[HTML][HTML] Bowman's capsule provides a protective niche for podocytes from cytotoxic CD8+ T cells

A Chen, K Lee, VD D'Agati, C Wei, J Fu… - The Journal of …, 2018 - Am Soc Clin Investig
A Chen, K Lee, VD D'Agati, C Wei, J Fu, TJ Guan, JC He, D Schlondorff, J Agudo
The Journal of clinical investigation, 2018Am Soc Clin Investig
T cells play a key role in immune-mediated glomerulonephritis, but how cytotoxic T cells
interact with podocytes remains unclear. To address this, we injected EGFP-specific CD8+ T
cells from just EGFP death inducing (Jedi) mice into transgenic mice with podocyte-specific
expression of EGFP. In healthy mice, Jedi T cells could not access EGFP+ podocytes.
Conversely, when we induced nephrotoxic serum nephritis (NTSN) and injected Jedi T cells,
EGFP+ podocyte transgenic mice showed enhanced proteinuria and higher blood urea …
T cells play a key role in immune-mediated glomerulonephritis, but how cytotoxic T cells interact with podocytes remains unclear. To address this, we injected EGFP-specific CD8+ T cells from just EGFP death inducing (Jedi) mice into transgenic mice with podocyte-specific expression of EGFP. In healthy mice, Jedi T cells could not access EGFP+ podocytes. Conversely, when we induced nephrotoxic serum nephritis (NTSN) and injected Jedi T cells, EGFP+ podocyte transgenic mice showed enhanced proteinuria and higher blood urea levels. Morphometric analysis showed greater loss of EGFP+ podocytes, which was associated with severe crescentic and necrotizing glomerulonephritis. Notably, only glomeruli with disrupted Bowman’s capsule displayed massive CD8+ T cell infiltrates that were in direct contact with EGFP+ podocytes, causing their apoptosis. Thus, under control conditions with intact Bowman’s capsule, podocytes are not accessible to CD8+ T cells. However, breaches in Bowman’s capsule, as also noted in human crescentic glomerulonephritis, allow access of CD8+ T cells to the glomerular tuft and podocytes, resulting in their destruction. Through these mechanisms, a potentially reversible glomerulonephritis undergoes an augmentation process to a rapidly progressive glomerulonephritis, leading to end-stage kidney disease. Translating these mechanistic insights to human crescentic nephritis should direct future therapeutic interventions at blocking CD8+ T cells, especially in progressive stages of rapidly progressive glomerulonephritis.
The Journal of Clinical Investigation