The HLA-DRA Knockout DLD-1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population derived from the DLD-1 colorectal adenocarcinoma line, designed for loss?of?function analysis of the HLA-DRA gene. The product consists of a heterogeneous pool of cells harboring targeted gene disruptions, generated by CRISPR/Cas9-mediated editing. This polyclonal format avoids clonal artifacts while ensuring collective ablation of HLA-DRA function, supplying a robust model of MHC class II deficiency in an epithelial cancer context.
The parental DLD-1 cell line originates from a male patient with Dukes’ type C colorectal adenocarcinoma. It is a near-diploid, adherent epithelial model commonly used in colorectal cancer research. DLD-1 cells recapitulate key features of intestinal tumorigenesis and provide a tractable platform for studying tumor?immune interactions, particularly those involving antigen presentation and CD4+ T cell responses.
HLA-DRA encodes the alpha subunit of MHC class II (MHC-II) molecules that present extracellular peptides to CD4+ T cells. The alpha chain dimerizes with beta chains such as HLA-DRB1, assisted by CD74, HLA-DM, and HLA-DO, to load antigens and traffic to the cell surface. TCR engagement initiates immune synapse formation and downstream ZAP70 signaling, triggering cytokine release including IL?2, IFN???, IL?4, and IL?17. Transcription of HLA-DRA is controlled by the CIITA?RFX complex (RFX5, RFXAP, RFXANK) and NF?Y, which are activated by interferon?gamma (IFNG). Disruption of HLA-DRA eliminates surface MHC-II, thereby impairing CD4+ T cell recognition and adaptive immune activation.
In the DLD-1 adenocarcinoma context, knockout of HLA-DRA abolishes endogenous MHC-II antigen presentation capability. This engineered deficiency enables precise investigation of how tumor cells evade CD4+ T cell surveillance, influence the immune microenvironment, and respond to immunotherapies. The model is particularly relevant for dissecting MHC-II-dependent immune checkpoints in colorectal cancer.
The knockout cells are suitable for co?culture assays with CD4+ T cells to analyze antigen presentation, using readouts such as IL?2 ELISA or flow cytometry for activation markers. Loss of MHC-II surface expression can be confirmed by flow cytometry and immunofluorescence, with transcriptional validation by RT?qPCR or RNA?seq. Additional applications include tumor vaccine screening, immune evasion studies, and compound testing for immunotherapy development. This polyclonal knockout population is a versatile resource for colorectal cancer immunology. For further technical information, please contact Ascent Research.
