Effective treatment of ocular HSK with a human apolipoprotein E mimetic peptide in a mouse eye model

PURPOSE. To evaluate efficacy of the small apolipoprotein E (apoE) mimetic dimer peptide (apoEdp) in the treatment of herpetic stromal keratitis in a mouse ocular model and determine its therapeutic effects against HSV-1-induced inflammatory cytokines. METHODS. Female C57B1/6 mice were corneally infected with HSV-1 strain KOS-GFP; topical treatment was initiated 24 hours after infection and continued for 10 consecutive days. Treatment groups were 1% apoEdp, 1% trifluorothymidine (TFT), and phosphate-buffered saline (PBS). The incidence and severity of stromal keratitis were monitored by slit lamp examination in a masked fashion. Infectious HSV-1 titer in eye swabs and alteration in inflammatory cytokines were determined in the early postinfection period by real-time RT-PCR. RESULTS. One percent apoEdp treatment, which significantly reduced the incidence and severity of HSK, was equal to the effect of 1% TFT; both groups had significantly lower incidence and severity than the placebo treatment group. The in vivo mouse ocular model results of apoEdp therapy correlated with accelerated clearance of virus from eye swabs. Topical 1% apoEdp treatment in mice significantly downregulated gene expression of mouse proinflammatory cytokines. CONCLUSIONS. These results suggest that topical treatment with apoE peptide has efficacy against HSK through anti-HSV-1 and anti-inflammatory activities.