102 research outputs found
Alzheimerās disease AdvaxCpG- adjuvanted MultiTEP-based dual and single vaccines induce high-titer antibodies against various forms of tau and AĪ² pathological molecules
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the articleās Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/Although Ī²-amyloid (AĪ²) may be the primary driver of Alzheimer's disease (AD) pathology, accumulation of pathological tau correlates with dementia in AD patients. Thus, the prevention/inhibition of AD may require vaccine/s targeting AĪ² and tau simultaneously or sequentially. Since high antibody titers are required for AD vaccine efficacy, we have decided to generate vaccines, targeting AĪ² (AV-1959R), Tau (AV-1980R) or AĪ²/tau (AV-1953R) B cell epitopes, based on immunogenic MultiTEP platform and evaluate the immunogenicity of these vaccines formulated with Advax(CpG), delta inulin, Alhydrogel(Ā®), Montanide-ISA51, Montanide-ISA720, MPLA-SM pharmaceutical grade adjuvants. Formulation of AV-1959R in Advax(CpG) induced the highest cellular and humoral immune responses in mice. The dual-epitope vaccine, AV-1953R, or the combination of AV-1959R and AV-1980R vaccines formulated with Advax(CpG) induced robust antibody responses against various forms of both, AĪ² and tau pathological molecules. While anti-AĪ² antibody titers after AV-1953R immunization were similar to that in mice vaccinated with AV-1959R or AV-1959R/AV-1980R combination, anti-tau titers were significantly lower after AV-1953R injection when compared to the AV-1980R or AV-1959R/AV-1980R. In silico 3D-modeling provided insight into the differences in immunogenicity of these vaccine constructs. In sum, AV-1959R and AV-1980R formulated with Advax(CpG) adjuvant were identified as promising immunogenic vaccines for ongoing pre-clinical assessment and future human clinical trials
TB financing in East Europe promotes unnecessary hospital admissions: the case of Armenia
Based on cost-effectiveness considerations and on the risk of nosocomial transmission of Mycobacterium tuberculosis strains, the World Health Organization (WHO) and other international institutions recommend to minimize unnecessary hospitalization of tuberculosis (TB) cases.
As in other Former Soviet Union (FSU) countries, the organisations of TB services in Armenia are heavily based on vertical and specialized services.
In Armenia, a country of 3.2 million inhabitants, TB is one of the major public health problems with overall notification and estimated mortality rates of 41 and 8.8 cases per 100,000 population in 2011, respectively. The prevalence of multidrug-resistant (MDR-TB) was 9.4% and 43.2% among new and previously treated cases, respectively, with 11.9% of them estimated to be extensively drug-resistant (XDR-TB).
Specialized TB services include 9 in-patient TB departments, 73 out-patient TB units (called TB cabinets) based in general health-care facilities, and 31 laboratories providing sputum smear microscopy, while culture and drug susceptibility testing is performed in the National TB Reference Laboratory. Following WHO recommendations, the Armenian National TB Programme (NTP) expanded the basic package of services provided in out-patient settings, allowing free access/free of charge TB diagnosis and treatment to the population, to achieve the global TB targets in the WHO European Region under the National Strategic Plan 2007-2015 and Consolidated Action Plan to Prevent and Combat M/XDR-TB in the WHO European Region 2011-2015.</br
TB financing in East Europe promotes unnecessary hospital admissions: the case of Armenia
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Testing a MultiTEP-based combination vaccine to reduce AĪ² and tau pathology in Tau22/5xFAD bigenic mice.
BackgroundAlzheimer disease (AD) is characterized by the accumulation of beta-amyloid (AĪ²) 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 AĪ² 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 AĪ² and tau might be needed for effective disease modification.MethodsA combinatorial vaccination approach was designed to concurrently target both AĪ² and tau pathologies. Tau22/5xFAD (T5x) bigenic mice that develop both pathological AĪ² and tau aggregates were injected intramuscularly with a mixture of two MultiTEP epitope vaccines: AV-1959R and AV-1980R, targeting AĪ² 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 AĪ²- and tau-targeting vaccines generated high AĪ²- 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 AĪ²42, 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
The immunological potency and therapeutic potential of a prototype dual vaccine against influenza and Alzheimer's disease
<p>Abstract</p> <p>Background</p> <p>Numerous pre-clinical studies and clinical trials demonstrated that induction of antibodies to the Ī²-amyloid peptide of 42 residues (AĪ²<sub>42</sub>) elicits therapeutic effects in Alzheimer's disease (AD). However, an active vaccination strategy based on full length AĪ²<sub>42 </sub>is currently hampered by elicitation of T cell pathological autoreactivity. We attempt to improve vaccine efficacy by creating a novel chimeric flu vaccine expressing the small immunodominant B cell epitope of AĪ²<sub>42</sub>. We hypothesized that in elderly people with pre-existing memory Th cells specific to influenza this dual vaccine will simultaneously boost anti-influenza immunity and induce production of therapeutically active anti-AĪ² antibodies.</p> <p>Methods</p> <p>Plasmid-based reverse genetics system was used for the rescue of recombinant influenza virus containing immunodominant B cell epitopes of AĪ²<sub>42 </sub>(AĪ²<sub>1-7/10</sub>).</p> <p>Results</p> <p>Two chimeric flu viruses expressing either 7 or 10 aa of AĪ²<sub>42 </sub>(flu-AĪ²<sub>1-7 </sub>or flu-AĪ²<sub>1-10</sub>) were generated and tested in mice as conventional inactivated vaccines. We demonstrated that this dual vaccine induced therapeutically potent anti-AĪ² antibodies and anti-influenza antibodies in mice.</p> <p>Conclusion</p> <p>We suggest that this strategy might be beneficial for treatment of AD patients as well as for prevention of development of AD pathology in pre-symptomatic individuals while concurrently boosting immunity against influenza.</p
Sleep disruption due to nocturnal heartburn: a review of the evidence and clinical implications
Nocturnal heartburn (NHB) is a symptom that affects up to 25% of the general population and has been shown to cause sleep disruption that adversely affects quality of life and psychomotor performance. Few studies have evaluated the association between occasional NHB and sleep disturbances; therefore, this connection may be underappreciated and left untreated by the primary care provider and patient, with potentially significant negative clinical consequences and effects on quality of life. This review sought to describe what is currently known about the interplay between occasional NHB and sleep disruption, and identify whether acid suppression therapy can improve symptoms of occasional NHB and associated sleep disruptions. The pathophysiology of heartburn-induced sleep disruption appears to follow a bidirectional cycle due to the normal physiologic changes that occur in the upper gastrointestinal tract during sleep and due to the potential for heartburn symptoms to cause sleep arousal. The majority of the identified studies suggested that pharmacologic interventions for acid reduction, including proton pump inhibitors or histamine type-2 receptor antagonists (H2RAs), improved objective and/or subjective sleep outcomes among individuals with gastroesophageal reflux disease (GERD) and NHB. Several studies specific to famotidine demonstrated that treatment with 10 mg or 20 mg reduced nighttime awakenings due to NHB. In conclusion, NHB symptoms can cause sleep dysfunction that can have a profound adverse downstream effect on quality of life, next-day functioning, and health-related outcomes. The current approach to managing occasional NHB is similar to that associated with GERD, highlighting the need for studies specific to the occasional heartburn population. Health care providers should investigate NHB as one of the potential causes of sleep complaints, and patients with heartburn should be questioned about sleep quality, recalled arousals, next-day vitality, early fatigue, and next-day functioning
Exosome loaded immunomodulatory biomaterials alleviate local immune response in immunocompetent diabetic mice post islet xenotransplantation
Foreign body response (FBR) to biomaterials compromises the function of implants and leads to medical complications. Here, we report a hybrid alginate microcapsule (AlgXO) that attenuated the immune response after implantation, through releasing exosomes derived from human Umbilical Cord Mesenchymal Stem Cells (XOs). Upon release, XOs suppress the local immune microenvironment, where xenotransplantation of rat islets encapsulated in AlgXO led to >170 days euglycemia in immunocompetent mouse model of Type 1 Diabetes. In vitro analyses revealed that XOs suppressed the proliferation of CD3/CD28 activated splenocytes and CD3+ T cells. Comparing suppressive potency of XOs in purified CD3+ T cells versus splenocytes, we found XOs more profoundly suppressed T cells in the splenocytes co-culture, where a heterogenous cell population is present. XOs also suppressed CD3/CD28 activated human peripheral blood mononuclear cells (PBMCs) and reduced their cytokine secretion including IL-2, IL-6, IL-12p70, IL-22, and TNFĪ±. We further demonstrate that XOs mechanism of action is likely mediated via myeloid cells and XOs suppress both murine and human macrophages partly by interfering with NFĪŗB pathway. We propose that through controlled release of XOs, AlgXO provide a promising new platform that could alleviate the local immune response to implantable biomaterials
Absence of microglia promotes diverse pathologies and early lethality in Alzheimerās disease mice
Microglia are strongly implicated in the development and progression of Alzheimer's disease (AD), yet their impact on pathology and lifespan remains unclear. Here we utilize a CSF1R hypomorphic mouse to generate a model of AD that genetically lacks microglia. The resulting microglial-deficient mice exhibit a profound shift from parenchymal amyloid plaques to cerebral amyloid angiopathy (CAA), which is accompanied by numerous transcriptional changes, greatly increased brain calcification and hemorrhages, and premature lethality. Remarkably, a single injection of wild-type microglia into adult mice repopulates the microglial niche and prevents each of these pathological changes. Taken together, these results indicate the protective functions of microglia in reducing CAA, blood-brain barrier dysfunction, and brain calcification. To further understand the clinical implications of these findings, human AD tissue and iPSC-microglia were examined, providing evidence that microglia phagocytose calcium crystals, and this process is impaired by loss of the AD risk gene, TREM2
Epitope analysis following active immunization with tau proteins reveals immunogens implicated in tau pathogenesis
Abstract
Background
Abnormal tau hyperphosphorylation and its accumulation into intra-neuronal neurofibrillary tangles are linked to neurodegeneration in Alzheimerās disease and similar tauopathies. One strategy to reduce accumulation is through immunization, but the most immunogenic tau epitopes have so far remained unknown. To fill this gap, we immunized mice with recombinant tau to build a map of the most immunogenic tau epitopes.
Methods
Non-transgenic and rTg4510 tau transgenic mice aged 5 months were immunized with either human wild-type tau (Wt, 4R0N) or P301L tau (4R0N). Each protein was formulated in Quil A adjuvant. Sera and splenocytes of vaccinated mice were collected to assess the humoral and cellular immune responses to tau. We employed a peptide array assay to identify the most effective epitopes. Brain histology was utilized to measure the effects of vaccination on tau pathology and inflammation.
Results
Humoral immune responses following immunization demonstrated robust antibody titers (up to 1:80,000 endpoint titers) to each tau species in both mice models. The number of IFN-Ī³ producing T cells and their proliferation were also increased in splenocytes from immunized mice, indicating an increased cellular immune response, and tau levels and neuroinflammation were both reduced. We identified five immunogenic motifs within either the N-terminal (9-15 and 21-27 amino acids), proline rich (168-174 and 220-228 amino acids), or the C-terminal regions (427-438 amino acids) of the wild-type and P301L tau protein sequence.
Conclusions
Our study identifies five previously unknown immunogenic motifs of wild-type and mutated (P301L) tau protein. Immunization with both proteins resulted in reduced tau pathology and neuroinflammation in a tau transgenic model, supporting the efficacy of tau immunotherapy in tauopathy.http://deepblue.lib.umich.edu/bitstream/2027.42/109522/1/12974_2014_Article_152.pd
An Update on the Surveillance of Livestock Diseases and Antimicrobial Use in Sierra Leone in 2021-An Operational Research Study.
In Sierra Leone, in 2020, a study by the Livestock and Veterinary Services Division (Ministry of Agriculture and Forestry) on the surveillance system of animal diseases and antimicrobial use found poor reporting. Of the expected weekly districts reports, <1% were received and only three of the 15 districts had submitted reports occasionally between 2016 and 2019. Following this, staff-capacity-building on reporting was undertaken. In 2021, we reassessed the improvement in reporting and used the reports to describe livestock diseases and antimicrobials utilized in their treatment. Between March and October 2021, 88% of expected weekly reports from all 15 districts were received. There were minor deficiencies in completeness and consistency in the terminology used for reporting animal disease and antimicrobials. Available reports showed that 25% of the livestock had an infectious disease, and a quarter of the sick animals had received an antimicrobial drug. Most animals received antimicrobials belonging to World Organization for Animal Health's "veterinary critically important" category (77%) and World Health Organization's "critically" (17%) and "highly important" (60%) categories for human health. These indicate a significant improvement in the animal health surveillance system and highlight the need for enhanced antimicrobial stewardship to prevent misuse of antimicrobials that are significant in animal and human health
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