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Study of the effect of Microparticles on hematopoietic cell cultures (Bachelor thesis)

Βέσκου, Ευτυχία/ Veskou, Eftychia

Umbilical cord blood (UCB) represents a rich source of hematopoietic stem cells (HSCs), while it also contains other blood cell populations. These cells are capable of releasing extracellular vesicles, including microparticles generated during cellular activation or apoptosis. Microparticles act as carriers of bioactive molecules, participate in intercellular communication, and may influence multiple cellular processes. The aim of the present study was to investigate the effect of microparticles on THP-1 cell cultures under inflammatory conditions. To determine their potential immunomodulatory properties, an in vitro inflammation model was applied using lipopolysaccharide (LPS) derived from E. coli. The impact of microparticles’, in the presence or absence of LPS, was evaluated by assessing cell viability and analyzing the gene expression levels of TLR4, IL-1β, IL-8 and CXCL1. The the addition of LPS (100 ng/mL) or microparticles did not affect THP-1 cells viability. Two different microparticle isolation protocols were evaluated. TLR4 expression did not demonstrate statistically significant differences among the experimental groups in either undifferentiated or differentiated THP-1 cells. In contrast, LPS stimulation increased the expression of the cytokine IL-1β and the chemokine IL 8, while the effect of microparticles varied depending on the isolation protocol employed. Specifically, microparticles isolated from whole blood plasma induced an increase in IL-1β and IL-8 expression, whereas microparticles obtained after plasma concentration did not alter gene expression levels. CXCL1 expression showed only a mild increase in response to LPS. Overall, the findings suggest that microparticles do not promote a pro-inflammatory phenotype in THP-1 derived monocytes and macrophages.