Pre-clinical characterisation of E2814, a high-affinity antibody targeting the microtubule-binding repeat domain of tau for passive immunotherapy in Alzheimer's disease

Tau deposition in the brain is a pathological hallmark of many neurodegenerative disorders, including Alzheimer’s disease (AD). During the course of these tauopathies, tau spreads throughout the brain via synaptically-connected pathways. Such propagation of pathology is thought to be mediated by tau species (“seeds”) containing the microtubule binding region (MTBR) composed of either three repeat (3R) or four repeat (4R) isoforms. The tau MTBR also forms the core of the neuropathological filaments identified in AD brain and other tauopathies. Multiple approaches are being taken to limit tau pathology, including immunotherapy with anti-tau antibodies. Given its key structural role within fibrils, specifically targetting the MTBR with a therapeutic antibody to inhibit tau seeding and aggregation may be a promising strategy to provide disease-modifying treatment for AD and other tauopathies. Therefore, a monoclonal antibody generating campaign was initiated with focus on the MTBR. Herein we describe the pre-clinical generation and characterisation of E2814, a humanised, high affinity, IgG1 antibody recognising the tau MTBR. E2814 and its murine precursor, 7G6, as revealed by epitope mapping, are antibodies bi-epitopic for 4R and mono-epitopic for 3R tau isoforms because they bind to sequence motif HVPGG. Functionally, both antibodies inhibited tau aggregation in vitro. They also immunodepleted a variety of MTBR-containing tau protein species. In an in vivo model of tau seeding and transmission, attenuation of deposition of sarkosyl-insoluble tau in brain could also be observed in response to antibody treatment. In AD brain, E2814 bound different types of tau filaments as shown by immunogold labelling and recognised pathological tau structures by immunohistochemical staining. Tau fragments containing HVPGG epitopes were also found to be elevated in AD brain compared to PSP or control. Taken together, the data reported here have led to E2814 being proposed for clinical developmen

Isotope labelling in ring a of gibberellin a ₂₀

Full assignments of the 1H-nmr chemical shifts of the ring A protons in gibberellin A20 methyl ester 13-acetate have been made on the basis of 1H-, 2H- and 13C-nmr data of various deuteriated derivatives. These assignments have been used to prove that catalytic deuteriogenation of GA5-16, 17- epoxide-13-acetate is a syn-addition from the less hindered β-face accompanied by allylic exchange at C-1 giving isotopic labels at the 1β-, 2β- and 3β- positions. The position and stereochemistry of isotopic labelling was confirmed by comparison with an authentic sample of [1β,2β,3β-2H3] GA20 methyl ester 13-acetate prepared by methods which introduce deuterium stereoselectively at C-1, C-2 and C-3. The preparation of [2α-2H]GA20 and [3α-2H]GA20 is described.</p

Ddt and pcbs in sediments of the venice gulf

The concentrations of DDT and PCBs in surface sediments collected in the Gulf of Venice are reported. The contribution of the lagoon and of the rivers to sea sediment contamination is discussed. Fresh waters reaching the sea through the lagoon or directly from rivers are responsible for relatively high ?DDT concentrations. The Porto Marghera industrial zone located in the inner border of the lagoon is probably the main PCB source. Two transport mechanisms have been identified: mobilization of suspended solids by tidal movements and direct dumping of industrial tailing and/or dredged materials from the lagoon canals. © 1983 Taylor & Francis Group, LLC