Cas9 Stable Cell Line - A20

The Cas9-stable A20 cell line is a genetically engineered derivative of the murine B-lymphocyte cell line, A20. The parental A20 cell line was originally isolated from a spontaneous reticulum cell sarcoma within an aged BALB/c mouse. This modified A20 cell line features the stable integration of the CRISPR-associated protein 9 (Cas9) nuclease, thereby providing continuous genomic editing capabilities without the need for repeated transfections. The parental A20 cells exhibit the characteristic features of mature B cells, expressing surface markers such as MHC Class II molecules, Fcγ receptors, and CD45, making them an invaluable model for immunological research. By virtue of its stable Cas9 expression, this cell line maintains high genomic editing efficiency across multiple passages while fully preserving critical B-cell signaling pathways, establishing it as an exceptional tool for dissecting immune mechanisms at genomic resolution.

In the study of autoimmune and inflammatory diseases, the Cas9-stable A20 cell line can be utilized to conduct genome-wide CRISPR screens. By targeting genes such as CD40, BTK, or components of the NF-κB pathway, researchers can identify key regulatory factors governing B-cell activation, immune tolerance checkpoints, and the mechanisms underlying "cytokine storms." Researchers can also leverage this cell line to construct models for studying lymphoma pathogenesis; by precisely knocking out tumor suppressor genes (e.g., PTEN) or knocking in oncogenic mutations (e.g., MYD88 L265P), they can conduct drug sensitivity testing within a genetically homogeneous background. In the development of immunotherapies, this cell line accelerates research into immune checkpoint inhibitors by enabling the editing of genes associated with the PD-L1/PD-1 axis, thereby facilitating the assessment of drug blockade efficacy and mechanisms of drug resistance. Furthermore, this cell line supports the construction of advanced co-culture systems for in-depth investigations into the interactions between B cells and T cells; by specifically disrupting co-stimulatory molecules (e.g., CD80/CD86) or genes involved in antigen presentation (e.g., MHC-II), researchers can precisely dissect the dynamic processes involved in the formation of immune synapses. In the field of vaccine development, this cell line can be utilized to knock out Fc receptor genes, thereby enabling the assessment of antibody-dependent cell-mediated cytotoxicity (ADCC) effects.