The OSBPL1A Knockout Raji Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population designed for loss-of-function studies of the OSBPL1A gene in a human B lymphoblastoid background. This polyclonal pool, derived from the Raji cell line, carries targeted disruptions of the OSBPL1A locus, resulting in abrogation of functional ORP1 protein expression. This reagent is suitable for investigating the roles of OSBPL1A-mediated cholesterol transport and signaling without the confounding effects of clonal variation.
Raji cells are an Epstein?CBarr virus-positive Burkitt lymphoma-derived B lymphoblastoid cell line that retains key characteristics of antigen-presenting cells, including surface immunoglobulin expression and the ability to present antigens via MHC class II molecules. Widely employed in immunological and oncological research, Raji cells serve as a robust model for adaptive immune responses, antibody production, and lymphomagenesis. Their well-characterized growth properties and genetic manipulability make them an optimal host for interrogating lipid metabolism pathways in the context of B-cell malignancies.
OSBPL1A encodes ORP1, a sterol-sensing protein belonging to the oxysterol-binding protein-related protein family. ORP1 acts as a lipid transfer protein that facilitates non-vesicular transport of cholesterol from the endoplasmic reticulum to the plasma membrane and other organelles, directly interacting with VAPA, RAB8A, PI4KIII??, OSBP, and CERT to coordinate lipid distribution. It regulates mTORC1 signaling by relaying sterol-sensitive signals through AKT phosphorylation and lipid droplet dynamics. Upstream, OSBPL1A is transcriptionally regulated by SREBP1, SREBP2, and LXR?? in response to oxysterol levels, while downstream it modulates mTORC1 activity, plasma membrane cholesterol content, and AKT-mediated survival pathways. This positions ORP1 at a critical nexus between cholesterol homeostasis and the PI3K/AKT/mTOR growth control circuitry.
In Raji B cells, disruption of OSBPL1A expression is anticipated to perturb intracellular cholesterol trafficking, leading to altered plasma membrane lipid composition and impaired lipid raft assembly. Such changes may impact B-cell receptor signaling, antigen presentation efficacy, and mitogenic signal transduction. Given the heightened metabolic demands and proliferative drive of B-lymphoma cells, OSBPL1A knockout is expected to compromise AKT/mTOR-mediated survival signaling, potentially sensitizing cells to metabolic stress and sterol-targeting agents. This model thus provides a physiologically relevant platform to dissect the contribution of ORP1 to lymphoma pathobiology and cholesterol-dependent regulatory networks.
This polyclonal knockout cell product is intended for a range of downstream applications, including fluorescence imaging of cholesterol localization, co-immunoprecipitation of OSBPL1A interaction partners, and quantitative analysis of mTORC1 activity via phospho-specific antibodies. Researchers may employ lipidomic profiling to map sterol intermediates, RT-qPCR panels for cholesterol metabolism genes such as ABCA1 and LXR?? targets, and drug sensitivity assays using statins or synthetic oxysterols to evaluate pathway dependencies. Functional assays like MTT or Annexin V/7-AAD staining can assess proliferation and apoptosis, while flow cytometry enables cell cycle analysis. For further information, please contact Ascent Research.
