Stimulation of bacterial biofilms on Th17 immune cells.

We investigated the role of bacterial biofilms in stimulating T helper 17 (Th17) cells in infected organisms. The formation of bacterial biofilms isolated from clinical lavage fluid samples was measured. Th17 cells and interleukin 17 (IL-17) levels in the peripheral blood of healthy individuals, people infected by biofilm bacteria, people infected by non-biofilm bacteria, and in the lavage fluid from people infected by bacteria were determined. Differences in those data were tested using the SPSS 17.0 statistical software. Th17 cells and IL-17 levels in the peripheral blood of biofilm bacteria-infected people, non-biofilm bacteria-infected people, and healthy controls were 0.59 ± 0.18% and 108.8 ± 20.5 pg/mL; 0.58 ± 0.18% and 100.1 ± 20.7 pg/mL; and 0.55 ± 0.17% and 100.0 ± 21.4 pg/mL, respectively; there were no statistically significant differences (P > 0.05). Th17 cells and IL-17 levels in the lavage fluid of biofilm bacteria-infected people and non-biofilm bacteria-infected people were 1.37 ± 0.34% and 157.4 ± 30.8 pg/mL; and 1.11 ± 0.21% and 136.2 ± 24.3 mg/mL, respectively; the differences were statistically significant (P < 0.05). Bacterial biofilms can increase the expression levels of Th17 cells and IL-17 in local infections; this may be the mechanism by which chronic injuries are caused by biofilm infections.