The HNRNPLL Knockout HAP1 Polyclonal Cells represent a targeted loss-of-function model generated by CRISPR/Cas9-mediated disruption of the HNRNPLL gene in the HAP1 cell line. This polyclonal knockout cell population enables researchers to investigate the functional consequences of HNRNPLL deficiency in a hemizygous, near-haploid hematopoietic background. The product is supplied as a population of edited cells, providing a robust tool for studying alternative splicing regulation and immune signaling pathways without the need for laborious single-cell clone isolation. Its polyclonal nature captures the genetic heterogeneity of CRISPR/Cas9 editing while maintaining a consistent loss of HNRNPLL expression.
The host HAP1 cell line is derived from the KBM-7 chronic myeloid leukemia (CML) cell line and features a near-haploid karyotype along with expression of the BCR-ABL fusion oncogene. HAP1 cells display an adherent, fibroblastoid morphology and serve as a versatile hematopoietic model for genetic screens and functional genomics. Their simplified diploid architecture reduces genetic redundancy, facilitating clean interpretation of gene perturbation phenotypes. The BCR-ABL oncogenic signaling present in HAP1 cells provides a relevant context for studying the intersection of oncogenic pathways and post-transcriptional gene regulation.
HNRNPLL encodes an RNA-binding protein that orchestrates alternative splicing of pre-mRNAs critical for immune cell function. Upon T cell receptor (TCR) stimulation, HNRNPLL expression is induced through the Ca2+/calcineurin/NFAT transcriptional axis. The protein then modulates splicing of key targets, including CD45 (PTPRC), by promoting inclusion of variable exons that determine receptor isoform expression. CD45 isoform switching, such as CD45RA to CD45RO, alters signaling thresholds during T cell activation. Additional downstream targets include CD44 and IKZF1, and HNRNPLL activity is influenced by interacting partners like HNRNPL and spliceosome components. Thus, HNRNPLL acts downstream of TCR/CD3 complex, ZAP70, LAT, and PLC??1, translating activation signals into changes in isoform repertoires.
In the HAP1 hematopoietic context, HNRNPLL knockout provides a tractable system to examine how loss of this splicing regulator impacts BCR-ABL-driven oncogenic signaling. Although HAP1 cells are not lymphoid in origin, they retain expression of many RNA-binding proteins and signaling molecules relevant to hematopoietic biology. Disruption of HNRNPLL can reveal dependencies between oncogenic tyrosine kinase activity and alternative splicing networks. This model allows dissection of the interplay between chronic myeloid leukemia signaling and the post-transcriptional mechanisms that govern proliferation, differentiation, and drug resistance, facilitating identification of novel vulnerabilities.
This knockout cell population is suitable for a wide range of applications, including T cell biology studies, mechanistic investigations of alternative splicing, and functional genomics in hematopoietic cells. Representative assays include RT-PCR isoform analysis, western blotting for CD45 isoforms, flow cytometry for surface markers, RNA immunoprecipitation (RIP), and RNA-seq for global splicing profiling. The cells can be employed in drug sensitivity screens using splicing inhibitors and in CRISPR screening validation experiments. For further details or to place an order, please contact Ascent Research.
