Corneal Endothelial Microparticles Production

Abstract

Purpose: : Endothelial microparticles (MP) are membrane fragments released in the vascular compartment during endothelial cells activation, thrombosis, which are also seen in pre-graft conditioning procedure. Their role in immune response regulation remains unknown. Neither MPs production by corneal endothelium nor their implication in modulating the immune response have been described. We have both studied MP production from a human corneal endothelium lineage (HCEC) and their ability to interact with particular dendritic cells (DC).

Methods: : MP were generated from a human corneal endothelium and isolated by flow cytometry on their size and external membrane expression of phosphatidyl serine (PS) binding annexine-V. These MP and different populations of DC - a lineage of plasmocytoïd dendritic cells (pDC) and blood derivated myeloid dendritic cells (mDC) - were co incubated in order to study their influence on DC phenotypic maturation. This was objectivised by an increase in HLA-DR and CD-83 DC expression.

Results: : MP production measurement was significantly different than background (p < 0.001) and increased by TNF-α (p = 0.021). In preliminary results, HLA-DR and CD83 expression were increased in case of co culture with mDC, not with pDC.

Conclusions: : HCEC can produce corneal endothelial microparticles "CEMP". These CEMP can induce phenotypic maturation of myeloid DC. On the contrary, this maturation wouldn't be observed in the case of pDC. This particular result differs from vascular endothelium. This study could be relevant in the CEMP capacity to regulate antigen presentation during corneal graft, but also as potential markers for corneal graft preservation condition.

Keywords: cornea: endothelium • cell-cell communication • cell membrane/membrane specializations