CD47 and PD-L1 overexpression in proliferating human hepatocytes attenuated immune responses and ameliorated acute liver injury in mice

Hepatocyte transplantation has the potential to treat acute liver failure and correct liver-based metabolic disorders. Proliferating human hepatocytes (ProliHHs) provide a large-scale source as an alternative to primary human hepatocytes. However, host rejection led to inefficient graft survival and function, which hindered the clinical application of cell therapy. Herein, we employed the lentiviral system to overexpress immunomodulatory factors programmed death-ligand 1 (cluster of differentiation 274) (CD274) and cluster of differentiation 47 (CD47) in ProliHHs. CD47+274 overexpression inhibited macrophage and T cell responses in vitro. After transplantation into mice via the spleen without immunosuppression, CD47+274 ProliHHs accumulation in the liver significantly increased for 48 hours compared with ProliHHs. Consistent with the in vitro results, CD47+274 ProliHHs were less aggregated and infiltrated by macrophages and also recruited fewer T cells in the liver. Seven days after transplantation, the human albumin level of engineered ProliHHs doubled compared with control group. CD47+274 ProliHHs further ameliorated the liver injury induced using concanavalin A. Overall, our results suggested CD47+274 overexpression reduced innate and adaptive immune responses during hepatocyte transplantation, and the survival rate and graft function of transplanted hepatocyte-like cells were all significantly improved.