OBJECTIVETo investigate the effects of different factors on the expressions of thymic stromal lymphopoietin (TSLP) in respiratory syncytial virus (RSV)-infected human airway epithelial cell line 16HBE cells.

METHODSRSV amplified by infecting Hep-2 cells was identified for its virulence. 16HBE cells were divided into six groups, namely the control group, RSV group, RSV/anti-TLR3 group, RSV/IFN-gamma group, RSV/IL-4 group and RSV/dexamethasone group with corresponding treatments. Real-time RT-PCR was used to examine the expression of TSLP mRNA in the cells 6 h after RSV infection. Western blotting was used to examine TSLP protein expression in the cells 24 h after the infection.

RESULTSThe expression of TSLP mRNA in 16HBE cells 6 h after RSV infection increased by 1.63-/+0.08 folds as compared to the expression level in the control cells. The expression of TSLP mRNA was significantly decreased in RSV-infected cells treated with anti-TLR3 antibody (P=0.034) and recombinant human IFN-gamma (P<0.001), but increased with the treatment by recombinant human IL-4 (P=0.025). Dexamethasone significantly inhibited the expression of TSLP mRNA in RSV-infected cells (P<0.001). The production of TSLP protein in 16HBE cells increased by 1.9 folds (P<0.001) 24 h after RSV infection, but underwent no significant changes after treatment with anti-TLR3 antibody (P=0.114). Recombinant human IFN-gamma significantly decreased while IL-4 enhanced the expression of TSLP protein in the infected cells (P=0.020 and 0.014, respectively). Dexamethasone significantly inhibited the increment of TSLP protein expression in RSV-infected cells (P<0.001).

CONCLUSIONSRSV infection can enhance the expressions of TSLP in human airway epithelial cells. IFN-gamma, anti-TLR3 and dexamethasone can inhibit the elevation of TSLP expression induced by RSV infection, but IL-4 synergistically enhances its expression.