Study On The Expression Level Of Toll-like Receptor-4 And Interleukin-17 In A Mouse Model Of Systemic Candidiasis

Objective:To study the relationship of histopathological changes and the levels of TLR-4 and IL-17 on systemic candidiasis, and the molecular mechanism of renal candidiasis.Methods: 40 BALB/c mice were divided into groups A-D: Control, low, medium and high doses(0, 103,104,105CFU/ml)of infection. By tail vein injection of a certain number of fungal spores, establish a murine model of systematic candidiasis. Organ fungal burden were determined with the plating dilution method. Sections of internal organs were made and stained by HE & PAS staining. The levels of TLR4 and IL-17 were detected by reverse transcription PCR (RT-PCR) method and enzyme-linked immunosorbent assay (ELISA).Results: The fungal colony counts in spleen or liver progressively declined in all infection mice and the histopathological changes were not obvious in 7 days. The 103 group had no significant pathological changes in renal tissue, but the colony counts in the kidney progressively increased in the 104 and 105 groups. The glomerular necrosis was obvious in the104 and 105 groups, and the hypha of Candida albicans was obvious in the kidney. The TLR4 was the most in 103 groups, while it was the least in 105 groups in the kidney. TLR4 in liver or spleen was more than that in kidney. IL-17 of renal tissure presented a tendency of increasing in the high does.Conclusion: The pathogenicity of Candida albicans is determined by the fungal doses. TLR4 levels in the visceral tissues are different under the same infectious condition. The TLR4 level in renal tissure is lower. With the increasing fungal burden, renal histopathological changes are obvious. The TLR4 level declined, the IL-17 level increased. TLR4 may play a key role in antifungal function. Inflammatory cytokine (IL-17) may promote renal candidiasis.