The ARL14EP Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the human near-haploid HAP1 cell line. This product disrupts the ARL14EP gene, creating a loss-of-function model for investigating ARL14EP-dependent mechanisms. The polyclonal format contains a heterogeneous pool of cells with diverse CRISPR-induced mutations, suitable for population-level analyses where clonal artifacts are not a concern.
The HAP1 host cell line is a near-haploid chronic myeloid leukemia (CML) line from a male patient in blast crisis, harboring the BCR-ABL1 fusion gene. Its predominantly haploid karyotype (with disomy for chromosome 15) facilitates haploid genetic screens and straightforward interpretation of knockout phenotypes. The myeloid origin and leukemic background make it a relevant model for hematopoietic cell biology and oncogenic signaling studies.
ARL14EP functions as a downstream effector of the small GTPase ARL14, recruiting myosin 1E (MYO1E) to drive actin-dependent trafficking of MHC class II-containing vesicles to the cell surface. This ARL14?CARL14EP?CMYO1E complex is critical for efficient antigen presentation to CD4+ T cells via T cell receptor engagement. Upstream signals such as interferon-gamma (IFN-??) and Toll-like receptor 4 (TLR4) stimulation enhance ARL14EP-mediated transport, thereby upregulating surface expression of HLA-DR and HLA-DQ. Loss of ARL14EP impairs MHC class II surface delivery, reducing T cell activation and adaptive immune responses, and disrupting immune synapse formation.
In the HAP1 leukemic context, ARL14EP knockout allows dissection of how BCR-ABL1 signaling intersects with immunoregulatory endosomal trafficking. Although HAP1 cells are not professional antigen-presenting cells, cytokine stimulation upregulates MHC class II machinery, and the near-haploid genome simplifies analysis of ARL14EP??s role in vesicle dynamics. This model can reveal mechanisms of immune evasion in leukemia and is amenable to haploid genetic screens for synthetic interactions affecting MHC class II surface expression or immune synapse function.
Key research applications include Western blot confirmation of knockout, flow cytometric quantification of MHC class II surface levels after IFN-?? treatment, and immunofluorescence imaging of intracellular MHC class II distribution. Co-immunoprecipitation assays validate disruption of the ARL14?CARL14EP?CMYO1E complex, while RT-qPCR assesses transcription of MHC class II genes. This polyclonal knockout pool is ideal for functional genomics screens and studies of endosomal trafficking in leukemia. For further information, please contact Ascent Research.
