinogenesis. This background combines viral immune evasion traits with transformed epithelial characteristics, making the knockout line particularly relevant for examining antigen presentation in the context of oncogenic HPV infection.
HLA-DRA transcription is regulated by the CIITA/RFX5 enhanceosome complex and is potently induced by IFN-?? via STAT1 and IRF1. The encoded protein pairs with HLA-DRB to form the peptide-binding groove, assisted by CD74 and HLA-DM during maturation. Peptide-loaded HLA-DR engages the T cell receptor on CD4+ T cells, triggering ZAP70 phosphorylation and activation of NF-??B and NFAT, which drive expression of cytokines including IL-2, IFN-??, and IL-4. Disruption of HLA-DRA abolishes this signaling cascade, severing the link to adaptive immunity.
In Ca Ski cells, HLA-DRA knockout recapitulates a common immune evasion strategy employed by HPV-associated tumors. The absence of HLA-DR prevents presentation of viral or tumor peptides to CD4+ T lymphocytes, crippling the adaptive immune response and allowing the carcinoma cells to evade immune surveillance. This model enables investigation of how oncogenic HPV proteins intersect with the antigen presentation machinery and how loss of MHC class II function contributes to tumor progression in an epithelial microenvironment.
The polyclonal knockout cells are ideal for flow cytometry-based monitoring of HLA-DR surface loss, RT-qPCR and Western blot verification of gene ablation, and antigen presentation assays using CD4+ T cell co-cultures. They support cytokine profiling, NF-??B/NFAT reporter studies, and high-throughput screening of immunomodulatory drugs or vaccine candidates. The population-level response mirrors heterogeneous tumor behavior, facilitating translational research. For further technical details, please contact Ascent Research.
