Expression Of TLR2 And Its Correlation With Th Cell Subsets In Patients With Early Syphilis

Objective To investigate the expression of Toll-like receptor 2 (TLR2) on the surface of CD14+ monocytes in peripheral blood and its correlation with Th1/Th2 cells in patients with untreated early syphilis; to explore the role of TLR2 in Treponema pallidum infection.Methods The expressions of TLR2 in peripheral blood monocytes (PBMCs) in 45 untreated early syphilitics (include 15 patients with primary syphilis, 15 with secondary syphilis and 15 with early latent syphilis) and 20 normal controls were detected by flow cytometry, and their levels of serum IFN-γ, IL-2, IL-4 and IL-10 which represent the percentages of Th1/Th2, were detected by ELISA.Results (1) Compared with the controls,percentages of CD14+ TLR2+ cells in patients with primary, secondary and early latent syphilis were increased significantly ( P <0. 05 ); the levels of Th1 cytokines (IFN-γand IL-2) in primary syphilics were respectively increased (P<0.01); the level of Th2 cytokine (IL-10) in secondary syphilics was notably increased (P<0.01); but there was no significant difference in the level of IFN-γ, IL-2, IL-4 and IL-10 in patients with early latent syphilis (P >0.05). (2) Compared with the primary group, percentages of CD14+ TLR2+ cells in patients with secondary and early latent syphilis were decreased notably and the levels of Th1 cytokines (IFN-γand IL-2) were significantly decreased (P <0.01); (3) The percentage of CD14+ TLR2+ cell was positively correlated with IL-4 (P<0.05), but had no correlation with RPR titer (P >0.05).Conclusions (1) There was an imbalance for Th1 and Th2 cytokines in peripheral blood in patients with early syphilis; Th1 cytokines were dominated in the early stage of syphilis, but they were decreased with the disease progressing, accompanying Th2 cytokines increase; (2) TLR2 and TLR2-mediated natural immunity play an important role in Treponema pallidum infection; TLR2 has a positive correlation with Th1 cytokines. These results suggest that TLR2 may be involved in the Th cells differentiation in patients with early syphilis and cause Th1 type immune response.