Keratocyte apoptosis and failure of corneal allografts.

Background: Murine models of high-risk and low-risk corneal transplantation were used to determine the role of keratocyte apoptosis in the failure of orthotopic allogeneic corneal transplants.

Materials And Methods: Normal (low-risk, low-rejecting) and inflamed/vascularized (high-risk, high-rejecting) BALB/c recipient beds received fully mismatched C57BL/6 corneal allografts. Apoptosis was detected in the corneal stroma at various time points using an in situ terminal deoxynucleotide tranferase-mediated dUTP nick-end labeling assay, and ex vivo via Western analysis for active caspase-3.

Corneal immunity is mediated by heterogeneous population of antigen-presenting cells.

Corneal antigen-presenting cells (APC), including dendritic cells (DC), were thought to reside exclusively in the peripheral cornea. Here, we present recent data from our group demonstrating that the central cornea is indeed endowed with a heterogeneous population of epithelial and stromal DC, which function as APC. Although the corneal periphery contains mature and immature resident bone marrow-derived CD11c(+) DC, the central cornea is endowed exclusively with immature and precursor DC, both in the epithelium and the stroma, wherein Langerhans cells and monocytic DC reside, respectively.