The CD4 Knockout Ca Ski Polyclonal Cells are a polyclonal population derived from the Ca Ski cervical carcinoma cell line after CRISPR/Cas9-mediated disruption of the CD4 gene. This heterogeneous pool offers a loss-of-function model free from clonal selection biases, providing a genetically diverse background for studying CD4-dependent processes. No particular editing outcome is implied, reflecting the range of indel mutations typical of CRISPR editing.
Ca Ski is an adherent epithelial cell line isolated from a mesenteric metastasis of a cervical epidermoid carcinoma. It harbors multiple copies of integrated HPV16 DNA and expresses the viral oncoproteins E6 and E7, which inactivate p53 and pRB, respectively, and sustain activation of PI3K/AKT and MAPK pathways. These characteristics make Ca Ski a widely used model for HPV-positive cervical cancer research.
The CD4 glycoprotein functions as a co-receptor in T cells by stabilizing TCR?CMHC-II interactions and recruiting the kinase Lck to phosphorylate ITAMs, which leads to activation of ZAP70 and the adaptor LAT. Downstream, PLC??1 triggers calcium mobilization and RAS-MAPK cascades, while PI3K-AKT signaling contributes to cell survival. These events activate transcription factors NF-??B, NFAT, and AP-1, which drive cytokine expression. In non?immune Ca Ski cells, exogenous CD4 may interface with similar adaptors and intersect with oncogenic signals from HPV16 E6/E7. CD4 transcription is governed by c-Myb, Ets-1, Runx3, and Th-POK, and is responsive to cytokines such as IL?2.
Loss of CD4 in the Ca Ski background enables dissection of its roles beyond T-cell biology, particularly in cervical cancer progression. As the primary receptor for HIV-1 gp120, CD4-null Ca Ski cells are a valuable tool for studying viral entry in an epithelial context. The presence of HPV16 oncoproteins that activate PI3K/AKT and MAPK pathways offers a unique opportunity to explore crosstalk between viral transformation and CD4-mediated signaling. The polyclonal nature preserves editing heterogeneity, better reflecting tumor cell variability.
Researchers can validate CD4 ablation by western blotting, flow cytometry, and RT?qPCR. Functional assays??including MTS proliferation, transwell migration/invasion, and co?cultures with immune cells??permit evaluation of CD4??s influence on tumor behavior. HIV pseudovirus infection assays can probe entry mechanisms, while phospho?signaling (phospho?AKT, phospho?ERK) and RNA?seq reveal downstream pathway changes. These cells are suited for drug screening and immune checkpoint research. For technical assistance, contact Ascent Research.
