title: Immunopathology of ocular onchocerciasis 3. Th-2 helper T cells in the conjunctiva.
abstract: Ocular onchocerciasis is the second most common infectious cause of blindness in the world. Th-2 helper T (Th-2) cells are thought to play a critical role in immediate hypersensitivity against allergens and extra-cellular parasitic infections. Th-2 cells secrete a high amount of IL-4, regulate IgE production, and recruit eosinophils and mast cells. Conjunctival biopsies from ten African patients with ocular onchocerciasis were evaluated for the presence of II-2, IL-4, mast cells and major basic protein (MBP), a marker for eosinophils. IL-4 mRNA was detected in seven of ten conjunctival specimens using in situ hybridization, yet IL-4 was detected in only one specimen using immunohistochemical staining. In contrast, IL-2 mRNA was detected in three of ten conjunctival specimens and IL-2 was detected in two specimens. There were greater numbers of mast cells and the presence of MBP in specimens with IL-4 mRNA. Furthermore, the three biopsies containing both IL-2 and IL-4 mRNA had greater numbers of CD4+cell infiltration and the patient with IL-4 protein in his conjunctiva also had the highest IgE in his aqueous humor. These findings suggest that Th-2 cells and their lymphokines are important for the localized host responsiveness to ocular onchocerciasis.
authors: Laboratory of Immunology, National Eye Institute, NIH, Bethesda, MD, USA.
authors: C C
authors: CC
authors: Chan
authors: Q
authors: Q
authors: Li
authors: A P
authors: AP
authors: Brezin
authors: S M
authors: SM
authors: Whitcup
authors: C
authors: C
authors: Egwuagu
authors: E A
authors: EA
authors: Otteson
authors: R B
authors: RB
authors: Nussenblatt