The Ifitm3 Knockout BV-2 Polyclonal Cells product comprises a CRISPR/Cas9-edited polyclonal knockout cell population generated from the BV-2 mouse microglial cell line. This pooled population harbors targeted disruption of the Ifitm3 gene, leading to loss of functional interferon-induced transmembrane protein 3. The cells are provided as a mixed pool, enabling immediate use in assays without clonal selection. This knockout model serves as a genetically defined tool for interrogating Ifitm3-dependent processes in microglial biology.
BV-2 cells are an immortalized microglial line derived from C57BL/6 mouse brain, transformed with a v-raf/v-myc retrovirus that retains key characteristics of primary microglia, including phagocytic capacity, responsiveness to inflammatory stimuli, and expression of microglial markers. They are widely employed in studies of immune surveillance, phagocytosis, and neuroinflammation, making them a suitable host for investigating gene function in central nervous system innate immunity.
Ifitm3 encodes an interferon-inducible transmembrane protein that restricts viral entry by blocking fusion of viral envelopes with host cell membranes, and it also modulates cell adhesion and contributes to oncogenic signaling. The gene is transcriptionally activated by type I interferons (IFN-??/??) and interferon-?? (IFN-??) through the JAK-STAT pathway. Upstream, the IFNAR receptor complex signals via JAK1 to phosphorylate STAT1 and STAT2, which assemble with IRF9 to form the ISGF3 transcription factor complex that drives Ifitm3 expression. Lipopolysaccharide (LPS) also upregulates Ifitm3 through interferon-dependent and -independent mechanisms. The protein interacts with tetraspanins such as CD81 and CD9, viral envelope proteins, and caveolin-1, and it functions downstream of interferon signaling to impede viral fusion machinery. Additionally, Ifitm3 influences cell adhesion by potentially regulating integrin activity. Disruption of Ifitm3 abolishes this interferon-inducible antiviral restriction and may alter adhesion and inflammatory cytokine production.
In BV-2 microglial cells, Ifitm3 plays a critical role in antiviral defense within the central nervous system. Microglia are resident immune cells that constantly survey the brain environment and mount rapid responses to pathogens. Loss of Ifitm3 in these cells can compromise the ability to control neurotropic viral infections, such as those caused by influenza or vesicular stomatitis virus (VSV). Moreover, given the emerging link between Ifitm3 and regulation of inflammatory pathways, this knockout model provides a platform to study how interferon-stimulated genes influence microglia-mediated neuroinflammation and phagocytosis, with implications for viral encephalitis and neurodegenerative conditions where microglial activation is dysregulated.
Typical research applications include mechanistic studies of interferon-dependent antiviral activity in microglia, investigations of Ifitm3??s role in neuroinflammatory signaling, and screening for compounds that inhibit viral entry. Representative assays include western blotting for Ifitm3 and STAT phosphorylation, RT-qPCR for inflammatory cytokines (e.g., IL-6, TNF-??), viral infection challenges with influenza A or VSV followed by immunofluorescence staining for viral antigens, flow cytometry to assess surface markers or viral entry, co-immunoprecipitation of Ifitm3 with tetraspanins or caveolin-1, and phagocytosis assays using labeled particles or pathogens. For further information, please contact Ascent Research.
