[Effect of IL-18 on peripheral blood monocytes from chronic hepatitis B patients].

OBJECTIVES

To explore the effect of IL-18 on peripheral blood monocytes (PBMCs) from chronic hepatitis B (CHB) patients and HBV DNA released by HepG2.2.15 cells, which were transfected with the gene of HBV.

METHODS

PBMCs were isolated from 25 healthy persons and 25 CHB patients, which were co-cultured with HBcAg and IL-18 at different concentrations for 72 hours. The level of IFN-gamma in the culture supernatant of PBMCs was determined by ELISA. One patient' PBMCs were co-cultured for 96 hours with various concentrations of IL-18 and HepG2.2.15 cells which had been cultured for 24 hours, the supernatant was collected to detect HBV DNA level by PCR.

RESULTS

When PBMCs were stimulated by HBcAg and IL-18 at various concentrations, the levels of supernatant IFN-gamma in the CHB group were much higher than those in the normal control group (at 0.2ng/ml: t=11.7, P<0.01; at 1.0ng/ml: t=16.19, P<0.01; at 5.0ng/ml: t=20.12, P<0.01), especially when the PBMCs were stimulated by HBcAg, IL-18 and IL-12 (1313.20pg/ml+-187.76pg/ml vs. 390.75pg/ml+-43.23pg/ml, t=23.94, P<0.01). The IFN-gamma level in the patients who were stimulated by HBcAg alone was much lower than the levels in the patients who were stimulated by HBcAg and IL-18 at various concentrations, and which were lower than those in the patients stimulated by HBcAg, IL-12 and IL-18 at the same concentrations (light: t=2.2, P<0.05; moderate: t=2.97, P<0.05). The HBV DNA content in the supernatant of co-cultivation with HepG2.2.15 cells and PBMCs was much higher than that of the two kinds of cells stimulated by HBcAg and IL-18 at various concentrations or HBcAg, IL-18 and IL-12/IFN-a1b.

CONCLUSION

IL-18 can improve the PBMCs from CHB patients to produce a great deal of IFN-gamma, so it has a good application prospect in two aspects: immunoregulatory effects and increasing the ability to kill the cells infected with virus.