PD-L1 Expression on Circulating CD34+ Hematopoietic Stem Cells Closely Correlated with T-cell Apoptosis in Chronic Hepatitis C Infected Patients
- Author:
Hussein ABDELLATIF
1
;
Gamal SHIHA
Author Information
- Publication Type:Original Article
- Keywords: CD34+ HSCs; PD-L1; B7-H1; T-lymphocytes; Apoptosis; HCV
- MeSH: Apoptosis; Coculture Techniques; Flow Cytometry; Hematopoietic Stem Cells; Hepatitis C, Chronic; Hepatitis, Chronic; Homeostasis; Humans; Immune System; Immunomagnetic Separation; Liver; Lymphocytes; Polymerase Chain Reaction; Stem Cell Research; T-Lymphocytes; Transplantation, Homologous
- From:International Journal of Stem Cells 2018;11(1):78-86
- CountryRepublic of Korea
- Language:English
- Abstract: BACKGROUND AND OBJECTIVES: Lack of understanding of the interplay between hematopoietic stem cells (HSCs) and the immune system has severely hampered stem cell research. Programmed death-1 (PD-L1) has been reported on parenchymal cells in patients with chronically inflamed livers and found to play an essential role in T cell homeostasis regulation. However, the bidirectional interaction between HSCs and lymphocytes remains elusive. Here, we aimed to get more insight into circulating CD34+ HSCs PD-L1 expression and T cell apoptosis in chronic HCV infected patients. METHODS: CD34+ HSCs were isolated and purified by immunomagnetic separation. PD-L1 expression was analyzed by quantitative PCR and flow cytometry. Furthermore, co-culture experiments between CD34+ HSCs and T-lymphocytes were established. T-cell lymphocyte apoptosis in peripheral blood and in cultures was detected. RESULTS: CD34+ HSCs constitutively express low levels of PD-L1. Its expression is up-regulated in chronic HCV infected patients. Moreover, PD-L1 expression on circulating CD34+ HSCs enhanced T cell apoptosis in peripheral blood and co-culture. CONCLUSION: Our results suggest novel bidirectional interplay between HSCs and lymphocytes mediated by PD-L1 expression on CD34+ HSCs. PD-L1 expression correlated with T-cell lymphocyte apoptosis. This may contribute to immunomodulatory properties of HSCs which improves its use for allogeneic transplantation.
