Protection from diabetes development by single-chain antibody-mediated delivery of a NF- B inhibitor specifically to -cells in vivo
Department of Internal Medicine I, Division of Endocrinology and Metabolism, Berufsgenossenschaftliches University Hospital Bergmannsheil, Bochum, Germany.AJP Endocrinology and Metabolism (Impact Factor: 3.79). 04/2011; 301(1):E83-90. DOI: 10.1152/ajpendo.00603.2010
Recently, we reported the generation of single-chain antibodies (SCAs) highly specific for rodent and human β-cells. Our current report describes the generation of a fusion protein of one of these SCAs (SCA B1) with a NF-κB essential modifier (NEMO)-binding domain (NBD) peptide, thereby creating a selective inhibitor of NF-κB activation in β-cells. The SCA B1-NBD fusion protein was cloned in the pIRES-EGFP, expressed in bacteria, and purified by metal affinity chromatography; the newly generated complex was then administered intravenously to rodents and evaluated for its ability to protect β-cells against cytokines in vitro and diabetogenic agents in vivo. First, it was shown clearly that our SCA B1-NBD fusion protein binds highly selective to CD rat β-cells in vivo. Second, we observed that SCA B1-mediated in vivo delivery of the NBD peptide completely blocked IL-1β + IFNγ- and TNFα + IFNγ-mediated induction of NF-κB as well as islet dysfunction in culture. Finally, repeated intravenous injection of SCA B1-NBD prior to multiple low-dose administration of streptozotocin in CD mice not only induced a striking resistance to diabetes development but also preserved β-cell mass. In conclusion, our data show for the first time that a SCA B1-NBD fusion peptide reliably protects β-cells against cytokines in vitro and allows protection from diabetes development in CD mice in vivo.
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- "Radiolabeled SCA B1, the β-cell targeting clone was injected into rats and the uptake by β-cells correlated with the pancreatic β-cell mass and inversely correlated with the plasma glucose levels during IPGTT (Ueberberg and Schneider, 2010; Ueberberg et al., 2009). In a follow up study, the authors linked the SCA B1 clone with a NF-κB essential modifier (NEMO), capable of inhibition of NF-κB mediated effects (Ueberberg et al., 2011). The fusion protein, called SCA B1–NBD was injected intravenously into non-diabetic rats and its effects on pancreatic β-cells were studied in vitro in the presence of cytokines . "
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