Sinomenine promotes differentiation of induced pluripotent stem cells into immature dendritic cells with high induction of immune tolerance

Abstract

BACKGROUND Immature dendritic cells (imDCs) play an important role in the induction of donor-specific transplant immunotolerance. However, these cells have limitations, such as rapid maturation and a short lifespan in vivo . In previous studies, induced pluripotent stem cells (iPSCs) differentiated into imDCs, and sinomenine (SN) was used to inhibit the maturation of imDCs. AIM To study the capacity of SN to maintain iPSC-derived imDCs (SN-iPSCs-imDCs) in an immature state and the mechanism by which SN-iPSCs-imDCs induce immunotolerance. METHODS In this study, mouse iPSCs were induced to differentiate into imDCs in culture medium without or with SN (iPSCs-imDCs and SN-iPSCs-imDCs). The imDC-related surface markers, endocytotic capacity of fluorescein isothiocyanate-Dextran and apoptosis were analyzed by flow cytometry. The effects of iPSCs-imDCs and SN-iPSCs-imDCs on T-cell stimulatory function, and regulatory T (Treg) cell proliferative function in vitro were analyzed by mixed lymphocyte reaction. Cytokine expression was detected by ELISA. The apoptosis-related proteins of iPSCs-DCs and SN-iPSCs-DCs were analyzed by western blotting. The induced immunotolerance of SN-iPSCs-DCs was evaluated by treating recipient Balb/c skin graft mice. Statistical evaluation of graft survival was performed using Kaplan–Meier curves. RESULTS Both iPSCs-imDCs and SN-iPSCs-imDCs were successfully obtained, and their biological characteristics and ability to induce immunotolerance were compared. SN-iPSCs-imDCs exhibited higher CD11c levels and lower CD80 and CD86 levels compared with iPSCs-imDCs. Reduced major histocompatibility complex II expression, worse T-cell stimulatory function, higher Treg cell proliferative function and stronger endocytotic capacity were observed with SN-iPSCs-imDCs ( P < 0.05). The levels of interleukin (IL)-2, IL-12, interferon-γ in SN-iPSCs-imDCs were lower than those in iPSCs-imDCs, whereas IL-10 and transforming growth factor-β levels were higher ( P < 0.05). The apoptosis rate of these cells was significantly higher ( P < 0.05), and the expression levels of cleaved caspase3, Bax and cleaved poly(ADP-ribose) polymerase were higher after treatment with lipopolysaccharides, but Bcl-2 was reduced. In Balb/c mice recipients immunized with iPSCs-imDCs or SN-iPSCs-imDCs 7 d before skin grafting, the SN-iPSCs-imDCs group showed lower ability to inhibit donor-specific CD4 + T-cell proliferation ( P < 0.05) and a higher capacity to induce CD4 + CD25 + FoxP3 + Treg cell proliferation in the spleen ( P < 0.05). The survival span of C57bl/6 skin grafts was significantly prolonged in immunized Balb/c recipients with a do...

The relation of the frequency and functional molecules expression on plasmacytoid dendritic cells to postpartum hepatitis in women with HBeAg-positive chronic hepatitis B virus infection

“…Mature pDCs can secrete a large amount of cytokines with pleiotropic effects to directly inhibit viral replication during viral infection, and can also activate mDCs, T cells, NK cells and B lymphocytes to form protective immune response, becoming a bridge connecting natural immunity and acquired immunity, with strong ability to activate initial immune response. Immature pDCs have a strong ability to capture antigen, but the ability to present antigen is weak, making T cells cannot be fully activated, and have a strong ability to induce regulatory T cells, which mediates the induction and maintenance of immune tolerance (14)(15)(16)(17)(18).…”

“…However, the surface of immature DCs lacks some costimulatory molecules, which cannot provide necessary costimulatory signals for T cell activation, making T cells unable to be fully activated and in a state of loss of function, meanwhile, immature DCs also induce antigen specific regulatory T cells, block the functional response of effector T cells, and also can induce immune tolerance ( 12 – 14 ). Mature DCs stimulate T lymphocytes by expressing major histocompatibility complexes and costimulatory molecules, and secreting cytokines such as IFN, thus initiating the cellular immune response ( 14 , 15 ). At present, research suggests that CD86 is a marker of DC activation, and CD83 is a specific marker of DC maturation.…”

“…can induce immune tolerance(12)(13)(14). Mature DCs stimulate T lymphocytes by expressing major histocompatibility complexes and costimulatory molecules, and secreting cytokines such as IFN, thus initiating the cellular immune response(14,15). At present, research suggests that CD86 is a marker of DC activation, and CD83 is a specific marker of DC maturation.…”

Enhancing the anticancer immune response with the assistance of drug repurposing and delivery systems

“…The establishment of immune tolerance largely depends on stromal cells expressing ubiquitous self‐antigens in the thymus (e.g., the medullary thymic epithelial cells) as well as APCs and regulatory immune cells in the periphery (e.g., immature DCs). 75 , 76 Tumours can highly express antigens that are also expressed in normal tissue at relatively low levels, termed tumour‐associated antigens (e.g., carcinoembryonic antigen). Tolerance to this type of antigen is responsible for the suppressed anticancer immune response.…”