Increased nucleolar localization of SpiA3G in classically but not alternatively activated macrophages

Abstract 

Macrophages play a key role in innate immune response to pathogens and in tissue homeostasis, inflammation and repair. A serpin A3G (SpiA3G) is highly induced in classically activated macrophages. We show increased localization of SpiA3G in the nucleolus and co-localization with cathepsin L, upon classical, but not alternative activation of macrophages. Despite the increased expression of cathepsin L in the nuclei of classically activated macrophages, no cathepsin activity was detected. Since only pro-inflammatory, but not anti-inflammatory stimuli induce increased nucleolar localization of SpiA3G, we propose that SpiA3g translocation into the nucleolus is important in host defense against pathogens.

Structured summary

MINT-7714245: fibrillarin (uniprotkb:P35550) and SpiA3G(uniprotkb:Q5I2A0) co-localize (MI:0403) by fluorescence microscopy(MI:0416)

MINT-7714241: SpiA3G (uniprotkb:Q5I2A0) and cathepsin L(uniprotkb:P06797) co-localize (MI:0403) by fluorescence microscopy (MI:0416)

Abbreviations: ABP, activity based probe, IFN-γ, interferon gamma, IL-4, interleukin-4, LPS, lipopolysaccharide, MHC, major histocompatibility complex, MENT, myeloid and erythroid nuclear termination stage-specific protein, SpiA3G, serpin A3G, TLR 4, toll-like receptor 4

Keywords: Cathepsin L, Macrophage activation, Nucleolus, Serpin A3G