Abstract
Tissue macrophages play an important role in organ homeostasis, immunity and the pathogenesis of various inflammation-driven diseases. One major challenge has been to selectively study resident macrophages in highly heterogeneous organs such as kidney. To address this problem, we adopted a Translational Ribosome Affinity Purification (TRAP)- approach and designed a transgene that expresses an eGFP-tagged ribosomal protein (L10a) under the control of the macrophage-specific c-fms promoter to generate c-fms-eGFP-L10a transgenic mice (MacTRAP). Rigorous characterization found no gross abnormalities in MacTRAP mice and confirmed transgene expression across various organs. Immunohistological analyses of MacTRAP kidneys identified eGFP-L10a expressing cells in the tubulointerstitial compartment which stained positive for macrophage marker F4/80. Inflammatory challenge led to robust eGFP-L10a upregulation in kidney, confirming MacTRAP responsiveness in vivo. We successfully extracted macrophage-specific polysomal RNA from MacTRAP kidneys and conducted RNA sequencing followed by bioinformatical analyses, hereby establishing a comprehensive and unique in vivo gene expression and pathway signature of resident renal macrophages. In summary, we created, validated and applied a new, responsive macrophage-specific TRAP mouse line, defining the translational profile of renal macrophages and dendritic cells. This new tool may be of great value for the study of macrophage biology in different organs and various models of injury and disease.
Highlights
Tissue macrophages play an important role in organ homeostasis, immunity and the pathogenesis of various inflammation-driven diseases
In the classical mononuclear phagocyte system (MPS) model, these cells originate from myeloid progenitor cells in the bone marrow and infiltrate the developing embryonal tissues via the vasculature to differentiate into tissue resident macrophages and dendritic cells[3,4]
Litters were of normal size and the transgene inherited in a Mendelian fashion
Summary
Tissue macrophages play an important role in organ homeostasis, immunity and the pathogenesis of various inflammation-driven diseases. We created, validated and applied a new, responsive macrophage-specific TRAP mouse line, defining the translational profile of renal macrophages and dendritic cells This new tool may be of great value for the study of macrophage biology in different organs and various models of injury and disease. In the classical mononuclear phagocyte system (MPS) model, these cells originate from myeloid progenitor cells in the bone marrow and infiltrate the developing embryonal tissues via the vasculature to differentiate into tissue resident macrophages and dendritic cells[3,4]. Laser-capture microdissection (LCM) and fluorescence-activated cell sorting (FACS) have been applied in solid tissues to enrich cell types of interest, but both require considerable, time-consuming manipulation of the tissue, which can significantly alter the naive expression profile of cells[18,19] This is true for inflammatory cells such as macrophages, that quickly respond to stress signals. We present the development and application of a new tool to study in vivo expression profiles of macrophages in the kidney and other organs based on the novel Translational Ribosome Affinity Purification (TRAP) strategy[20,21,22]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
