BACKGROUND: Interleukin-18 (IL-18), a pro-inflamma- tory cytokine that induces interferon-γ (IFN-γ) production in T cells and natural killer cells, plays a critical role in the T-lymphocyte helper type 1 ( Th1) resp...BACKGROUND: Interleukin-18 (IL-18), a pro-inflamma- tory cytokine that induces interferon-γ (IFN-γ) production in T cells and natural killer cells, plays a critical role in the T-lymphocyte helper type 1 ( Th1) response. This study was designed to explore the effect of IL-18 on peripheral blood mononuclear cells ( PBMCs) derived from chronic hepatitis B (CHB) and on hepatitis B virus (HBV) DNA released by HepG2.2.15 cell lines, which were transfected with hepatitis B virus gene in vitro. METHODS: PBMCs isolated from 25 healthy people and 25 patients with CHB were stimulated with HBcAg and IL-18 of various concentrations for 72 hours. The levels of IFN-γ in the supernatants of cultured PBMCs were determined by ELISA. After the stimulation of IL-18 of various concentra- tions, PBMCs derived from one patient were co-cultured for 96 hours with HepG2. 2. 15 cells which had been cul- tured for 24 hours, and then the supernatants were collected by centrifugation and used for HBV DNA quantitative as- say. RESULTS: When PBMCs were stimulated by HBcAg and IL-18 at various concentrations, the levels of IFN-γ in the supernatants of CHB groups were much higher than those in normal control groups, at 0.2 ng/ml: t =11.70, P< 0.01; at 1.0 ng/ml: t =16.19, P<0.01; and at5.0 ng/ml: t =20.12, P <0.01. In the CHB groups, the levels of IFN-γ in the supernatants of PBMCs stimulated by HBcAg alone were lower than both those stimulated by HBcAg and EL-18 at various concentrations and those stimulated by HBcAg and EL-18 (5.0 ng/ml) together with EL-12 (mild: t = 2.20, P<0.05; moderate; t=2.97, P<0.05; severe; t = 0.66, P >0.05). The content of HBV DNA in the superna- tant of co-cultivation of HepG2. 2. 15 cells and PBMCs without stimulated materials was higher than that stimula-ted by HBcAg and EL-18 at various concentrations of HBc- Ag and IL-18 together with IL-12/IFN-α1lb. CONCLUSION: DL-18 can induce IFN-γ secretion and pro- bably play a key role in the modulation of both innate and adaptive immunity. It has implications in improving im- munoregulatory effect and increasing the ability of immune cells to kill cells infected by virus.展开更多
文摘BACKGROUND: Interleukin-18 (IL-18), a pro-inflamma- tory cytokine that induces interferon-γ (IFN-γ) production in T cells and natural killer cells, plays a critical role in the T-lymphocyte helper type 1 ( Th1) response. This study was designed to explore the effect of IL-18 on peripheral blood mononuclear cells ( PBMCs) derived from chronic hepatitis B (CHB) and on hepatitis B virus (HBV) DNA released by HepG2.2.15 cell lines, which were transfected with hepatitis B virus gene in vitro. METHODS: PBMCs isolated from 25 healthy people and 25 patients with CHB were stimulated with HBcAg and IL-18 of various concentrations for 72 hours. The levels of IFN-γ in the supernatants of cultured PBMCs were determined by ELISA. After the stimulation of IL-18 of various concentra- tions, PBMCs derived from one patient were co-cultured for 96 hours with HepG2. 2. 15 cells which had been cul- tured for 24 hours, and then the supernatants were collected by centrifugation and used for HBV DNA quantitative as- say. RESULTS: When PBMCs were stimulated by HBcAg and IL-18 at various concentrations, the levels of IFN-γ in the supernatants of CHB groups were much higher than those in normal control groups, at 0.2 ng/ml: t =11.70, P< 0.01; at 1.0 ng/ml: t =16.19, P<0.01; and at5.0 ng/ml: t =20.12, P <0.01. In the CHB groups, the levels of IFN-γ in the supernatants of PBMCs stimulated by HBcAg alone were lower than both those stimulated by HBcAg and EL-18 at various concentrations and those stimulated by HBcAg and EL-18 (5.0 ng/ml) together with EL-12 (mild: t = 2.20, P<0.05; moderate; t=2.97, P<0.05; severe; t = 0.66, P >0.05). The content of HBV DNA in the superna- tant of co-cultivation of HepG2. 2. 15 cells and PBMCs without stimulated materials was higher than that stimula-ted by HBcAg and EL-18 at various concentrations of HBc- Ag and IL-18 together with IL-12/IFN-α1lb. CONCLUSION: DL-18 can induce IFN-γ secretion and pro- bably play a key role in the modulation of both innate and adaptive immunity. It has implications in improving im- munoregulatory effect and increasing the ability of immune cells to kill cells infected by virus.
