The F12 Knockout Raji Polyclonal Cells consist of a heterogeneous pool of Raji cells with CRISPR/Cas9-mediated F12 gene disruption. This polyclonal knockout population, containing a mix of edited genotypes, enables factor XII (FXII) loss-of-function studies without clonal selection bias, reflecting more physiological variability. It facilitates interrogation of the contact activation pathway in a human B lymphocyte cellular context.
The Raji parental line is a human B lymphocyte line derived from Burkitt??s lymphoma, extensively utilized in immunological research. These mature B cells express surface immunoglobulins and are capable of antigen presentation and cytokine production, offering a robust model for humoral immunity studies. Employing this knockout within Raji cells enables dissection of how coagulation factors, particularly FXII, intersect with B cell function and malignant lymphoid behavior.
Factor XII, encoded by F12, is a serine protease that initiates the intrinsic coagulation cascade upon autoactivation by negatively charged surfaces such as platelet-released polyphosphates or collagen. Activated FXII (FXIIa) converts prekallikrein (KLKB1) to kallikrein, which then cleaves high molecular weight kininogen (KNG1) to release the vasoactive peptide bradykinin. Simultaneously, FXIIa activates factor XI (F11), propagating coagulation. This system is inhibited by C1 inhibitor (SERPING1). Downstream, bradykinin drives inflammation and vascular permeability, while factor XIa promotes thrombin generation. Thus, F12 knockout disrupts the initiation of both procoagulant and proinflammatory signaling cascades.
Knockout of F12 in the Raji B lymphocyte background creates a unique platform for examining contact activation in the immune system. B cells can synthesize components of the kallikrein-kinin system and may contribute to local bradykinin production during inflammation, making this model pertinent to hereditary angioedema (HAE) where bradykinin overproduction causes angioedema attacks. Additionally, pairing FXII deficiency with a malignant B cell line permits exploration of coagulation-immune interactions in autoimmune disorders, thrombosis, and stroke. It also aids in dissecting FXII??s involvement in complement and fibrinolytic pathways.
Researchers can confirm gene disruption by Sanger sequencing of the CRISPR target locus and assess knockdown efficiency via RT-qPCR and Western blotting. Functional FXII loss is measurable through chromogenic FXIIa activity assays and aPTT-based clotting tests, while flow cytometry detects residual surface expression. This polyclonal model is highly suitable for screening pharmacological FXII inhibitors, investigating how FXII modulates B cell activation, proliferation, and antibody secretion, and studying crosstalk between the contact system and adaptive immunity. For technical support and customization options, please contact Ascent Research.
