Faculty Bibliography

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

In the United States, estimates indicate there are between 250,000 and 400,000 individuals with Down syndrome (DS), and nearly all will develop Alzheimer's disease (AD) pathology starting in their 30s. With the current lifespan being 55 to 60 years, approximately 70% will develop dementia, and if their life expectancy continues to increase, the number of individuals developing AD will concomitantly increase. Pathogenic and mechanistic links between DS and Alzheimer's prompted the Alzheimer's Association to partner with the Linda Crnic Institute for Down Syndrome and the Global Down Syndrome Foundation at a workshop of AD and DS experts to discuss similarities and differences, challenges, and future directions for this field. The workshop articulated a set of research priorities: (1) target identification and drug development, (2) clinical and pathological staging, (3) cognitive assessment and clinical trials, and (4) partnerships and collaborations with the ultimate goal to deliver effective disease-modifying treatments.

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.

INTRODUCTION: Characterization of the type and topography of structural changes and their alterations throughout the lifespan of individuals with autism is essential for understanding the mechanisms contributing to the autistic phenotype. The aim of this stereological study of neurons in 16 brain structures of 14 autistic and 14 control subjects from 4 to 64 years of age was to establish the course of neuronal nuclear and cytoplasmic volume changes throughout the lifespan of individuals with autism. RESULTS: Our data indicate that a deficit of neuronal soma volume in children with autism is associated with deficits in the volume of the neuronal nucleus and cytoplasm. The significant deficits of neuronal nuclear and cytoplasmic volumes in 13 of 16 examined subcortical structures, archicortex, cerebellum, and brainstem in 4- to 8-year-old autistic children suggest a global nature of brain developmental abnormalities, but with region-specific differences in the severity of neuronal pathology. The observed increase in nuclear volumes in 8 of 16 structures in the autistic teenagers/young adults and decrease in nuclear volumes in 14 of 16 regions in the age-matched control subjects reveal opposite trajectories throughout the lifespan. The deficit in neuronal nuclear volumes, ranging from 7% to 42% in the 16 examined regions in children with autism, and in neuronal cytoplasmic volumes from 1% to 31%, as well as the broader range of interindividual differences for the nuclear than the cytoplasmic volume deficits, suggest a partial distinction between nuclear and cytoplasmic pathology. CONCLUSIONS: The most severe deficit of both neuronal nucleus and cytoplasm volume in 4-to 8-year-old autistic children appears to be a reflection of early developmental alterations that may have a major contribution to the autistic phenotype. The broad range of functions of the affected structures implies that their developmental and age-associated abnormalities contribute not only to the diagnostic features of autism but also to the broad spectrum of clinical alterations associated with autism. Lack of clinical improvement in autistic teenagers and adults indicates that the observed increase in neuron nucleus and cytoplasm volume close to control level does not normalize brain function.

INTRODUCTION: In vivo profiles of aldosterone synthase inhibitors (ASIs) have been investigated utilizing various rodent models. Due to lack of CYP17 activity, rodents produce corticosterone rather than cortisol as that of humans, which raised concern to their effectiveness in translational pharmacological characterization of ASI. METHODS: A rhesus monkey model that combines a low sodium diet with adrenocorticotropin (ACTH) treatment was developed. Plasma concentrations of steroid metabolites associated with reactions catalyzed by CYP11B2 and CYP11B1 were measured concurrently by a UPLC/MS method. RESULTS: Plasma concentration of aldosterone in regular diet fed rhesus monkeys was low at 109pg/mL. Aldosterone concentrations were increased to 252pg/mL when animals were maintained on a low sodium diet for 3weeks, and to 300pg/mL with ACTH treatment at 0.3mg/kg. The combination of low sodium diet with ACTH treatment further increased plasma concentration of aldosterone to 730pg/mL and other steroid metabolites at various levels. Intravenous administration of ASI, fadrozole (0.001-1mg/kg) or LCI699 (0.003-3mg/kg), led to dose-dependent reductions in aldosterone and 18-hydroxycorticosterone, increases in 11-deoxycorticosterone and 11-deoxycortisol, and bell-shaped changes in cortisol and corticosterone. In vivo selectivity of CYP11B2/CYP11B1 for fadrazole was 26-fold and LCI-699 was 27-fold, which was consistent with relative selectivity using in vitro values from recombinant cells transfected with rhesus monkey CYP11B2 and CYP11B1. DISCUSSION: This model enables concurrent characterization of pharmacokinetics, pharmacodynamics and selectivity of CYP11B2 over CYP11B1 inhibition in the same animal. It may be used as a translational model for pharmacological characterization of ASI.