Blockade of VEGFR3-signalling specifically inhibits lymphangiogenesis in inflammatory corneal neovascularisation.
OBJECTIVE
Inflammatory corneal hem- and lymphangiogenesis occurring both prior to as well as after penetrating keratoplasty significantly increase the risk for subsequent immune rejections. The purpose of this study was to analyze whether the blocking anti-VEGFR3 antibody mF4-31C1 is able to inhibit the outgrowth of pathologic new lymphatic vessels in a mouse model of suture-induced, inflammatory corneal neovascularisation, and whether this antibody specifically inhibits lymphangiogenesis without affecting hemangiogenesis.


METHODS
Three interrupted 11-0 nylon sutures were placed into the corneal stroma of BALB/c mice (6 weeks old) and left in place for 7 days to induce neovascularisation. The treatment group (n = 9) received the anti-VEGFR3 antibody mF4-31C1 intraperitoneally on the day of surgery and 3 days later (0.5 mg/mouse). Control mice received an equal amount of control IgG solution. For immunohistochemistry, corneal flat mounts were stained with LYVE-1 as a specific lymphatic vascular endothelial marker and with CD31 as panendothelial marker. Morphometry was performed with the image analysis software analySIS;B (Soft Imaging Systems GmbH, Münster, Germany). To improve the objectivity and precision of the morphometrical analysis, we established a modified method using grey filter sampling on monochromatic pictures.


RESULTS
The mF4-31C1 antibody-treated mice displayed nearly complete inhibition of lymphangiogenesis compared with IgG controls (p < 0.006). In contrast, there was no significant inhibitory effect observed with respect to blood vessel growth (p > 0.05).


CONCLUSIONS
Inflammatory corneal lymphangiogenesis seems to depend on VEGFR3-signalling. By blocking this receptor the ingrowths of lymphatic vessels can be inhibited almost completely, and specifically without affecting hemangiogenesis. This may open new treatment options to promote (corneal) graft survival without affecting hemangiogenesis.
Bock
Felix
F
Department of Ophthalmology, University of Erlangen-Nürnberg, Schwabachanlage 6, 91054, Erlangen, Germany. felix.bock@uk-erlangen.de
Onderka
Jasmine
J
Dietrich
Tina
T
Bachmann
Björn
B
Pytowski
Bronislaw
B
Cursiefen
Claus
C
D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology*; D016510:Corneal Neovascularization / Q000188:drug therapy* / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006023:Glycoproteins / Q000378:metabolism; D007274:Injections, Intraperitoneal; D042583:Lymphangiogenesis / Q000187:drug effects*; D042601:Lymphatic Vessels / Q000187:drug effects* / Q000378:metabolism; D026901:Membrane Transport Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000276:immunology*
D019138:Antibodies, Blocking; D006023:Glycoproteins; D026901:Membrane Transport Proteins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D040321:Vascular Endothelial Growth Factor Receptor-3; C492273:LYVE1 protein, mouse