CD4(+) depletion selectively inhibits eosinophil recruitment to the cornea and abrogates Onchocerca volvulus keratitis (River blindness).

Previous studies demonstrated that in the murine model of Onchocerca volvulus keratitis, neutrophils and eosinophils are recruited into the cornea in a biphasic manner in response to intrastromal injection. To determine if CD4(+) T cells regulate migration of neutrophils and eosinophils into the cornea, CD4(+) cells were depleted using monoclonal antibody GK1.5 before intrastromal injection of parasite antigens. Depletion of CD4(+) cells abrogated corneal opacification at later but not early stages of disease. Consistent with this observation, CD4 depletion significantly impaired recruitment of eosinophils to the cornea but had no effect on neutrophils. These data indicate that CD4(+) T cells mediate sustained O. volvulus keratitis by regulating eosinophil recruitment to the cornea.