Biochemistry and Cell Biology - Journal Articles
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Item Low adenovirus vaccine doses administered to skin using microneedle patches induce better functional antibody immunogenicity as compared to systemic injection(MDPI AG, 2021) Flynn, Olivia; Dillane, Kate; Lanza, Juliane S.; Marshall, Jennifer M.; Jin, Jing; Silk, Sarah E.; Draper, Simon J.; Moore, Anne C.; Health Research BoardAdenovirus-based vaccines are demonstrating promising clinical potential for multiple infectious diseases, including COVID-19. However, the immunogenicity of the vector itself decreases its effectiveness as a boosting vaccine due to the induction of strong anti-vector neutralizing immunity. Here we determined how dissolvable microneedle patches (DMN) for skin immunization can overcome this issue, using a clinically-relevant adenovirus-based Plasmodium falciparum malaria vaccine, AdHu5–PfRH5, in mice. Incorporation of vaccine into patches significantly enhanced its thermostability compared to the liquid form. Conventional high dose repeated immunization by the intramuscular (IM) route induced low antigen-specific IgG titres and high anti-vector immunity. A low priming dose of vaccine, by the IM route, but more so using DMN patches, induced the most efficacious immune responses, assessed by parasite growth inhibitory activity (GIA) assays. Administration of low dose AdHu5–PfRH5 using patches to the skin, boosted by high dose IM, induced the highest antigen-specific serum IgG response after boosting, the greatest skewing of the antibody response towards the antigen and away from the vector, and the highest efficacy. This study therefore demonstrates that repeated use of the same adenovirus vaccine can be highly immunogenic towards the transgene if a low dose is used to prime the response. It also provides a method of stabilizing adenovirus vaccine, in easy-to-administer dissolvable microneedle patches, permitting storage and distribution out of cold chain.Item eIF2α controls memory consolidation via excitatory and somatostatin neurons(Nature Research, 2020-10-07) Sharma, Vijendra; Sood, Rapita; Khlaifia, Abdessattar; Eslamizade, Mohammad Javad; Hung, Tzu-Yu; Lou, Danning; Asgarihafshejani, Azam; Lalzar, Maya; Kiniry, Stephen J.; Stokes, Matthew P.; Cohen, Noah; Nelson, Alissa J.; Abell, Kathryn; Possemato, Anthony P.; Gal-Ben-Ari, Shunit; Truong, Vinh T.; Wang, Peng; Yiannakas, Adonis; Saffarzadeh, Fatemeh; Cuello, A. Claudio; Nader, Karim; Kaufman, Randal J.; Costa-Mattioli, Mauro; Baranov, Pavel V.; Quintana, Albert; Sanz, Elisenda; Khoutorsky, Arkady; Lacaille, Jean-Claude; Rosenblum, Kobi; Sonenberg, Nahum; International Development Research Centre; Azrieli Foundation; Canadian Institutes of Health Research; Israel Science Foundation; National Institutes of Health; Ministerio de Ciencia, Innovación y Universidades; European Research Council; Ministerio de Economía y Competitividad; Agència de Gestió d’Ajuts Universitaris i de Recerca; National Institute of Neurological Disorders and Stroke; Richard and Edith Strauss FoundationAn important tenet of learning and memory is the notion of a molecular switch that promotes the formation of long-term memory1,2,3,4. The regulation of proteostasis is a critical and rate-limiting step in the consolidation of new memories5,6,7,8,9,10. One of the most effective and prevalent ways to enhance memory is by regulating the synthesis of proteins controlled by the translation initiation factor eIF211. Phosphorylation of the α-subunit of eIF2 (p-eIF2α), the central component of the integrated stress response (ISR), impairs long-term memory formation in rodents and birds11,12,13. By contrast, inhibiting the ISR by mutating the eIF2α phosphorylation site, genetically11 and pharmacologically inhibiting the ISR kinases14,15,16,17, or mimicking reduced p-eIF2α with the ISR inhibitor ISRIB11, enhances long-term memory in health and disease18. Here we used molecular genetics to dissect the neuronal circuits by which the ISR gates cognitive processing. We found that learning reduces eIF2α phosphorylation in hippocampal excitatory neurons and a subset of hippocampal inhibitory neurons (those that express somatostatin, but not parvalbumin). Moreover, ablation of p-eIF2α in either excitatory or somatostatin-expressing (but not parvalbumin-expressing) inhibitory neurons increased general mRNA translation, bolstered synaptic plasticity and enhanced long-term memory. Thus, eIF2α-dependent mRNA translation controls memory consolidation via autonomous mechanisms in excitatory and somatostatin-expressing inhibitory neurons.Item Colonic microbiota is associated with inflammation and host epigenomic alterations in inflammatory bowel disease(Springer Nature, 2020-03-23) Ryan, Fergal J.; Ahern, A. M.; Fitzgerald, R. S.; Laserna-Mendieta, E. J.; Power, E. M.; Clooney, A. G.; O'Donoghue, K. W.; McMurdie, P. J.; Iwai, S.; Crits-Christoph, A.; Sheehan, F.; Moran, C.; Flemer, B.; Zomer, A. L.; Fanning, A.; O'Callaghan, J.; Walton, Janette; Temko, Andriy; Stack, W.; Jackson, L.; Joyce, Susan A.; Melgar, Silvia; DeSantis, Todd Z.; Bell, Bell, Jordana T.; Shanahan, Fergus; Claesson, Marcus J.; Science Foundation Ireland; Health Research Board; Irish Research Council; Second Genome, Inc., United StatesStudies of inflammatory bowel disease (IBD) have been inconclusive in relating microbiota with distribution of inflammation. We report microbiota, host transcriptomics, epigenomics and genetics from matched inflamed and non-inflamed colonic mucosa [50 Crohn’s disease (CD); 80 ulcerative colitis (UC); 31 controls]. Changes in community-wide and within-patient microbiota are linked with inflammation, but we find no evidence for a distinct microbial diagnostic signature, probably due to heterogeneous host-microbe interactions, and show only marginal microbiota associations with habitual diet. Epithelial DNA methylation improves disease classification and is associated with both inflammation and microbiota composition. Microbiota sub-groups are driven by dominant Enterbacteriaceae and Bacteroides species, representative strains of which are pro-inflammatory in vitro, are also associated with immune-related epigenetic markers. In conclusion, inflamed and non-inflamed colonic segments in both CD and UC differ in microbiota composition and epigenetic profiles.Item Evaluation of bile salt hydrolase inhibitor efficacy for modulating host bile profile and physiology using a chicken model system(Springer Nature, 2020-03-18) Geng, Wenjing; Long, Sarah L.; Chang, Yun-Juan; Saxton, Arnold M.; Joyce, Susan A.; Lin, Jun; University of Tennessee; U.S. Department of Agriculture; National Institute of Food and Agriculture; Department of Agriculture, Food and the Marine, Ireland; Science Foundation Ireland; European CommissionGut microbial enzymes, bile salt hydrolases (BSHs) are the gateway enzymes for bile acid (BA) modification in the gut. This activity is a promising target for developing innovative non-antibiotic growth promoters to enhance animal production and health. Compelling evidence has shown that inhibition of BSH activity should enhance weight gain by altering the BA pool, host signalling and lipid metabolism. We recently identified a panel of promising BSH inhibitors. Here, we address the potential of them as alternative, effective, non-antibiotic feed additives, for commercial application, to promote animal growth using a chicken model. In this study, the in vivo efficacy of three BSH inhibitors (caffeic acid phenethylester, riboflavin, carnosic acid) were evaluated. 7-day old chicks (10 birds/group) were either untreated or they received one of the specific BSH inhibitors (25 mg/kg body weight) via oral gavage for 17 days. The chicks in treatment groups consistently displayed higher body weight gain than the untreated chicks. Metabolomic analysis demonstrated that BSH inhibitor treatment led to significant changes in both circulating and intestinal BA signatures in support of blunted intestinal BSH activity. Consistent with this finding, liver and intestinal tissue RNA-Seq analysis showed that carnosic acid treatment significantly altered expression of genes involved in lipid and bile acid metabolism. Taken together, this study validates microbial BSH activity inhibition as an alternative target and strategy to antibiotic treatment for animal growth promotion.Item Microbial bile salt hydrolases mediate the efficacy of faecal microbiota transplant in the treatment of recurrent Clostridioides difficile infection(BMJ Publishing Group, 2019-02-11) Mullish, Benjamin H.; McDonald, Julie A. K.; Pechlivanis, Alexandros; Allegretti, Jessica R.; Kao, Dina; Barker, Grace F.; Kapila, Diya; Petrof, Elaine O.; Joyce, Susan A.; Gahan, Cormac G.; Glegola-Madejska, Izabela; Williams, Horace R. T.; Holmes, Elaine; Clarke, Thomas B.; Thursz, Mark R.; Marchesi, Julian R.; National Institute for Health Research; Biomedical Research CentreObjective: Faecal microbiota transplant (FMT) effectively treats recurrent Clostridioides difficile infection (rCDI), but its mechanisms of action remain poorly defined. Certain bile acids affect C. difficile germination or vegetative growth. We hypothesised that loss of gut microbiota-derived bile salt hydrolases (BSHs) predisposes to CDI by perturbing gut bile metabolism, and that BSH restitution is a key mediator of FMT’s efficacy in treating the condition.Design Using stool collected from patients and donors pre-FMT/post-FMT for rCDI, we performed 16S rRNA gene sequencing, ultra performance liquid chromatography mass spectrometry (UPLC-MS) bile acid profiling, BSH activity measurement, and qPCR of bsh/baiCD genes involved in bile metabolism. Human data were validated in C. difficile batch cultures and a C57BL/6 mouse model of rCDI.Results From metataxonomics, pre-FMT stool demonstrated a reduced proportion of BSH-producing bacterial species compared with donors/post-FMT. Pre-FMT stool was enriched in taurocholic acid (TCA, a potent C. difficile germinant); TCA levels negatively correlated with key bacterial genera containing BSH-producing organisms. Post-FMT samples demonstrated recovered BSH activity and bsh/baiCD gene copy number compared with pretreatment (p<0.05). In batch cultures, supernatant from engineered bsh-expressing E. coli and naturally BSH-producing organisms (Bacteroides ovatus, Collinsella aerofaciens, Bacteroides vulgatus and Blautia obeum) reduced TCA-mediated C. difficile germination relative to culture supernatant of wild-type (BSH-negative) E. coli. C. difficile total viable counts were ~70% reduced in an rCDI mouse model after administration of E. coli expressing highly active BSH relative to mice administered BSH-negative E. coli (p<0.05).Conclusion Restoration of gut BSH functionality contributes to the efficacy of FMT in treating rCDI.