Secreted Factors from Umbilical Cord-Mesenchymal Stem Cells Affect CD86 Expression on B Lymphocytes and Increase CCL5 Chemokine Secretion by Healthy Donors' PBMC

A growing number of autoimmune diseases, allergies, and atopic conditions in recent years are calling for the development of innovative therapies, such as those using stem cells with immunoregulatory activity. Because of the few and often conflicting results in the scientific literature, it is still uncertain whether mesenchymal stem cells (MSC) could be a useful therapeutic strategy for targeting B lymphocytes and be helpful in treating autoimmune and allergy patients or those with a variety of viral infections. In connection with the aforementioned, our team investigated the influence of umbilical cord MSC-secreted factors on healthy donors' B-cell CD86 expression and CCL5 secretion by peripheral blood mononuclear cells (PBMC) in vitro. When healthy donors' PBMC were cultivated with conditioned medium derived from umbilical cord MSC, CD86 density on the B-cell membrane statistically decreased, but the percentage of B cells expressing this co-stimulatory molecule was slightly but significantly increased. We also found significantly increased secretion of the chemokine CCL5 by PBMC under the influence of the MSC secretome.