The HLA-DRA Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human colorectal adenocarcinoma HT-29 cell line. This product features targeted disruption of the HLA-DRA gene, which encodes the alpha chain of the MHC class II HLA-DR heterodimer. The polyclonal nature of this knockout pool ensures a heterogeneous loss-of-function model, suitable for studying immune recognition in a genetically diverse background. Unlike clonal isolates, polyclonal populations preserve inherent cellular heterogeneity, offering a more physiologically relevant system for investigating gene function in cancer immunology.
The HT-29 host cell line was originally established from a colorectal adenocarcinoma of a 44-year-old Caucasian female. These epithelial cells are adherent and form polarized monolayers, expressing intestinal markers and retaining the capacity to differentiate into enterocyte-like cells upon appropriate culture conditions. HT-29 cells are widely used as a model of the intestinal epithelium, making them particularly relevant for studying colorectal cancer biology and intestinal immune responses. Their robust growth and well-characterized signaling pathways further enhance their utility in loss-of-function screens and co-culture experiments.
HLA-DRA encodes the alpha subunit of the HLA-DR class II molecule, which is critical for presenting exogenous peptide antigens to CD4+ T cells, thereby initiating adaptive immune responses. Expression of HLA-DRA is tightly regulated by interferon-gamma (IFN-??) signaling via the JAK-STAT pathway and the transcriptional activators CIITA and the RFX complex (RFX5, RFXANK, RFXAP). The HLA-DR heterodimer assembles with the invariant chain CD74 and is loaded with peptides through the activity of HLA-DM in endosomal compartments. Surface-expressed HLA-DR interacts directly with the T-cell receptor (TCR) and CD4 co-receptor, triggering downstream TCR signaling pathways and T helper cell differentiation. Targeted disruption of HLA-DRA leads to loss of MHC class II surface expression, impairing CD4+ T cell activation and antigen-specific immune responses.
In the context of the HT-29 colorectal adenocarcinoma model, knockout of HLA-DRA provides a powerful tool to investigate immune evasion mechanisms in colorectal cancer. Loss of MHC class II expression is a common strategy employed by tumors to avoid adaptive immune surveillance, and this polyclonal knockout population enables the study of tumor?Cimmune cell interactions without confounding functional antigen presentation. This model is particularly relevant for dissecting the role of CD4+ T cell responses in the intestinal tumor microenvironment and for evaluating therapeutic strategies aimed at restoring immune recognition.
The HLA-DRA Knockout HT29 Polyclonal Cells are ideally suited for a range of advanced research applications, including tumor-immune co-culture models, MHC class II deficiency studies, and autoreactive T cell assays. Representative assays include flow cytometry for surface HLA-DR, Western blotting, RT-qPCR, T cell activation and proliferation assays, antigen presentation assays, and immunofluorescence microscopy. These knockout cells empower investigations into colorectal cancer immune escape, inflammatory bowel disease, and autoimmune pathogenesis. For further information or to discuss your project requirements, please contact Ascent Research.
