Targeting of viral XXXX with an antibody fragment specific to damaged arthritic cartilage improves its therapeutic potency.

@entity32 @entity625 @entity19 @entity26 @entity1618 @entity2720 @entity5782
INTRODUCTION: We previously demonstrated that a single-chain fragment variable (scFv) specific to collagen type II (CII) posttranslationally modified by reactive @entity26 species (ROS) can be used to target anti-inflammatory therapeutics specifically to inflamed @entity2720 . The objective of the present study was to demonstrate the superior efficacy of anti-inflammatory cytokines when targeted to inflamed @entity2720 by the anti-ROS modified CII (anti-ROS-CII) scFv in a @entity19 model of @entity625 . METHODS: Viral @entity1618 (vIL-10) was fused to anti-ROS-CII scFv (1-11E) with a matrix-metalloproteinase (MMP) cleavable linker to create 1-11E/vIL-10 fusion. Binding of 1-11E/vIL-10 to ROS-CII was determined by enzyme-linked immunosorbent assay (ELISA), Western blotting, and immune-staining of arthritic cartilage, whereas vIL-10 bioactivity was evaluated in vitro by using an @entity19 cell-proliferation assay. Specific in vivo localization and therapeutic efficacy of 1-11E/vIL-10 was tested in the @entity19 model of antigen-induced @entity625 . RESULTS: 1-11E/vIL-10 bound specifically to ROS-CII and to damaged arthritic cartilage. Interestingly, the in vitro vIL-10 activity in the fusion protein was observed only after cleavage with @entity5782 . When systemically administered to arthritic @entity19 , 1-11E/vIL-10 localized specifically to the arthritic knee, with peak accumulation observed after 3 days. Moreover, 1-11E/vIL-10 reduced @entity32 significantly quicker than vIL-10 fused to the control anti-hen egg lysozyme scFv (C7/vIL10). CONCLUSIONS: Targeted delivery of anti-inflammatory cytokines potentiates their anti-arthritic action in a @entity19 model of @entity625 . Our results further support the hypothesis that targeting biotherapeutics to @entity2720 may be extended to include anti-inflammatory cytokines that lack efficacy when administered systemically.
