Higher toll-like receptor 3 expression in umbilical cord blood B cells than in adult blood B cells

Background Umbilical cord blood (UCB), which is considered a rich source of stem cells, has been used for applications in different clinical settings. Therefore, it is crucial to examine the toll-like receptor (TLR) expression levels in UCB B cells as compared to adult blood cells. Aim To determine the phenotypes of B cells in UCB and to investigate their expression of TLR3 as compared to adult blood. Patients and methods Samples of UCB were collected (n=20) after delivery, and peripheral blood samples were collected from female healthy volunteers (n=10) in K2EDTA tubes. Cells were washed twice, then stained using anti-CD19 and anti-TLR3. The samples were acquired by flow cytometry to assess the phenotype of B cells and their expression of TLR3. Besides, the liver and kidney functions were assessed. Results The relative number of CD19(+) cells showed lower numbers (5.35%) in UCB than adult blood (15.64%). Additionally, the absolute number of CD19(+) cells showed lower numbers by two-fold in cord blood than in adult blood. The relative expression of TLR3 on CD19(+) cells showed lower expression in UCB as compared to adult blood by 5.8-fold. However, the absolute number of TLR3+CD19(+) was higher in UCB than in adult blood by two-fold. The liver and kidney function showed normal values as investigated the enzyme activity of aspartate aminotransferase, alanine aminotransferase, bilirubin, and creatinine in both cord and adult. Conclusion B cells express lower TLR3 in cord blood than in adult blood. The data from this study open new avenues for the manipulation of cord blood by TLR agonists for clinical application.