Effects of antimicrobial peptide LL-37 expressed and purified from prokaryotes in the murine model of vaginal candidiasis / 中华妇产科杂志

ABSTRACT

Objective To study the effects of antimicrobial peptide LL-37 expressed and purified from prokaryotes on candida albicans growth. Methods (1) Thirty female Kunming mice were treated with estrogen and white candida yeast suspension were poured into vagina to establish a vulvovaginal candidiasis (VVC) murine model. After successful establishing the VVC mouse model, mice were randomly sorted into test group (n=15) and control group (n=15) . Suspension(30μl, 100μg/ml)of recombinant peptide LL-37 expressed and purified in Prokaryotes was given by intravaginal administration to the test group for 5 days, while the same amount of phosphate buffered saline (PBS) was given to the control group. (2) Tweenty-four hours after treatment, the fungal burden and colony-forming unit (CFU) of vaginal fluids were evaluated. All mice were subsequently sacrificed and vaginal tissues were harvested for tissue homogenate preparation. ELISA was used to determine the levels of nterleukin-10(IL-10)and interferon-γ(IFN-γ)in the isolated vaginal tissues. Results (1) VVC mouse model was established successfully in this study. Vaginal mucosa congestion, edema, vaginal plica disappearing were obviously observed in the control group. After treatment with recombinant protein LL-37 vaginal mucosa has no obvious change in the test group. (2) Fungal burden and CFU of vaginal fluids were significantly lower in the test group [(4.8±1.0)×104 CFU/ml] than that in the control group [(8.5 ± 2.1) × 104 CFU/ml, P=0.017]. IFN-γlevel of the test group was increased [(257 ± 11) vs (197 ± 4) pg/ml, P=0.000], while the level of IL-10 was reduced [ (287 ± 15) vs (379 ± 17) pg/ml P=0.000] resulting in a the ratio of IFN-γ/IL-10 was in significantly higher in test group (0.892±0.008 vs 0.496±0.013, P=0.000). Conclusion Recombinant protein LL-37 expressed and purified from prokaryotes inhibits the growth candida albicans and improves vaginal immunity by adjusting IFN-γand IL-10 secretion in the VVC mouse model, highlighting the therapeutic potential of LL-37 for VVC.