The HLA-DRA Knockout SK-HEP-1 Polyclonal Cells are a CRISPR/Cas9-edited cell population derived from the human liver adenocarcinoma line SK-HEP-1, engineered to disrupt the HLA-DRA gene. This polyclonal pool contains a spectrum of editing events, providing a heterogeneous loss-of-function model for the major histocompatibility complex class II alpha chain. The polyclonal format avoids clonal selection artifacts and is ideal for bulk assays requiring stable ablation of HLA-DRA expression.
SK-HEP-1 cells were originally established from the ascitic fluid of a 52-year-old male with liver adenocarcinoma and are extensively used as a hepatocellular carcinoma model. These tumorigenic epithelial cells exhibit robust growth, invasive potential, and a well-characterized genomic landscape, facilitating mechanistic studies in hepatic cancer. Their baseline expression of antigen presentation components makes them suitable for interrogating immune-related pathways. This knockout cell population leverages the reproducible background of SK-HEP-1 to investigate MHC-II function in a liver cancer context.
HLA-DRA encodes the alpha subunit of HLA class II molecules, which present extracellular antigens to CD4+ T cells. Its expression is driven by the CIITA transactivator in concert with the RFX complex (RFX5, RFXAP, RFXANK) and is upregulated by interferon-gamma via JAK-STAT signaling. The HLA-DRA protein pairs with beta chains (e.g., HLA-DRB1) and the chaperone CD74, then loads peptide with the help of HLA-DM. Surface MHC-II engages the CD4 receptor, triggering Lck/ZAP70-mediated T cell activation and adaptive immunity.
Abolishing HLA-DRA in SK-HEP-1 cells eliminates surface MHC-II, disrupting antigen presentation to T helper cells. This mimics immune evasion strategies seen in liver tumors where MHC-II downregulation correlates with diminished anti-tumor immunity. The knockout model enables dissection of tumor?CT cell interactions, including effects on cytokine secretion and T cell differentiation. Co-culture with antigen-specific CD4+ T cells can uncover roles of co-signaling molecules, while restoration studies with exogenous HLA-DRA facilitate structure-function analysis of MHC-II-mediated immune responses in hepatocellular carcinoma.
The HLA-DRA knockout polyclonal cells are suited for flow cytometric assessment of MHC-II loss, RT-qPCR and Western blotting for gene and protein expression, and co-immunoprecipitation to probe alpha?Cbeta chain interactions. Functional T cell assays, such as ELISpot or proliferation analyses, reveal the consequences of impaired antigen presentation. High-throughput screening for immunomodulatory compounds that restore CIITA/MHC-II expression is readily performed. These cells also serve autoimmune disease research and immunotherapy target validation. For additional information or custom clonal isolation, contact Ascent Research.
