The KLRB1 Knockout CAL-27 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population with disrupted KLRB1 gene, eliminating CD161 receptor expression. Derived from CAL-27 oral squamous cell carcinoma cells, this mixed pool retains parental heterogeneity while providing a loss-of-function model for studying CD161-mediated signaling. Unlike monoclonal lines, this polyclonal format enables population-level analyses without selection bias, suitable for screening and functional studies of the CD161/LLT1 immune checkpoint axis.
The CAL-27 cell line is an adherent epithelial model of human oral squamous cell carcinoma, derived from a tongue carcinoma. It harbors a TP53 R273H mutation, impairing p53 function and commonly found in head and neck cancers. CAL-27 cells are widely used to investigate oral cancer biology, drug responses, and tumor-immune interactions, offering a well-characterized platform for gene editing to study oncogenic signaling and immune resistance.
KLRB1 encodes CD161, a C-type lectin-like inhibitory receptor on NK and T cells. Upon LLT1 (CLEC2D) binding, CD161 recruits SHP-1 and SHP-2 via its ITIM motif, leading to dephosphorylation of p56Lck and ZAP70, which attenuates PI3K/Akt signaling and suppresses cytotoxicity and pro-inflammatory cytokine secretion (IFN-??, TNF-??). KLRB1 expression is regulated by IL-2, IL-15, and transcription factors T-bet and Eomes. Thus, CD161 acts as a key negative regulator of immune effector functions.
In oral squamous cell carcinoma, CD161-LLT1 interactions may promote immune evasion. CAL-27 cells express LLT1, potentially engaging CD161 on infiltrating lymphocytes to inhibit antitumor responses. CRISPR/Cas9-mediated KLRB1 disruption in CAL-27 eliminates this inhibitory signaling, creating a model to study checkpoint blockade in tumor-immune interactions. The p53-mutant background further provides a clinically relevant context, as p53 dysregulation may intersect with immune modulation.
This polyclonal knockout pool supports diverse functional studies. Co-cultures with NK or T cells can assess cytotoxicity and cytokine release (IFN-??, TNF-??). Protein loss and signaling changes are verified by flow cytometry, western blotting, and phospho-SHP-1/Akt detection. Migration/invasion assays and RT-qPCR confirm KLRB1 ablation. These cells facilitate investigation of CD161/LLT1 as a therapeutic target in oral cancer and compound screening. For further information, contact Ascent Research.
