Organelle Specific Macrophage Engineered Vesicles Differentially Reprogram Macrophage Polarization.

Area of Science:

• Immunology
• Cancer Biology
• Cell Biology

Background:

• Tumor-associated macrophages (TAMs) are abundant in the tumor microenvironment, promoting immune suppression and tumor growth.
• TAMs typically exhibit an anti-inflammatory (M2) phenotype, but their plasticity allows for reprogramming towards an anti-tumoral (M1) phenotype.
• Engineered vesicles derived from macrophages can be programmed to alter macrophage phenotype.

Purpose of the Study:

• To investigate the differential properties of macrophage-engineered subcellular vesicles (MEVs) based on their organelle of origin.
• To evaluate the efficacy of endoplasmic reticulum-specific MEVs (erMEVs) versus plasma membrane-specific MEVs (pmMEVs) in repolarizing M2 macrophages.
• To assess the anti-cancer potential of erMEVs and pmMEVs.

Main Methods:

• Generation of pro-inflammatory macrophage-engineered subcellular vesicles (MEVs) originating from the endoplasmic reticulum (erMEVs) and plasma membrane (pmMEVs).
• Treatment of M2 macrophages with erMEVs and pmMEVs in vitro.
• Assessment of pro-inflammatory cytokine production by treated M2 macrophages.
• In vitro co-culture assays to evaluate the efficacy of MEVs in suppressing cancer cell viability.
• Analysis of membrane protein differences between erMEVs and pmMEVs and their role in M2 to M1 repolarization.

Main Results:

• erMEVs induced enhanced pro-inflammatory cytokine production in M2 macrophages compared to pmMEVs.
• erMEVs demonstrated superior efficacy in suppressing cancer cell viability in vitro compared to pmMEVs.
• Differences in membrane proteins between erMEVs and pmMEVs were observed, influencing M2 macrophage repolarization.
• The M2 to M1 repolarizing efficacy of MEVs can be modulated by altering the activity of their membrane proteins.

Conclusions:

• Macrophage-engineered subcellular vesicles exhibit distinct properties based on their organelle of origin, impacting their therapeutic potential.
• Endoplasmic reticulum-derived MEVs (erMEVs) show enhanced efficacy in repolarizing M2 macrophages towards an M1 phenotype and suppressing cancer cell growth.
• Targeting specific organelles for MEV generation offers a promising strategy for reprogramming TAMs and developing novel cancer immunotherapies.