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Updated: Dec 10, 2025
Simultaneous Study of the Recruitment of Monocyte Subpopulations Under Flow In Vitro
Published on: November 26, 2018
Live Imaging of Monocyte Subsets in Immune Complex-Mediated Glomerulonephritis Reveals Distinct Phenotypes and
Tabitha Turner-Stokes1, Ana Garcia Diaz1, Damilola Pinheiro1
1Centre for Inflammatory Disease, Imperial College London, London, UK.
Insights
In crescentic glomerulonephritis (CrGN), distinct monocyte subsets play key roles. Non-classical monocytes initiate inflammation, while classical monocytes drive glomerular damage and proteinuria.
Area of Science:
- Nephrology
- Immunology
- Cell Biology
Background:
- Immune complexes in glomerular capillaries trigger crescentic glomerulonephritis (CrGN).
- Monocytes and macrophages are crucial in CrGN pathogenesis.
- Subpopulations of these cells and their specific roles in glomerular inflammation require further investigation.
Purpose of the Study:
- To investigate the distinct roles of monocyte subsets in mediating glomerular inflammation during experimental CrGN.
- To phenotype monocyte subpopulations and their contributions to kidney damage.
Main Methods:
- Utilized live glomerular imaging with confocal microscopy in a novel reporter rat strain to observe monocyte behavior during nephrotoxic nephritis (NTN).
- Employed flow cytometry and quantitative PCR (qPCR) for ex vivo analysis of glomerular leukocyte infiltrates.
- Assessed monocyte subset recruitment and endothelial interactions.
Main Results:
- Non-classical monocytes perform endothelial surveillance via lymphocyte function-associated antigen 1 (LFA-1) in steady-state and during NTN.
- Initial recruitment of non-classical monocytes was followed by classical monocyte accumulation, correlating with glomerular damage.
- Monocyte recruitment occurred intravascularly without transendothelial migration, indicating predominantly intravascular inflammation.
- A specific chemokine axis overexpressed by glomerular endothelium and non-classical monocytes may drive myeloid cell recruitment.
- Reduced classical monocyte recruitment in Lewis rats highlighted CD16's role in glomerular damage.
Conclusions:
- Distinct monocyte subsets with unique phenotypes and functions are integral to driving inflammation in immune complex-mediated CrGN.
- Non-classical monocytes, through LFA-1-dependent surveillance and CD16, may orchestrate the inflammatory response by retaining classical monocytes intravascularly, leading to glomerular damage and proteinuria.
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.
