Abstract:

【Abstract】Objective  To investigate the expression of interferon-gamma (IFN-gamma) and interleukin 4 (IL-4) produced by the peripheral blood mononuclear cells from atopic dermatitis patients and normal controls under different concentrations(0mg/L, 50mg/L, 150mg/L and 250mg/L) of haptoglobin. Methods  The peripheral blood mononuclear cells were separated from 30 patients and 15 healthy controls by gradient centrifugation density, and cultured with or without the presence of haptoglobin for 72 hours. The concentrations of IFN-gamma　and IL-4 in the culture supernatant from all the subjects were measured by enzyme linked immnuosorbent　assay (ELISA). The expression of IFN-gamma and IL-4 gene in cultured peripheral blood mononuclear cells were detected by semiquantitative reverse-transcriptase-polymerase chain reaction (RT-PCR). Results  With comparison to normal controls, the level of IFN-gamma in patient’s culture supernatant was obviously lower(433.75±87.83 vs 567.76±51.51 ng/L) （P＜0.05）whereas IL-4 was higher (117.88±12.25 vs 101.84±12.86 ng/L ) （P＜0.05） without the presence of haptoglobin. But the expression of IFN-gamma(0.79±0.10 vs 0.56±0.11) and IL-4 (0.74±0.13 vs 0.65±0.10) gene were all increased（P＜0.05）. Haptoglobin resulted in a dose-dependent influence of  IFN-gamma and IL-4 release in culture supernatant from patients and controls. The level of IFN-gamma in the three culture systems（with haptoglobin 50mg/L, 150mg/L and 250mg/L）from patients and controls were 524.73±78.40/647.88±19.85 ng/L, 527.74±69.92/683.68±75.80 ng/L, 533.19±34.24/689.59±75.30 ng/L. The level of IL-4 from that were 100.57±12.46/94.97±11.82 ng/L, 91.32±11.81/90.74±10.93 ng/L, 74.56±11.71/74.76±13.58 ng/L. Which showed the release of IFN-gamma increased but IL-4 decreased. Influence was found on IFN-gamma and IL-4 gene expression in cultured cells from patients and normal controls under different concentrations of  haptoglobin. With haptoglobin increasing, IFN-gamma and IL-4 gene showed the tendency of gradually down in patients. The level of IFN-gamma gene was not consistent with the change of protein. IFN-gamma gene showed the tendency of up in normal controls which contrary to patients. The change on IL-4 gene was consistent with protein level. Conclusion  Haptoglobin plays a modulating role on the Th1/Th2 balance by promoting a dominant Th1 cellular response in atopic dermatitis patients . This points a role of haptoglobin in the immunoregulation of atopic dermatitis. A post-transcriptional defect was found in the peripheral blood mononuclear cells from atopic dermatitis patients in IFN-gamma.