Abstract:

Objective To investigate the expression of Toll-like receptor 2（TLR2） and TLR4 mRNA in peripheral blood mononuclear cells （PBMC） and in the liver of patients with hepatic alveolar echinococcosis （HAE）, and their correlations with related cytokines in plasma. Methods Twenty-eight HAE patients hospitalized in the First Affiliated Hospital of Xinjiang Medical University during January 2012 and June 2015 and 28 healthy volunteers as a control were enrolled in this study. Plasma levels of interferon-γ （IFN-γ）, interleukin-5 （IL-5）, IL-23, and IL-10 were measured by ELISA. qRT-PCR was performed to detect TLR2 and TLR4 mRNA levels in PBMCs and hepatic tissues. The percentage of peripheral blood eosinophil （Eo%） was determined by a hematology analyzer. The correlations of TLR2 and TLR4 mRNA levels in PBMCs with levels of related cytokines and Eo% were analyzed with the Spearman Correlation method. Results ELISA results showed that the plasma levels of IFN-γ, IL-5, IL-23, and IL-10 in the HAE group were （301.100±47.290）, （43.420±11.380）, （86.580±31.990） and （8.766±7.568） pg/ml respectively, which were higher than those in the control［（301.100±67.790）, （40.970±6.310）, （46.770±15.490） and （6.272±10.360） pg/ml］ with a statistical significance for IL-23 （P<0.01）. Results of qRT-PCR showed that the expression level of TLR2 in the HAE group （0.100±0.084） was significantly higher than that in the control （0.055±0.040） （P<0.05）, while the expression level of TLR4 in the HAE group （0.004±0.003） was comparable to that in the control（0.003±0.002）（P>0.05）. The expression of TLR2 and TLR4 mRNA in HAE lesions in the HAE group（29.680±25.650 and 21.340±16.640, respectively） were both significantly higher than that in para-lesion regions（2.308±4.140 and 5.541±9.233） and that in tissues of the control （1.112±1.431 and 1.100±1.734）（P<0.01）. There was also a significant difference in Eo% between the HAE（0.448±0.240） and the control（0.110±0.100） groups. Spearman correlation coefficients revealed a positive correlation of TLR2 mRNA in PBMCs with plasma IL-23 level and peripheral blood Eo% in HAE subjects（r=0.368, r=0.382, respectively）. Conclusion There are increases in TLR2 and TLR4 mNRA expression in PBMCs and in HAE lesions in HAE patients. The TLR2 mNRA expression in PBMCs positively correlates with plasma IL-23 level and peripheral Eo%.

Key words: Hepatic alveolar echinococcosis, Toll-like receptor, Cytokines, Immune modulation, Immune tolerance