Abstract
Purpose: :
The aim of this study is to observe the types and the expression patterns of dendritic cells (DCs) in human corneal tissue with or without infection and to investigate the roles of DCs of corneal infection.
Methods: :
The expression patterns of DCs were immunohistochemically observed in 20 corneal tissue specimens from 20 eyes (8 with infection, 12 without infection). DCs were characterized by the expression of 5 DC-related markers (CD1a: epithelial DCs, Langerin: langerhans cells, DC-SIGN: immature DCs, CD83: mature DCs, S-100 protein: pan-DC). We observed the type, location of appearance, density (numbers/mm2 section) of DCs in the central (6-7mm in diameter) and the peripheral part of corneal tissues. Expression of activin A (a factor to accelerate DC migration), Ki-67 (a marker for cell proliferation) and numbers of vessels in the sections were compared in infected and in non-infected cases.
Results: :
The mean cell densities of total DCs and CD83+ DCs in the infected cases were greater than that in the non-infected cases.(DCs: 5.53 vs. 1.39 /mm2, p=0.034, CD83+DCs: 0.93 vs. 0.04, p=0.014) The mean cell densities of epithelial or immature types of DCs should difference between infected and non-infected cases. Activin A and Ki67 were detected in the epithelial cells and anterior layer of corneal stroma in comparison with posterior layer and co-expressed in the inflammatory cells in 8 of 11 eyes with infection. Activin A and Ki67 were also detected in the endothelial cells of the limbal vessels 2 of 11 eyes with bacterial infection.
Conclusions: :
These results suggested that more and various types of DCs migrate to the center of the cornea in the infected cases.The endothelial cells of newly formed limbal vessels expressed activin A, which may be related to the DC migration from the peripheral vessels into the cornea.
Keywords: cornea: basic science • immunohistochemistry • inflammation