Bone marrow-derived cells in normal human corneal stroma.
OBJECTIVE
To examine the normal human corneal stroma for the presence of bone marrow-derived cells.


METHODS
Thirty-four corneas from donors aged 56 to 71 years were used. The stroma of the donor corneas was examined immunohistochemically by fluorescent microscopy. CD45-positive and -negative cells were separated from collagenase-digested stroma by magnetic beads, and the expression of toll-like receptor 4 was analyzed.


RESULTS
CD45-positive cells were mainly found in the anterior stroma of the central and paracentral cornea as well as all stromal layers of the peripheral cornea (n = 5). These cells uniformly expressed CD11b, CD11c, CD14, and HLA-DR antigen but not CD3, CD19, CD56, or CD66, indicative of bone marrow-derived monocyte lineage cells, which can include monocytes, macrophages, or dendritic cells. CD45-positive cells isolated with magnetic beads accounted for 6.0% of total stromal cells (n = 20). Stromal CD45-positive cells, but not CD45-negative cells, expressed toll-like receptor 4 by flow cytometry and reverse-transcriptase polymerase chain reaction.


CONCLUSIONS
Our findings demonstrate that DR antigen-positive bone marrow-derived monocyte lineage cells exist in the anterior and peripheral posterior stroma of normal human cornea. Clinical Relevance These cells may play a role in the innate and adaptive immune responses in the human cornea.
Yamagami
Satoru
S
Departments of Corneal Tissue Regeneration and Ophthalmology, University of Tokyo Graduate School of Medicine, Hongo 7-3-1, Bunkyo-ku, Tokyo, Japan 113-8655. syamagami-tky@umin.ac.jp
Ebihara
Nobuyuki
N
Usui
Tomohiko
T
Yokoo
Seiichi
S
Amano
Shiro
S
D000368:Aged; D001854:Bone Marrow Cells / Q000166:cytology* / Q000378:metabolism; D002452:Cell Count; D019070:Cell Lineage; D002469:Cell Separation / Q000379:methods; D003319:Corneal Stroma / Q000166:cytology* / Q000378:metabolism; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D018189:Immunomagnetic Separation; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014019:Tissue Donors; D051197:Toll-Like Receptor 4 / Q000235:genetics
D012333:RNA, Messenger; D051197:Toll-Like Receptor 4; D017493:Leukocyte Common Antigens