Article

Development of a novel recombinant biotherapeutic with applications in targeted therapy of human arthritis.

Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Arthritis & Rheumatology (Impact Factor: 7.48). 09/2011; 63(12):3758-67. DOI: 10.1002/art.30650
Source: PubMed

ABSTRACT To isolate recombinant antibodies with specificity for human arthritic synovium and to develop targeting reagents with joint-specific delivery capacity for therapeutic and/or diagnostic applications.
In vivo single-chain Fv (scFv) antibody phage display screening using a human synovial xenograft model was used to isolate antibodies specific to the microvasculature of human arthritic synovium. Single-chain Fv antibody tissue-specific reactivity was assessed by immunostaining of synovial tissues from normal controls and from patients with rheumatoid arthritis and osteoarthritis, normal human tissue arrays, and tissues from other patients with inflammatory diseases displaying neovasculogenesis. In vivo scFv antibody tissue-specific targeting capacity was examined in the human synovial xenograft model using both (125)I-labeled and biotinylated antibody.
We isolated a novel recombinant human antibody, scFv A7, with specificity for the microvasculature of human arthritic synovium. We showed that in vivo, this antibody could efficiently target human synovial microvasculature in SCID mice transplanted with human arthritic synovial xenografts. Our results demonstrated that scFv A7 antibody had no reactivity with the microvasculature or with other cellular components found in a comprehensive range of normal human tissues including normal human synovium. Further, we showed that the reactivity of the scFv A7 antibody was not a common feature of neovasculogenesis associated with chronic inflammatory conditions.
Here we report for the first time the identification of an scFv antibody, A7, that specifically recognizes an epitope expressed in the microvasculature of human arthritic synovium and that has the potential to be developed as a joint-specific pharmaceutical.

0 Bookmarks
 · 
221 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Atherosclerosis is a complex disease in which vessels develop plaques comprising dysfunctional endothelium, monocyte derived lipid laden foam cells and activated lymphocytes. Considering that humans and animal models of the disease develop quite distinct plaques, we used human plaques to search for proteins that could be used as markers of human atheromas. Phage display peptide libraries were probed to fresh human carotid plaques, and a bound phage homologous to plexin B1, a high affinity receptor for CD100, was identified. CD100 is a member of the semaphorin family expressed by most hematopoietic cells and particularly by activated T cells. CD100 expression was analyzed in human plaques and normal samples. CD100 mRNA and protein were analyzed in cultured monocytes, macrophages and foam cells. The effects of CD100 in oxLDL-induced foam cell formation and in CD36 mRNA abundance were evaluated. Human atherosclerotic plaques showed strong labeling of CD100/SEMA4D. CD100 expression was further demonstrated in peripheral blood monocytes and in in vitro differentiated macrophages and foam cells, with diminished CD100 transcript along the differentiation of these cells. Incubation of macrophages with CD100 led to a reduction in oxLDL-induced foam cell formation probably through a decrease of CD36 expression, suggesting for the first time an atheroprotective role for CD100 in the human disease. Given its differential expression in the numerous foam cells and macrophages of the plaques and its capacity to decrease oxLDL engulfment by macrophages we propose that CD100 may have a role in atherosclerotic plaque development, and may possibly be employed in targeted treatments of these atheromas.
    PLoS ONE 01/2013; 8(9):e75772. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVES: The synovial endothelium targeting peptide (SyETP) CKSTHDRLC has been identified previously and was shown to preferentially localise to synovial xenografts in the human/severe combined immunodeficient (SCID) mouse chimera model of rheumatoid arthritis (RA). The objective of the current work was to generate SyETP-anti-inflammatory-cytokine fusion proteins that would deliver bioactive cytokines specifically to human synovial tissue. METHODS: Fusion proteins consisting of human interleukin (IL)-4 linked via a matrix metalloproteinase (MMP)-cleavable sequence to multiple copies of either SyETP or scrambled control peptide were expressed in insect cells, purified by Ni-chelate chromatography and bioactivity tested in vitro. The ability of SyETP to retain bioactive cytokine in synovial but not control skin xenografts in SCID mice was determined by in vivo imaging using nano-single-photon emission computed tomography-computed tomography (nano-SPECT-CT) and measuring signal transducer and activator of transcription 6 (STAT6) phosphorylation in synovial grafts following intravenous administration of the fusion protein. RESULTS: In vitro assays confirmed that IL-4 and the MMP-cleavable sequence were functional. IL-4-SyETP augmented production of IL-1 receptor antagonist (IL-1ra) by fibroblast-like synoviocytes (FLS) stimulated with IL-1β in a dose-dependent manner. In vivo imaging showed that IL-4-SyETP was retained in synovial but not in skin tissue grafts and the period of retention was significantly enhanced through increasing the number of SyETP copies from one to three. Finally, retention correlated with increased bioactivity of the cytokine as quantified by STAT6 phosphorylation in synovial grafts. CONCLUSIONS: The present work demonstrates that SyETP specifically delivers fused IL-4 to human rheumatoid synovium transplanted into SCID mice, thus providing a proof of concept for peptide-targeted tissue-specific immunotherapy in RA. This technology is potentially applicable to other biological treatments providing enhanced potency to inflammatory sites and reducing systemic toxicity.
    Annals of the rheumatic diseases 07/2012; · 8.11 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Specific delivery of TNF-α antagonist to the inflamed site can increase its efficacy and reduce the side effects. In this study, we constructed a bispecific diabody (BsDb) that targets TNF-α and ED-B-containing fibronectin (B-FN), a fibronectin isoform specifically expressed in the pannus of the inflamed joint in rheumatoid arthritis. BsDb was produced in E. coli as inclusion bodies, purified to homogeneity, and refolded to the functional form. Our data demonstrate that BsDb could simultaneously bind to human TNF-α and B-FN and neutralize TNF-α action. In the collagen-induced arthritis mouse model, we compared the biodistrubtion and therapeutic efficacy of BsDb with those of the anti-TNF-α scFv (TNF-scFv). Similar to TNF-scFv, BsDb penetrated into the synovial tissue quickly, showing a rapid clearance from blood and normal organs. In contrast, BsDb could selectively accumulate and retain in arthritic joints of mice for a long period time, resulting in a much stronger inhibition of arthritis progression in mice than TNF-scFv. The findings described herein indicate that BsDb has a good specificity to the inflamed joint, with low toxicity to normal organs and seems to be an ideal biological agent for the treatment of RA and other chronic inflammatory disease.
    Journal of biotechnology. 06/2014;

Full-text (2 Sources)

Download
15 Downloads
Available from
May 16, 2014