Live imaging of monocyte subsets in immune complex-mediated glomerulonephritis reveals distinct phenotypes and effector functions.
File(s)
Author(s)
Type
Journal Article
Abstract
BACKGROUND: Immune complexes within glomerular capillary walls cause crescentic GN (CrGN). Monocytes and macrophages are important in mediating CrGN, but little work has been done to phenotype the subpopulations involved and determine their respective contributions to glomerular inflammation. METHODS: Live glomerular imaging using confocal microscopy monitored intravascular monocyte subset behavior during nephrotoxic nephritis (NTN) in a novel WKY-hCD68-GFP monocyte/macrophage reporter rat strain. Flow cytometry and qPCR further analyzed ex vivo the glomerular leukocyte infiltrate during NTN. RESULTS: Non-classical monocytes surveyed the glomerular endothelium via lymphocyte function-associated antigen 1 (LFA-1) in the steady state. During NTN, non-classical monocytes were recruited first, but subsequent recruitment and retention of classical monocytes was associated with glomerular damage. Monocytes recruited to the glomerular vasculature did not undergo transendothelial migration. This finding suggests that inflammation in immune complex-mediated CrGN is predominantly intravascular, driven by dynamic interactions between intravascular blood monocytes and the endothelium. Glomerular endothelium and non-classical monocytes overexpressed a distinct chemokine axis, which may orchestrate inflammatory myeloid cell recruitment and expression of damage mediators. Reduced classical monocyte recruitment in Lewis rats during NTN confirmed a role for CD16 in mediating glomerular damage. CONCLUSIONS: Monocyte subsets with distinct phenotypes and effector functions may be important in driving inflammation in experimental CrGN resulting from immune complexes formed within the glomerular capillary wall. LFA-1-dependent endothelial surveillance by non-classical monocytes may detect immune complexes through CD16, orchestrating the inflammatory response through intravascular retention of classical monocytes, which results in glomerular damage and proteinuria.
Date Issued
2020-09
Date Acceptance
2020-06-22
Citation
Journal of the American Society of Nephrology, 2020, 31 (9), pp.1-1
ISSN
1046-6673
Publisher
American Society of Nephrology
Start Page
1
End Page
1
Journal / Book Title
Journal of the American Society of Nephrology
Volume
31
Issue
9
Copyright Statement
© 2020 by the American Society of Nephrology
Sponsor
Medical Research Council (MRC)
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/32868399
PII: ASN.2019121326
Grant Number
MR/M003159/1
Subjects
glomerulonephritis
immune complexes
immunology
macrophages
Publication Status
Published online
Coverage Spatial
United States
Date Publish Online
2020-08-31