IMMUNOHISTOCHEMICAL AND TOPOGRAPHIC STUDIES OF DENDRITIC CELLS AND MACROPHAGES IN HUMAN FETAL CORNEA

Citation
Cm. Diazaraya et al., IMMUNOHISTOCHEMICAL AND TOPOGRAPHIC STUDIES OF DENDRITIC CELLS AND MACROPHAGES IN HUMAN FETAL CORNEA, Investigative ophthalmology & visual science, 36(3), 1995, pp. 644-656
Citations number
51
Categorie Soggetti
Ophthalmology
ISSN journal
01460404
Volume
36
Issue
3
Year of publication
1995
Pages
644 - 656
Database
ISI
SICI code
0146-0404(1995)36:3<644:IATSOD>2.0.ZU;2-C
Abstract
Purpose. To investigate the distribution and phenotype of major histoc ompatibility complex (MHC) class II-positive dendritic cells and macro phages in normal human fetal cornea in the age range 10 to 25 weeks ge station. Methods. Peroxidase and gold immunohistochemistry were used t o visualize MHC class II and macrophage antigen (S22) immunoreactive c ells. Cell distributions were analyzed quantitatively, and topographic maps were produced. Results. Immunoreactive cells, concentrated centr ally, were present at 10 weeks gestation in the corneal epithelium and stroma. Average densities increased steadily up to 25 weeks gestation . Two morphologic forms of MHC class II and S22 immunoreactive cells w ere observed-large, dendritiform cells and small, rounded cells with s hort processes. Electron microscopy revealed that most MHC class II-po sitive cells were morphologically consistent with previous ultrastruct ural descriptions of corneal Langerhans cells. Immunoreactive cells we re more numerous in immunogold-labeled specimens than in peroxidase-la beled specimens of similar ages. However, quantitative analysis of bot h techniques revealed that S22-positive cells comprised 30% to 50% of MHC class II-positive cells. Conclusions. This study provides a detail ed description of heterogeneous populations of MHC class II and S22 im munoreactive cells in the human fetal cornea. In contrast to the adult cornea, which is typically devoid of MHC class II-positive cells, imm unoreactive cells in the fetal cornea are concentrated centrally and i ncrease in density up to at least 25 weeks gestation. These results in dicate that reduction in Langerhans cell numbers to adult levels must occur after 25 weeks gestation. The presence of dendritic cells and ma crophages in the fetal cornea has important implications for the under standing of corneal immunology.