Jun-Xia Wang

Investigation of the immunosuppressive activity of artemether on T-cell activation and proliferation

Artemisinin and its derivatives exhibit potent immunosuppressive activity. The purpose of the current study was to examine the immunosuppressive activity of artemether directly on T lymphocytes and to explore its potential mode of action.

SM905, an artemisinin derivative, inhibited NO and pro-inflammatory cytokine production by suppressing MAPK and NF-κB pathways in RAW 264.7 macrophages

AbstractAim:To elucidate the anti-inflammatory potentials and underlying mechanisms of SM905, a novel artemisinin derivative, in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells.Methods:Nitric oxide (NO) generation, cytokine production, and the protein expression levels of inducible nitric-oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were examined using a Griess assay, an enzyme-linked immunosorbent assay (ELISA) and a Western blotting assay, respectively. The mRNA expression was measured using real-time PCR. The phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2), p38, c-jun N-terminal kinase (JNK), and the degradation of IκBα were assessed by Western blotting analysis. The nuclear translocation of nuclear factor-κB (NF-κB) was observed using confocal microscopy.Results:Pretreatment with SM905 (0, 0.1, 1, and 10 μmol/L) suppressed LPS-induced NO, TNF-α, IL-1β, and IL-6 production, and decreased both protein and mRNA levels of iNOS and COX-2. The mRNA expression of LPS receptor Toll-like receptor 4 (TLR4) and myeloid differentiation protein-2 (MD-2) was not changed, while LPS-induced CD14 expression was slightly reduced after SM905 treatment. SM905 markedly decreased the activation of ERK1/2, p38 and JNK suppressed the degradation of IκBα, but did not modify the expression of interferon regulatory factor-1 (IRF-1), signal transducer and activator of transcription 1 (STAT1) or interferon-inducible protein-10 (IP-10). By using confocal microscopy, we further observed that NF-κB was correspondingly inhibited in SM905-treated cells.Conclusion:SM905 inhibited NO and pro-inflammatory cytokine production in LPS-stimulated RAW 264.7 cells and these effects are at least partially mediated through suppression of the MAPK and NF-κB signaling pathways.

The new water-soluble artemisinin derivative SM905 ameliorates collagen-induced arthritis by suppression of inflammatory and Th17 responses

Our previous study showed that SM905, a novel artemisinin derivative, exhibited potent immunosuppressive activity. In this study, we evaluate preventive and therapeutic effect of SM905 on collagen‐induced arthritis (CIA) in DBA/1 mice, and investigate its mechanisms both in inflammatory and autoimmune aspects of the disease.

A novel artemisinin derivative, 3-(12-beta-artemisininoxy) phenoxyl succinic acid (SM735), mediates immunosuppressive effects in vitro and in vivo.

AbstractAim:To study the immunosuppressive activity of SM735 {[3 -(12-β-artemisininoxy)] phenoxyl succinic acid}, a synthetic artemisinin derivative with nonsteroidal anti-inflammatory drug structure, with the aim of finding potential immunosuppressive agents.Methods:Concanavalin A (ConA), lipopolysaccharide (LPS), and mixed lymphocyte reaction (MLR), were used to induce the proliferation of splenocytes, and [3H]-thymidine incorporation was used to evaluate the proliferation of splenocytes. Cytokine production was promoted with ConA, LPS, or PMA plus ionomycin, and was detected with the enzyme-linked immunosorbent assay. Dinitrofluorobenzene (DNFB) and sheep red blood cells (SRBC) were used to induce delayed-type hypersensitivity and quantitative hemolysis of SRBC (QHS) mouse models, as criteria for the evaluation of in vivo immune activity.Results:SM735 strongly inhibited the proliferation of splenocytes induced by ConA, LPS, or MLR, with IC50 values of 0.33 μmol/L, 0.27 μmol/L, and 0.51 μmol/L, respectively. When compared with a CC50 value of 53.1 μmol/L, SM735 had a favorable safety range. SM735 dose-dependently inhibited proinflammatory cytokine production [including interleukins (IL)-12, interferon (IFN)-γ and IL-6] induced by LPS or PMA plus ionomycin. Upon ConA stimulation, SM735 suppressed IFN-γ in a dose-dependent manner, but did not affect IL-2 secretion. SM735 also strongly suppressed both T-cell-mediated delayed-type hypersensitivity (DTH) and B-cell-mediated QHS reactions.Conclusion:SM735 had strong immunosuppressive activity in vitro and in vivo, suggesting a potential role for SM735 as an immunosuppressive agent, and established the groundwork for further research onSM735.

SM934, a water-soluble derivative of arteminisin, exerts immunosuppressive functions in vitro and in vivo.

In the present study, we investigated the immunosuppressive effects and underlying mechanisms of beta-aminoarteether maleate (SM934), a derivative of artemisinin, against T cell activation in vitro and in vivo. In vitro, SM934 significantly inhibited the proliferation of splenocytes induced by concanavalin A (Con A), lipopolysaccharide (LPS), mixed lymphocyte reaction (MLR), and anti-CD3 plus anti-CD28 (anti-CD3/28). SM934 significantly inhibited interferon (IFN)-gamma production and CD4(+) T cell division stimulated by anti-CD3/28. SM934 also promoted apoptosis of CD69(+) population in CD4(+) T cells stimulated by anti-CD3/28. Furthermore, SM934 inhibited interleukin (IL)-2 mediated proliferation and survival through blocking Akt phosphorylation in activated T cells. In ovalbumin (OVA)-immunized mice, oral administration of SM934 suppressed OVA-specific T cell proliferation and IFN-gamma production. SM934 treatment also significantly inhibited the sheep red blood cell (SRBC)-induced delayed type hypersensitivity (DTH) reactions in mice. Taken together, SM934 showed potent immunosuppressive activities in vitro and in vivo. Our results demonstrated that SM934 might be a potential therapeutic agent for immune-related diseases.

S-adenosyl-L-homocysteine hydrolase inactivation curtails ovalbumin-induced immune responses

The reversible S-adenosyl-l-homocysteine (AdoHcy) hydrolase inhibitor methyl 4-(adenin-9-yl)-2-hydroxybutanoate (DZ2002) suppresses macrophage activation and function. The effects of DZ2002 on T cell function, however, are still unclear. Here, we examined whether DZ2002 alters type 1 helper T cell (Th1) and/or type 2 helper T cell (Th2) immune responses, and whether these effects are associated with both the inhibition of AdoHcy hydrolase and intracellular elevation of endogenous AdoHcy. Male C57BL/6 mice immunized with ovalbumin (OVA) were treated with DZ2002 (1, 5, and 25 mg/kg/day) after which lymphocyte proliferation, cytokine production, and IgG responses to OVA were monitored. Administration of DZ2002 dose dependently suppressed OVA-specific lymphocyte proliferation and anti-OVA IgG production compared with controls. Interleukin (IL)-2 and interferon (IFN)-γ as well as anti-OVA IgG2a and IgG3, indicators of Th1 immune responses, were markedly decreased in mice treated with DZ2002, whereas IL-4 and anti-OVA IgG1, indicators of Th2 immune responses, were only mildly suppressed. AdoHcy hydrolase activity in spleens of DZ2002-treated mice was substantially blocked, and not surprisingly, AdoHcy levels were significantly elevated compared with controls. Finally, similar immunosuppressive effects were also observed in mice treated with AdoHcy. These data strongly indicate that DZ2002 suppresses antigen-induced specific immune responses, particularly Th1 responses, through inhibition of AdoHcy hydrolase and elevation of endogenous AdoHcy.

(5 R )-5-hydroxytriptolide inhibits IFN-γ-related signaling

AbstractAim:(5R)-5-hydroxytriptolide (LLDT-8) displayed anti-arthritis and anti-allogenic transplantation rejection activities in our previous studies. Here, we aim to further clarify the effect of LLDT-8 on the pro-inflammatory cytokine IFN-γ.Methods:T cells were activated with anti-CD3 antibody or concanavalin A (ConA). The expression of cell surface molecules was detected with flow cytometry. Cells were labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) to test cell division. IFN-γ production was determined by enzyme-linked immunosorbent assay. Cell proliferation was evaluated by [3H]-thymidine uptake. Mice were immunized with ovalbumin to assess the in vivo immune response. RT-PCR and Real-time PCR were applied to determine the mRNA expression. The protein phosphorylation levels were detected by Western immunoblot assay.Results:LLDT-8 at 100 nmol/L did not change the CD25, CD69, and CD154 expressions in anti-CD3-stimulated T cells. LLDT-8 markedly blocked the cell division of CD4 and CD8 T cells after ConA stimulation. LLDT-8 inhibited T cell-derived IFN-γ production. Moreover, LLDT-8 suppressed the ovalbumin-specific T cell proliferation and IFN-γ generation. In anti-CD3-activated T cells, LLDT-8 abrogated the mRNA expression of signal transducer and activator of transcription 1 (STAT1), T-box transcription factor, IL-12 receptor β2, STAT4, and interferon regulatory factor 1 in the IFN-γ expression pathway. Western blot analysis showed that LLDT-8 blocked the phosphorylation levels of extracellular signal-regulated kinase, stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase in anti-CD3 plus anti-CD28-activated T cells. In addition, LLDT-8 reduced the transcripts of macrophage inflammatory protein (Mip)-1α, Mip-1β, regulated upon activation normally T-cell expressed and secreted, induc-ible protein-10, IFN-inducible T cell a chemoattractant, and monokine induced by IFN-γ in IFN-γ-stimulated murine macrophage cell line Raw 264.7 cells.Conclusion:LLDT-8 was a potential inhibitor for IFN-γ-associated signaling.