The LMAN1 Knockout Raji Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt endogenous LMAN1 expression in the human Raji B lymphocyte background. This polyclonal pool, derived from bulk gene editing without single-cell cloning, provides a genetically heterogeneous loss-of-function model that recapitulates the natural diversity of editing outcomes while maintaining the key cellular context for studying ER-to-Golgi trafficking and glycoprotein secretion. The product enables robust investigation of LMAN1 function in a suspension-adapted lymphoblastoid system, offering a practical tool for high-throughput and physiologically relevant assays.
The Raji host cell line is an Epstein-Barr virus (EBV)-positive Burkitt lymphoma-derived lymphoblastoid line that grows in suspension and retains many features of mature B lymphocytes, including the capacity for antibody production and involvement in humoral immunity. Widely employed in immunology and cancer research, Raji cells exhibit active secretory pathways essential for immunoglobulin synthesis and surface receptor presentation, making them an ideal backdrop for dissecting early secretory pathway components. Their robust proliferation and genetic tractability facilitate CRISPR-based engineering and functional screening, and their B-cell identity provides a unique platform for exploring how defects in cargo transport intersect with immune cell biology.
LMAN1 (lectin, mannose-binding 1), also known as ERGIC-53, functions as a cargo receptor that recognizes mannose-containing oligosaccharides on newly synthesized glycoproteins in the endoplasmic reticulum. In a complex with MCFD2, LMAN1 facilitates selective packaging of client proteins, including coagulation factors V and VIII, cathepsin Z, and alpha-1-antitrypsin, into COPII-coated vesicles for anterograde transport to the Golgi. This process is orchestrated by COPII coat components such as SEC23, SEC24, and the small GTPase SAR1B, and is sensitive to upstream ER stress sensors IRE1 and PERK. Disruption of LMAN1 impairs secretion of these critical cargoes, recapitulating defects observed in combined factor V and VIII deficiency, a congenital bleeding disorder. Downstream, loss of LMAN1 leads to intracellular accumulation of its targets and may activate compensatory pathways, while its interacting partner MCFD2 remains available for functional studies.
In the Raji B lymphocyte context, LMAN1 knockout provides a powerful model to interrogate how ER-to-Golgi trafficking defects influence humoral immunity. B cells rely on efficient glycoprotein secretion for antibody release and surface receptor expression, and LMAN1-mediated transport may support the processing of immunoglobulins or other secreted factors. Although LMAN1 deficiency primarily manifests as a coagulation disorder, the Raji knockout system allows researchers to explore broader roles in immune cell homeostasis, including potential perturbations in unfolded protein response signaling or alterations in the surface display of glycoproteins relevant to B-cell function and lymphoma biology. This model bridges hematologic and immunologic research, enabling multifaceted studies.
Research applications for these polyclonal knockout cells are extensive and directly leverage the representative assays provided. Users can perform Western blotting and immunofluorescence to confirm LMAN1 disruption and assess localization of ER and Golgi markers, secretion assays for coagulation factors V and VIII or cathepsin Z to quantify trafficking defects, and co-immunoprecipitation to examine residual LMAN1-MCFD2 complex formation. Furthermore, RT-qPCR can monitor unfolded protein response gene expression, and flow cytometry can evaluate surface presentation of glycoproteins. These tools position the product for investigations of ER-to-Golgi transport mechanisms, cargo receptor specificity, and disease modeling, particularly for combined factor V and VIII deficiency. For additional technical details, please contact Ascent Research.
