Testing a MultiTEP-based combination vaccine to reduce Aβ and tau pathology in Tau22/5xFAD bigenic mice.

BackgroundAlzheimer disease (AD) is characterized by the accumulation of beta-amyloid (Aβ) plaques and neurofibrillary tangles composed of hyperphosphorylated tau, which together lead to neurodegeneration and cognitive decline. Current therapeutic approaches have primarily aimed to reduce pathological aggregates of either Aβ or tau, yet phase 3 clinical trials of these approaches have thus far failed to delay disease progression in humans. Strong preclinical evidence indicates that these two abnormally aggregated proteins interact synergistically to drive downstream neurodegeneration. Therefore, combinatorial therapies that concurrently target both Aβ and tau might be needed for effective disease modification.MethodsA combinatorial vaccination approach was designed to concurrently target both Aβ and tau pathologies. Tau22/5xFAD (T5x) bigenic mice that develop both pathological Aβ and tau aggregates were injected intramuscularly with a mixture of two MultiTEP epitope vaccines: AV-1959R and AV-1980R, targeting Aβ and tau, respectively, and formulated in AdvaxCpG, a potent polysaccharide adjuvant. Antibody responses of vaccinated animals were measured by ELISA, and neuropathological changes were determined in brain homogenates of vaccinated and control mice using ELISA and Meso Scale Discovery (MSD) multiplex assays.ResultsT5x mice immunized with a mixture of Aβ- and tau-targeting vaccines generated high Aβ- and tau-specific antibody titers that recognized senile plaques and neurofibrillary tangles/neuropil threads in human AD brain sections. Production of these antibodies in turn led to significant reductions in the levels of soluble and insoluble total tau, and hyperphosphorylated tau as well as insoluble Aβ42, within the brains of bigenic T5x mice.ConclusionsAV-1959R and AV-1980R formulated with AdvaxCpG adjuvant are immunogenic and therapeutically potent vaccines that in combination can effectively reduce both of the hallmark pathologies of AD in bigenic mice. Taken together, these findings warrant further development of this vaccine technology for ultimate testing in human AD

A database of immunoglobulins with integrated tools: DIGIT

The DIGIT (Database of ImmunoGlobulins with Integrated Tools) database (http://biocomputing.it/digit) is an integrated resource storing sequences of annotated immunoglobulin variable domains and enriched with tools for searching and analyzing them. The annotations in the database include information on the type of antigen, the respective germline sequences and on pairing information between light and heavy chains. Other annotations, such as the identification of the complementarity determining regions, assignment of their structural class and identification of mutations with respect to the germline, are computed on the fly and can also be obtained for user-submitted sequences. The system allows customized BLAST searches and automatic building of 3D models of the domains to be performed

A chromosome conformation capture ordered sequence of the barley genome

201

Morpho-functional study of the hypothalamic proline-rich polypeptide apoptotic activity against mouse Ehrlich ascites carcinoma

A new type of bioactive polypeptides of the neurosecretory hypothalamus called proline-rich peptides (PRPs), which are isolated from bovine neurosecretory granules of the neurohypophysis, are synthesized in the form of a common precursor protein (neurophysin vasopressin-associated glycoprotein). Proline-rich polypetide 1 (PRP-1; also known as galarmin) is comprised of 15 amino acids residues, and has been suggested to possess anti-neurodegenerative, immunoregulatory, hematopoietic, antimicrobial and antitumor properties. The cytostatic, antiproliferative effect of PRP-1 was demonstrated in the human chondrosarcoma JJ012 and triple negative breast carcinoma MDA MB 231 cell lines. PRP-1 action is disease and tissue specific. To further explore the antitumorigenic and possible cytotoxic effects of PRP-1, a morpho-functional study on the effect of PRP-1 on a mouse Ehrlich ascites carcinoma (EAC) model was conducted. The PRP-1-induced morphological features of EAC cells confirmed the apoptotic nature of PRP-1, as manifested by cell shrinkage, membrane blebbing, chromosome condensation (pyknosis) and nuclear fragmentation (karyorrhexis). The effect of PRP-1 on the number of tumor cells incubated for 24 h and their viability in trypan blue-stained samples lead to a 44% reduction in the number of viable cells on day 11 post-inoculation vs. 22% inhibition of viable cells after PRP-1 treatment (0.1 µg/ml) on day 7 post-inoculation. Apoptosis experiments using an Annexin V-cyanine 3 apoptosis detection kit indicated that 24 h incubation with 0.1 µg/ml PRP-1 caused a significant increase in the number of apoptotic cells, reaching 50.33%, compared to 8.33% in the sample control on day 7 post-inoculation

Promiscuous antibodies characterised by their physico-chemical properties:From sequence to structure and back

AbstractHuman B cells produce antibodies, which bind to their cognate antigen based on distinct molecular properties of the antibody CDR loop. We have analysed a set of 10 antibodies showing a clear difference in their binding properties to a panel of antigens, resulting in two subsets of antibodies with a distinct binding phenotype. We call the observed binding multiplicity ‘promiscuous’ and selected physico-chemical CDRH3 characteristics and conformational preferences may characterise these promiscuous antibodies. To classify CDRH3 physico-chemical properties playing a role in their binding properties, we used statistical analyses of the sequences annotated by Kidera factors. To characterise structure-function requirements for antigen binding multiplicity we employed Molecular Modelling and Monte Carlo based coarse-grained simulations. The ability to predict the molecular causes of promiscuous, multi-binding behaviour would greatly improve the efficiency of the therapeutic antibody discovery process

A MultiTEP platform-based epitope vaccine targeting the phosphatase activating domain (PAD) of tau: therapeutic efficacy in PS19 mice.

Pathological tau correlates well with cognitive impairments in Alzheimer's disease (AD) patients and therefore represents a promising target for immunotherapy. Targeting an appropriate B cell epitope in pathological tau could in theory produce an effective reduction of pathology without disrupting the function of normal native tau. Recent data demonstrate that the N-terminal region of tau (aa 2-18), termed the "phosphatase activation domain (PAD)", is hidden within native Tau in a 'paperclip'-like conformation. Conversely, PAD is exposed in pathological tau and plays an essential role in the inhibition of fast axonal transport and tau polymerization. Thus, we hypothesized that anti-tau2-18 antibodies may safely and specifically reduce pathological tau and prevent further aggregation, which in turn would neutralize tau toxicity. Therefore, we evaluated the immunogenicity and therapeutic efficacy of our MultiTEP platform-based vaccine targeting tau2-18 formulated with AdvaxCpG adjuvant (AV-1980R/A) in PS19 tau transgenic mice. The AV-1980R/A induced extremely high antibody responses and the resulting sera recognized neurofibrillary tangles and plaque-associated dystrophic neurites in AD brain sections. In addition, under non-denaturing conditions AV-1980R/A sera preferentially recognized AD-associated tau. Importantly, vaccination also prevented age-related motor and cognitive deficits in PS19 mice and significantly reduced insoluble total and phosphorylated tau species. Taken together, these findings suggest that predominantly targeting misfolded tau with AV-1980R/A could represent an effective strategy for AD immunotherapy

A MultiTEP platform-based epitope vaccine targeting the phosphatase activating domain (PAD) of tau: therapeutic efficacy in PS19 mice.

Pathological tau correlates well with cognitive impairments in Alzheimer's disease (AD) patients and therefore represents a promising target for immunotherapy. Targeting an appropriate B cell epitope in pathological tau could in theory produce an effective reduction of pathology without disrupting the function of normal native tau. Recent data demonstrate that the N-terminal region of tau (aa 2-18), termed the "phosphatase activation domain (PAD)", is hidden within native Tau in a 'paperclip'-like conformation. Conversely, PAD is exposed in pathological tau and plays an essential role in the inhibition of fast axonal transport and tau polymerization. Thus, we hypothesized that anti-tau2-18 antibodies may safely and specifically reduce pathological tau and prevent further aggregation, which in turn would neutralize tau toxicity. Therefore, we evaluated the immunogenicity and therapeutic efficacy of our MultiTEP platform-based vaccine targeting tau2-18 formulated with AdvaxCpG adjuvant (AV-1980R/A) in PS19 tau transgenic mice. The AV-1980R/A induced extremely high antibody responses and the resulting sera recognized neurofibrillary tangles and plaque-associated dystrophic neurites in AD brain sections. In addition, under non-denaturing conditions AV-1980R/A sera preferentially recognized AD-associated tau. Importantly, vaccination also prevented age-related motor and cognitive deficits in PS19 mice and significantly reduced insoluble total and phosphorylated tau species. Taken together, these findings suggest that predominantly targeting misfolded tau with AV-1980R/A could represent an effective strategy for AD immunotherapy