CPN1 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the CPN1 gene, which encodes the catalytic subunit of carboxypeptidase N. This gene-edited pool eliminates target protein function across a heterogeneous cell population without single-cell cloning, providing a robust model for studying loss-of-function phenotypes in B lymphocyte biology. The polyclonal format preserves population-level diversity, making it suitable for assays where bulk responses are measured, such as cytokine profiling or signaling pathway analysis. As a polyclonal population, it is not a monoclonal cell line, and users should validate knockout efficiency in their specific experimental context. The product is intended for research use only and advances the study of complement-mediated signaling and anaphylatoxin regulation.
The host cell line, Raji, is a human B lymphoblastoid cell line derived from a Burkitt’s lymphoma patient. Raji cells are Epstein-Barr virus (EBV)-positive and lack surface immunoglobulin, yet express characteristic B cell markers including CD19 and CD20. These features make Raji cells a widely accepted model for investigating B cell receptor-independent signaling, EBV biology, and hematological malignancies. Their lymphoblastoid nature facilitates growth in suspension culture, enabling scalable experiments for high-throughput screening or large-scale biochemical analyses. The use of Raji cells as the host background provides a clinically relevant context for exploring CPN1 function in B cell-derived cancers and immune disorders.
CPN1 encodes the catalytic subunit of carboxypeptidase N, a zinc-dependent plasma metalloprotease that cleaves C-terminal basic amino acids from peptides and proteins. This enzyme is a key regulator of the complement and kinin-kallikrein systems, inactivating potent pro-inflammatory anaphylatoxins such as C3a, C4a, and C5a, as well as degrading bradykinin, kallidin, and enkephalins. CPN1 functions as a heterotetrameric complex with its regulatory subunit, CPN2, and its activity is modulated by upstream inflammatory stimuli including lipopolysaccharide (LPS), cytokines such as IL-6 and TNF-??, and glucocorticoids. Downstream, the cleavage products influence signaling through anaphylatoxin receptors C5aR1 and C3aR, and intersect with components like kallikrein B1 (KLKB1) and kininogens. In the absence of CPN1, these peptides persist, prolonging inflammatory and vasoactive signaling cascades.
In the Raji B lymphocyte context, CRISPR/Cas9-mediated disruption of CPN1 creates a powerful tool for dissecting the role of carboxypeptidase N in complement-driven B cell biology. Elimination of CPN1 catalytic activity prevents the inactivation of anaphylatoxins, leading to sustained C5aR1 and C3aR signaling that can modulate B cell activation, survival, or migration. This model is particularly relevant for studying the inflammatory microenvironment of lymphomas, where complement activation may shape tumor growth and immune escape. Additionally, the CPN1 knockout mimics aspects of carboxypeptidase N deficiency, allowing researchers to explore how loss of anaphylatoxin clearance contributes to excessive inflammatory responses in B cell malignancies. The Raji background also permits investigations into potential crosstalk between EBV latency programs and complement pathway alterations.
This polyclonal knockout cell population is suitable for a range of research applications, including the study of complement-mediated B cell activation, anaphylatoxin signaling in lymphoma, and drug screening for complement inhibitors. Representative assays include Western blotting to confirm CPN1 and CPN2 protein levels, ELISA-based measurement of C3a and C5a accumulation in culture supernatants, and flow cytometry to assess C5aR1 expression. Functional readouts such as calcium mobilization assays, chemotaxis experiments, and RNA sequencing to profile inflammatory gene signatures can further elucidate CPN1-dependent pathways. Researchers can also use this model to explore the interplay between the complement system and B cell receptor-independent signaling in an EBV-positive background. For additional details or custom orders, please contact Ascent Research.
