Selective targeting of 3 repeat Tau with brain penetrating single chain antibodies for the treatment of neurodegenerative disorders

Abstract

Alzheimer's disease (AD) is the most common form of dementia in the elderly affecting more than 5 million people in the U.S. AD is characterized by the accumulation of β-amyloid (Aβ) and Tau in the brain, and is manifested by severe impairments in memory and cognition. Therefore, removing tau pathology has become one of the main therapeutic goals for the treatment of AD. Tau (tubulin-associated unit) is a major neuronal cytoskeletal protein found in the CNS encoded by the gene MAPT. Alternative splicing generates two major isoforms of tau containing either 3 or 4 repeat (R) segments. These 3R or 4RTau species are differentially expressed in neurodegenerative diseases. Previous studies have been focused on reducing Tau accumulation with antibodies against total Tau, 4RTau or phosphorylated isoforms. Here, we developed a brain penetrating, single chain antibody that specifically recognizes a pathogenic 3RTau. This single chain antibody was modified by the addition of a fragment of the apoB protein to facilitate trafficking into the brain, once in the CNS these antibody fragments reduced the accumulation of 3RTau and related deficits in a transgenic mouse model of tauopathy. NMR studies showed that the single chain antibody recognized an epitope at aa 40-62 of 3RTau. This single chain antibody reduced 3RTau transmission and facilitated the clearance of Tau via the endosomal-lysosomal pathway. Together, these results suggest that targeting 3RTau with highly specific, brain penetrating, single chain antibodies might be of potential value for the treatment of tauopathies such as Pick's Disease.

Systemic peptide mediated delivery of an siRNA targeting α-syn in the CNS ameliorates the neurodegenerative process in a transgenic model of Lewy body disease

“…We have previously delivered peptides and proteins across the BBB following intraperitoneal injections when they are fused to a 38-amino acid LDL-R binding domain of ApoB (Spencer et al, 2018;Spencer et al, 2014a;Spencer et al, 2016c;Spencer et al, 2015;Spencer et al, 2014b). In contrast, experiments delivering C2-9r/siα-syn were performed following intra-venous injection (Javed et al, 2016).…”

“…In this study we have identified an alternative peptide for the transport of nucleotides across the BBB based on the apolipoprotein B (ApoB) protein targeted to the family of LDL-R (Masliah and Spencer, 2015b;Spencer and Verma, 2007). For previous studies we utilized a 38 aa peptide (Spencer et al, 2018;Spencer et al, 2014a;Spencer et al, 2016c;Spencer et al, 2015;Spencer et al, 2014b) expressed from a lentiviral vector while for the present study we used a reduced 11-amino acid sequence from the apoB protein (ApoB 11 ) protein, coupled with a 9-amino acid arginine linker for transporting siRNAs across the BBB to neuronal and glial cells following intra-peritoneal injection. We tested the effectiveness of this approach by delivering an siRNA targeting α-syn (siα-syn) into an α-syn tg mouse model of PD/DLB and showed reduced accumulation of α-syn associated with amelioration of the neurodegenerative and inflammatory pathology.…”

Fibrillar form of α-synuclein-specific scFv antibody inhibits α-synuclein seeds induced aggregation and toxicity

“…the brain in the case of neurodegenerative diseases. Addition of cell permeable peptide molecules has been shown to facilitate delivery of target molecules to intracellular locations as well as to aid in crossing the blood-brain barrier (BBB) 41,42 . Recently, cell-penetrating peptide (CPP) has also been shown to deliver cargo molecules into a variety of cell systems and across the BBB 41 .…”

“…Addition of cell permeable peptide molecules has been shown to facilitate delivery of target molecules to intracellular locations as well as to aid in crossing the blood-brain barrier (BBB) 41,42 . Recently, cell-penetrating peptide (CPP) has also been shown to deliver cargo molecules into a variety of cell systems and across the BBB 41 . We decided to use a 16-amino acid long CPP obtained from the third helix of the Antennapedia homeodomain from Drosophila in our scFv coding sequence to enable it to cross cell membranes 29,42 .…”

Intramuscular injection of vectorized-scFvMC1 reduces pathological tau in two different tau transgenic models

“…We have previously shown [ 43 ] that the AAV vectorized-scFvMC1, a recombinant version of the native anti-tau conformational mAb (monoclonal antibody) MC1, significantly reduces brain pathological tau in adult JNPL3 mice, by one-time intracranial injection. In parallel with AAV-based delivery, Spencer et al [ 44 ] have shown that systemic injection of a lentiviral vector (LV) carrying a scFv directed to 3Rtau and enhanced for brain penetration (LV-3RT-apoB) was able to reduce tau accumulation, neurodegeneration and behavioral deficit in a tau transgenic model. Although using third-generation lentiviral vectors has emerged as a promising therapeutic option for conditions as primary immunodeficiencies and cancers, it is still necessary to understand the long-term safety and efficacy of these vectors in humans, especially in respect to their potential for insertional oncogenesis [ 51 ].…”