Nutrition and Health Sciences, Department of


Document Type


Date of this Version



Curr Dev Nutr. 2022 Jun; 6(Suppl 1): 297. Published online 2022 Jun 14.

doi: 10.1093/cdn/nzac053.038

PMCID: PMC9193350


Milk exosomes (MEs) and their microRNA cargos constitute novel bioactive food compounds, and bovine MEs (BMEs) are being considered for use in drug delivery. The internalization of MEs by macrophages and degradation in lysosomes (in all cells) limit biological activities. Here, we determined whether BMEs internalized by murine bone marrow-derived macrophages (BMDMs) retrofuse with the intralumenal membrane in the multivesicular body (MVB) for subsequent release into the extracellular space or whether BMEs are destined for degradation in lysosomes.

Conclusions: The retrofusion of BME-derived intralumenal MVBs and secretion of BME into the extracellular space is quantitatively minor in BMDMs. The majority of BMEs localizes to lysosomes for degradation in BMDMs.