Human Amniotic Mesenchymal Stem Cells Inhibit aGVHD by Regulating Balance of Treg and T Effector Cells

Abstract

Ya Gao,1,* Weiru Li,1,* Xiaoyin Bu,1,* Ying Xu,1 Shengchun Cai,1 Jinman Zhong,1 Meixue Du,1 Haitao Sun,2 Liping Huang,3 Yongjian He,4 Xiumei Hu,4 Qifa Liu,1 Hua Jin,1 Qian Wang,2,4 Baohong Ping5 1Department of Hematology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People’s Republic of China; 2Department of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, 510280, People’s Republic of China; 3Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People’s Republic of China; 4Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People’s Republic of China; 5Department of Hematology, Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People’s Republic of China*These authors contributed equally to this workCorrespondence: Baohong PingDepartment of Hematology, Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People’s Republic of ChinaTel [phone]Fax [phone]Email [email protected] WangDepartment of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People’s Republic of ChinaTel [phone]Fax [phone]Email [email protected]: Acute graft versus host disease (aGVHD) remains a leading cause of transplant-related mortality following allogeneic haematopoietic cell transplantation (allo-HCT). Human amniotic mesenchymal stem cells (hAMSCs) are a novel mesenchymal stem cells (MSCs), which have stronger proliferation and immunomodulatory ability compared with bone marrow mesenchymal stem cells (BM-MSCs). Besides, as the amniotic membrane is often treated as medical waste after delivery, hAMSCs can be obtained conveniently and noninvasively. The aim of this study was to explore the therapeutic efficacy and underlying mechanisms of hAMSCs transplantation for the humanized aGVHD mouse model.Methods: We established a humanized aGVHD mouse model by transplanting human peripheral blood mononuclear cells (PBMCs) into NOD-PrkdcscidIL2rγnull (NPG) mice, human amniotic membrane collected from discarded placenta of healthy pregnant women after delivery and hAMSCs were extracted from amniotic membrane and expanded in vitro. Mice were divided into untreated group (Control), aGVHD group (aGVHD), and hAMSCs treatment group (aGVHD+hAMSCs), the hAMSCs labeled with GFP were administered to aGVHD mice to explore the homing ability of hAMSCs. T effector and regulatory T cells (Tregs) levels and cytokines of each group in target organs were detected by flow cytometry and cytometric bead array (CBA), respectively.Results: We successfully established a humanized aGVHD mouse model using NPG mice. The hAMSCs have the ability to inhibit aGVHD in this mouse model through reduced villous blunting and lymphocyte infiltration of the gut while reducing inflammatory edema, tissue destruction and lymphocyte infiltration into the parenchyma of the liver and lung. hAMSCs suppressed CD3+CD4+ T and CD3+CD8+ T cell expression and increased the proportion of Tregs, and besides, hAMSCs can reduce the levels of IL-17A, INF-γ, and TNF in aGVHD target organs.Conclusion: The NPG murine environment was capable of activating human T cells to produce aGVHD pathology to mimic aGVHD as in humans. The hAMSCs controlled aGVHD by decreasing inflammatory cytokine secretion within target organs by modulating the balance of Tregs and T effector cells in humanized mice.Keywords: acute graft versus host disease, humanized mouse model, NPG mice, amniotic mesenchymal stem cells, immunomodulatory

Keywords

• acute graft versus host disease
• humanized mouse model
• npg mice
• amniotic mesenchymal stem cells
• immunomodulatory