The CD4 Knockout CAL-27 Polyclonal Cells product provides a polyclonal population of CAL-27 cells that have been subjected to CRISPR/Cas9-mediated disruption of the CD4 gene. This knockout pool contains a heterogeneous mixture of edited alleles, offering a genetically diverse model for functional studies without the selection of a single-cell clone. It is designed for researchers seeking to investigate CD4-related biology in an epithelial cell context.
CAL-27 is a human oral squamous cell carcinoma cell line originally derived from a tongue tumour of a 56-year-old male patient. As a widely used model for head and neck cancer, CAL-27 cells retain epithelial morphology and are frequently employed in cancer biology research, drug sensitivity testing, and invasion assays. Their established use in the field provides a robust platform for integrating CD4 knockout studies into existing oral cancer research frameworks.
CD4 encodes a transmembrane glycoprotein that functions as a co-receptor for the T cell receptor (TCR) through binding to non-polymorphic regions of MHC class II molecules on antigen-presenting cells. This interaction recruits the Src-family kinase Lck to the TCR/CD3 complex, initiating phosphorylation of ZAP70 and the adaptor LAT, and activating downstream MAPK cascades (ERK, JNK, p38), calcium flux, and the NFAT and AP-1 transcription factors. CD4 also engages the PI3K-Akt axis, amplifying signals for T cell activation and cytokine production. Additionally, CD4 serves as a primary receptor for HIV-1, binding gp120 to mediate viral entry. Among its regulators, IL-16 and MHC class II engagement are key upstream signals.
Disruption of CD4 in the CAL-27 epithelial background provides a unique tool to dissect non-canonical roles of CD4, particularly in the context of tumour?Cimmune cell interactions. Head and neck cancers often contain infiltrating T cells, and this model permits co-culture experiments to evaluate how loss of CD4 influences immune synapse formation, cytokine cross-talk, and tumour cell responses to T-cell-derived signals. Such studies may reveal novel aspects of immune evasion in oral squamous cell carcinoma.
This polyclonal knockout pool supports a broad spectrum of applications, including co-culture assays with CD4-expressing immune cells to assess activation and signalling, western blot and flow cytometric analysis of CD4 protein expression, and genomic PCR/sequencing for knockout confirmation. It is also suitable for HIV-1 pseudovirus entry assays following ectopic CD4 expression, drug sensitivity screening, and migration/invasion studies. For further details or custom requirements, please contact Ascent Research.
