Effects Of Triptolide And Triptolide On Interferon-stimulating Gene Expression In Peripheral Blood Mononuclear Cells

PurposeIn this study, we investigated in vitro if triptolide and celastrol, which are two major components of Tripterygium wilfordii Hook F (TwHF), could inhibit the expression of interferon-stimulated gene (ISG) after lipopolysaccharide (LPS) stimulation, to determine whether TwHF can reduce the degree of immune activation in HIV/AIDS patients, and try to offer a plausible explanation of the therapeutic mechanism of TwHF.MethodWe recruited26HIV/AIDS patients from the HIV/AIDS research center of Peking Union Medical College Hospital, in which9patients had been treated with cART (combined antiretroviral therapy) according to the current guidelines for more than6months, others were referred to as Naive patients who hadn’t receive any antiretroviral therapy, we also recruit8volunteers as healthy control group. After recruitment, PBMC was collected from the peripheral blood and cultured with different concentration of triptolide (1ng/ml,5ng/ml,10ng/ml) and celastrol (5ng/ml,10ng/ml,40ng/ml), with or without the stimulation of LPS (1ug/ml). Then we applied the extraction of total mRNA from the cultured cells and two-step PCR to measure the relative expression level of ISGs. The main statistical tests being used included Kolmogorov-smirnov test, Shapiro-Wilk test, Levene test, paired t test, etc. A P-value of<0.05was considered significant.Results1. Conditions of the recruited patients and control groupThe cART group (n=13):CD4+T cell count494.8±164.1/μl, with viremia completely restained. Naive group (n=13):CD4+T cell count278.1±191.1/μl Control group (n=8):HIV-Ab negative, Age25-26.2. The baseline expression level of ISGs were different between the three groups without LPS stimulationThe relative level of ISG15of the cART group, Naive group and Control group, were0.23±0.09,0.28±0.11,0.45±0.26respectively. 3. The expression level of ISGs were induced by LPSThe ISG15, MxA genes were strongly induced by the stimulation of LPS with the concentration at lug/ml (P<0.05), while MxB gene didn’t show much difference.4. The effect of triptolide and celastrol on the expression of ISGs stimulated by LPS in PBMCTreatment of triptolide (1ng/ml,5ng/ml,10ng/ml) and celastrol (5ng/ml,10ng/ml,40ng/ml) could significantly inhibit the expression level of ISGs with LPS stimulation, for example, the relative expression of ISG15gene was induced from9.64±1.40to2.35±0.51(P=0.000) with triptolide given at10ng/ml.Conclusion1. The expression level of ISGs reflects the degree of immune activation.2. LPS stimulation induces significant increasing in expression of ISGs.3. Triptolide and celastrol can inhibit the expression of ISGs, which is correlated with the degree of immune activation.