CBL-B is an E3 ubiquitin-protein ligase which has been identified as a negative regulator of T-cell activation. Using CRISPR/Cas9 to inactivate CBL-B has been shown to be sufficient to inhibit T-cell expansion. The CBL-B CRISPR/Cas9 Lentiviruses are replication incompetent, HIV-based, VSV-G pseudotyped lentiviral particles that are ready to infect almost all types of mammalian cells, including primary and non-dividing cells. The particles contain a CRISPR/Cas9 gene driven by an EF1a promoter, along with 5 sgRNA (single guide RNAs) targeting human CBL-B driven by a U6 promoter. The integrating lentivirus integrates randomly into the cellular genome to express both Cas9 and the sgRNA. Puromycin selection forces high expression levels of both Cas9 and the sgRNA, and can be used with the integrating lentivirus to quickly and easily achieve high knockdown efficiencies in a cell pool. Efficiencies may vary, depending on the cell type and the gene of interest.
