Choroidal neovascular membranes express toll-like receptor 3.
BACKGROUND
Recent evidence has suggested a role for toll-like receptor 3 (TLR3) in experimental models of age-related macular degeneration (AMD). To date, however, few data exist about TLR3 in human AMD. The purpose of this study was to investigate the expression of TLR3 in human choroidal neovascular (CNV) membranes.


METHODS
Immunostaining for TLR3 was performed on sections of CNV membranes from 8 AMD patients and eyes from 4 donors without CNV.


RESULTS
All CNV membranes expressed TLR3 in retinal pigment epithelial (RPE) cells. One was classified as having strong intensity, 5 as having moderate intensity and 2 as having weak intensity. All cases had ≥30% of the RPE cells staining for TLR3, ranging from 30 to 90%. No expression of TLR3 was observed in vascular endothelial cells or fibroblasts in any CNV membrane. In the donor eyes, the RPE cells near the ora serrata stained stronger than those at the posterior pole, where no staining was observed in 3 out of 4 cases.


CONCLUSIONS
TLR3 was found in all CNV membranes and was expressed exclusively in RPE cells. The observed difference in RPE staining for TLR3 in donor eyes and CNV membranes suggests a possible role for this receptor in human neovascular AMD.
Maloney
Shawn C
SC
Henry C. Witelson Ocular Pathology Laboratory, McGill University, Montreal, Que., Canada. shawn.maloney@mail.mcgill.ca
Antecka
Emilia
E
Orellana
Maria E
ME
Fernandes
Bruno F
BF
Odashiro
Alexandre N
AN
Eghtedari
Masoomeh
M
Burnier
Miguel N
MN
D000368:Aged; D000369:Aged, 80 and over; D020256:Choroidal Neovascularization / Q000378:metabolism*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008268:Macular Degeneration / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D055213:Retinal Pigment Epithelium / Q000378:metabolism; D014019:Tissue Donors; D051196:Toll-Like Receptor 3 / Q000378:metabolism*
C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3