Center for Technology Commercialization

Novel Blood-Brain-Barrier Targeted Protein Delivery

(CHMC Ref. Id: 2010-1203)

Overview:

The efficacy of therapeutic proteins for brain disorders is restricted due to the limited ability of these neurotherapeutics to cross the blood brain barrier (BBB). This technology reports a novel and non-invasive approach for neuro-therapeutics to cross the blood brain barrier and provide therepeutic effect. This will improve the efficacy of those neurotherapeutics and thereby benefit patients suffering from neuro diseases.

This technology reports that the fusion of receptor binding domain (Rb) of Apolipoproteins (apo) to alpha-L-iduronidase (IDUA) can enable the modified protein to bind members of low-density lipoprotein receptor family (LDLRf) on BBB and transcytose to the CNS. The candidate proteins were evaluated for the possibility of transcytosis across the BBB using an in vitro BBB model with bovine microvascular endothelial cells cultured on collagen-coated transwells. Both IDUA-Rb candidates introduced IDUA levels significantly higher than IDUA3Myc control (up to 3.2 fold) in the lower chambers after pause-chase with the same amounts of IDUA activities on the top chambers.

The potential brain delivery of IDUA-Rb in vivo by hydrodynamic injection into MPS I mice with plasmids introducing liver-specific expression of fusion proteins. Elevated IDUA activities (22-120 fold of normal plasma IDUA levels) were found in plasma of all MPS I mice 2 days after injection. These in vivo secreted fusion proteins could be captured by immunoprecipitation with anti-myc antibody and are catalytically active while remaining bound. Moreover, capillary-depleted brain tissues from well-perfused animals injected with IDUA-Rb exhibited significant IDUA activities (3-5% of heterozygous levels), while only background levels were detected in those injected with IDUA3Myc control. Further studies have identified in situ the types of brain cells that have uptaken IDUA-Rb by immunohistochemistry analysis, including neurons and astrocytes. In summary, we have identified two Rb candidates by in vitro and in vivo evaluation that could mediate efficient IDUA delivery across the BBB via LRPI receptor mediated transcytosis.

This novel and non-invasive approaches would be beneficial in treating brain diseases by unlocking the blood-brain barrier specifically to potent neurotherapeutics that otherwise would never have a chance in combating with brain diseases. Further work is in progress and CHMC is seeking a collaborative partner to further develop the technology and commercialize it.

Applications: