Poster Presentations P2: mouse microglia to degrade human amyloid deposits in ex vivo assay at micromolar concentrations. Immunization of young adult mice with hIVIG at 1g/kg i.p. or i.v. resulted in the formation of neutralizing cross-species antibodies as expected, but tolerance developed after both ways of administration in 4-6 weeks. Intraperitoneal administration of hIVIG once weekly for 14 weeks resulted in significant accumulation of human IgG immunoreactivity in the hippocampus of APP/PS1 mice and in some cases opsonization of amyloid plaques. Conclusions: The data suggest that hIVIG contains antibodies that are able to bind Abeta and induce amyloid degradation if provided at high enough concentrations. Development of crossspecies immune response and blood-brain barrier do not prevent testing these effects in transgenic amyloid producing mice also in vivo. P2-355
TRIMER A42 GENE VACCINE ELICITS A HIGH LEVEL OF ANTIBODY PRODUCTION WHEN DELIVERED WITH THE GAL4-UAS SYSTEM AND THE GENE GUN
Bao-Xi Qu1, Min Fu1, Stephen A. Johnston2, Roger N. Rosenberg1, 1UT Southwestern Medical Center, Dallas, TX, USA; 2The Arizona State University, Tempe, AZ, USA. Contact e-mail:
[email protected] Background: Amyloid  42 (A42) gene vaccination is a potential therapy for prevention and treatment of Alzheimer’s disease. A key concern in this approach is the need for high level antibody response without inducing CTL against A. Methods: Using the gene gun mediated delivery method, we demonstrate that the binary Gal4/UAS system encoding the trimer A42 gene ( 3 copies of the A42 cDNA) may meet this criteria, eliciting a high level of antibody production in vivo against A42. The Gal4/UAS system consists of an activator construct that expresses a yeast transcription factor, Gal4, and an effector construct that contains DNA-binding motifs for Gal4 (UAS) linked to the trimer A42 gene. Results: Co-shooting of these two plasmids into the mouse ear skin with the gene gun elicits high anti-A42 antibody production, 10- 25 g/ml compared to 2 to 6 g/ml with A42 monomer constructs. The serotype ratio is approximately 2:1 (IgG1:IgG2a). Importantly, no significant cytotoxic T cell response is elicited as tested by the ELISPOT assay for gamma interferon levels in mouse spleen T cells. In vitro transfection of the human cell line HEK293 shows higher A42 peptide production with the trimer construct compared to the monomer A42 construct. Conclusions: We believe that more antigen (A42) production is the reason for an increased level of antibody production with the trimer A42 construct compared to the A42 monomer construct. These high titers of anti-A42 antibody elicited by the trimer A42 construct provide levels of anti-A42 antibody that offer potential therapy for Alzheimer’s disease. P2-356
VACCINATION AGAINST GENERIC PREFIBRILLAR AMYLOID OLIGOMER ANTIGENS IS EFFECTIVE IN PROTECTING COGNITIVE FUNCTION IN Tg2576 MICE
Suhail Rasool, Hilda Martinez-Coria, Leonid Breydo, Charles G. Glabe, UC Irvine, Irvine, CA, USA. Contact e-mail:
[email protected] Background: Accummulation of beta-amyloid (A) is an important molecular event in Alzheimer’s disease (AD). It is now well known that vaccination against fibrillar A prevents amyloid accumulation and preserves cognitive function in transgenic mouse models. Methods: To study the effect of vaccination against generic oligomer epitopes, A oligomers, islet amyloid polypeptide (IAPP) oligomers & A fibrils were used to vaccinate Tg2576 mice, which develop a progressive accumulation of plaques and cognitive impairment. We vaccinated Tg2576 mice monthly with the above mentioned vaccines and studied various cognitive parameters at 6 months and 10 months age. We tested escape latency, number of platform crosses in the Morris water maze test (MWM) (which is related to hippocampus) and novel object recognition (which is related to cortex). Results: It was found that A oligomer, IAPP oligomer and A fibril
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vaccinated mice have a significant improvement in cognitive function compared to controls. We also find a significant difference in cognitive functions between 6 months and 10 months old vaccinated mice. Conclusions: Our conclusion is that vaccination against generic amyloid oligomer epitopes attenuates cognitive impairment and that the amyloid A sequence is not necessary to produce a protective immune response, suggesting that vaccination against a non-human amyloid oligomer epitope may be an effective strategy for developing a vaccine that does not have the potential for autoinflammatory immune complications. P2-357
EFFECTS OF RESVERATROL ON MICROGLIAL INFLAMMATORY AND PHAGOCYTIC ACTIVITY
Johannes C. M. Schlachetzki1, Eduardo Candelario-Jalil2, Antonio C. Pinheiro de Oliveira1, Harsharan S. Bhatia1, Bernd L. Fiebich1, Michael Hu¨ll1, 1University of Freiburg, Freiburg, Germany; 2University of New Mexico Health Sciences Center, Albuquerque, NM, USA. Contact e-mail:
[email protected] Background: In Alzheimer’s disease (AD), microglial cells may act as a double-edged sword. Microglial cells may be neuroprotective by increasing phagocytic activity and thereby clearing the brain of amyloid beta (A), or detrimental by secreting pro-inflammatory and neurotoxic agents. Therefore it is highly desirable to find compounds, which promote on one hand microglial phagocytic activity and restrain on the other hand these cells from producing pro-inflammatory and neurotoxic factors such as cytokines, members of the arachidonic acid cascade or nitric oxid. Passive and active vaccination strategies have been shown to increase A clearance by phagocytosis but excessive pro-inflammatory activation remains a serious concern. A decreased risk to develop AD has been attributed to a moderate consumption of red wine. Positive effects of red wine have been attributed to resveratrol, a polyphenolic compound with antioxidative, anti-inflammatory, and neuroprotective properties. In neuronal cell lines, resveratrol was found to enhance intracellular A degradation. Objective: The aim of this study was to determine the effect of resveratrol on primary microglial cell with regard to phagocytic activity and inflammation. Methods: To study phagocytosis, microglial cells were treated with different concentrations of resveratrol and incubated with fluorescein (FAM) labeled A1-42. After 6 h, we measured the uptake of FAM-A1-42 in the cells. The influence of resverarol on the production of proinflammatory mediators was studied in lipopolysaccarid (LPS) stimulated microglial cells. Results: We did not observe a beneficial effect on microglial phagocytosis of FAM-A1-42. Resveratrol reduced the production of prostaglandin E2 (PGE2) by decreasing the LPS-induced expression of microsomal prostaglandin E2 synthase 1 (mPGES1), the terminal synthase responsible for convertion of PGH2 to PGE2 (de Oliveira et al., 2008). Conclusions: In summary, our results show, that resveratrol may exert anti-inflammatory properties but does not stimulate microglial cells to remove extracellular A. P2-358
SEN1269: A NOVEL INHIBITOR OF AMYLOIDBETA TOXICITY
David I. Scopes1, Hozefa Amijee1, Edmund Nerou1, Mark Treherne1, Eugene O’Hare2, Ross Jeggo3, Andrew Whyment3, David Spanswick3, 1 Senexis Limited, Cambridge, United Kingdom; 2Queen’s University, Belfast, United Kingdom; 3NeuroSolutions Limited, Coventry, United Kingdom. Contact e-mail:
[email protected] Background: RS-0406 is a small molecule with an activity profile which indicates that it is an effective inhibitor against the toxicity of amyloid  (A). In vitro, it is neuroprotective against an insult of synthetic A1-42, rescuing the deficit in long-term potentiation (LTP) caused by the toxic forms of this peptide. The advantages of RS-0406, apart from its biological profile, are its low molecular weight, chemical tractability and options for structural modifications. Senexis is conducting a research program to examine the potential of RS-0406 as a basis for identifying therapeutically effective inhibitors of toxic assemblies of A. Methods: Modifications to RS-0406 have focused on improving its potency as well as addressing the
