Vaccines targeting the primary amino acid sequence and conformational epitope of amyloid-ß had distinct effects on neuropathology and cognitive deficits in EAE/AD mice.

BACKGROUND AND PURPOSE: Immunotherapeutic intervention is one of the most promising strategies for the prevention and treatment of Alzheimer's disease (AD). Although they showed great success in AD mouse models, the clinical trials of many immune approaches failed due to low efficacy and safety. Thus, an animal model which can show the potential side effects of vaccines or antibodies is urgently needed. In this study, we generated EAE/AD mice by crossing APP/PS1 mice with experimental autoimmune encephalomyelitis (EAE) mice. We then investigated the efficacy and safety of two vaccines: the immunogens of which were Aß1-42 aggregates (Aß42 vaccine) and an oligomer-specific conformational epitope (AOE1 vaccine), respectively. EXPERIMENTAL APPROACH: EAE/AD mice were immunized with the Aß42 vaccine or AOE1 vaccine five times at biweekly intervals. After the final immunization, cognitive function was evaluated by the Morris water maze, Y maze, and object recognition tests. Neuropathological changes in the mouse brains were analysed by immunohistochemistry and ELISA. KEY RESULTS: In contrast to previous findings in conventional AD animal models, Aß42 immunization promoted neuroinflammation, enhanced Aß levels and plaque burden, and failed to restore cognitive deficits in EAE/AD mice. By contrast, AOE1 immunization dramatically attenuated neuroinflammation, reduced Aß levels, and improved cognitive performance in EAE/AD mice. CONCLUSION AND IMPLICATIONS: These results suggest that the EAE/AD mouse model can exhibit the potential side effects of AD immune approaches that conventional AD animal models fail to display. Furthermore, strategies specifically targeting Aß oligomers may be safe and show clinical benefit for AD treatment.

Intravenous immunoglobulin ameliorates motor and cognitive deficits and neuropathology in R6/2 mouse model of Huntington's disease by decreasing mutant huntingtin protein level and normalizing NF-κB signaling pathway.

Huntington's disease (HD) is a fatal neurodegenerative disorder characterized by progressive movement disorders and cognitive deficits, which is caused by a CAG-repeat expansion encoding an extended polyglutamine (polyQ) tract in the huntingtin protein (HTT). Reduction of mutant HTT levels and inhibition of neuroinflammation has been proposed as a major therapeutic strategy in treating HD. Intravenous immunoglobulin (IVIg) therapy has been firmly established for the treatment of several autoimmune or inflammatory neurological diseases, either as adjunctive treatment or as first-line therapy. However, whether IVIg has therapeutic potential on HD remains unclear. Here we for the first time demonstrated that IVIg treatment remarkably rescued motor and cognitive deficits, prevented synaptic degeneration, attenuated neuroinflammation and oxidative stress in R6/2 mouse model. Further investigation showed that the beneficial effects of IVIg resulted from the reduced levels of mutant HTT and inhibition of NF-κB signalling pathway. These findings suggest that IVIg is a promising therapeutic potential for HD.

Fruitless Wolfberry-Sprout Extract Rescued Cognitive Deficits and Attenuated Neuropathology in Alzheimer's Disease Transgenic Mice.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease featured by memory loss, neuroinflammation and oxidative stress. Overproduction or insufficient clearance of Aß leads to its pathological aggregation and deposition, which is considered the predominant neuropathological hallmark of AD. Therefore, reducing Aß levels and inhibiting Aß-induced neurotoxicity are feasible therapeutic strategies for AD treatment. Wolfberry has been traditionally used as a natural antioxidant and anti-aging product. However, whether wolfberry species has therapeutic potential on AD remains unknown. METHOD: The effects of fruitless wolfberry-sprout extract (FWE) on Aß fibrillation and fibril disaggregation was measured by thioflavin T fluorescence and transmission electron microscope imaging; Aß oligomer level was determined by dot-blot; Cell viability and apoptosis was assessed by MTT and TUNEL assay. The levels of Aß40/42, oxidative stress biomarkers and inflammatory cytokines were detected by corresponding kits. 8-month-old male APP/PS1 mice and their age-matched WT littermates were treated with FWE or vehicle by oral administration (gavage) once a day for 4 weeks. Then the cognitive performance was determined using object recognition test and Y-maze test. The Aß burden and gliosis was evaluated by immunostaining and immunoblotting, respectively. RESULTS: FWE significantly inhibited Aß fibrillation and disaggregated the formed Aß fibrils, lowered Aß oligomer level and Aß-induced neuro-cytotoxicity, and attenuated oxidative stress in vitro. Oral administration of FWE remarkably improved cognitive function, reduced Aß burden, decreased gliosis and inflammatory cytokines release, and ameliorated oxidative stress in the brains of APP/PS1 mice. CONCLUSION: These findings indicate that FWE is a promising natural agent for AD treatment.

Intravenous immunoglobulin improves glucose control and ß-cell function in human IAPP transgenic mice by attenuating islet inflammation and reducing IAPP oligomers.

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by ß-cell loss, insulin resistance, islet inflammation and amyloid deposits derived from islet amyloid polypeptide (IAPP). Reducing toxic IAPP oligomers and inhibiting islet inflammation may provide therapeutic benefit in treating T2DM. Intravenous immunoglobulin (IVIg) is an efficient anti-inflammatory and immunomodulatory agent for the treatment of several autoimmune or inflammatory neurological diseases. However, whether IVIg has therapeutic potential on T2DM remains unclear. In present study, we showed that IVIg treatment significantly improved glucose control and insulin sensitivity, and prevented ß-cell apoptosis by lowering toxic IAPP oligomer levels, attenuating islet inflammation and activating autophagy in human IAPP transgenic mouse model. These results suggest that IVIg is a promising therapeutic potential for T2DM treatment.

A scFv antibody targeting common oligomeric epitope has potential for treating several amyloidoses.

Overproduction or poor clearance of amyloids lead to amyloid aggregation and even amyloidosis development. Different amyloids may interact synergistically to promote their aggregation and accelerate pathology in amyloidoses. Amyloid oligomers assembled from different amyloids share common structures and epitopes, and are considered the most toxic species in the pathologic processes of amyloidoses, which suggests that an agent targeting the common epitope of toxic oligomers could provide benefit to several amyloidoses. In this study, we firstly showed that an oligomer-specific single-chain variable fragment antibody, W20 simultaneously improved motor and cognitive function in Parkinson's disease and Huntington's disease mouse models, and attenuated a number of neuropathological features by reducing α-synuclein and mutant huntingtin protein aggregate load and preventing synaptic degeneration. Neuroinflammation and oxidative stress in vivo were also markedly inhibited. The proposed strategy targeting the common epitopes of amyloid oligomers presents promising potential for treating Parkinson's disease, Huntington's disease, Alzheimer's disease, and other amyloidoses.

Interleukin-1ß-Targeted Vaccine Improves Glucose Control and ß-Cell Function in a Diabetic KK-Ay Mouse Model.

Interleukin-1ß (IL-1ß) has been implicated as a key proinflammatory cytokine involved in the pancreatic islet inflammation of type 2 diabetes mellitus (T2DM). Excess IL-1ß impairs islet function by inducing insulin resistance and ß-cell apoptosis. Therefore, specifically reducing IL-1ß activity provides a therapeutic improvement for T2DM by sustaining the inhibition of IL-1ß-mediated islet inflammation. In this study, we developed an IL-1ß-targeted epitope peptide vaccine adjuvanted with polylactic acid microparticles (1ßEPP) and applied it to a diabetic KK-Ay mouse model. Results showed that the 1ßEPP elicited high antibody responses, which neutralized the biological activity of IL-1ß, and induced barely detectable inflammatory activity. 1ßEPP immunization reduced body weight gain, protected KK-Ay mice from hyperglycemia, improved glucose tolerance and insulin sensitivity, and decreased the serum levels of free fatty acids, total cholesterol and triglyceride. Moreover, 1ßEPP restored ß-cell mass; inhibited ß-cell apoptosis; decreased the expression of IL-1ß; and interrupted NF-κB activation by reducing IKKß and pRelA levels. These studies indicated that the IL-1ß-targeted vaccine may be a promising immunotherapeutic for T2DM treatment.