Molecular engineering of short half-life small peptides (VIP, αMSH and γ3MSH) fused to latency-associated peptide results in improved anti-inflammatory therapeutics

Abstract

ObjectiveTo facilitate the targeting to inflammation sites of small anti-inflammatory peptides, with short half-lives, by fusion with the latency-associated peptide (LAP) of transforming growth factor β1 through a cleavable matrix metalloproteinase (MMP) linker. This design improves efficacy, overcoming the limitations to their clinical use.MethodsWe generated latent forms of vasoactive intestinal peptide (VIP), α-melanocyte-stimulating hormone (MSH) and γ3MSH by fusion to LAP through an MMP cleavage site using recombinant DNA technology. The biological activities of these latent therapeutics were studied in vivo using monosodium urate (MSU)-induced peritonitis and collagen-induced arthritis (CIA) models. We assessed gene therapy and purified protein therapy.ResultsThe recruitment of the polymorphonuclear cells induced by MSU injection into mouse peritoneal cavity was reduced by 35% with γ3MSH (1 nmol), whereas administration of a much lower dose of purified latent LAP–MMP–γ3MSH (0.03 nmol) attenuated leucocyte influx by 50%. Intramuscular gene delivery of plasmids coding LAP–MMP–VIP and LAP–MMP–αMSH at disease onset reduced the development of CIA compared with LAP–MMP, which does not contain any therapeutic moiety. Histological analysis confirmed a significantly lower degree of inflammation, bone and cartilage erosion in groups treated with LAP–MMP–VIP or LAP–MMP–αMSH. Antibody titres to collagen type II and inflammatory cytokine production were also reduced in these two groups.ConclusionIncorporation of small anti-inflammatory peptides within the LAP shell and delivered as recombinant protein or through gene therapy can control inflammatory and arthritic disease. This platform delivery can be developed to control human arthritides and other autoimmune diseases.