CD4(+) depletion selectively inhibits eosinophil recruitment to the corneaand abrogates Onchocerca volvulus keratitis (river blindness)

Previous studies demonstrated that in the murine model of Onchocerca volvul us keratitis, neutrophils and eosinophils are recruited into the cornea in a biphasic manner in response to intrastromal injection. To determine if CD 4(+) T cells regulate migration of neutrophils and eosinophils into the cor nea, CD4 cells were depleted using monoclonal antibody GK1.5 before intrast romal injection of parasite antigens. Depletion of CD4(+) cells abrogated c orneal opacification at later but not early stages of disease. Consistent w ith this observation, CD4 depletion significantly impaired recruitment of e osinophils to the cornea but had no effect on neutrophils. These data indic ate that CD4(+) T cells mediate sustained O. volvulus keratitis by regulati ng eosinophil recruitment to the cornea.