Search

The aim of this study was to determine the biological function of hpsh4590 in Helicobacter pylori . After Hpsh4590 was expressed using a prokaryotic expression system, the cytotoxic effects and IL-8 production of Hpsh4590 were analyzed by co-culturing with GES-1 cells. Meanwhile, the antibody of rHpsh4590, produced by immunizing rabbit, was used for localization and protein interaction studies. Hpsh4590 fusion protein was expressed successfully in Escherichia coli Rosetta (DE3), and the polyclonal antibody was produced at high titers. The MTT assay showed that the inhibition ratio of GES-1 cells cultured with 0.1 μg/mL rHpsh4590 (3.02% ± 0.02%) was significantly lower than that of 20 μg/mL rHpsh4590 (57.57% ± 0.03%, p < 0.01 ), while DAPI staining showed the cytotoxic effects of rHpsh4590 for GES-1 cells. The up-regulation of cleaved caspase-3 and cleaved PARP was observed after GES-1 cells co-cultured with rHpsh4590 by Western blot. Co-culturing of GES-1 cells with rHpsh0459 (20 μg/mL) led to significant production of IL-8 at 12 h(1097.74 ± 212.37 pg/mL) and 24 h (1379.55 ± 209.58 pg/mL) then at 6 h(134.68 ± 14.64 pg/mL, p < 0.01). These observations suggest that the cytotoxicity of Hpsh4590 occurred in a concentration dependent manner, which is related with IL-8 secretion from gastric mucosal epithelial cells. Hpsh4590 was found localized in the membrane and the periplasm of H. pylori , interacted with zinc finger protein and methionine ABC transporter ATP-binding protein, and potentially regulates DNA uptake or transfer. [ABSTRACT FROM AUTHOR]

Abstract: CD4+ T cells are the main targets of HIV-1 and play a central role during the progression of AIDS, but the mechanism has not been clearly elucidated. In the present study, blood samples were collected from HIV-1-infected Chinese individuals, including typical progressors (TPs) and long-term nonprogressors (LTNPs). More HIV-1 productively infected CD4+ T cells were obtained through co-cultures and the infected CD4+ T cells were discriminated from bystander cells by intracellular p24 staining. The activation level and dynamics of cytokine expression of CD4+ T cells were analyzed. After stimulating the freshly isolated PBMCs with PHA, the frequencies of CD69+CD4+ T cells/CD25+CD4+ T cells were higher in TP than in LTNP group and were positively correlated with viral load and negatively correlated with CD4+ T cell counts. The activation level of CD4+ T cells in the co-cultured PBMCs was higher in TP than in LTNP group, and HIV-1 productively infected CD4+ T cells were more activated than bystander CD4+ T cells. The expression of Th1 cytokines (IL-2 and IFN-γ) and the frequency of Th1 cells in co-cultured PBMCs were lower in TP than in LTNP group. HIV-1 productively infected CD4+ T cells expressed higher level of Th1/Th2 cytokines than bystander cells. More productive HIV-1 infection occurred in Th1 than in Th2 cells, followed by Th0 cells. The present results suggest that the excessive activation level of CD4+ T cells and the preferential replication of HIV-1 in Th1 cells that lead to the shift of Th1 to Th2 are likely crucial to AIDS progression in HIV-1-infected Chinese individuals. [Copyright &y& Elsevier]