Systemic administration of an anti-tumor necrosis factor-alpha monoclonal antibody protects against endotoxin-induced uveitis in rats

OBJECTIVE: This study was to evaluate the effect of systemic injection of an anti-tumor necrosis factor alpha (TNF-α) monoclonal antibody (mAb) on endotoxin-induced uveitis (EIU). MATERIALS AND METHODS: Fifty-six male Wistar rats (6–8 weeks old) were randomly divided into three groups: EIU, anti-TNF-α mAb + EIU, and control. EIU was induced by injecting Escherichia coli O55:B5 lipopolysaccharide (LPS) into the hind footpad of the rats (150 μg/rat). The anti-TNF-α mAb (1 μg/kg) was administrated 30 min before LPS injection through one-time intravenous injection. The onset time and peak time of EIU were recorded. The serum and aqueous humor (AH) TNF-α, interleukin (IL)-6, and IL-10 levels were measured by ELISA at 4, 24, and 72 h post-LPS injection. Clinical manifestations of EIU and eye histopathology were scored. RESULTS: Compared with the EIU rats, anti-TNF-α mAb + EIU rats showed significantly delayed onset of uveitis (t = 7.41, P < 0.001), lower clinical scores and histopathological grades (t = 3.18/2.22, P < 0.001), reduced levels of TNF-α (F = 15.06/59.43, P < 0.001) and IL-6 (F = 99.63/14.92, P < 0.001), and increased levels of IL-10 (F = 24.94/8.99, P < 0.001) in the serum and AH. AH TNF-α, serum IL-6, and AH IL-6 levels are positively correlated, whereas serum IL-10 levels were negatively correlated with EIU activity. CONCLUSION: Antagonizing TNF-α by system injection of the anti-TNF-α mAb protects against EIU in rats. Blocking TNF-α signaling could be a useful strategy for managing uveitis.