TNF-α Blockade Mitigates Immune Checkpoint–Related Nephritis in a Humanized Mouse Model

Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events (irAEs), with acute interstitial nephritis (ICI-AIN) being the most common irAE. While the exact mechanism remains unclear, upregulation of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) pathways has been implicated. This study used a humanized chimeric PD-1/PD-L1 mouse model to assess renal effects of ICIs, alone or combined with pro-inflammatory cytokines, and to test if selective TNF-α blockade could prevent ICI-AIN. Mice were randomly divided into four experimental groups: Control, ICI-Only, ICI-Cytokines (ICI-Cyt), and ICI-Block (ICI-TNF-α blockade). Renal function and cytokine profiles were assessed, while kidney tissue was analyzed using microscopy and single-cell RNA sequencing. Histology revealed increased renal infiltration of CD4⁺/CD8⁺ T cells in ICI-treated groups and decreased TNF-α expression following TNF-α blockade. Additionally, kidney tissue ELISA demonstrated reduced IFN-γ levels following TNF-α blockade. Plasma IL-6, MCP-1, and TNF-α were lower in ICI-Block mice. Single-cell RNA sequencing revealed shifts in immune cell populations and genes of interest including: Bcl2a1, Icos, Il18r1, Ccr2, and Jaml. This humanized model replicates ICI-AIN key features, revealing a synergistic role of ICIs and pro-inflammatory cytokines. TNF-α blockade demonstrated protective effects, supporting its potential role in mitigating the risk of ICI-AIN.