Targeting allograft inflammatory factor 1 reprograms kidney macrophages to enhance repair

Area of Science:

• Nephrology
• Immunology
• Regenerative Medicine

Background:

• The role of macrophages (MΦs) in kidney injury and repair is not fully understood.
• MΦ plasticity offers potential for therapeutic polarization towards injury resolution in native and transplanted kidneys.

Purpose of the Study:

• To investigate the role of allograft inflammatory factor 1 (AIF-1) in kidney macrophages during injury and repair.
• To determine if targeting AIF-1 can modulate MΦ phenotype and improve kidney outcomes.

Main Methods:

• Genetic deletion of Aif1 in mice to assess MΦ polarization and kidney fibrosis.
• Adoptive transfer of Aif1-/- MΦs to evaluate protection against ischemia-reperfusion injury (I/RI).
• Analysis of human kidney biopsies for AIF-1 expression in various kidney diseases and allograft rejection.

Main Results:

• Aif1 genetic deletion promoted MΦ polarization towards a reparative phenotype, halting kidney fibrosis.
• Aif1-/- MΦs enhanced kidney tubular epithelial cell proliferation and reduced cell death post-I/RI.
• Increased AIF-1 expression was observed in human kidney disease and allograft rejection biopsies.

Conclusions:

• AIF-1 is a marker of renal inflammation in MΦs.
• Targeting AIF-1 can decouple MΦ reparative functions from profibrotic roles.
• Inhibiting AIF-1 presents a potential therapeutic strategy to mitigate kidney disease burden.