Ueberberg S.,Berufsgenossenschaftliches University Hospital Bergmannsheil |
Deutschbein T.,Berufsgenossenschaftliches University Hospital Bergmannsheil |
Klein H.H.,Berufsgenossenschaftliches University Hospital Bergmannsheil |
Dietrich J.W.,Berufsgenossenschaftliches University Hospital Bergmannsheil |
And 5 more authors.
American Journal of Physiology - Endocrinology and Metabolism | Year: 2011
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 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-1 β + 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. © 2011 the American Physiological Society.