The APOBEC3C Knockout HeLa Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population featuring targeted disruption of the APOBEC3C gene in the HeLa cell line. This heterogeneous pool of edited cells provides a versatile loss-of-function model for functional studies of APOBEC3C, enabling investigation of its roles in innate antiviral immunity and nucleic acid editing without the need for clonal isolation. The polyclonal format ensures a diverse representation of knockout alleles, which is particularly useful for capturing population-level phenotypes and minimizing clonal artifacts.
The host HeLa cell line originates from a human cervical adenocarcinoma and harbors integrated HPV-18 DNA, resulting in the expression of viral oncoproteins E6 and E7. These oncoproteins target and inactivate the tumor suppressors p53 and RB, respectively, leading to cell immortalization and wide utility in cancer biology and virology. HeLa cells support robust replication of diverse viruses, including HIV-1, making them a suitable host for studying pathogen-host interactions and antiviral mechanisms.
APOBEC3C encodes a cytidine deaminase that acts on single-stranded DNA, catalyzing C-to-U mutations in retroviral minus-strand DNA and retrotransposons such as LINE-1 and Alu elements. This enzymatic activity is a central component of interferon-driven innate antiviral defenses: type I interferons (IFN-??/??) engage the IFNAR receptor, activating JAK1 and TYK2 kinases, which phosphorylate STAT1 and STAT2. Phosphorylated STAT proteins combine with IRF9 to form the ISGF3 transcription complex, which promotes APOBEC3C expression. The antiviral function of APOBEC3C is counteracted by HIV-1 accessory proteins Vif and Vpr, which facilitate its proteasomal degradation. Thus, APOBEC3C forms part of an interferon-inducible restriction network that combats retroviruses through mutagenic hypermutation.
In the HeLa context, where p53 and RB pathways are disrupted, this knockout model permits focused dissection of APOBEC3C-mediated mutagenesis, a process frequently observed in HPV-positive cancers and other malignancies. The absence of these tumor suppressors eliminates confounding effects on DNA damage responses, allowing researchers to directly assess APOBEC3C-driven genomic instability. Moreover, the integrated HPV-18 genome provides a unique opportunity to investigate how viral oncoproteins modulate interferon-induced innate effectors, offering insights into immune evasion strategies in persistent infections.
Typical applications include HIV-1 infectivity assays, cytidine deaminase activity assays, RNA-seq, co-immunoprecipitation, Western blotting, and flow cytometry. This model supports studies on HIV-1 pathogenesis, hepatitis B, and APOBEC mutagenesis in cancer. Contact Ascent Research for further details.
