Human single-chain variable fragment that specifically targets arthritic cartilage.
OBJECTIVE
To demonstrate that posttranslational modification of type II collagen (CII) by reactive oxygen species (ROS), which are known to be present in inflamed arthritic joints, can give rise to epitopes specific to damaged cartilage in rheumatoid arthritis (RA) and osteoarthritis (OA) and to establish a proof of concept that antibodies specific to ROS-modified CII can be used to target therapeutics specifically to inflamed arthritic joints.


METHODS
We used a semisynthetic phage display human antibody library to raise single-chain variable fragments (scFv) specific to ROS-modified CII. The specificity of anti-ROS-modified CII scFv to damaged arthritic cartilage was assessed in vitro by immunostaining articular cartilage from RA and OA patients and from normal controls. The in vivo targeting potential was tested using mice with antigen-induced arthritis, in which localization of anti-ROS-modified CII scFv in the joints was determined. The therapeutic effect of anti-ROS-modified CII scFv fused to soluble murine tumor necrosis factor receptor II-Fc fusion protein (mTNFRII-Fc) was also investigated.


RESULTS
The anti-ROS-modified CII scFv bound to damaged arthritic cartilage from patients with RA and OA but not to normal preserved cartilage. When systemically administered to arthritic mice, the anti-ROS-modified CII accumulated selectively at the inflamed joints. Importantly, when fused to mTNFRII-Fc, it significantly reduced inflammation in arthritic mice, as compared with the effects of mTNFRII-Fc alone or of mTNFRII-Fc fused to an irrelevant scFv.


CONCLUSIONS
Our findings indicate that biologic therapeutics can be targeted specifically to arthritic joints and suggest a new approach for the development of novel treatments of arthritis.
Hughes
Chris
C
Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK.
Faurholm
Bjarne
B
Dell'Accio
Francesco
F
Manzo
Antonio
A
Seed
Michael
M
Eltawil
Noha
N
Marrelli
Alessandra
A
Gould
David
D
Subang
Christina
C
Al-Kashi
Adam
A
De Bari
Cosimo
C
Winyard
Paul
P
Chernajovsky
Yuti
Y
Nissim
Ahuva
A
D000818:Animals; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000276:immunology*; D002356:Cartilage / Q000276:immunology* / Q000473:pathology; D002358:Cartilage, Articular / Q000276:immunology / Q000473:pathology; D002417:Cattle; D004195:Disease Models, Animal; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000276:immunology; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D010003:Osteoarthritis / Q000235:genetics / Q000276:immunology; D053244:Osteoprotegerin / Q000276:immunology; D017382:Reactive Oxygen Species / Q000276:immunology; D057127:Single-Chain Antibodies / Q000235:genetics*
D000939:Epitopes; D007141:Immunoglobulin Fc Fragments; D053244:Osteoprotegerin; D017382:Reactive Oxygen Species; D057127:Single-Chain Antibodies