Copper chelation delays the onset of prion disease.

The prion protein (PrP) binds copper and under some conditions copper can facilitate its folding into a more protease resistant form. Hence, copper levels may influence the infectivity of the scrapie form of prion protein (PrP Sc ). To determine the feasibility of copper-targeted therapy for prion disease, we treated mice with a copper chelator, D-(؊)-penicillamine (D-PEN), starting immediately following intraperitoneal scrapie inoculation. D-PEN delayed the onset of prion disease in the mice by about 11 days (p ‫؍‬ 0.002), and reduced copper levels in brain by 29% (p < 0.01) and in blood by 22% (p ‫؍‬ 0.03) compared with control animals. Levels of other metals were not significantly altered in the blood or brain. Modest correlation was observed between incubation period and levels of copper in brain (p ‫؍‬ 0.08) or blood (p ‫؍‬ 0.04), indicating that copper levels are only one of many factors that influence the rate of progression of prion disease. In vitro, copper dose-dependently enhanced the proteinase K resistance of the prion protein, and this effect was counteracted in a dose-dependent manner by co-incubation with D-PEN. Overall, these findings indicate that copper levels can influence the conformational state of PrP, thereby enhancing its infectivity, and this effect can be attenuated by chelatorbased therapy

Immunomodulation Targeting Abnormal Protein Conformation Reduces Pathology in a Mouse Model of Alzheimer's Disease

Many neurodegenerative diseases are characterized by the conformational change of normal self-proteins into amyloidogenic, pathological conformers, which share structural properties such as high β-sheet content and resistance to degradation. The most common is Alzheimer's disease (AD) where the normal soluble amyloid β (sAβ) peptide is converted into highly toxic oligomeric Aβ and fibrillar Aβ that deposits as neuritic plaques and congophilic angiopathy. Currently, there is no highly effective treatment for AD, but immunotherapy is emerging as a potential disease modifying intervention. A major problem with most active and passive immunization approaches for AD is that both the normal sAβ and pathogenic forms are equally targeted with the potential of autoimmune inflammation. In order to avoid this pitfall, we have developed a novel immunomodulatory method that specifically targets the pathological conformations, by immunizing with polymerized British amyloidosis (pABri) related peptide which has no sequence homology to Aβ or other human proteins. We show that the pABri peptide through conformational mimicry induces a humoral immune response not only to the toxic Aβ in APP/PS1 AD transgenic mice but also to paired helical filaments as shown on AD human tissue samples. Treated APP/PS1 mice had a cognitive benefit compared to controls (p<0.0001), associated with a reduction in the amyloid burden (p = 0.0001) and Aβ40/42 levels, as well as reduced Aβ oligomer levels. This type of immunomodulation has the potential to be a universal β-sheet disrupter, which could be useful for the prevention or treatment of a wide range of neurodegenerative diseases

Clearance of interstitial fluid (ISF) and CSF (CLIC) group-part of Vascular Professional Interest Area (PIA): Cerebrovascular disease and the failure of elimination of Amyloid-β from the brain and retina with age and Alzheimer's disease-Opportunities for Therapy.

Two of the key functions of arteries in the brain are (1) the well-recognized supply of blood via the vascular lumen and (2) the emerging role for the arterial walls as routes for the elimination of interstitial fluid (ISF) and soluble metabolites, such as amyloid beta (Aβ), from the brain and retina. As the brain and retina possess no conventional lymphatic vessels, fluid drainage toward peripheral lymph nodes is mediated via transport along basement membranes in the walls of capillaries and arteries that form the intramural peri-arterial drainage (IPAD) system. IPAD tends to fail as arteries age but the mechanisms underlying the failure are unclear. In some people this is reflected in the accumulation of Aβ plaques in the brain in Alzheimer's disease (AD) and deposition of Aβ within artery walls as cerebral amyloid angiopathy (CAA). Knowledge of the dynamics of IPAD and why it fails with age is essential for establishing diagnostic tests for the early stages of the disease and for devising therapies that promote the clearance of Aβ in the prevention and treatment of AD and CAA. This editorial is intended to introduce the rationale that has led to the establishment of the Clearance of Interstitial Fluid (ISF) and CSF (CLIC) group, within the Vascular Professional Interest Area of the Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment

Vaccination of Alzheimer's model mice with A? derivative in alum adjuvant reduces A? burden without microhemorrhages

Immunotherapy holds great promise for Alzheimer's disease (AD) and other conformational disorders but certain adverse reactions need to be overcome. The meningoencephalitis observed in the first AD vaccination trial was likely related to excessive cell-mediated immunity caused by the immunogen, amyloid-? (A?) 1–42, and the adjuvant, QS?21. To avoid this toxicity, we have been using A? derivatives in alum adjuvant that promotes humoral immunity. Other potential side effects of immunotherapy are increased vascular amyloid and associated microhemorrhages that may be related to rapid clearance of parenchymal amyloid. Here, we determined if our immunization strategy was associated with this form of toxicity, and if the therapeutic effect was age-dependent. Tg2576 mice and wild-type littermates were immunized from 11 or 19 months and their behaviour evaluated prior to killing at 24 months. Subsequently, plaque- and vascular-A? burden, A? levels and associated pathology was assessed. The therapy started at the cusp of amyloidosis reduced cortical A? deposit burden by 31% and A? levels by 30–37%, which was associated with cognitive improvements. In contrast, treatment from 19 months, when pathology is well established, was not immunogenic and therefore did not reduce A? burden or improve cognition. Significantly, the immunotherapy in the 11–24 months treatment group, that reduced A? burden, did not increase cerebral bleeding or vascular A? deposits in contrast to several A? antibody studies. These findings indicate that our approach age-dependently improves cognition and reduces A? burden when used with an adjuvant suitable for humans, without increasing vascular A? deposits or microhemorrhages

Cellular immune responses in peripheral blood lymphocytes of Giardia infected squirrel monkey (Saimiri boliviensis boliviensis) treated with Fenbendazole.

Cellular immune responses were tested to determine the effect of fenbendazole on the function of lymphocytes from Bolivian squirrel monkeys (Samiri boliviensis boliviensis). Giardia-infected squirrel monkeys were treated with commercially available fenbendazole (FBZ)-medicated monkey chow. Immune responses were compared between historical controls (Giardia naïve, untreated with FBZ (control animals)) and Giardia-infected, FBZ-treated squirrel monkeys (study animals). Peripheral blood lymphocytes from study monkeys had significantly lower stimulation indices compared to control animals when cultured in vitro with concanavalin A (Con A) (p<0.0001), phytohaemagglutinin (PHA) (p<0.0001) and lipopolysaccharide (LPS) (p<0.0001). PBMCs were also analyzed for IFN-γ producing cells in response to stimulation with Con A, PHA, PWM, and LPS by the cytokine ELISPOT assay. Significantly higher responses to Con A- (p<0.0001), and PHA- (p<0.001) stimulated cultures from Giardia-infected and fenbendazole treated compared to controls. Flow cytometric analysis for expression of cell surface markers revealed a significant increase in B- and NKT-lymphocytes and significant decrease in CD14+CD16+ monocytes after FBZ treatment. Also, circulating plasma cytokines IFN-γ, TNF-α, IL-12p40, IL-1β, IL-10, IL-13, IL-1ra, IL-6 and IL-4 were significantly decreased after FBZ treatment. Comparison of hematologic parameters between controls and FBZ-treated squirrel monkeys revealed significantly lower numbers of total leukocytes, neutrophils, monocytes, and eosinophils compared to controls. However, erythrocyte indices (red cell count, hemoglobin and hematocrit were significantly higher in FBZ-treated monkeys. Our findings suggest that fenbendazole treatment may alter sensitive immune and molecular measures of inflammation. Postponing the experimental use of squirrel monkeys until at least 6 weeks after FBZ treatment should be considered

Characterization of polymerized ABri.

<p>A Western blot using specific polyclonal anti-ABri antisera is shown in panel A. The freshly dissolved ABri peptide was run in lane 1. This preparation of ABri is mainly monomeric with some lower order aggregates of dimers and tetramers in contrast to the polymerized ABri peptide which has less monomer with a predominance of higher order aggregates in a range of 30 to 100 kDa (lane 2). Shown in panel B is the circular dichroism of these peptides. The freshly dissolved ABri peptide has a predominant random coil structure with a minimum at 195 nm, in contrast to the polymerized ABri peptide that has a predominant β-sheet structure with a minimum at 220 nm and a maximum at 195 nm. In panel C an electron micrograph of negatively stained polymerized ABri peptide is shown, which is predominately in the form of spherical particles of ∼10 nm (Scale bar, 100 nm).</p

Levels of Aβ40 and Aβ42 in the formic acid and DEA extracted material from brains of control Tg and pABri vaccinated Tg mice.

<p>A) In the formic acid extract fraction Aβ40 and Aβ43 were reduced 64% and 53%, respectively (*p<0.0001) in the vaccinated mice. B) In the DEA extracted fraction Aβ40 (*p<0.0001) and Aβ42 (**p = .0002) were reduced by 71% and 57%, respectively in the vaccinated mice.</p

Antibody levels in control and pABri vaccinated mice.

<p>Shown are bar graphs of the IgG and IgM antibody levels against polymerized ABri, Aβ42 and PHF at T0, T6 and TF. In A and B, titers of IgM and IgG in controls are shown, respectively. In C and D, titers of IgM and IgG in pABri vaccinated mice are shown, respectively (*p<0.0001, #p<0.01).</p