Artesunate promotes Th1 differentiation from CD4+ T cells to enhance cell apoptosis in ovarian cancer via miR-142

The aim of this study was to evaluate the influence of artesunate on Th1 differentiation and its anti-tumor effect on ovarian cancer. A Murine ovarian cancer model was established by ID8 cells transplantation. The expression of miR-142 and Sirt1 proteins in peripheral CD4+ T cells were quantified with qRT-PCR and western blot, respectively. Peripheral CD4+ T cells were induced for Th1 differentiation. The percentages of apoptosis of Th1/CD4+ T cells and ovarian cancer cells were analyzed by flow cytometry. The IFN-γ level was examined through enzyme-linked immunosorbent assay. Artesunate promoted miR-142 expression in peripheral CD4+ T cells and Th1 differentiation from CD4+ T cells. Artesunate promoted cell apoptosis of ovarian cancer cells by inducing Th1 differentiation. By up-regulating miR-142, artesunate suppressed Sirt1 level and promoted Th1 differentiation. Artesunate enhanced the pro-apoptotic effects of Th1 cells on ovarian cancer via the miR-142/Sirt1 pathway. Artesunate promoted Th1 differentiation from CD4+ T cells by down-regulating Sirt1 through miR-142, thereby enhancing cell apoptosis in ovarian cancer.

Elevated Levels of T Helper 17 Cells Are Associated with Disease Activity in Patients with Rheumatoid Arthritis

BACKGROUND: Interleukin-17 (IL-17)-producing T helper (Th) 17 cells are considered as a new subset of cells critical to the development of rheumatoid arthritis (RA). We aimed to investigate the distribution of Th1 and Th17 cells and their association with disease activity, and determine the Th17-related cytokine levels in the peripheral blood of RA patients. METHODS: Peripheral blood mononuclear cells from 55 RA and 20 osteoarthritis (OA) patients were stimulated with mitogen, and the distributions of CD4+Interferon (INF)+IL-17- (Th1 cells) and CD4+INF-IL-17+ (Th17 cells) were examined by flow cytometry. Serum levels of IL-6, IL-17, IL-21, IL-23, and tumor necrosis factor (TNF)-alpha were measured by ELISA. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were recorded. The 28-joint disease activity score (DAS28) was also assessed. RESULTS: The median percentage of Th17 cells was higher in RA patients than in OA patients (P=0.04), and in active than in inactive RA (P=0.03), whereas that of Th1 cells was similar in both groups. Similarly, the levels of IL-17, IL-21, and IL-23 were detected in a significantly higher proportion of RA patients than OA patients and the frequencies of detectable IL-6, IL-17, and IL-21 were higher in active RA than in inactive RA group. The percentage of Th17 cells positively correlated with the DAS28, ESR, and CRP levels. CONCLUSIONS: These observations suggest that Th17 cells and Th17-related cytokines play an important role in RA pathogenesis and that the level of Th17 cells in peripheral blood is associated with disease activity in RA.

Differences in Circulating Dendritic Cell Subtypes in Pregnant Women, Cord Blood and Healthy Adult Women

Different subtypes of dendritic cells (DC) influence the differentiation of naive T lymphocytes into T helper type 1 (Th1) and Th2 effector cells. We evaluated the percentages of DC subtypes in peripheral blood from pregnant women (maternal blood) and their cord blood compared to the peripheral blood of healthy non pregnant women (control). Circulating DC were identified by flow cytometry as lineage (CD3, CD14, CD16, CD19, CD20, and CD56)-negative and HLA-DR-positive cells. Subtypes of DC were further characterized as myeloid DC (CD11c+/CD123+/-), lymphoid DC (CD11c-/CD123+++) and less differentiated DC (CD11c-/CD123+/-). The frequency of DC out of all nucleated cells was significantly lower in maternal blood than in control (P<0.001). The ratio of myeloid DC/lymphoid DC was significantly higher in maternal blood than in control (P<0.01). HLA-DR expressions of myeloid DC as mean fluorescence intensity (MFI) were significantly less in maternal blood and in cord blood than in control (P<0.001, respectively). The DC differentiation factors, TNF-alpha and GM-CSF, released from mononuclear cells after lipopolysaccharide stimulation were significantly lower in maternal blood than in control (P<0.01). The distribution of DC subtypes was different in maternal and cord blood from those of non-pregnant women. Their role during pregnancy remains to be determined.

Association of TBX21 polymorphisms in a Korean population with rheumatoid arthritis

TBX21 (T-bet) is a member of the T-box family of transcriptional factors that contain a conserved DNA binding domain. TBX21 is a critical regulator of the commitment to the Th1 lineage and IFN-gamma production. Th1 and Th2 cells cross-regulate the differentiation of each other, and in this way TBX21 could be an attractive candidate gene for treating autoimmune disease such as rheumatoid arthritis (RA). In present study, we analyzed the genotypic frequencies of six polymorphisms of the TBX21 gene between the 367 RA patients and the 572 healthy controls. We showed that the g.-1514T>C and c.99C>G polymorphisms are suggestively associated with RA susceptibility. It is interesting that the genotypic frequencies of the TBX21 polymorphisms (g.-1514T>C and c.2103A>C) in the male RA patients were significantly different from the male control group (P = 0.0016 and 0.045, respectively). We also found that the g.-1514T>C and c.2103A>C polymorphisms of the TBX21 gene in the male RA patients have significant association with the levels of anti-CCP (P = 0.05) and rheumatoid factor (P = 0.03), respectively. These results suggest that the polymorphisms of the TBX21 gene might be associated with the susceptibility to male RA patients.

Expression of co-stimulatory molecules B7.1 & B7.2 on macrophages infected with various strains of Mycobacterium tuberculosis & its influence on T-cell apoptosis.

BACKGROUND & OBJECTIVE: Activation of T cells is mediated through two critical signals provided by activated macrophages. The first signal is triggered when T cell receptor (TCR) binds to the major histocompatibility antigen (MHC/Ag) complex. The second signal is the interaction of co-stimulatory molecules with their respective ligands on T cells for their activation and proliferation. We undertook this study to observe the modulation in B7.1 (CD80) and B7.2 (CD86) co-stimulatory molecules on Mycobacterium tuberculosis infected monocyte derived macrophages (MDM) and their role in T helper (Th1) cell apoptosis. METHODS: M. tuberculosis clinical strains (S7 and S10) and laboratory strains (H37Ra and H37Rv) were used to infect the MDMs. The modulation of apoptosis was assessed by treating T cells with anti-CD3 and anti-CD28 antibodies. The infected MDMs were co-cultured with autologous PPD pulsed T cells to ascertain the role of co-stimulatory molecules during infection. RESULTS: In infected MDMs, all strains on day 1 but only S7 on day 2 showed significant decrease (P<0.05) in B7.1 expression compared to uninfected. The expression levels of B7.2 were also low on day 1 in S7, S10 and H37Ra infected MDMs. The anit-CD3 induced apoptosis in PPD pulsed Tcells showed further reduction with anti-CD28 antibodies. However, the modulation observed in B7.1 expression in infected MDMs was not reflected in T cell apoptosis in co-culture experiments. INTERPRETATION & CONCLUSION: Our results confirmed the role of B7.1 in rescuing the activated Tcells from undergoing apoptosis. During infection when the expression of B7.1 is downregulated, other co-stimulatory molecules may take over its crucial role to confer protective immune response against M. tuberculosis.

The low efficiency of dendritic cells and macrophages from mice susceptible to Paracoccidioides brasiliensis in inducing a Th1 response

In the present study we evaluated T cell proliferation and Th lymphokine patterns in response to gp43 from Paracoccidioides brasiliensis presented by isolated dendritic cells from susceptible and resistant mice. T cell proliferation assays showed that dendritic cells from susceptible mice were less efficient than those from resistant mice. The pattern of T cell lymphokines stimulated by dendritic cells was always Th1, although the levels of IL-2 and IFN-gamma were lower in T cell cultures from susceptible mice. To determie whether different antigen-presenting cells such as macrophages and dendritic cells stimulated different concentrations of Th1 lymphokines, the production of IFN-gamma and IL-2 was measured. It was observed that dendritic cells were more efficient than macrophages in stimulating lymphoproliferation in resistant mice. However, no significant difference was observed for IFN-gamma or IL-2 production. When cells from susceptible mice were used, macrophages were more efficient in stimulating lymphoproliferation than dendritic cells, but no difference was observed in the production of Th1 cytokine. Taken together, these results suggest the lower efficiency of dendritic cells and macrophages from B10.A mice in stimulating T cells that secrete Th1 lymphokines in vitro, an effect that may be involved in the progression of the disease in vivo