ar1529 ARJ Poster presentation <p>Short-fibre modification facilitates adenovirus-mediated gene delivery in rheumatoid arthritis synoviocytes and synovium: role of RGD and non-RGD binding integrins</p> Toh M-L Hong S-S Franqueville L Lindholm L Boulanger P Miossec P

Department of Immunology and Rheumatology, Mixed Unit Civil Hospital of Lyon-Biomerieux, Edouard Herriot Hospital, Lyon, France

Laboratory of Virology and Viral Pathogenesis, CNRS UMR-5537, Faculty of Medicine RTH Laennec, Lyon, France

Department of Medical Microbiology and Immunology, University of Göteborg, and Got-A-Gene AB, Göteborg, Sweden

 Arthritis Research & Therapy <p>25<sup>th</sup> European Workshop for Rheumatology Research</p> The organizer would like to thank the following companies who have generously supported the meeting: Abbott Immunology (Main sponsor), Bristol-Myers Squibb, Schering-Plough, Wyeth, AstraZeneca, MSD, Amgen Meeting abstracts <p>25<sup>th</sup> European Workshop for Rheumatology Research</p> Glasgow, UK 24-27 February 2005 1478-6354 2005 7 Suppl 1 P8 10.1186/ar1529 11 1 2005 17 2 2005 2005 BioMed Central Ltd

Objective

Adenovirus 5 (Ad5) receptors other than Cocksackie-ad receptor have not been well explored in rheumatoid arthritis (RA) human fibroblast-like synoviocytes (FLS). Defining these receptors may enable development of improved Ad5 vectors to specific synovial targets. As Cocksackie-ad receptor is absent in RA FLS, we investigated the efficacy and receptor usage of fibre-modified Ad5 vectors for gene delivery in vitro and ex vivo.

Methods

Short fibre modified vectors with seven fibre repeats (Ad5GFP-R7-knob, Ad5GFP-R7-RGD) were compared with wild-type (WT) 22 repeats (Ad5GFP-FiWT) and GFP expression measured in RA human FLS and a synovium explant model. Integrin expression was determined by flow cytometry. Receptor usage was examined by competition binding assays with viral penton base (PB) WT, RGD and LDV-mutant peptides, and antibodies against PB and integrins. Viral neutralization by synovial fluid was examined.

Results

Ad5GFP-R7-knob gene transduction was 25-fold higher than Ad5GFP-R7-RGD and 40-fold to 50-fold higher than Ad5GFP-FiWT in FLS. Ad5GFP-R7-knob gene transduction was reduced with PB, RGD and LDV, and antibodies against PB and αv, αvβ3, αvβ5, and β1 integrins. Ad5GFP-R7-knob transduction was increased by tumour necrosis factor and IL-1, remained 30-fold to 40-fold higher than Ad5GFP-FiWT in the presence of synovial fluid and preferentially transduced synovium explant outgrowth/tissue.

Conclusion

Ad5GFP-R7-knob has broadened viral tropism superior to RGD-modified and WT vectors, mediated by integrin-binding RGD and non-RGD motifs in viral PB capsomers in RA FLS. Ad5 short fibre modifications utilize tropism of the native PB to optimise integrin usage as both attachment and endocytotic receptors. This may be a useful strategy of enhancing gene delivery in RA, reducing vector dose and induction of inflammation and toxicity.