RESUMO
BACKGROUND: Regulatory B cells (Bregs) is an indispensable element in inducing immune tolerance after liver transplantation. As one of the microRNAs (miRNAs), miR-29a-3p also inhibits translation by degrading the target mRNA, and yet the relationship between Bregs and miR-29a-3p has not yet been fully explored. This study aimed to investigate the impact of miR-29a-3p on the regulation of differentiation and immunosuppressive functions of memory Bregs (mBregs) and ultimately provide potentially effective therapies in inducing immune tolerance after liver transplantation. METHODS: Flow cytometry was employed to determine the levels of Bregs in peripheral blood mononuclear cells. TaqMan low-density array miRNA assays were used to identify the expression of different miRNAs, electroporation transfection was used to induce miR-29a-3p overexpression and knockdown, and dual luciferase reporter assay was used to verify the target gene of miR-29a-3p. RESULTS: In patients experiencing acute rejection after liver transplantation, the proportions and immunosuppressive function of mBregs in the circulating blood were significantly impaired. miR-29a-3p was found to be a regulator of mBregs differentiation. Inhibition of miR-29a-3p, which targeted nuclear factor of activated T cells 5 (NFAT5), resulted in a conspicuous boost in the differentiation and immunosuppressive function of mBregs. The inhibition of miR-29a-3p in CD19+ B cells was capable of raising the expression levels of NFAT5, thereby promoting B cells to differentiate into mBregs. In addition, the observed enhancement of differentiation and immunosuppressive function of mBregs upon miR-29a-3p inhibition was abolished by the knockdown of NFAT5 in B cells. CONCLUSIONS: miR-29a-3p was found to be a crucial regulator for mBregs differentiation and immunosuppressive function. Silencing miR-29a-3p could be a potentially effective therapeutic strategy for inducing immune tolerance after liver transplantation.
RESUMO
Background: Despite the emergence of immune checkpoint inhibitors (ICIs) as first-line treatment for advanced hepatocellular carcinoma (HCC), there is an unmet need regarding subsequent treatments in patients that fail ICI. Regorafenib is a vascular endothelial growth factor receptor (VEGFR) inhibitor, which could increase programmed death-ligand 1 (PD-L1) expression in tumors and increase intra-tumoral CD8+ T-cell infiltration by normalizing the cancer vasculature and improving the efficacy of the programmed cell death protein 1 (PD-1) antibody. Thus, we evaluated the combination of regorafenib and a PD-1 inhibitor for advanced HCC patients that had failed combined tyrosine kinase inhibitors (TKIs) plus ICI. Methods: Data of patients with advanced HCC who had failed combined TKIs plus ICI treatment and were afterwards treated with combined regorafenib plus a PD-1 inhibitor were reviewed. All patients had received PD-1 inhibitors as part of the first-line treatment and regorafenib every 4 weeks until disease progression, intolerable toxicities, or physician/patient withdrawal. The clinical data, previous treatment strategies, follow-up imaging results, and adverse events (AEs) during follow-ups were recorded. Common Terminology Criteria for Adverse Events (CTCAE) v. 5.0 was used to evaluate AEs and Response Evaluation Criteria in Solid Tumors (RECIST) v. 1.1 was used to evaluate response. The primary endpoint was safety, and the secondary endpoints were the objective response rate (ORR), progression-free survival (PFS), disease control rate (DCR), overall survival (OS), and duration of response (DOR). Results: From November 15, 2020, to January 31, 2022, data of 17 patients with advanced HCC that met the criteria were reviewed. The cohort included 16 men and 1 woman with a median age of 54 years (interquartile range, 46 to 63 years). Sixteen patients had Child-Pugh class A (n=16, 94.12%) and one with class B (n=1, 15.9%) liver disease. Thirteen patients received second-line treatment, and the remaining patients received third-line treatment. All patients received at least 1 dose of PD-1 inhibitors. The median follow-up duration was 7.62 months. Twelve recipients experienced treatment-related AEs. The most frequent AE (≥5%) included fatigue (17.64%), diarrhea (17.65%), proteinuria (5.88%), bleeding gums (11.76%), and hypertension (11.76%). No grade-4 AE or new safety signals were identified. The ORR and DCR were 41.2% and 64.7%, respectively, and the median PFS was 5.09 months. Conclusions: Regorafenib combined with PD-1 inhibitor is a promising regimen in treating patients with advanced HCC owing to its safety and effectiveness as well as low incidence of serious AEs with its use.
