Chronic Intranasal Treatment with an Anti-Aβ30-42 scFv Antibody Ameliorates Amyloid Pathology in a Transgenic Mouse Model of Alzheimer's Disease

Amyloid-beta peptide (Aβ)-directed active and passive immunization therapeutic strategies reduce brain levels of Aβ, decrease the severity of beta-amyloid plaque pathology and reverse cognitive deficits in mouse models of Alzheimer's disease (AD). As an alternative approach to passive immunization with full IgG molecules, single-chain variable fragment (scFv) antibodies can modulate or neutralize Aβ-related neurotoxicity and inhibit its aggregation in vitro. In this study, we characterized a scFv derived from a full IgG antibody raised against the C-terminus of Aβ, and studied its passage into the brains of APP transgenic mice, as well as its potential to reduce Aβ-related pathology. We found that the scFv entered the brain after intranasal application, and that it bound to beta-amyloid plaques in the cortex and hippocampus of APP transgenic mice. Moreover, the scFv inhibited Aβ fibril formation and Aβ-mediated neurotoxicity in vitro. In a preventative therapeutic approach chronic intranasal treatment with scFv reduced congophilic amyloid angiopathy (CAA) and beta-amyloid plaque numbers in the cortex of APPswe/PS1dE9 mice. This reduction of CAA and plaque pathology was associated with a redistribution of brain Aβ from the insoluble fraction to the soluble peptide pool. Due to their lack of the effector domain of full IgG, scFv may represent an alternative tool for the treatment of Aβ-related pathology without triggering Fc-mediated effector functions. Additionally, our observations support the possibility that Aβ-directed immunotherapy can reduce Aβ deposition in brain vessels in transgenic mice

Sören Kierkegaard als Kommunikationsanalytiker und Sozialkritiker

Kierkegaard gilt weitgehend als Interpret des einsamen, auf sich selbst zurückgeworfenen Individuums. Aber: Er beschreibt auch einen Existenz-Typus, der eine intensive Kommunikation mit seinen Mitmenschen unterhält, und zwar eine destruktive: den Dämonischen. Diese Kommunikation ist in sich widersprüchlich und paradox. Die gleiche Kommunikationsform entdeckt er bei Massenmedien, Massenorganisationen und Ideologien. Kierkegaard ist damit auch ein Deuter unserer gegenwärtigen Gesellschaft.Kierkegaard normally is considered to be the interpreter of the lonely individual, which is set back to istself. But: nevertheless he describes also a typus of existence, which effects very intensive human relations, but destructive ones: the daemonic. This communication is in itself contradictory and paradox. The same form of communication he diagnosis in mass media, mass organisations, and ideologies. Kierkegaard therefore is also an interpreter of our present society

Effect of IVIG Formulation on IgG Binding to Self- and Exo- Antigens In Vitro and In Vivo.

In relation to the recent trials of Intravenous Immunoglobulin (IVIG) in Alzheimer's Disease (AD) it was demonstrated that different IgG preparations contain varying amounts of natural anti-amyloid β (Aβ) antibodies as measured by ELISA. We therefore investigated the relevance of ELISA data for measuring low-affinity antibodies, such as anti-Aβ. We analysed the binding of different commercial Immunoglobulin G (IgG) preparations to Aβ, actin and tetanus toxoid in different binding assays to further investigate the possible cause for observed differences in binding to Aβ and actin between different IgG preparations. We show that the differences of commercial IgG preparations in binding to Aβ and actin in ELISA assays are artefactual and only evident in in vitro binding assays. In functional assays and in vivo animal studies the different IVIG preparations exhibited very similar potency. ELISA data alone are not appropriate to analyse and rank the binding capacity of low-affinity antibodies to Aβ or other endogenous self-antigens contained in IgG preparations. Additional analytical methods should be adopted to complement ELISA data

Combined expression of tau and the Harlequin mouse mutation leads to increased mitochondrial dysfunction, tau pathology and neurodegeneration

Mitochondrial dysfunction and oxidative stress play an important role in ageing and have been implicated in several age-related neurodegenerative conditions including Alzheimer's disease (AD) and other tauopathies characterized by the presence of intracellular accumulations of the hyperphosphorylated microtubule-associated protein tau. To study the interaction between mitochondrial dysfunction and tau pathology in vivo, we generated a novel mouse model by crossbreeding two existing lines: the Harlequin (Hq) mutant mice which suffer from mitochondrial dysfunction and oxidative stress due to a lack of the mitochondrial apoptosis-inducing factor (AIF), and the P301L tau transgenic mice, a mouse model of human tau pathology. Combined expression of the Hq mouse mutation and the tau transgene in the Tau/Hq double mutant mice led to an increase in tau pathology and apoptotic neurodegeneration when compared to single expression of the two mutations. Neurodegeneration was most prominent in the dentate gyrus and was significantly increased in the cerebellum leading to aggravated motor deficits. Functional activity measurements of the mitochondrial respiratory chain (MRC) in the Tau/Hq mice revealed early decreased activities of multiple MRC complexes and depleted ATP levels which preceded neurodegeneration and elevated oxidative stress markers. These results suggest an age-dependent mutual reinforcement of the tau pathology and mitochondrial dysfunction in vivo, which may contribute to neurodegeneration in patients suffering from AD and other age-related tauopathies

<i>In vitro</i> Comparison of reformulated IgG preparations activity to Aβ, actin and tetanus toxoid by ELISA and Octet.

<p>Unformulated Privigen (in H₂O) was formulated in Proline pH 4.8, Glycine pH 4.7 or Glycine pH 4.2. (A) ELISA measurements on plate-bound Aβ oligomers. The panel shows combined results from repeated measurements (n = 3). (B) Octet binding measurements to immobilized Aβ and <b>C</b> to bound tetanus toxoid. Privigen Fc fragments were used as negative controls.</p

<i>In vivo</i> pharmacokinetics of different IgG preparations, proline and glycine in rats.

<p>Clr:CD(SD) rats (n = 10 in groups 0 min and 2 min; n = 5 in groups 6h and 24h) were intravenously injected with 500 mg/kg of Privigen 10%, Gammagard 10%, Octagam 10% or Gamunex 10%, repectively. Blood was taken at baseline (0 min) as well as 2 min, 6h and 24h after injection. Plasma (10% citrate) was prepared and analyzed for total IgG by Nephelometry and Proline and Glycine concentration by HPLC. The elimination profile for IgG is shown in (A) and for proline and glycine in (B).</p

<i>In vivo</i> comparison of the binding to Aβ, Actin, tetanus toxoid and Varicella Zoster Virus by ELISA.

<p>Clr:CD(SD) rats (n = 10 in groups 0 min and 2 min; n = 5 in groups 6h and 24h) were intravenously injected with 500 mg/kg of Privigen 10%, Gammagard 10%, Octagam 10% or Gamunex 10%, respectively. Blood was taken at baseline (0 min) as well as 2 min, 6h and 24h after injection. Plasma (10% citrate) was prepared and the binding capacity to oligomeric Aβ (A and B), actin (C and D), Tetanus Toxoid (E and F), and VZV (G and H) was analyzed by ELISA. (*p<0.05, **p<0.01). Each ELISA was performed 3 times n = 3 (with all animals n = 30) except VZV t = 2 min n = 2 (with all animals n = 30) due to limited sample volume.</p