Abstract:

Objective To explore the expression of the regulatory T cell transcription factor Foxp3 and interleukin-8(IL-8) in liver lesions in patients with echinococcosis. Methods Liver tissues were collected from 16 patients with alveolar echinococcosis(AE), 23 patients with cystic echinococcosis(CE) and 8 patients with hepatic hemangioma. HE staining and immunohistochemical(IHC) analysis were performed to examine Foxp3 in liver tissue. Western blotting was performed to detect protein levels of Foxp3. Total RNA was extracted from liver tissue by Trizol, and the mRNA levels of Foxp3 and IL-8 were tested by Real-time PCR. The correlation between Foxp3 and IL-8 was analzyed by Spearman method. Between-group comparisons were made by t test. 　Results  H&E staining results showed incomplete horny layer and growth layer of the liver in AE cases, a thick horny layer in CE cases, and complete liver structures in hepatic hemangioma cases. Liver IHC results showed abundant cells positive for Foxp3 in the AE group, in contrast with few in the CE group and absence in  the hepatic hemangioma cases. Western blotting analysis revealed that the gray values of Foxp3 were (0.977 ± 0.082), (0.728 ± 0.094), and (0.290 ± 0.084), respectively in the AE, CE and hepatic hemangioma groups. There were significant differences in the gray value between AE or CE group and the hepatic hemangioma group(both P < 0.05), but there was no difference between AE and CE groups（P > 0.05）. Results of real-time PCR showed that the relative levels of Foxp3 mRNA were(0.013 ± 0.003), (0.007 ± 0.002), and (0.004 ± 0.001), respectively in the AE, CE and hepatic hemangioma groups. There was a significant difference in the Foxp3 mRNA level between AE and hepatic hemangioma groups (P < 0.05), but no difference was found for CE versus AE or CE versus hepatic hemangioma(P > 0.05). The IL-8 mRNA levels were(0.402 ± 0.068), (0.005 ± 0.019), and(0.002 ± 0.001), respectively in the AE, CE and hepatic hemangioma groups, with significant differences for all the between-group comparisons(P < 0.01). The Spearman correlation analysis demonstrated that the Foxp3 and IL-8 mRNA levels were positively correlated in the AE group (r = 0.802, P < 0.01).  Conclusion Foxp3 and IL-8 mRNA in the liver tissue are both higher in AE than in CE, suggesting that AE may stimulate secretion of a large amount of IL-8, which, together with Foxp3, causes severe inflammation at the foci.

Key words: Cystic echinococcosis, Alveolar echinococcosis, Regulatory T cell, Transcription factor Foxp3, Interleukin-8