Faculty Bibliography

Background: We have previously demonstrated that anti-beta-sheet conformational monoclonal antibodies (mAbs) recognize pathological oligomeric forms of Abeta and Tau in tissue samples of human Alzheimer's Disease (AD) brains and in AD mouse models (Goni et al 2015, Alzheimer & Dementia pp 845-6). We have now tested one of our mAbs in aged 3xTg AD animals with extensive preexisting Abeta and Tau related pathology with weekly injections of the TABP1 mAb. Methods: Two groups of 16 months old 3xTg AD animals were inoculated i.p. biweekly for three weeks and weekly thereafter for 5 weeks with either 100 mug of TABP1 in 100 muL of sterile saline or with 100 muL of vehicle alone. Radial Arm Maze behavioral analysis was performed after the treatment, followed by sacrifice and harvesting of the brains for immuno-histochemical and biochemical analyses. Results: No adverse reactions were demonstrated during the treatment. The TABP1 infused animals showed significant cognitive rescue compared to the controls. No significant differences were noted with the immunohistochemical quantitation of amyloid plaques or tau pathology; although there was a trend for reduced deposition in the infused animals. However, there was a significant decrease of the soluble and oligomeric Abeta (mainly Abeta1-42) and pathological Tau in the infused animals versus the controls. Conclusions: Anti-conformational monoclonal antibodies infused i.p. can ameliorate behavioral deficits in AD model mice. The mechanism is likely related to reductions of the levels of soluble oligomeric forms of Abeta and Tau; these species have been most closely linked to the cognitive deficits in AD patients. The results are encouraging for the further testing of humanized versions of these mAbs in clinical trials

Background: It has been increasingly recognized that the pathogenesis of many neurodegenerative diseases is related to the accumulation of diverse proteins in aggregated/oligomeric forms. The pathological conformers can spread to different areas of the brain via a "prion-like" conversion mechanism mediated by the mobile b-sheet oligomeric structure of each particular peptide or protein. Previously we have characterized conformational monoclonal antibodies that react to both oligomers of Abeta and tau in AD, as well as to prion disease proteins. We have nowdetermined their binding specificity and capacity to be extended to synthetic oligomers of alpha-synuclein and to pathological intracellular structures present in Lewy body containing neurons of Parkinson's disease (PD) subjects. Methods: Recombinant alpha-synuclein was produced and characterized in monomeric, oligomeric and fibrillar forms by electron microscopy and circular dichroism. Histological specimens of formalin fixed brains from human AD and PD confirmed cases were used for reaction with three anti-conformational mAbs IgM previously described. The mAbs that reacted to oligomeric Abeta and tau and showed high affinity, specific binding by surface plasmon resonance, and/or were shown to reverse AD pathology after infusion in old 3xTg AD animal models were used for immunohistochemical detection on human PD brain specimens and detection of different alpha-synuclein conformers. Results: By SDS-PAGE the mAbs IgM showed specificity for oligomeric forms of polymerized alpha-synuclein but not to the monomeric forms. The mAbs showed specific intraneuronal reactivity around the Lewy bodies in human brains from confirmed cases of PD. Conclusions: Conformational monoclonal antibodies that are well characterized to react against pathological conformers in AD human brains and that can produce amelioration of existing AD pathology in AD animal models can also recognize oligomeric forms of alpha-synuclein and intraneuronal structures associated with Lewy bodies. Monoclonal antibodies that are specific for pathology associated conformations are good candidates to be used as immunotherapeutical agents alone or in combination with other approaches in many neurodegenerative diseases including Parkinson's disease

Background: We have previously demonstrated that immuno-intervention in AD animal models can lead to prevention of some pathology through innate immune system stimulation via TLR9 induced by CpG ODN (Scholtzova et al 2014) or the modulation of the adaptive immune system through active vaccination with the beta-sheet oligomeric form of the polymerized Bri peptide (Goni et al 2014). A challenge to therapeutic immune stimulation of old AD Tg animals, with preexisting extensive pathology, is senescence of the immune system. We have now vaccinated old 3xTg AD animals with both Abeta and tau pathology, with the pBri as a conformational antigen and CpGODNas an immune stimulator. Methods: Two groups of at least 15 months old 3xTg AD animals were inoculated four times over a period of two months with either vehicle or oligomeric pBri in Alum as previously described. Another group was inoculated from 12 to 17 month old with five doses of pBri or CpG ODN in alternate weeks as reported. Behavioral and locomotor tests were performed after the 17 month of age. The animals were then euthanized, followed by histological and biochemical analyses. Results: We show that old animals still could mount a conformational immune response that results in diminished pathology, as well as rescue of cognitive function. Both groups vaccinated with pBri and pBri-CpG ODN showed behavioral rescue when compared to age matched controls. Biochemistry and immuno-histology showed improvements of some pathological features; importantly including diminished oligomeric Abeta and tau. Conclusions: The active immunomodulation using polymerized beta-sheet oligomeric pBri can elicit a conformational antibody response even in old animals. These antibodies directed to beta-sheet conformation can retard the progression and reverse some preexisting pathology. The use of CpG ODN can help to boost the innate immune system, in senescent animals, to help establish the subsequent adaptive conformational response

Alzheimer's disease (AD) is the most prevalent form of dementia worldwide and is an emerging global epidemic. It is characterized by an imbalance between production and clearance of amyloid beta (Abeta) and tau proteins. Oligomeric forms of Abeta and tau are believed to be the most toxic. Dramatic results from AD animal models showed great promise for active and passive immune therapies targeting Abeta. However, there is very limited evidence in human studies of the clinical benefits from these approaches. Immunotherapies targeting only tau pathology have had some success but are limited so far to mouse models. The majority of current methods is based on immunological targeting of a self-protein; hence, benefits need to be balanced against risks of stimulating excessive autoimmune toxic inflammation. For greater efficacy the next generation of vaccines needs to focus more on concurrently targeting all the intermediate toxic conformers of oligomeric Abeta and tau species.

Prion disease is a unique category of illness, affecting both animals and humans, in which the underlying pathogenesis is related to a conformational change of a normal, self-protein called PrP(C) (C for cellular) to a pathological and infectious conformer known as PrP(Sc) (Sc for scrapie). Bovine spongiform encephalopathy (BSE), a prion disease believed to have arisen from feeding cattle with prion contaminated meat and bone meal products, crossed the species barrier to infect humans. Chronic wasting disease (CWD) infects large numbers of deer and elk, with the potential to infect humans. Currently no prionosis has an effective treatment. Previously, we have demonstrated we could prevent transmission of prions in a proportion of susceptible mice with a mucosal vaccine. In the current study, white-tailed deer were orally inoculated with attenuated Salmonella expressing PrP, while control deer were orally inoculated with vehicle attenuated Salmonella. Once a mucosal response was established, the vaccinated animals were boosted orally and locally by application of polymerized recombinant PrP onto the tonsils and rectal mucosa. The vaccinated and control animals were then challenged orally with CWD-infected brain homogenate. Three years post CWD oral challenge all control deer developed clinical CWD (median survival 602 days), while among the vaccinated there was a significant prolongation of the incubation period (median survival 909 days; p=0.012 by Weibull regression analysis) and one deer has remained CWD free both clinically and by RAMALT and tonsil biopsies. This negative vaccinate has the highest titers of IgA in saliva and systemic IgG against PrP. Western blots showed that immunoglobulins from this vaccinate react to PrP(CWD). We document the first partially successful vaccination for a prion disease in a species naturally at risk.

Alzheimer inverted question marks disease (AD) is the most common cause of dementia, and currently, there is no effective treatment. The major neuropathological lesions in AD are accumulation of amyloid beta (Abeta) as amyloid plaques and congophilic amyloid angiopathy, as well as aggregated tau in the form of neurofibrillary tangles (NFTs). In addition, inflammation and microglia/macrophage function play an important role in AD pathogenesis. We have hypothesized that stimulation of the innate immune system via Toll-like receptor 9 (TLR9) agonists, such as type B CpG oligodeoxynucleotides (ODNs), might be an effective way to ameliorate AD related pathology. We have previously shown in the Tg2576 AD model that CpG ODN can reduce amyloid deposition and prevent cognitive deficits. In the present study, we used the 3xTg-AD mice with both Ass and tau related pathology. The mice were divided into 2 groups treated from 7 to 20 months of age, prior to onset of pathology and from 11 to 18 months of age, when pathology is already present. We demonstrated that immunomodulatory treatment with CpG ODN reduces both Ass and tau pathologies, as well as levels of toxic oligomers, in the absence of any apparent inflammatory toxicity, in both animal groups. This pathology reduction is associated with a cognitive rescue in the 3xTg-AD mice. Our data indicates that modulation of microglial function via TLR9 stimulation is effective at ameliorating all the cardinal AD related pathologies in an AD mouse model mice suggesting such an approach would have a greater chance of achieving clinical efficacy.

Alzheimer's disease (AD) is the most common cause of dementia worldwide. In AD the normal soluble amyloid beta (sAbeta) peptide is converted into oligomeric/fibrillar Abeta. The oligomeric forms of Abeta are thought to be the most toxic, while fibrillar Abeta becomes deposited as amyloid plaques and congophilic angiopathy, which serve as neuropathological markers of the disease. In addition the accumulation of abnormally phosphorylated tau as soluble toxic oligomers and as neurofibrillary tangles is a critical part of the pathology. Numerous therapeutic interventions are under investigation to prevent and treat AD. Among the more exciting and advanced of these approaches is vaccination. Active and passive Immunotherapy targeting only Abeta has been successful in many AD model animal trials; however, the more limited human data has shown much less benefit so far, with encephalitis occurring in a minority of patients treated with active immunization and vasogenic edema or amyloid-related imaging abnormalities (ARIA) being a complication in some passive immunization trials. Therapeutic intervention targeting only tau has been tested only in mouse models; and no approaches targeting both pathologies concurrently has been attempted, until very recently. The immune approaches tried so far were targeting a self-protein, albeit in an abnormal conformation; however, effective enhanced clearance of the disease associated conformer has to be balanced with the potential risk of stimulating excessive toxic inflammation. The design of future more effective immunomodulatory approaches will need to target all aspects of AD pathology, as well as specifically targeting pathological oligomeric conformers, without the use of any self-antigen.