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1.
Eur J Immunol ; 54(7): e2350610, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38576227

ABSTRACT

Mycobacterium abscessus is an emerging pathogen that causes chronic pulmonary infection. Treatment is challenging owing in part to our incomplete understanding of M. abscessus virulence mechanisms that enable pathogen persistence, such as the differing pathogenicity of M. abscessus smooth (S) and rough (R) colony morphotype. While R M. abscessus is associated with chronic infection and worse patient outcomes, it is unknown how immune responses to S and R M. abscessus differ in an acute pulmonary infection setting. In this study, immunological outcomes of M. abscessus infection with S and R morphotypes were examined in an immune-competent C3HeB/FeJ murine model. R M. abscessus infection was associated with the rapid production of inflammatory chemokines and recruitment of activated, MHC-II+ Ly6C+ macrophages to lungs and mediastinal LN (mLN). While both S and R M. abscessus increased T helper 1 (Th1) phenotype T cells in the lung, this was markedly delayed in mice infected with S M. abscessus. However, histopathological involvement and bacterial clearance were similar regardless of colony morphotype. These results demonstrate the importance of M. abscessus colony morphotype in shaping the development of pulmonary immune responses to M. abscessus, which further informs our understanding of M. abscessus host-pathogen interactions.


Subject(s)
Adaptive Immunity , Immunity, Innate , Lung , Mycobacterium Infections, Nontuberculous , Mycobacterium abscessus , Animals , Mycobacterium abscessus/immunology , Mice , Mycobacterium Infections, Nontuberculous/immunology , Lung/immunology , Lung/pathology , Lung/microbiology , Disease Models, Animal , Macrophages/immunology , Th1 Cells/immunology , Mice, Inbred C3H , Female
2.
Immunol Cell Biol ; 2024 May 17.
Article in English | MEDLINE | ID: mdl-38757764

ABSTRACT

Delta inulin, or Advax, is a polysaccharide vaccine adjuvant that significantly enhances vaccine-mediated immune responses against multiple pathogens and was recently licensed for use in the coronavirus disease 2019 (COVID-19) vaccine SpikoGen. Although Advax has proven effective as an immune adjuvant, its specific binding targets have not been characterized. In this report, we identify a cellular receptor for Advax recognition. In vitro uptake of Advax particles by macrophage cell lines was substantially greater than that of latex beads of comparable size, suggesting an active uptake mechanism by phagocytic cells. Using a lectin array, Advax particles were recognized by lectins specific for various carbohydrate structures including mannosyl, N-acetylgalactosamine and galactose moieties. Expression in nonphagocytic cells of dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), a C-type lectin receptor, resulted in enhanced uptake of fluorescent Advax particles compared with mock-transfected cells. Advax uptake was reduced with the addition of ethylenediaminetetraacetic acid and mannan to cells, which are known inhibitors of DC-SIGN function. Finally, a specific blockade of DC-SIGN using a neutralizing antibody abrogated Advax uptake in DC-SIGN-expressing cells. Together, these results identify DC-SIGN as a putative receptor for Advax. Given the known immunomodulatory role of DC-SIGN, the findings described here have implications for the use of Advax adjuvants in humans and inform future mechanistic studies.

3.
FASEB J ; 36(12): e22664, 2022 12.
Article in English | MEDLINE | ID: mdl-36412511

ABSTRACT

Altered fetal growth, which can occur due to environmental stressors during pregnancy, may program a susceptibility to metabolic disease. Gestational exposure to the air pollutant ozone is associated with fetal growth restriction in humans and rodents. However, the impact of this early life ozone exposure on offspring metabolic risk has not yet been investigated. In this study, fetal growth restriction was induced by maternal inhalation of 0.8 ppm ozone on gestation days 5 and 6 (4 hr/day) in Long Evans rats. To uncover any metabolic inflexibility, or an impaired ability to respond to a high-fat diet (HFD), a subset of peri-adolescent male and female offspring from filtered air or ozone exposed dams were fed HFD (45% kcal from fat) for 3 days. By 6 weeks of age, male and female offspring from ozone-exposed dams were heavier than offspring from air controls. Furthermore, offspring from ozone-exposed dams had greater daily caloric consumption and reduced metabolic rate when fed HFD. In addition to energy imbalance, HFD-fed male offspring from ozone-exposed dams had dyslipidemia and increased adiposity, which was not evident in females. HFD consumption in males resulted in the activation of the protective 5'AMP-activated protein kinase (AMPKα) and sirtuin 1 (SIRT1) pathways in the liver, regardless of maternal exposure. Unlike males, ozone-exposed female offspring failed to activate these pathways, retaining hepatic triglycerides following HFD consumption that resulted in increased inflammatory gene expression and reduced insulin signaling genes. Taken together, maternal ozone exposure in early pregnancy programs impaired metabolic flexibility in offspring, which may increase susceptibility to obesity in males and hepatic dysfunction in females.


Subject(s)
Diet, High-Fat , Ozone , Pregnancy , Animals , Rats , Humans , Male , Female , Adolescent , Diet, High-Fat/adverse effects , Rats, Long-Evans , Ozone/toxicity , Fetal Growth Retardation , Obesity/metabolism , Vitamins
4.
J Pharmacol Exp Ther ; 374(1): 93-103, 2020 07.
Article in English | MEDLINE | ID: mdl-32366601

ABSTRACT

ALD403 is a genetically engineered, humanized immunoglobulin G1 monoclonal antibody that inhibits the action of human calcitonin gene-related peptide (CGRP). Clinical trial data indicate that ALD403 is effective as a preventive therapy for migraine and has an acceptable safety profile. For preclinical characterization of ALD403, rabbit antibodies targeting α-CGRP were humanized and modified to eliminate fragment crystallizable (Fc) γ receptor (FcγR) and complement interactions. The ability of ALD403 to inhibit CGRP-induced cAMP production was assessed using a cAMP bioassay (Meso Scale Discovery). The IC50 for inhibition of cAMP release was 434 and 288 pM with the rabbit-human chimera antibody and the humanized ALD403, respectively. ALD403 inhibited α-CGRP binding with an IC50 of 4.7 × 10-11 and 1.2 × 10-10 M for the α-CGRP and AMY1 receptors, respectively. ALD403 did not induce antibody-dependent cellular cytotoxicity or complement-dependent cytotoxicity and did not stably interact with any of the FcγR mediating these functions, exhibiting only weak binding to FcγRI. ALD403 significantly lowered capsaicin-induced blood flow responses in rodents at all time points starting at 5 minutes postapplication in a dose-dependent manner. In conclusion, ALD403 is a potent functional ligand inhibitor of α-CGRP‒driven pharmacology. SIGNIFICANCE STATEMENT: α-Calcitonin gene-related peptide blockade by ALD403 was assessed via radiolabeled ligand displacement, in vitro inhibition of cell signaling, and in vivo inhibition of capsaicin-induced vasodilation. Lack of engagement of fragment crystallizable-mediated immune-effector functions by ALD403 was shown.


Subject(s)
Antibodies, Monoclonal, Humanized/immunology , Antibodies, Neutralizing/immunology , Calcitonin Gene-Related Peptide/immunology , Amino Acid Sequence , Animals , Antibodies, Monoclonal, Humanized/chemistry , Antibodies, Neutralizing/chemistry , Antibody Specificity , Humans , Kinetics , Rabbits , Signal Transduction
5.
J Pharmacol Exp Ther ; 369(1): 26-36, 2019 04.
Article in English | MEDLINE | ID: mdl-30643015

ABSTRACT

Migraine is a debilitating disease that affects almost 15% of the population worldwide and is the first cause of disability in people under 50 years of age, yet its etiology and pathophysiology remain incompletely understood. Recently, small molecules and therapeutic antibodies that block the calcitonin gene-related peptide (CGRP) signaling pathway have reduced migraine occurrence and aborted acute attacks of migraine in clinical trials and provided prevention in patients with episodic and chronic migraine. Heterogeneity is present within each diagnosis and patient's response to treatment, suggesting migraine as a final common pathway potentially activated by multiple mechanisms, e.g., not all migraine attacks respond to or are prevented by anti-CGRP pharmacological interventions. Consequently, other unique mechanisms central to migraine pathogenesis may present new targets for drug development. Pituitary adenylate cyclase-activating peptide (PACAP) is an attractive novel target for treatment of migraines. We generated a specific, high-affinity, neutralizing monoclonal antibody (ALD1910) with reactivity to both PACAP38 and PACAP27. In vitro, ALD1910 effectively antagonizes PACAP38 signaling through the pituitary adenylate cyclase-activating peptide type I receptor, vasoactive intestinal peptide receptor 1, and vasoactive intestinal peptide receptor 2. ALD1910 recognizes a nonlinear epitope within PACAP and blocks its binding to the cell surface. To test ALD1910 antagonistic properties directed against endogenous PACAP, we developed an umbellulone-induced rat model of neurogenic vasodilation and parasympathetic lacrimation. In vivo, this model demonstrates that the antagonistic activity of ALD1910 is dose-dependent, retaining efficacy at doses as low as 0.3 mg/kg. These results indicate that ALD1910 represents a potential therapeutic antibody to address PACAP-mediated migraine.


Subject(s)
Antibodies, Monoclonal, Humanized/immunology , Pituitary Adenylate Cyclase-Activating Polypeptide/immunology , Animals , Antibody Specificity , Dose-Response Relationship, Immunologic , Epitopes/immunology , Humans , Kinetics , Male , Migraine Disorders/immunology , Migraine Disorders/prevention & control , PC12 Cells , Rats , Rats, Sprague-Dawley
6.
Inhal Toxicol ; 30(4-5): 178-186, 2018.
Article in English | MEDLINE | ID: mdl-29947284

ABSTRACT

Apelin has cardiopulmonary protective properties that promote vasodilation and maintenance of the endothelial barrier. While reductions in apelin have been identified as a contributor to various lung diseases, including pulmonary edema, its role in the effect of air pollutants has not been examined. Thus, in the current study, we sought to investigate if apelin is a downstream target of inhaled ozone and if such change in expression is related to altered DNA methylation in the lung. Male, Long-Evans rats were exposed to filtered air or 1.0 ppm ozone for 4 h. Ventilation changes were assessed using whole-body plethysmography immediately following exposure, and markers of pulmonary edema and inflammation were assessed in the bronchoaveolar lavage (BAL) fluid. The enzymatic regulators of DNA methylation were measured in the lung, along with methylation and hydroxymethylation of the apelin promoter. Data showed that ozone exposure was associated with increased enhanced pause and protein leakage in the BAL fluid. Ozone exposure reduced DNA cytosine-5-methyltransferase (DNMT) activity and Dnmt3a/b gene expression. Exposure-induced upregulation of proliferating cell nuclear antigen, indicative of DNA damage, repair, and maintenance methylation. Increased methylation and reduced hydroxymethylation were measured on the apelin promoter. These epigenetic modifications accompanied ozone-induced reduction of apelin expression and development of pulmonary edema. In conclusion, epigenetic regulation, specifically increased methylation of the apelin promoter downstream of DNA damage, may lead to reductions in protective signaling of the apelinergic system, contributing to the pulmonary edema observed following the exposure to oxidant air pollution.


Subject(s)
Apelin/genetics , DNA Damage , DNA Methylation/drug effects , Epigenesis, Genetic/drug effects , Inhalation Exposure , Lung/drug effects , Ozone/toxicity , Pulmonary Edema/chemically induced , Animals , Apelin/metabolism , CpG Islands , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methyltransferase 3A , Lung/metabolism , Lung/physiopathology , Male , Proliferating Cell Nuclear Antigen/metabolism , Promoter Regions, Genetic , Pulmonary Edema/genetics , Pulmonary Edema/metabolism , Pulmonary Edema/physiopathology , Pulmonary Ventilation/drug effects , Rats, Long-Evans , DNA Methyltransferase 3B
7.
J Occup Environ Hyg ; 13(7): 529-37, 2016 07.
Article in English | MEDLINE | ID: mdl-26861729

ABSTRACT

This article for the first time reports a large set of monitoring results for formaldehyde exposure during grossing activities in health care anatomic pathology laboratories, and compares the effectiveness of different local exhaust ventilation systems on the exposure. To control the confounding effects from grossing work load, sampling duration, and the sizes of specimens grossed, only 15-min short-term personal exposure samples collected during large tissue specimen grossing were used for the comparison of the effectiveness of these local exhaust systems. While we also collected long-term 8-hr time weighted average samples, these are not treated in this analysis. The systems examined were canopy receiving hoods, slot exhausts, and commercially available pre-manufactured backdraft grossing stations, both recirculating and ducted exhaust types. Out of over 2,000 personal short-term air samples, 307 samples from 163 surveys met the data selection criteria. Over a third of the data were less than the analytical laboratory limits of detection. Using the robust maximum likelihood estimation method for multiple limits of detection, the mean and geometric mean of the dataset for each type of local exhaust system were found to be less than the short-term personal exposure regulatory limit of 2 ppm. Nonparametric Wilcoxon rank-sum pairwise tests of five types of engineering controls showed a statistically significant difference among these controls, with the most effective being the manufactured backdraft grossing stations ducted to the outside, and the least effective being canopy exhaust systems and manufactured filtered recirculating grossing stations. Finally, exposure with each of the major engineering control types was rated by the American Industrial Hygiene Association exposure control rating scheme.


Subject(s)
Air Pollutants, Occupational/analysis , Formaldehyde/analysis , Laboratories, Hospital , Occupational Exposure/prevention & control , Ventilation/instrumentation , Pathology, Clinical
8.
Vaccines (Basel) ; 12(2)2024 Jan 26.
Article in English | MEDLINE | ID: mdl-38400112

ABSTRACT

Tuberculosis (TB), caused by Mycobacterium tuberculosis, results in approximately 1.6 million deaths annually. BCG is the only TB vaccine currently in use and offers only variable protection; however, the development of more effective vaccines is hindered by a lack of defined correlates of protection (CoP) against M. tuberculosis. Pulmonary vaccine delivery is a promising strategy since it may promote lung-resident immune memory that can respond rapidly to respiratory infection. In this study, CysVac2, a subunit protein previously shown to be protective against M. tuberculosis in mouse models, was combined with either Advax® adjuvant or a mixture of alum plus MPLA and administered intratracheally into mice. Peripheral immune responses were tracked longitudinally, and lung-local immune responses were measured after challenge. Both readouts were then correlated with protection after M. tuberculosis infection. Although considered essential for the control of mycobacteria, induction of IFN-γ-expressing CD4+ T cells in the blood or lungs did not correlate with protection. Instead, CD4+ T cells in the lungs expressing IL-17A correlated with reduced bacterial burden. This study identified pulmonary IL-17A-expressing CD4+ T cells as a CoP against M. tuberculosis and suggests that mucosal immune profiles should be explored for novel CoP.

9.
Microorganisms ; 10(4)2022 Mar 31.
Article in English | MEDLINE | ID: mdl-35456886

ABSTRACT

The authors wish to make the following corrections to this paper [...].

10.
PLoS One ; 17(12): e0271707, 2022.
Article in English | MEDLINE | ID: mdl-36520946

ABSTRACT

Although the increased risk of developing sporadic Alzheimer's disease (AD) associated with the inheritance of the apolipoprotein E4 (APOE4) allele is well characterized, the molecular underpinnings of how ApoE4 imparts risk remains unknown. Enhanced proteolysis of the ApoE4 protein with a toxic-gain of function has been suggested and a 17 kDa amino-terminal ApoE4 fragment (nApoE41-151) has been identified in post-mortem human AD frontal cortex sections. Recently, we demonstrated in vitro, exogenous treatment of nApoE41-151 in BV2 microglial cells leads to uptake, trafficking to the nucleus and increased expression of genes associated with cell toxicity and inflammation. In the present study, we extend these findings to zebrafish (Danio rerio), an in vivo model system to assess the toxicity of nApoE41-151. Exogenous treatment of nApoE41-151 to 24-hour post-fertilization for 24 hours resulted in significant mortality. In addition, developmental abnormalities were observed following treatment with nApoE41-151 including improper folding of the hindbrain, delay in ear development, deformed yolk sac, enlarged cardiac cavity, and significantly lower heart rates. A similar nApoE31-151 fragment that differs by a single amino acid change (C>R) at position 112 had no effects on these parameters under identical treatment conditions. Decreased presence of pigmentation was noted for both nApoE31-151- and nApoE41-151-treated larvae compared with controls. Behaviorally, touch-evoked responses to stimulus were negatively impacted by treatment with nApoE41-151 but did not reach statistical significance. Additionally, triple-labeling confocal microscopy not only confirmed the nuclear localization of the nApoE41-151 fragment within neuronal populations following exogenous treatment, but also identified the presence of tau pathology, one of the hallmark features of AD. Collectively, these in vivo data demonstrating toxicity as well as sublethal effects on organ and tissue development support a novel pathophysiological function of this AD associated-risk factor.


Subject(s)
Alzheimer Disease , Apolipoprotein E4 , Animals , Humans , Apolipoprotein E4/metabolism , Zebrafish/metabolism , Neurons/metabolism , Microglia/metabolism , Inflammation/metabolism , Alzheimer Disease/metabolism , Apolipoprotein E3/metabolism , Apolipoproteins E/metabolism
11.
Mucosal Immunol ; 15(6): 1405-1415, 2022 06.
Article in English | MEDLINE | ID: mdl-36411332

ABSTRACT

Multiple SARS-CoV-2 vaccine candidates have been approved for use and have had a major impact on the COVID-19 pandemic. There remains, however, a significant need for vaccines that are safe, easily transportable and protective against infection, as well as disease. Mucosal vaccination is favored for its ability to induce immune memory at the site of infection, making it appealing for SARS-CoV-2 vaccine strategies. In this study we performed in-depth analysis of the immune responses in mice to a subunit recombinant spike protein vaccine formulated with the delta-inulin adjuvant Advax when administered intratracheally (IT), versus intramuscular delivery (IM). Both routes produced robust neutralizing antibody titers (NAb) and generated sterilizing immunity against SARS-CoV-2. IT delivery, however, produced significantly higher systemic and lung-local NAb that resisted waning up to six months post vaccination, and only IT delivery generated inducible bronchus-associated lymphoid tissue (iBALT), a site of lymphocyte antigen presentation and proliferation. This was coupled with robust and long-lasting lung tissue-resident memory CD4+ and CD8+ T cells that were not observed in IM-vaccinated mice. This study provides a detailed view of the lung-resident cellular response to IT vaccination against SARS-CoV-2 and demonstrates the importance of delivery site selection in the development of vaccine candidates.


Subject(s)
COVID-19 , SARS-CoV-2 , Mice , Animals , Humans , Inulin , COVID-19 Vaccines , CD8-Positive T-Lymphocytes , Immunologic Memory , Pandemics , COVID-19/prevention & control , Immunization , Vaccines, Synthetic , Vaccination , Adjuvants, Immunologic , Gastric Mucosa , Lung
12.
Mucosal Immunol ; 14(3): 762-773, 2021 05.
Article in English | MEDLINE | ID: mdl-33542494

ABSTRACT

There is an urgent need for novel vaccination strategies to combat respiratory pathogens. Mucosal vaccine delivery is an attractive option as it directly targets the site of infection; however, preclinical development has been hindered by a lack of suitable mucosal adjuvants and a limited understanding of their immune effects in the lung environment. Herein, we define the early immune events following the intrapulmonary delivery of a vaccine incorporating the adjuvant delta-inulin. Analysis of the early inflammatory response showed vaccine-induced innate cell recruitment to lungs and local lymph nodes (LN) was transient and non-polarised, correlating with an increase in pulmonary chemotactic factors. Use of fluorescently labelled adjuvant revealed widespread tissue dissemination of adjuvant particles, coupled with broad cellular uptake and transit to the lung-draining LN by a range of innate immune cells. Mass cytometric analysis revealed extensive phenotypic changes in innate and adaptive cell subsets induced by vaccination; this included identification of unconventional lymphocytes such as γδ-T cells and MAIT cells that increased following vaccination and displayed an activated phenotype. This study details a comprehensive view of the immune response to intrapulmonary adjuvant administration and provides pre-clinical evidence to support delta-inulin as a suitable adjuvant for pulmonary vaccines.


Subject(s)
Inulin/analogs & derivatives , Lung/immunology , Mucosal-Associated Invariant T Cells/immunology , T-Lymphocytes/immunology , Vaccines/immunology , Adjuvants, Immunologic , Animals , Female , Immunity, Innate , Immunization , Inulin/immunology , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Vaccination
13.
Front Immunol ; 12: 740117, 2021.
Article in English | MEDLINE | ID: mdl-34759923

ABSTRACT

Tuberculosis (TB) remains one of the leading causes of death worldwide due to a single infectious disease agent. BCG, the only licensed vaccine against TB, offers limited protection against pulmonary disease in children and adults. TB vaccine research has recently been reinvigorated by new data suggesting alternative administration of BCG induces protection and a subunit/adjuvant vaccine that provides close to 50% protection. These results demonstrate the need for generating adjuvants in order to develop the next generation of TB vaccines. However, development of TB-targeted adjuvants is lacking. To help meet this need, NIAID convened a workshop in 2020 titled "Advancing Vaccine Adjuvants for Mycobacterium tuberculosis Therapeutics". In this review, we present the four areas identified in the workshop as necessary for advancing TB adjuvants: 1) correlates of protective immunity, 2) targeting specific immune cells, 3) immune evasion mechanisms, and 4) animal models. We will discuss each of these four areas in detail and summarize what is known and what we can advance on in order to help develop more efficacious TB vaccines.


Subject(s)
Adjuvants, Immunologic/therapeutic use , Mycobacterium tuberculosis/physiology , Tuberculosis Vaccines/immunology , Tuberculosis/immunology , Animals , Congresses as Topic , Disease Models, Animal , Humans , Immune Evasion , Immunity , National Institute of Allergy and Infectious Diseases (U.S.) , Tuberculosis/therapy , United States
14.
NPJ Vaccines ; 6(1): 143, 2021 Nov 30.
Article in English | MEDLINE | ID: mdl-34848711

ABSTRACT

Global control of COVID-19 requires broadly accessible vaccines that are effective against SARS-CoV-2 variants. In this report, we exploit the immunostimulatory properties of bacille Calmette-Guérin (BCG), the existing tuberculosis vaccine, to deliver a vaccination regimen with potent SARS-CoV-2-specific protective immunity. Combination of BCG with a stabilised, trimeric form of SARS-CoV-2 spike antigen promoted rapid development of virus-specific IgG antibodies in the blood of vaccinated mice, that was further augmented by the addition of alum. This vaccine formulation, BCG:CoVac, induced high-titre SARS-CoV-2 neutralising antibodies (NAbs) and Th1-biased cytokine release by vaccine-specific T cells, which correlated with the early emergence of T follicular helper cells in local lymph nodes and heightened levels of antigen-specific plasma B cells after vaccination. Vaccination of K18-hACE2 mice with a single dose of BCG:CoVac almost completely abrogated disease after SARS-CoV-2 challenge, with minimal inflammation and no detectable virus in the lungs of infected animals. Boosting BCG:CoVac-primed mice with a heterologous vaccine further increased SARS-CoV-2-specific antibody responses, which effectively neutralised B.1.1.7 and B.1.351 SARS-CoV-2 variants of concern. These findings demonstrate the potential for BCG-based vaccination to protect against major SARS-CoV-2 variants circulating globally.

15.
Int J Alzheimers Dis ; 2020: 5380346, 2020.
Article in English | MEDLINE | ID: mdl-32308993

ABSTRACT

Human clinical trials seek to ameliorate the disease states and symptomatic progression of illnesses that, as of yet, are largely untreatable according to clinical standards. Ideally, clinical trials test "disease-modifying drugs," i.e., therapeutic agents that specifically modify pathological features or molecular bases of the disease and would presumably have a large impact on disease progression. In the case of Alzheimer's disease (AD), however, this approach appears to have stalled progress in the successful development of clinically useful therapies. For the last 25 years, clinical trials involving AD have centered on beta-amyloid (Aß) and the Aß hypothesis of AD progression and pathology. According to this hypothesis, the progression of AD begins following an accumulation of Aß peptide, leading to eventual synapse loss and neuronal cell death: the true overriding pathological feature of AD. Clinical trials arising from the Aß hypothesis target causal steps in the pathway in order to reduce the formation of Aß or enhance clearance, and though agents have been successful in this aim, they remain unsuccessful in rescuing cognitive function or slowing cognitive decline. As such, further use of resources in the development of treatment options for AD that target Aß, its precursors, or its products should be reevaluated. The purpose of this review was to give an overview of how human clinical trials are conducted in the USA and to assess the results of recent failed trials involving AD, the majority of which were based on the Aß hypothesis. Based on these current findings, it is suggested that lowering Aß is an unproven strategy, and it may be time to refocus on other targets for the treatment of this disease including pathological forms of tau.

16.
NPJ Vaccines ; 5(1): 105, 2020 Nov 12.
Article in English | MEDLINE | ID: mdl-33298977

ABSTRACT

The development of effective vaccines against bacterial lung infections requires the induction of protective, pathogen-specific immune responses without deleterious inflammation within the pulmonary environment. Here, we made use of a polysaccharide-adjuvanted vaccine approach to elicit resident pulmonary T cells to protect against aerosol Mycobacterium tuberculosis infection. Intratracheal administration of the multistage fusion protein CysVac2 and the delta-inulin adjuvant Advax™ (formulated with a TLR9 agonist) provided superior protection against aerosol M. tuberculosis infection in mice, compared to parenteral delivery. Surprisingly, removal of the TLR9 agonist did not impact vaccine protection despite a reduction in cytokine-secreting T cell subsets, particularly CD4+IFN-γ+IL-2+TNF+ multifunctional T cells. CysVac2/Advax-mediated protection was associated with the induction of lung-resident, antigen-specific memory CD4+ T cells that expressed IL-17 and RORγT, the master transcriptional regulator of Th17 differentiation. IL-17 was identified as a key mediator of vaccine efficacy, with blocking of IL-17 during M. tuberculosis challenge reducing phagocyte influx, suppressing priming of pathogen-specific CD4+ T cells in local lymph nodes and ablating vaccine-induced protection. These findings suggest that tuberculosis vaccines such as CysVac2/Advax that are capable of eliciting Th17 lung-resident memory T cells are promising candidates for progression to human trials.

17.
Front Aging Neurosci ; 12: 256, 2020.
Article in English | MEDLINE | ID: mdl-32922284

ABSTRACT

Despite the fact that harboring the apolipoprotein E4 (APOE4) allele represents the single greatest risk factor for late-onset Alzheimer's disease (AD), the exact mechanism by which ApoE4 contributes to disease progression remains unknown. Recently, we demonstrated that a 151 amino-terminal fragment of ApoE4 (nApoE41-151) localizes within the nucleus of microglia in the human AD brain and traffics to the nucleus causing toxicity in BV2 microglia cells. In the present study, we examined in detail what genes may be affected following treatment by nApoE41-151. Transcriptome analyses in BV2 microglial cells following sublethal treatment with nApoE41-151 revealed the upregulation of almost 4,000 genes, with 20 of these genes upregulated 182- to 715-fold compared to untreated control cells. The majority of these 20 genes play a role in the immune response and polarization toward microglial M1 activation. As a control, an identical nApoE31-151 fragment that differed by a single amino acid at position 112 (Cys→Arg) was tested and produced a similar albeit lower level of upregulation of an identical set of genes. In this manner, enriched pathways upregulated by nApoE31-151 and nApoE41-151 following exogenous treatment included Toll receptor signaling, chemokine/cytokine signaling and apoptosis signaling. There were unique genes differentially expressed by at least two-fold for either fragment. For nApoE31-151, these included 16 times as many genes, many of which are involved in physiological functions within microglia. For nApoE41-151, on the other hand the number genes uniquely upregulated was significantly lower, with many of the top upregulated genes having unknown functions. Taken together, our results suggest that while nApoE31-151 may serve a more physiological role in microglia, nApoE41-151 may activate genes that contribute to disease inflammation associated with AD. These data support the hypothesis that the link between harboring the APOE4 allele and dementia risk could be enhanced inflammation through activation of microglia.

18.
Mol Metab ; 42: 101094, 2020 12.
Article in English | MEDLINE | ID: mdl-33031959

ABSTRACT

OBJECTIVE: The importance of the placenta in mediating the pre- and post-natal consequences of fetal growth restriction has been increasingly recognized. However, the influence of placental sexual dimorphism on driving these outcomes has received little attention. The purpose of this study was to characterize how sex contributes to the relationship between placental metabolism and fetal programming utilizing a novel rodent model of growth restriction. METHODS: Fetal growth restriction was induced by maternal inhalation of 0.8 ppm ozone (4 h/day) during implantation receptivity (gestation days [GDs] 5 and 6) in Long-Evans rats. Control rats were exposed to filtered air. At GD 21, placental and fetal tissues were obtained for metabolic and genomic assessments. RESULTS: Growth-restricted male placentae exhibited increased mitochondrial biogenesis, increased oxygen consumption, and reduced nutrient storage. Male growth-restricted fetuses also had evidence of reduced adiposity and downregulation of hepatic metabolic signaling. In contrast, placentae from growth-restricted females had elevated markers of autophagy accompanied by an observed protection against hepatic metabolic perturbations. Despite this, growth restriction in females induced a greater number of hypothalamic gene and pathway alterations compared to growth-restricted males. CONCLUSIONS: Increases in mitochondrial metabolism in growth-restricted male placentae likely initiates a sequela of adaptations that promote poor nutrient availability and adiposity. Divergently, the female placenta expresses protective mechanisms that may serve to increase nutrient availability to support fetal metabolic development. Collectively, this work emphasizes the importance of sex in mediating alterations in placental metabolism and fetal programming.


Subject(s)
Fetal Growth Retardation/metabolism , Fetus/metabolism , Placenta/metabolism , Adiposity , Animals , Female , Fetal Development , Fetal Growth Retardation/physiopathology , Male , Mitochondria/metabolism , Ozone/adverse effects , Ozone/metabolism , Pregnancy , Prenatal Exposure Delayed Effects/metabolism , Rats , Rats, Long-Evans , Sex Characteristics , Sex Factors
19.
Microorganisms ; 7(8)2019 Aug 12.
Article in English | MEDLINE | ID: mdl-31409028

ABSTRACT

Tuberculosis (TB) caused by Mycobacterium tuberculosis infection is responsible for the most deaths by a single infectious agent worldwide, with 1.6 million deaths in 2017 alone. The World Health Organization, through its "End TB" strategy, aims to reduce TB deaths by 95% by 2035. In order to reach this goal, a more effective vaccine than the Bacillus Calmette-Guerin (BCG) vaccine currently in use is needed. Subunit TB vaccines are ideal candidates, because they can be used as booster vaccinations for individuals who have already received BCG and would also be safer for use in immunocompromised individuals in whom BCG is contraindicated. However, subunit TB vaccines will almost certainly require formulation with a potent adjuvant. As the correlates of vaccine protection against TB are currently unclear, there are a variety of adjuvants currently being used in TB vaccines in preclinical and clinical development. This review describes the various adjuvants in use in TB vaccines, their effectiveness, and their proposed mechanisms of action. Notably, adjuvants with less inflammatory and reactogenic profiles that can be administered safely via mucosal routes, may have the biggest impact on future directions in TB vaccine design.

20.
Toxicol Sci ; 168(2): 535-550, 2019 04 01.
Article in English | MEDLINE | ID: mdl-30649513

ABSTRACT

Implantation is a sensitive window in reproductive development during which disruptions may increase the risk of adverse pregnancy outcomes including intrauterine growth restriction. Ozone exposure during implantation in rats reduces fetal weight near the end of gestation, potentially though impaired trophoblast migration and invasion and altered implantation. The current study characterized changes in ventilation, pulmonary injury, and circulating factors including hormonal, inflammatory, and metabolic markers related to exposure to ozone (0.4-1.2 ppm) for 4-h on gestation days 5 and 6 (window of implantation) in Long-Evans dams. To determine the effects of this exposure on trophoblast function, placental-derived, first trimester, HTR-8/SVneo cells were exposed to serum from air- or ozone (0.8 ppm×4 h)-exposed dams and examined for impacts on metabolic capacity, wound-closure, and invasion. Peri-implantation exposure to ozone induced ventilatory dysfunction and lung vascular leakage in pregnant rats, with little effect on most of the circulating markers measured. However, ozone inhalation induced a significant reduction in several serum cytokines (interferon-γ, interleukin-6, and interleukin-13). Treatment of HTR-8/SVneo trophoblasts with serum from ozone-exposed dams for 16-h downregulated metabolic capacity, wound-closure, and invasion through a Matrigel membrane compared with both air-serum and fetal bovine serum-treated cells. Ozone-serum treated cells increased the release of a critical inhibitor of invasion and angiogenesis (soluble fms-like receptor 1; sFlt1) compared with air-serum treatment. Together, our data suggest that circulating factors in the serum of pregnant rats exposed to ozone during implantation receptivity can hinder critical processes of implantation (eg, invasion and migration) and impair trophoblast metabolic capacity.


Subject(s)
Air Pollutants/toxicity , Embryo Implantation/drug effects , Maternal Exposure/adverse effects , Ozone/toxicity , Serum/metabolism , Trophoblasts/drug effects , Animals , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/cytology , Cytokines/blood , Female , In Vitro Techniques , Plethysmography, Whole Body , Pregnancy , Rats, Long-Evans
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