Engineered Immunologic Niche Monitors Checkpoint Blockade Response and Probes Mechanisms of Resistance

Area of Science:

• Immunology
• Oncology
• Biomarker Discovery

Background:

• Anti-programmed cell death protein 1 (anti-PD-1) immunotherapy shows promise for triple-negative breast cancer (TNBC).
• Predictive biomarkers for anti-PD-1 response in TNBC are lacking, limiting clinical benefit for many patients.
• Existing immunological niche models support tissue formation with immune cell composition similar to vital organs.

Purpose of the Study:

• To investigate dynamic gene expression within an immunological niche to identify biomarkers predicting response to anti-PD-1 therapy.
• To explore the potential of an immunological niche for monitoring immunotherapy response and understanding treatment resistance mechanisms.

Main Methods:

• Utilized a 4T1 mouse model of metastatic TNBC to assess sensitivity and resistance to anti-PD-1 therapy.
• Biopsied an established subcutaneous immunological niche at multiple time points (pre-, during, post-therapy).
• Analyzed niche biopsies for cell types and gene expression patterns indicative of treatment response or refractivity.

Main Results:

• Observed distinct alterations in myeloid cell-to-lymphocyte ratios between sensitive and resistant groups.
• Longitudinal gene expression analysis revealed dynamic myeloid cell functions that differentiated treatment sensitivity from resistance.
• Developed a niche-derived gene signature that accurately predicted anti-PD-1 therapy sensitivity or resistance prior to treatment initiation.

Conclusions:

• The immunological niche can provide dynamic biomarkers for predicting anti-PD-1 immunotherapy response in TNBC.
• Monitoring gene expression within the niche offers a novel strategy for personalizing cancer care.
• This approach facilitates the investigation of mechanisms underlying immunotherapy resistance.