The FGA Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the Raji B cell line, engineered to disrupt the fibrinogen alpha chain (FGA) gene. This loss-of-function model enables investigation of fibrinogen-dependent processes while maintaining population diversity for experimental consistency.
Raji is an EBV-positive Burkitt lymphoma B lymphoblastoid cell line expressing CD19 and CD20. It serves as a model for B cell biology, antigen presentation, and immune signaling. In its native state, Raji cells participate in adhesion and inflammatory interactions that may involve fibrinogen, making the knockout suitable for dissecting fibrinogen-linked pathways in an immune context.
FGA encodes the alpha subunit of fibrinogen, a glycoprotein that assembles with FGB and FGG into a (A??B?¦?)? heterohexamer essential for hemostasis. The alpha chain contains binding sites for platelet integrin ??IIb??3, mediating platelet aggregation, and for fibronectin, vitronectin, and other adhesive molecules, thereby promoting endothelial adhesion, angiogenesis, and leukocyte recruitment during inflammation. FGA expression is activated by IL-6, oncostatin M, glucocorticoids, and STAT3/C/EBP?? downstream of acute-phase responses. CRISPR/Cas9-mediated disruption of FGA prevents heterohexamer formation, eliminating thrombin-catalyzed fibrin polymerization, Factor XIIIa crosslinking, and integrin ??IIb??3-dependent platelet aggregation. Consequently, downstream events such as plasminogen activation by tPA and urokinase, and fibrin-dependent cell adhesion are abrogated.
In the Raji B lymphoblastoid context, this FGA knockout provides a unique platform to dissect how fibrinogen deficiency reshapes immune cell behavior. Although Raji cells are not physiological fibrinogen producers, they express integrins and other receptors that normally engage fibrinogen during inflammatory cell adhesion and signaling. This polyclonal knockout population permits analysis of fibrinogen-dependent B cell adhesion, migration, and cytokine production, as well as the evaluation of compensatory hemostatic mechanisms and integrin-mediated signaling pathways in the absence of endogenous alpha chain. The model is particularly useful for studying the intersection of hemostatic and immune functions.
Applications encompass modeling afibrinogenemia and dysfibrinogenemia, elucidating fibrinogen-independent pathways of platelet aggregation, screening anti-thrombotic compounds that block the fibrinogen?C??IIb??3 interaction, and exploring the fibrinogen’s role in acute inflammation and angiogenesis. The polyclonal format offers flexibility for multiple downstream assays including Western blotting, ELISA, RT-qPCR, immunofluorescence, flow cytometry, coagulation assays, and platelet adhesion assays. Moreover, the knockout allows investigation of fibrinogen’s influence on B cell receptor signaling, antigen presentation, and cytokine profiles in response to inflammatory stimuli. For additional technical details or support, please contact Ascent Research.
