Investigation of changes in profile of exosome/microparticles during the storage of erythrocytesuspensions

Exosomes are EVs (Extracellular Vesicles) released by various cell types and play roles in cell-cell communication. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for transfer between cells of the membrane and cytosolic proteins, lipids, and RNA. Whole blood from healthy donors (10) was transferred to two separate blood bags by an equal amount converted into erythrocyte suspension (ES). One of the bags was passed through the leukocyte filter to obtain reduced leukocyte (LA-ES) and non-reduced ESs (NL-ES) and divided into four equal blood bags. Flow cytometry was used to identify and quantify exosomes in the samples on the 0th, 14th, 28th and 42nd days at 4 °C. The exosomes were first coated with anti-CD9 antibodies with carboxylates beads and exosome volumes were determined by BCA Protein Assay to determine the amount of exosome-containing samples to be bound by beads and investigated by flow cytometry. T and T cytotoxic lymphocyte-derived exosome levels in both groups (leukocyte reduced and non leukocyte reduced) decreased in the group of leukocytes in the cell-derived group on the 42th day decreased significantly less than the 0th day, Tc lymphocyte origin in the group of the day 14th and 42th in the leukocyte unreduced samples 0 (p <0.05). The exosomal levels of B lymphocytes were decreased in both groups. The leukocyte group was significantly reduced on the 28th and 42nd-day samples compared to day 0 (p <0.05). MDSC and G-MDSC exosomes decreased significantly in both groups (p <0.05). The results obtained from the study suggest that immunosuppressive MDSC and G-MDSC exosomes may play a role in immunomodulation. The effects of transplanted exosomes on the transfusion receptor are not yet known. The results of the study showed that exosomes are not affected by leukoreduction. One of the reasons why immunomodulation cannot be prevented by leukoreduction may be exosomes that can pass through filters.