The Chimera antigen receptor (CAR)-T cell therapy has gained great success in the clinic. However, there are still major challenges for its wider applications in a variety of cancer types including lack of effectiveness due to the highly complex tumor microenvironment, and the forbiddingly high cost due to the personalized manufacturing procedures. In order to overcome these hurdles, numerous efforts have been spent focusing on optimizing Chimera antigen receptors, engineering and improving T cell capacity, exploiting features of subsets of T cell or NK cells, or making off-the-shelf universal cells. Here, we developed induced pluripotent stem cells (iPSCs)-derived, CAR-expressing macrophage cells (CAR-iMac). CAR expression confers antigen-dependent macrophage functions such as expression and secretion of cytokines, polarization toward the pro-inflammatory/anti-tumor state, enhanced phagocytosis of tumor cells, and in vivo anticancer cell activity. This technology platform for the first time provides an unlimited source of iPSC-derived engineered CAR-macrophage cells which could be utilized to eliminate cancer cells.

RNA methylation is an important epigenetic modification. Recent studies on RNA methylation mainly focus on the m6A modification of mRNA, but very little is known about the m5C modification. NSUN2 is an RNA methyltransferase responsible for the m5C modification of multiple RNAs. In this study, we knocked down the NSUN2 gene in HepG2 cells by CRISPR/Cas9 technology and performed high-throughput RNA-BisSeq. An important tumor-related lncRNA H19 was identified to be targeted by NSUN2. Studies have shown that the expression of H19 lncRNA is abnormally elevated and has a carcinogenic effect in many types of tumors. Our results demonstrated that m5C modification of H19 lncRNA can increase its stability. Interestingly, m5C-modified H19 lncRNA can be specifically bound by G3BP1, a well-known oncoprotein which further leads to MYC accumulation. This may be a novel mechanism by which lncRNA H19 exerts its oncogenic effect. Besides, both the m5C methylation level and the expression level of H19 lncRNA in hepatocellular carcinoma tissues were significantly higher than those in adjacent non-cancer tissues, which were closely associated with poor differentiation of hepatocellular carcinoma (HCC). In conclusion, we found that H19 RNA is a specific target for the NSUN2 modifier. The m5C-modified H19 lncRNA may promote the occurrence and development of tumors by recruiting the G3BP1 oncoprotein. Our findings may provide a potential target and biomarker for the diagnosis and treatment of HCC.

Summary Circulating CD4+ CD25+ regulatory T cells (Tregs) have been demonstrated to maintain immunotolerance and suppress the antigen‐specific or antigen‐non‐specific T‐cell responses, but their role in chronic hepatitis B (CHB) infection in humans has not been well characterized. In this study, we analysed the frequency and phenotypic characteristics of CD4+ CD25+ Tregs in patients of different hepatitis B virus (HBV) infection status, and investigated the effect of Tregs on antiviral immune responses in CHB patients, and the mechanism of this effect. A total of 137 subjects, including 79 CHB patients, 26 asymptomatic HBV carriers (ASCs), 12 acute hepatitis B (AHB) patients and 20 healthy controls, were enrolled in the study. We found that the frequency of CD4+ CD25high Tregs in AHB patients was comparable to that in healthy controls, while it was significantly increased in CHB patients. CD4+ CD25+ Tregs produced interleukin (IL)‐10 but little or no interferon (IFN)‐γ under anti‐CD3 stimulation. In CHB patients, the frequency of CD4+ CD25high Tregs positively correlated with serum viral load, and the Tregs were capable of suppressing the proliferation and IFN‐γ production of autologous peripheral blood mononuclear cells (PBMC) mediated by HBV antigen stimulation in vitro. However, combined administration of anti‐programmed death‐1 (PD‐1) and anti‐cytotoxic lymphocyte antigen‐4 (CTLA‐4) monoclonal antibody slightly enhanced the cellular proliferation and significantly increased the IFN‐γ production of PBMC cocultured with Tregs at a ratio of 2 : 1. Thus, the frequency of circulating CD4+ CD25+ Tregs is increased in patients with CHB, and this may play an important role in viral persistence by modulating virus‐specific immune responses.

In this study, we compared four decellularization protocols and finally developed an optimized one through which a porcine bladder acellular matrix (BAM) with well-preserved extracellular bioactive factors had been prepared. In this protocol, the intact bladder was treated with trypsin/ethylenediaminetetraacetic acid to remove the urothelium, then with hypotonic buffer and Triton X-100 in hypertonic buffer to remove the membranous and cytoplasmic materials, and finally with nuclease to degrade the cellular nuclear components. Bladder distention and mechanical agitation were simultaneously used to facilitate cell removal. Meanwhile, several preservative techniques, including limitation of wash time, supplement with inhibitors of proteinase, control of the pH value and temperature of the wash buffer, ethylene oxide sterilization, and lyophilization of the scaffold for storage, were used to protect the extracellular bioactive factors. This decellularization protocol had completely removed the cellular materials and well preserved the extracellular collagen, sulfated glycosaminoglycan (GAG), and bioactive factors. The preserved bioactive factors had a great potential of promoting the proliferation and migration of both human bladder smooth muscle cell and human umbilical vein endothelial cell. It was also found that the amount of two representative bioactive factors, platelet-derived growth factor BB and vascular endothelial growth factor, was positively correlated with the sulfated GAG content in the porcine BAM, implying that the amount of sulfated GAG might be a determinant for preservation of bioactive factors in the decellularized tissues. In conclusion, the porcine BAM with well-preserved extracellular bioactive factors might be a favorable scaffold for tissue engineering applications.