Protective effect of anti-glycoprotein D antibody on herpetic chorioretinitis in newborn rabbits

Subcutaneous injection of type 2 herpes simplex virus (HSV-2) (10(3) PFU) to newborn rabbits produced severe skin lesions and wide dissemination of the virus to various organs including the eye. Ocular lesions were characterized by retinal folds and choroiditis. HSV could be isolated from mononuclear cells (MNCs) of infected animal blood. Newborn rabbits treated with monoclonal antibody (MAb) against glycoprotein D (gD) of HSV on days 0, 2 and 4 postinfection had little or no skin lesions (0.0-2.3 mm) compared to controls (2.8-13.0 mm). In addition, the MAb treatment significantly suppressed dissemination of the virus to the eye (0% in MAb-treated vs 83% in control) and other organs and reduced the rate of chorioretinitis (0% in MAb-treated vs 50% in control). The treatment of HSV-infected MNCs with MAb resulted in 91-100% reduction in infectivity of the cells. The results suggest that anti-gD MAb protects newborn rabbits from HSV-2 eye infection by neutralizing the virus in skin and inactivating HSV-infected MNCs in blood.