The CD4 Knockout A2780 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human ovarian adenocarcinoma cell line A2780. This product provides a heterogeneous pool of cells with targeted disruption of the CD4 gene, enabling loss-of-function studies in an oncology-relevant epithelial background. The polyclonal format retains the diversity of editing outcomes, suitable for pooled screening and population-level functional assays.
The A2780 cell line is a well-established model of human ovarian carcinoma, originating from an untreated patient and retaining epithelial characteristics and sensitivity to cisplatin. This cell line is widely used in drug discovery, cancer biology, and chemoresistance research. Its adherent growth and robust proliferative capacity make it compatible with high-throughput assays. Although primarily of epithelial origin, A2780 cells have been reported to express low levels of CD4, offering a unique system to dissect CD4-related functions outside the lymphoid lineage.
CD4 is a transmembrane glycoprotein that serves as a co-receptor for the T cell receptor (TCR) complex, binding to MHC class II molecules and recruiting the Src family kinase Lck (p56Lck). This interaction promotes phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) on CD3 chains, leading to recruitment and activation of ZAP70, LAT, and PLC??1, and propagation of signals through NFAT and AP-1 transcription factors. CD4 is also the primary receptor for HIV entry via interaction with the viral envelope glycoprotein gp120. Upstream regulators include TCR stimulation, IL-16, and cytokines such as IL-2 and IL-4, while transcription factors TCF-1 and GATA-3 control CD4 expression. In T cells, CD4 is essential for T helper cell differentiation, Th1/Th2 lineage commitment, and immune synapse formation. Disruption of CD4 abrogates these signaling cascades, impairing downstream activation and effector functions.
In the A2780 ovarian cancer background, CD4 knockout offers a novel platform to study non-canonical CD4 signaling in epithelial tumor cells. While CD4 is predominantly a T cell marker, its expression in certain carcinomas has been linked to tumor-immune interactions and potential modulation of MHC class II-mediated survival signals. Polyclonal CD4 null A2780 cells enable dissection of CD4-dependent pathways that may influence tumor cell proliferation, apoptosis, or response to immunotherapies. Moreover, these cells can be engineered to express CD4 and HIV co-receptors for viral entry assays, providing a tractable epithelial model to investigate HIV host cell interactions without T cell-specific variables. The knockout system also facilitates co-culture experiments with immune cells to study synapse-like contacts and paracrine signaling.
Typical experimental applications include HIV infection assays using gp120-pseudotyped viral particles, phospho-signaling analysis by western blotting or flow cytometry to assess CD4-dependent kinase activation, RT-qPCR profiling of NFAT or AP-1 target genes, and co-culture activation assays with T cells or antigen-presenting cells. These polyclonal knockout cells are suitable for immunofluorescence microscopy to examine receptor localization and for immune checkpoint research, particularly when combined with MHC class II-positive target cells. For further information on product availability and customization, please contact Ascent Research.
