To investigate how CD169-associated macrophage states evolve during colitis-associated colorectal cancer (CAC) development and their role in immune regulation.
Approach:
Study Design: Integrated genetic depletion, pharmacological intervention, single-cell transcriptomic profiling, and in vitro functional validation.
Model: Established a colitis-associated colorectal cancer model in mice using azoxymethane (AOM) and dextran sulfate sodium (DSS).
Analysis: Conducted macroscopic examination, histopathological analysis, and flow cytometric analysis to assess the role of CD169⁺ macrophages.
Key Findings:
Depletion of CD169⁺ macrophages resulted in reduced inflammation-driven colorectal tumorigenesis.
A distinct population of CD169-high macrophages was found to be enriched in late-stage CAC.
CD169⁺ macrophages may facilitate immunosuppressive macrophage reprogramming via APP–CD74 signaling.
Targeting CD169 with cyanidin-3-O-glucoside (C3G) was shown to slow CAC progression.
Interpretation:
CD169 identifies macrophage states with varying immune properties across disease stages, linking it to inflammatory responses in colitis and tumor progression in colorectal cancer.
Limitations:
The study primarily utilized mouse models, which may not fully replicate human disease.
Further investigation is needed to elucidate the specific mechanisms of CD169-associated macrophage reprogramming.
Conclusion:
CD169-associated macrophage states warrant further investigation as they may play a role in inflammation-driven colorectal tumorigenesis.
