scholarly journals Bacille Calmette-Guérin vaccine reprograms human neonatal lipid metabolism in vitro and in vivo

Author(s):  
Joann Diray-Arce ◽  
Asimenia Angelidou ◽  
Kristoffer Jarlov Jensen ◽  
Maria Giulia Conti ◽  
Rachel S. Kelly ◽  
...  

SummaryVaccines have generally been developed with limited insight into their molecular impact. While systems vaccinology, including metabolomics, enables new characterization of vaccine mechanisms of action, these tools have yet to be applied to infants at high risk of infection and receive the most vaccines. Bacille Calmette-Guérin (BCG) protects infants against disseminated tuberculosis (TB) and TB-unrelated infections via incompletely understood mechanisms. We employed mass spectrometry-based metabolomics of blood plasma to profile BCG-induced infant responses in Guinea Bissau in vivo and the U.S. in vitro. BCG selectively altered plasma lipid pathways, including lysophospholipids. BCG-induced lysophosphatidylcholines (LPCs) correlated with both TLR agonist- and purified protein derivative (PPD, mycobacterial antigen)-induced blood cytokine production in vitro, raising the possibility that LPCs contribute to BCG immunogenicity. Analysis of an independent newborn cohort from The Gambia demonstrated shared vaccine-induced metabolites such as phospholipids and sphingolipids. BCG-induced changes to the plasma lipidome and LPCs may contribute to its immunogenicity and inform the discovery and development of early life vaccines.HighlightsNeonatal BCG immunization generates distinct metabolic shifts in vivo and in vitro across multiple independent cohorts.BCG induces prominent changes in concentrations of plasma lysophospholipids (LPLs)BCG induced changes in plasma lysophosphatidylcholines (LPCs) correlate with BCG effects on TLR agonist- and mycobacterial antigen-induced cytokine responses.Characterization of vaccine-induced changes in metabolism may define predictive signatures of vaccine responses and inform early life vaccine development.Abstract FigureGraphical abstract:BCG vaccination perturbs metabolic pathways in vivo and in vitro.Vaccines have traditionally been developed empirically, with limited insight into their impact on molecular pathways. Metabolomics provides a new approach to characterizing vaccine mechanisms but has not yet been applied to human newborns, who are at the highest risk of infection and receive the most vaccines. Bacille Calmette-Guérin (BCG) prevents disseminated mycobacterial disease in children and can induce broad protection to reduce mortality due to non-TB infections. Underlying mechanisms are incompletely characterized. Employing mass spectrometry-based metabolomics, we demonstrate that early BCG administration alters the human neonatal plasma metabolome, especially lipid metabolic pathways such as lysophosphatidylcholines (LPCs), both in vivo and in vitro. Plasma LPCs correlated with both innate TLR-mediated and PPD antigen-induced cytokine responses suggesting that BCG-induced lipids might contribute to the immunogenicity of this vaccine. Vaccine-induced metabolic changes may provide fresh insights into vaccine immunogenicity and inform the discovery and development of early life vaccines.

2005 ◽  
Vol 289 (1) ◽  
pp. G108-G115 ◽  
Author(s):  
Pieter Janssen ◽  
Nicolaas H. Prins ◽  
Benoit Moreaux ◽  
Ann L. Meulemans ◽  
Romain A. Lefebvre

We aimed to evaluate the gastric relaxant capacity of the 5-HT1/7-receptor agonist 5-carboxamidotryptamine (5-CT) in conscious dogs and to clarify the mechanism of action by use of selective antagonists, vagotomy, and in vitro experiments. A barostat enabled us to monitor the intragastric volume in response to different treatments (intravenously administered) before and after supradiaphragmatic vagotomy [results presented as the maximum volume change after treatment (mean; n = 5–11)]. In vitro experiments were performed with isolated muscle strips cut from four different stomach regions of the vagotomized dogs [results were fitted to the operational model of agonism to determine the efficacy parameter τ ( n = 5)]. 5-CT (0.5–10 μg/kg) caused a dose-dependent gastric relaxation (29–267 ml) that was completely blocked by the selective 5-HT7-receptor antagonist SB-269970 (50 μg/kg). After vagotomy, the relaxation to 10 μg/kg 5-CT was significantly less pronounced (73 vs. 267 ml; P < 0.05) but still blocked by SB-269970, whereas the response to the nitric oxide donor nitroprusside was similar to that before vagotomy (178 vs. 218 ml). In vitro, 5-CT concentration dependently inhibited the PGF2α-contracted muscle strips before and after vagotomy. Although before and after vagotomy the response in every region was mediated by 5-HT7 receptors (apparent affinity dissociation constant: SB-269970, 8.2–8.6 vs. 8.3–8.6, respectively), the response after vagotomy was less efficacious (log τ: 1.9 to 0.5 vs. 1.4 to −0.1). The results indicate that the 5-CT-induced proximal stomach relaxation in conscious dogs before and after vagotomy is mediated via 5-HT7 receptors. The decreased efficacy of 5-CT in vitro after vagotomy is probably related to vagotomy-induced changes in receptor density or coupling efficiency and provides a possible explanation for the decreased in vivo response to 5-CT after vagotomy.


Author(s):  
Francesco Tavanti ◽  
Alfonso Pedone ◽  
Maria Cristina Menziani

One of the principal hallmarks of Alzheimer&rsquo;s disease (AD) is related to the aggregation of amyloid-&beta; fibrils in an insoluble form in the brain, also known as amyloidosis. Therefore, a prominent therapeutic strategy against AD consists either in blocking the amyloid aggregation and/or destroying the already formed aggregates. Natural products have shown significant therapeutic potential as amyloid inhibitors from in vitro studies as well as in vivo animal tests. In this study, the interaction of five natural biophenols (curcumin, dopamine, (-)-Epigallocatechin-3-gallate, Quercetin, and Rosmarinic acid) with the amyloid-&beta;(1-40) fibrils has been studied through computational simulations. The results allowed the identification and characterization of the different binding modalities of each compounds and their consequences on fibril dynamics and aggregation. It emerges that the lateral aggregation of the fibrils is strongly influenced by the intercalation of the ligands, which modulate the double-layered structure stability.


eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Suwen Zhao ◽  
Ayano Sakai ◽  
Xinshuai Zhang ◽  
Matthew W Vetting ◽  
Ritesh Kumar ◽  
...  

Metabolic pathways in eubacteria and archaea often are encoded by operons and/or gene clusters (genome neighborhoods) that provide important clues for assignment of both enzyme functions and metabolic pathways. We describe a bioinformatic approach (genome neighborhood network; GNN) that enables large scale prediction of the in vitro enzymatic activities and in vivo physiological functions (metabolic pathways) of uncharacterized enzymes in protein families. We demonstrate the utility of the GNN approach by predicting in vitro activities and in vivo functions in the proline racemase superfamily (PRS; InterPro IPR008794). The predictions were verified by measuring in vitro activities for 51 proteins in 12 families in the PRS that represent ~85% of the sequences; in vitro activities of pathway enzymes, carbon/nitrogen source phenotypes, and/or transcriptomic studies confirmed the predicted pathways. The synergistic use of sequence similarity networks3 and GNNs will facilitate the discovery of the components of novel, uncharacterized metabolic pathways in sequenced genomes.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mariana Noelia Viale ◽  
Kun Taek Park ◽  
Belén Imperiale ◽  
Andrea Karina Gioffre ◽  
María Alejandra Colombatti Olivieri ◽  
...  

ThelprG-p55operon ofMycobacterium tuberculosisandMycobacterium bovisis involved in the transport of toxic compounds. P55 is an efflux pump that provides resistance to several drugs, while LprG is a lipoprotein that modulates the host's immune response against mycobacteria. The knockout mutation of this operon severely reduces the replication of both mycobacterial species during infection in mice and increases susceptibility to toxic compounds. In order to gain insight into the function of LprG in theMycobacterium aviumcomplex, in this study, we assayed the effect of the deletion oflprG gene in the D4ER strain ofMycobacterium aviumsubsp.avium. The replacement oflprG gene with a hygromycin cassette caused a polar effect on the expression ofp55. Also, a twofold decrease in ethidium bromide susceptibility was observed and the resistance to the antibiotics rifampicin, amikacin, linezolid, and rifabutin was impaired in the mutant strain. In addition, the mutation decreased the virulence of the bacteria in macrophagesin vitroand in a mice modelin vivo. These findings clearly indicate that functional LprG and P55 are necessary for the correct transport of toxic compounds and for the survival of MAAin vitroandin vivo.


2005 ◽  
Vol 6 (2) ◽  
pp. 173-197 ◽  
Author(s):  
Jeremy J. Kroll ◽  
Michael B. Roof ◽  
Lorraine J. Hoffman ◽  
James S. Dickson ◽  
D. L. Hank Harris

AbstractProliferative enteropathy (PE; ileitis) is a common intestinal disease affecting susceptible pigs raised under various management systems around the world. Major developments in the understanding of PE and its causative agent,Lawsonia intracellularis, have occurred that have led to advances in the detection of this disease and methods to control and prevent it. Diagnostic tools that have improved overall detection and early onset of PE in pigs include various serological and molecular-based assays. Histological tests such as immunohistochemistry continue to be the gold standard in confirmingLawsonia-specific lesions in pigspost mortem. Despite extreme difficulties in isolatingL. intracellularis, innovations in the cultivation and the development of pure culture challenge models, have opened doors to better characterization of the pathogenesis of PE throughin vivoandin vitro L. intracellularis–host interactions. Advancements in molecular research such as the genetic sequencing of the entireLawsoniagenome have provided ways to identify various immunogens, metabolic pathways and methods for understanding the epidemiology of this organism. The determinations of immunological responsiveness in pigs to virulent and attenuated isolates ofL. intracellularisand identification of various immunogens have led to progress in vaccine development.


2007 ◽  
Vol 96 (7) ◽  
pp. 1821-1831 ◽  
Author(s):  
Nehal J. Lakhani ◽  
Alex Sparreboom ◽  
X.i.a. Xu ◽  
Timothy D. Veenstra ◽  
Jürgen Venitz ◽  
...  

2017 ◽  
Vol 114 (5) ◽  
pp. 1129-1134 ◽  
Author(s):  
Mara H. Sherman ◽  
Ruth T. Yu ◽  
Tiffany W. Tseng ◽  
Cristovao M. Sousa ◽  
Sihao Liu ◽  
...  

A fibroinflammatory stromal reaction cooperates with oncogenic signaling to influence pancreatic ductal adenocarcinoma (PDAC) initiation, progression, and therapeutic outcome, yet the mechanistic underpinning of this crosstalk remains poorly understood. Here we show that stromal cues elicit an adaptive response in the cancer cell including the rapid mobilization of a transcriptional network implicated in accelerated growth, along with anabolic changes of an altered metabolome. The close overlap of stroma-induced changes in vitro with those previously shown to be regulated by oncogenic Kras in vivo suggests that oncogenic Kras signaling—a hallmark and key driver of PDAC—is contingent on stromal inputs. Mechanistically, stroma-activated cancer cells show widespread increases in histone acetylation at transcriptionally enhanced genes, implicating the PDAC epigenome as a presumptive point of convergence between these pathways and a potential therapeutic target. Notably, inhibition of the bromodomain and extraterminal (BET) family of epigenetic readers, and of Bromodomain-containing protein 2 (BRD2) in particular, blocks stroma-inducible transcriptional regulation in vitro and tumor progression in vivo. Our work suggests the existence of a molecular “AND-gate” such that tumor activation is the consequence of mutant Kras and stromal cues, providing insight into the role of the tumor microenvironment in the origin and treatment of Ras-driven tumors.


2012 ◽  
Vol 32 (5) ◽  
pp. 479-490 ◽  
Author(s):  
Gergana M. Deevska ◽  
Manjula Sunkara ◽  
Andrew J. Morris ◽  
Mariana N. Nikolova-Karakashian

The propensity of LDLs (low-density lipoproteins) for aggregation and/or oxidation has been linked to their sphingolipid content, specifically the levels of SM (sphingomyelin) and ceramide. To investigate this association in vivo, ldlr (LDL receptor)-null mice (ldlr−/−) were fed on a modified (atherogenic) diet containing saturated fats and cholesterol. The diet led to significantly elevated SM content in all serum lipoproteins. In contrast, ceramide increased only in the LDL particles. MS-based analyses of the lipid acyl chain composition revealed a marked elevation in C16:0 fatty acid in SM and ceramide, consistent with the prevalence of palmitic acid in the modified diet. The diet also led to increased activity of the S-SMase [secretory SMase (sphingomyelinase)], a protein that is generated by ASMase (acid SMase) and acts on serum LDL. An increased macrophage secretion seemed to be responsible for the elevated S-SMase activity. ASMase-deficient mice (asm−/−/ldlr−/−) lacked S-SMase activity and were protected from diet-induced elevation in LDL ceramide. LDL from asm−/−/ldlr−/− mice fed on the modified diet were less aggregated and oxidized than LDL from asm+/+/ldlr−/− mice. When tested in vitro, the propensity for aggregation was dependent on the SM level: only LDL from animals on modified diet that have high SM content aggregated when treated with recombinant S-SMase. In conclusion, LDL-SM content and S-SMase activity are up-regulated in mice fed on an atherogenic diet. S-SMase mediates diet-induced changes in LDL ceramide content and aggregation. S-SMase effectiveness in inducing aggregation is dependent on diet-induced enrichment of LDL with SM, possibly through increased hepatic synthesis.


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