The HLA-DRA Knockout Jurkat Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Jurkat T lymphoblastoid cell line, engineered to disrupt the HLA-DRA gene. This loss-of-function model eliminates expression of the alpha chain of the HLA-DR major histocompatibility complex (MHC) class II heterodimer, thereby abolishing surface display of functional HLA-DR molecules. The polyclonal nature ensures a heterogeneous pool of editing events, reflecting a range of loss-of-function alleles suitable for pooled functional genomic studies.
The parental Jurkat cell line, established from the peripheral blood of a patient with acute T cell leukemia, is a widely employed model for dissecting T cell receptor (TCR) signaling, activation, and leukemogenesis. As a CD4+ T lymphoblastoid line, Jurkat cells retain key characteristics of immature T cells and respond to stimulation through the TCR/CD3 complex, making them a versatile platform for immunological investigation. The cell line??s robust growth and genetic tractability facilitate efficient CRISPR-based genome modification and downstream phenotypic analyses.
HLA-DRA encodes the constant alpha subunit of HLA-DR, a critical component of the MHC class II molecule that presents exogenously derived peptide antigens to CD4+ T helper cells. Expression of HLA-DRA is transcriptionally regulated by the class II transactivator CIITA, which is induced by interferon-gamma (IFN-??) signaling through the JAK1/2?CSTAT1 pathway and modulated by the RFX complex and IRF1. The HLA-DRA protein associates with polymorphic HLA-DRB beta chains, the invariant chain CD74, and the peptide editor HLA-DM to form functional antigen-presenting complexes. Upon peptide binding, these complexes engage the CD4 co-receptor and TCR on cognate T lymphocytes, triggering activation cascades involving Lck and ZAP70, leading to cytokine secretion, proliferation, and immune synapse formation.
In the Jurkat context, disruption of HLA-DRA provides a clean background to dissect MHC class II-dependent antigen presentation without interference from endogenous HLA-DR expression. This knockout model allows researchers to reconstitute with variant HLA-DR molecules or to investigate the upstream regulation by IFN-?? and CIITA in a controlled manner. Moreover, it enables the study of the functional consequences of HLA-DR deficiency on T?CT cell interactions, which are relevant to autoimmune pathogenesis and immunotherapy resistance. The polyclonal population is particularly suited for drug screening assays where a diversity of knockout efficiencies may reveal dose-response relationships.
Research applications of these polyclonal knockout cells include examining MHC class II antigen presentation pathways, investigating T cell activation requirements in co-culture experiments with CD4+ responder cells, and dissecting the IFN-??/CIITA signaling axis in response to inflammatory stimuli. The cells are amenable to flow cytometric quantitation of HLA-DR surface loss, western blotting and RT-qPCR for HLA-DRA expression, and functional assays such as cytokine ELISA and proliferation measurements. Confocal microscopy can further be employed to study intracellular trafficking of MHC class II components. For further technical specifications and ordering information, please contact Ascent Research.
