Goat milk extracellular vesicles: immuno-modulation effects on porcine monocyte-derived macrophages in vitro

IntroductionExtracellular vesicles (EVs) are nanometric-membrane-bound sub-cellular structures, which can be recovered from milk. Milk EVs have drawn increasing interest due to their potential biomedical applications, therefore it is important to investigate their impact on key immune cells, such as macrophages. MethodsIn this work, the immunomodulatory effects of goat milk EVs on untreated (moMCYRILLIC CAPITAL LETTER EF) and classically activated (moM1) porcine monocyte-derived macrophages were investigated using flow cytometry, ELISA, and gene expression assays. ResultsThese particles were efficiently internalized by macrophages and high doses (60 mg protein weight) triggered the upregulation of MHC I and MHC II DR on moMCYRILLIC CAPITAL LETTER EF, but not on moM1. In moMCYRILLIC CAPITAL LETTER EF, exposure to low doses (0.6 mg) of mEVs enhanced the gene expression of IL10, EBI3, and IFNB, whereas high doses up-regulated several pro-inflammatory cytokines. These nanosized structures slightly modulated cytokine gene expression on moM1. Accordingly, the cytokine (protein) contents in culture supernatants of moMCYRILLIC CAPITAL LETTER EF were mildly affected by exposure to low doses of mEVs, whereas high doses promoted the increased release of TNF, IL-8, IL-1a, IL-1b, IL-1Ra, IL-6, IL-10, and IL-12. The cytokines content in moM1 supernatants was not critically affected. DiscussionOverall, our data support a clinical application of these molecules: they polarized macrophages toward an M1-like phenotype, but this activation seemed to be controlled, to prevent potentially pathological over-reaction to stressors.

Automated summary

This study investigated the immunomodulatory effects of goat milk extracellular vesicles (EVs) on untreated and classically activated porcine monocyte-derived macrophages. The results showed that these particles were efficiently internalized by macrophages and high doses upregulated MHC I and MHC II DR on untreated macrophages, while low doses enhanced the gene expression of IL10, EBI3, and IFNB. High doses also upregulated several pro-inflammatory cytokines. Overall, these findings support the clinical application of these molecules in polarizing macrophages towards an M1-like phenotype.