Obejctive Superantigens are potent inflammatory stimuli which derive from pathogenic microbes such as bacteria, viruses and protozoa The aim of this study was to investigate the role of superantigens on the function of rabbit maxillary sinus epithelium Methods Twenty New Zealand white rabbits were divided into 4 groups Rabbit sinus mucosa was separated under a surgical microscope and mounted in Ussing chambers to record short circuit current, conductance and permeability to horseradish peroxidase (HRP) Group A was used as normal control Group B was stimulated with an injection of superantigen into the sinus for 4 hours The sinus mucosa of Group C was stimulated by the addition of tumor necrosis factor α (TNF α) into Ussing chambers Group D sinus mucosa was stimulated by superantigen after pretreatment with anti TNF α antibody Results Superantigen evoked increases in sinus epithelial cell baseline short circuit current, conductance and permeability to HRP stimulated by the addition of TNF α into Ussing chambers These were similar to results from superantigen stimulation in vivo The effect of superantigen on sinus epithelial cells could be blocked by pretreatment with anti TNF α antibody Conclusions Superantigen affected the function of sinus epithelial cells, including the capability of epithelial defensive barrier, which might be mediated by TNF α Obejctive Superantigens are potent inflammatory stimuli which derive from pathogenic microbes such as bacteria, viruses and protozoa The aim of this study was to investigate the role of superantigens on the function of rabbit maxillary sinus epithelium Methods Twenty New Zealand white rabbits were divided into 4 groups Rabbit sinus mucosa was separated under a surgical microscope and mounted in Ussing chambers to record short circuit current, conductance and permeability to horseradish peroxidase (HRP) Group A was used as normal control Group B was stimulated with an injection of superantigen into the sinus for 4 hours The sinus mucosa of Group C was stimulated by the addition of tumor necrosis factor α (TNFα) into Ussing chambers Group D sinus mucosa was stimulated by superantigen after pretreatment with anti TNF α antibody Results Superantigen evoked increases in sinus epithelial cell baseline short circuit current , conductance and permeability to HRP stimulat ed by the addition of TNF α into Ussing chambers These were similar to results from superantigen stimulation in vivo The effect of superantigen on sinus epithelial cells could be blocked by pre treatment with anti TNF α antibody Conclusions Superantigen affected the function of sinus epithelial cells, including the capability of epithelial defensive barrier, which might be mediated by TNFα