Project description:Passive transfer studies in humans clearly demonstrated the protective role of IgG antibodies against malaria. Identifying the precise parasite antigens that mediate immunity is essential for vaccine design, but has proved difficult. Completion of the Plasmodium falciparum genome revealed thousands of potential vaccine candidates, but a significant bottleneck remains in their validation and prioritization for further evaluation in clinical trials. Focusing initially on the Plasmodium falciparum merozoite proteome, we used peer-reviewed publications, multiple proteomic and bioinformatic approaches, to select and prioritize potential immune targets. We expressed 109 P. falciparum recombinant proteins, the majority of which were obtained using a mammalian expression system that has been shown to produce biologically functional extracellular proteins, and used them to create KILchip v1.0: a novel protein microarray to facilitate high throughput multiplexed antibody detection from individual samples. The microarray assay was highly specific; antibodies against P. falciparum proteins were detected exclusively in sera from malaria-exposed but not malaria-naïve individuals. The intensity of antibody reactivity varied as expected from strong to weak across well-studied antigens such as AMA1 and RH5 (Kruskal-Wallis H test for trend: p-value <0.0001). The inter-assay and intra-assay variability was minimal, with reproducible results obtained in re-assays using the same chip over duration of 3 months. Antibodies quantified using the multiplexed format in KILchip v1.0 were highly correlated with those measured in the gold-standard monoplex ELISA (median (range) Spearman’s R of 0.84 (0.65-0.95)). KILchip v1.0 is a robust, scalable and adaptable protein microarray that has broad applicability to studies of naturally acquired immunity against malaria by providing a standardized tool for the detection of antibody correlates of protection. It will facilitate rapid high-throughput validation and prioritization of potential Plasmodium falciparum merozoite-stage antigens paving the way for urgently needed clinical trials for the next-generation of malaria vaccines.

Project description:Smoking cessation is the most effective measure for reducing the risk of smoking-related diseases but switching to less harmful products (modified-risk tobacco products) can be an alternative for smokers who would otherwise not quit. In an 18-month chronic carcinogenicity/toxicity study in A/J mice (OECD Test Guideline 453), we assessed aerosol from the Tobacco Heating System 2.2 (THS 2.2), a candidate modified-risk tobacco product based on the heat-not-burn principle, compared with 3R4F cigarette smoke (CS). To capture toxicity- and disease-relevant mechanisms, we complemented standard toxicology endpoints with in-depth systems toxicology analyses. Briefly, female A/J mice were exposed to fresh air (Sham), three concentrations of THS 2.2 aerosol corresponding to nicotine concentrations of 6.7 (Low; L), 13.4 (Medium; M), and 26.8 (High; H) µg nicotine\L test atmosphere, or to one concentration of 3R4F CS (13.4 µg nicotine\L test atmosphere) in whole-body exposure chambers for 6 h per day, 5 days per week, and up to 18 months. Interim dissections were scheduled for months 1, 5, and 10. Male mice were exposed to either fresh air (Sham) or to the high THS 2.2 aerosol concentration for 15 months. Chronic toxicity and carcinogenicity endpoints outlined in the OECD protocol were assessed; detailed findings will be reported separately (Wong et al.). For evaluation of non-OECD endpoints following a systems toxicology approach (proteomics, transcriptomics, and genomics), several tissues were collected for further analysis. Housing and all procedures involving animals were performed in accordance with the approved Institutional Animal Care and Use Committee protocol in an Agri-Food & Veterinary Authority of Singapore-licensed and Association for Assessment and Accreditation of Laboratory Animal Care International-accredited facility, where the care and use of the animals for scientific purposes were in accordance with the National Advisory Committee for Laboratory Animal Research (NACLAR) Guideline (NACLAR, 2004). Animals allocated to the omics endpoints (N=8-20) were dissected within 16-24 h of the last exposure and following randomization of all planned necropsies for the dissection time point in question. All efforts to minimize potential nucleic acid and protein degradation were made, and samples were frozen as rapidly as possible once ex vivo. Lungs collected after month 1 were snap-frozen and the right caudal lobe was used for proteomics analysis. These are the protein expression data for the respiratory nasal epithelium assessed by iTRAQÂ®-based quantitative proteomics.

Project description:Smoking cessation is the most effective measure for reducing the risk of smoking-related diseases but switching to less harmful products (modified-risk tobacco products) can be an alternative for smokers who would otherwise not quit. In an 18-month chronic carcinogenicity/toxicity study in A/J mice (OECD Test Guideline 453), we assessed aerosol from the Tobacco Heating System 2.2 (THS 2.2), a candidate modified-risk tobacco product based on the heat-not-burn principle, compared with 3R4F cigarette smoke (CS). To capture toxicity- and disease-relevant mechanisms, we complemented standard toxicology endpoints with in-depth systems toxicology analyses. Briefly, female A/J mice were exposed to fresh air (Sham), three concentrations of THS 2.2 aerosol corresponding to nicotine concentrations of 6.7 (Low; L), 13.4 (Medium; M), and 26.8 (High; H) µg nicotine\L test atmosphere, or to one concentration of 3R4F CS (13.4 µg nicotine\L test atmosphere) in whole-body exposure chambers for 6 h per day, 5 days per week, and up to 18 months. Interim dissections were scheduled for months 1, 5, and 10. Male mice were exposed to either fresh air (Sham) or to the high THS 2.2 aerosol concentration for 15 months. Chronic toxicity and carcinogenicity endpoints outlined in the OECD protocol were assessed; detailed findings will be reported separately (Wong et al.). For evaluation of non-OECD endpoints following a systems toxicology approach (proteomics, transcriptomics, and genomics), several tissues were collected for further analysis. Housing and all procedures involving animals were performed in accordance with the approved Institutional Animal Care and Use Committee protocol in an Agri-Food & Veterinary Authority of Singapore-licensed and Association for Assessment and Accreditation of Laboratory Animal Care International-accredited facility, where the care and use of the animals for scientific purposes were in accordance with the National Advisory Committee for Laboratory Animal Research (NACLAR) Guideline (NACLAR, 2004). Animals allocated to the omics endpoints (N=8-20) were dissected within 16-24 h of the last exposure and following randomization of all planned necropsies for the dissection time point in question. All efforts to minimize potential nucleic acid and protein degradation were made, and samples were frozen as rapidly as possible once ex vivo. Lungs collected after month 1 were snap-frozen and the right caudal lobe was used for proteomics analysis. These are the protein expression data for lung tissue assessed by iTRAQ®-based quantitative proteomics.

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Toxicology study on KhES-3 cells.

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