Abstract
Purpose: :
Donor type bone marrow derived dendritic cells (DCs), conditioned and converted to tolerogenic DCs have been successfully used for suppressing transplant rejection, including corneal transplantation. The central part of the cornea is endowed with CD14+ precursor cells and we hypothesize that these cells can be conditioned to tolerogenic DCs ex-vivo and prior to transplantation.
Methods: :
Corneal buttons (central 2mm) were harvested from C57BL/6 mice and incubated for 4 days in tissue culture medium (minimum essential medium, MEM) containing GMCSF, TGF-β1 and IL-10. Lipopolysaccharide (LPS) was added to the medium 16 hours before evaluation of the corneas. Immunostaining was performed on corneal flat mounts and the expression of CD45, MHC-II, and costimulatory molecules was analyzed and compared to the corneas harvested from freshly euthanized mice.
Results: :
Fresh corneas were endowed with CD45+ MHC-II+ /CD86+ and CD45+ MHC-II-/CD86- cells. Four days of culture in the conditioning cytokines resulted in the generation of CD45+ cells which were uniformly MHC-II-/CD86- even in the presence of LPS (maturation-resistant tolerogenic DCs).
Conclusions: :
Our data suggest that maturation-resistant tolerogenic DCs can be expanded from the CD45+ cells that already exist in the central part of the cornea. The utility of these cells in corneal transplantation requires further investigation.
Keywords: transplantation • cornea: basic science • immunomodulation/immunoregulation