ORCID Profile
0000-0002-4688-0598
Current Organisations
MALARIA VACCINE AND DRUG DEVELOPMENT CENTER
,
University of Southampton
,
University of Adelaide
,
University of Southampton Faculty of Medicine
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Publisher: Frontiers Media SA
Date: 29-11-2017
Publisher: Public Library of Science (PLoS)
Date: 17-07-2017
Publisher: Elsevier BV
Date: 03-2021
Publisher: Cold Spring Harbor Laboratory
Date: 15-05-2021
DOI: 10.1101/2021.05.12.21257086
Abstract: The worldwide pandemic caused by SARS-CoV-2 has claimed millions of lives and has had a profound effect on global life. Understanding the pathogenicity of the virus and the body’s response to infection is crucial in improving patient management, prognosis, and therapeutic strategies. To address this, we performed functional transcriptomic profiling to better understand the generic and specific effects of SARS-CoV-2 infection. Whole blood RNA sequencing was used to profile a well characterised cohort of patients hospitalised with COVID-19, during the first wave of the pandemic prior to the availability of approved COVID-19 treatments and who went on to survive or die of COVID-19, and patients hospitalised with influenza virus infection between 2017 and 2019. Clinical parameters between patient groups were compared, and several bioinformatic tools were used to assess differences in transcript abundances and cellular composition. The analyses revealed contrasting innate and adaptive immune programmes, with transcripts and cell subsets associated with the innate immune response elevated in patients with influenza, and those involved in the adaptive immune response elevated in patients with COVID-19. Topological analysis identified additional gene signatures that differentiated patients with COVID-19 from patients with influenza, including insulin resistance, mitochondrial oxidative stress and interferon signalling. An efficient adaptive immune response was furthermore associated with patient survival, while an inflammatory response predicted death in patients with COVID-19. A potential prognostic signature was found based on a selection of transcript abundances, associated with circulating immunoglobulins, nucleosome assembly, cytokine production and T cell activation, in the blood transcriptome of COVID-19 patients, upon admission to hospital, which can be used to stratify patients likely to survive or die. The results identified distinct immunological signatures between SARS-CoV-2 and influenza, prognostic of disease progression and indicative of different targeted therapies. The altered transcript abundances associated with COVID-19 survivors can be used to predict more severe outcomes in patients with COVID-19.
Publisher: Springer Science and Business Media LLC
Date: 16-01-2020
DOI: 10.1038/S41467-019-14125-X
Abstract: Langerhans cells (LC) can prime tolerogenic as well as immunogenic responses in skin, but the genomic states and transcription factors (TF) regulating these context-specific responses are unclear. Bulk and single-cell transcriptional profiling demonstrates that human migratory LCs are robustly programmed for MHC-I and MHC-II antigen presentation. Chromatin analysis reveals enrichment of ETS-IRF and AP1-IRF composite regulatory elements in antigen-presentation genes, coinciding with expression of the TFs, PU.1, IRF4 and BATF3 but not IRF8. Migration of LCs from the epidermis is accompanied by upregulation of IRF4, antigen processing components and co-stimulatory molecules. TNF stimulation augments LC cross-presentation while attenuating IRF4 expression. CRISPR-mediated editing reveals IRF4 to positively regulate the LC activation programme, but repress NF2EL2 and NF-kB pathway genes that promote responsiveness to oxidative stress and inflammatory cytokines. Thus, IRF4-dependent genomic programming of human migratory LCs appears to enable LC maturation while attenuating excessive inflammatory and immunogenic responses in the epidermis.
Publisher: Springer Science and Business Media LLC
Date: 26-05-2016
Publisher: Public Library of Science (PLoS)
Date: 11-01-2016
Publisher: Springer Science and Business Media LLC
Date: 19-05-2023
DOI: 10.1038/S41467-023-38588-1
Abstract: Regulation of cutaneous immunity is severely compromised in inflammatory skin disease. To investigate the molecular crosstalk underpinning tolerance versus inflammation in atopic dermatitis, we utilise a human in vivo allergen challenge study, exposing atopic dermatitis patients to house dust mite. Here we analyse transcriptional programmes at the population and single cell levels in parallel with immunophenotyping of cutaneous immunocytes revealed a distinct dichotomy in atopic dermatitis patient responsiveness to house dust mite challenge. Our study shows that reactivity to house dust mite was associated with high basal levels of TNF-expressing cutaneous Th17 T cells, and documents the presence of hub structures where Langerhans cells and T cells co-localised. Mechanistically, we identify expression of metallothioneins and transcriptional programmes encoding antioxidant defences across all skin cell types, that appear to protect against allergen-induced inflammation. Furthermore, single nucleotide polymorphisms in the MTIX gene are associated with patients who did not react to house dust mite, opening up possibilities for therapeutic interventions modulating metallothionein expression in atopic dermatitis.
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.VETPAR.2016.05.022
Abstract: Leishmania infantum is one of the causative agents of visceral leishmaniasis (VL). VL is the most severe form of leishmaniasis and can be fatal if it is not properly treated. Although several PCR works are intended to detect L. infantum, in silico analysis of available primers and/or primer-probes reveals potential cross species lification. Here, a TaqMan-based quantitative real time PCR (qPCR) assay was developed for specific detection and quantitation of L. infantum in tissue s les from experimentally or naturally infected animals, mice or dogs, respectively. For this assay, primers and probes were designed for the kinetoplast minicircle DNA of L. infantum. The qPCR assay achieved a detection limit of 0.01pg of parasite DNA, and allowed specific lification of L. infantum in both asymptomatic and symptomatic naturally infected dogs with inter-assay variation coefficients between 0.05-0.11. There was no cross lification with dog DNA or with L. braziliensis, L. donovani, L. major, L. tropica or Trypanosoma cruzi. In addition, our assay detected a significantly higher parasite load in symptomatic than in the asymptomatic animals (p<0.0001). We believe this approach will be a valuable tool for the specific detection of L. infantum in regions of sympatric transmission of VL-causing parasites.
Publisher: Elsevier BV
Date: 2010
Publisher: Springer Science and Business Media LLC
Date: 06-02-2016
Publisher: Elsevier BV
Date: 08-2013
DOI: 10.1016/J.JPROT.2013.06.011
Abstract: Proteomic analysis by two-dimensional electrophoresis (2D)-mass spectrometry was used to identify differentially expressed proteins in the Clostridium sp. native strain (IBUN 158B) in two phases of the 1,3-propanediol (1,3-PD) production (lag phase and exponential growth phase). Intracellular protein fraction extraction conditions were standardised, as well as the 2D electrophoresis. Differences were found between both of the growth phases evaluated here. Thirty-two of the differentially expressed proteins were chosen to be identified by tandem mass spectrometry (MALDI TOF/TOF). The presence of four enzymes implicated in the 1,3-PD metabolic pathway was recorded: one from the reductive route (1,3-propanediol dehydrogenase) and three from the oxidative route (3-hydroxybutyryl-CoA dehydrogenase, NADPH-dependent butanol dehydrogenase and phosphate butyryl transferase). The following enzymes which have not been previously reported for Clostridium sp., were also identified: phosphoglycerate kinase, glucose 6-phosphate isomerase, deoxyribose phosphate aldolase, transketolase, cysteine synthetase, O-acetylhomoserine sulphhydrylase, glycyl-tRNA ligase, aspartate-β-semialdehyde dehydrogenase, inosine-5-monophosphate dehydrogenase, aconitate hydratase and the PrsA protein. The foregoing provides a novel contribution towards knowledge of the native strain for the purpose of designing genetic manipulation strategies to obtain strains with high production of 1,3-PD. The article "Protein identification in two phases of 1,3-propanediol production by proteomic analysis" provides a novel contribution towards knowledge regarding the Colombian Clostridium sp. native strain (IBUN 158B) because this is a new approximation in comparative proteomics in two phases of the bacterial growth and 1,3-propanediol (1,3-PD) production conditions. The proteomic studies are very important to identify the enzymes that are expressed at different stages of production and therefore genes of interest in the genetic manipulation strategies the results can be taken into account in future studies in metabolic engineering when optimising 1,3-PD production, in a cost-effective process having direct industrial applications.
Publisher: Oxford University Press (OUP)
Date: 20-09-2020
DOI: 10.1111/BJD.19431
Publisher: Cold Spring Harbor Laboratory
Date: 23-08-2015
DOI: 10.1101/025338
Abstract: Plasmodium vivax is the most prevalent malarial species in South America and exerts a substantial burden on the populations is affects. Its control and eventual elimination are a global health priority. Genomic research contributes to this objective by improving our understanding of the biology of P. vivax and through the development of new genetic markers that can be used to monitor efforts to reduce malaria transmission. Here we analyze whole genome data from eight field s les from a region in Cord ́ oba, Colombia where malaria is endemic. We find considerable genetic ersity within this population, a result that contrasts with earlier studies suggesting that P. vivax had limited ersity in the Americas. We also identify a selective sweep around a substitution known to confer resistance to sulphadoxine-pyrimethamine (SP). This is the first observation of a selective sweep for SP resistance in this parasite. These results indicate that P. vivax has been exposed to SP pressure even when the drug is not in use as a first line treatment for patients afflicted by this parasite. We identify multiple non-synonymous substitutions in three other genes known to be involved with drug resistance in Plasmodium species. Finally, we found extensive microsatellite polymorphisms. Using this information we developed 18 microsatellite loci that are polymorphic and easy to score and can thus be used in epidemiological investigations in South America.
Publisher: Elsevier BV
Date: 05-2022
Publisher: American Society for Clinical Investigation
Date: 21-07-2021
DOI: 10.1172/JCI148136
Publisher: Elsevier BV
Date: 2010
Publisher: Springer Science and Business Media LLC
Date: 30-08-2016
Publisher: American Society for Clinical Investigation
Date: 02-08-2021
DOI: 10.1172/JCI141895
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1LC00292A
Abstract: Pirouette coupling involves Dean flow for cell and reporter bead inertial ordering for efficient co-encapsulation, achieving a throughput of 1 million cells per hour, a 2.5% multiplet rate and a 70% cell capture efficiency.
Publisher: Springer Science and Business Media LLC
Date: 05-2014
Publisher: Public Library of Science (PLoS)
Date: 26-06-2017
Publisher: Cold Spring Harbor Laboratory
Date: 09-04-2021
DOI: 10.1101/2021.04.08.439026
Abstract: The future of single cell ersity screens involves ever-larger s le sizes, dictating the need for higher throughput methods with low analytical noise to accurately describe the nature of the cellular system. Current approaches are limited by the Poisson statistic, requiring dilute cell suspensions and associated losses in throughput. In this contribution, we apply Dean entrainment to both cell and bead inputs, defining different volume packets to effect efficient co-encapsulation. Volume ratio scaling was explored to identify optimal conditions. This enabled the co-encapsulation of single cells with reporter beads at rates of ~1 million cells/hour, while increasing assay signal-to-noise with cell multiplet rates of ~2.5% and capturing ~70% of cells. The method, called Pirouette-seq, extends our capacity to investigate biological systems. Pirouette-seq involves cell and reporter bead inertial ordering for efficient co-encapsulation, achieving a throughput of 1 million cells/hour, a 2.5% multiplet rate and a 70% cell capture efficiency.
Publisher: Oxford University Press (OUP)
Date: 24-11-2020
Abstract: Crohn’s disease [CD] arises through host-environment interaction. Abnormal gene expression results from disturbed pathway activation or response to bacteria. We aimed to determine activated pathways and driving cell types in paediatric CD. We employed contemporary targeted autoimmune RNA sequencing, in parallel to single-cell sequencing, to ileal tissue derived from paediatric CD and controls. Weighted gene co-expression network analysis [WGCNA] was performed and differentially expressed genes [DEGs] were determined. We integrated clinical data to determine co-expression modules associated with outcomes. In all, 27 treatment-naive CD [TN-CD], 26 established CD patients and 17 controls were included. WGCNA revealed a 31-gene signature characterising TN-CD patients, but not established CD, nor controls. The CSF3R gene is a hub within this module and is key in neutrophil expansion and differentiation. Antimicrobial genes, including S100A12 and the calprotectin subunit S100A9, were significantly upregulated in TN CD compared with controls [p = 2.61 x 10-15 and p = 9.13 x 10-14, respectively] and established CD [both p = 0.0055]. Gene-enrichment analysis confirmed upregulation of the IL17-, NOD- and Oncostatin-M-signalling pathways in TN-CD patients, identified in both WGCNA and DEG analyses. An upregulated gene signature was enriched for transcripts promoting Th17-cell differentiation and correlated with prolonged time to relapse [correlation-coefficient-0.36, p = 0.07]. Single-cell sequencing of TN-CD patients identified specialised epithelial cells driving differential expression of S100A9. Cell groups, determined by single-cell gene expression, demonstrated enrichment of IL17-signalling in monocytes and epithelial cells. Ileal tissue from treatment-naïve paediatric patients is significantly upregulated for genes driving IL17-, NOD- and Oncostatin-M-signalling. This signal is driven by a distinct subset of epithelial cells expressing antimicrobial gene transcripts.
Publisher: BMJ
Date: 05-2021
Abstract: Natural killer (NK) cells are increasingly being recognized as agents for cancer immunotherapy. The killer cell immunoglobulin-like receptors (KIRs) are expressed by NK cells and are immunogenetic determinants of the outcome of cancer. In particular, KIR2DS2 is associated with protective responses to several cancers and also direct recognition of cancer targets in vitro. Due to the high homology between activating and inhibitory KIR genes to date, it has been challenging to target in idual KIR for therapeutic benefit. A novel KIR2DS2-targeting therapeutic peptide:MHC DNA vaccine was designed and used to immunize mice transgenic for KIR genes (KIR-Tg). NK cells were isolated from the livers and spleens of vaccinated mice and then analyzed for activation by flow cytometry, RNA profiling and cytotoxicity assays. In vivo assays of NK cell function using a syngeneic cancer model (B16 melanoma) and an adoptive transfer model for human hepatocellular carcinoma (Huh7) were performed. Injecting KIR-Tg mice with the vaccine construct activated NK cells in both liver and spleens of mice, with preferential activation of KIR2DS2-positive NK cells. KIR-specific activation was most marked on the CD11b+CD27+ mature subset of NK cells. RNA profiling indicated that the DNA vaccine upregulated genes associated with cellular metabolism and downregulated genes related to histone H3 methylation, which are associated with immune cell maturation and NK cell function. Vaccination led to canonical and cross-reactive peptide:MHC-specific NK cell responses. In vivo, DNA vaccination led to enhanced antitumor responses against B16F10 melanoma cells and also enhanced responses against a tumor model expressing the KIR2DS2 ligand HLA-C*0102. We show the feasibility of a peptide-based KIR-targeting vaccine strategy to activate NK cells and hence generate functional antitumor responses. This approach does not require detailed knowledge of the tumor peptidomes nor HLA matching with the patient. It therefore offers a novel opportunity for targeting NK cells for cancer immunotherapy.
Publisher: Springer Science and Business Media LLC
Date: 12-2022
DOI: 10.1038/S42003-022-04265-0
Abstract: Mycobacterium tuberculosis (Mtb) is one of the most successful human pathogens. Several cytokines are known to increase virulence of bacterial pathogens, leading us to investigate whether Interferon-γ (IFN-γ), a central regulator of the immune defense against Mtb , has a direct effect on the bacteria. We found that recombinant and T-cell derived IFN-γ rapidly induced a dose-dependent increase in the oxygen consumption rate (OCR) of Mtb , consistent with increased bacterial respiration. This was not observed in attenuated Bacillus Calmette–Guérin (BCG), and did not occur for other cytokines tested, including TNF-α. IFN-γ binds to the cell surface of intact Mtb , but not BCG. Mass spectrometry identified mycobacterial membrane protein large 10 (MmpL10) as the transmembrane binding partner of IFN-γ, supported by molecular modelling studies. IFN-γ binding and the OCR response was absent in Mtb Δmmpl10 strain and restored by complementation with wildtype mmpl10 . RNA-sequencing and RT-PCR of Mtb exposed to IFN-γ revealed a distinct transcriptional profile, including genes involved in virulence. In a 3D granuloma model, IFN-γ promoted Mtb growth, which was lost in the Mtb Δmmpl10 strain and restored by complementation, supporting the involvement of MmpL10 in the response to IFN-γ. Finally, IFN-γ addition resulted in sterilization of Mtb cultures treated with isoniazid, indicating clearance of phenotypically resistant bacteria that persist in the presence of drug alone. Together our data are the first description of a mechanism allowing Mtb to respond to host immune activation that may be important in the immunopathogenesis of TB and have use in novel eradication strategies.
Publisher: The American Association of Immunologists
Date: 15-07-2022
Abstract: NK cells are promising cellular therapeutics against hematological and solid malignancies. Immunogenetic studies have identified that various activating killer cell Ig-like receptors (KIRs) are associated with cancer outcomes. Specifically, KIR2DS2 has been associated with reduced incidence of relapse following transplant in hematological malignancies and improved outcomes in solid tumors, but the mechanism remains obscure. Therefore, we investigated how KIR2DS2 expression impacts NK cell function. Using a novel flow cytometry panel, we show that human NK cells with high KIR2DS2 expression have enhanced spontaneous activation against malignant B cell lines, liver cancer cell lines, and primary chronic lymphocytic leukemia cells. Surface expression of CD16 was increased on KIR2DS2high NK cells, and, accordingly, KIR2DS2high NK cells had increased activation against lymphoma cells coated with the clinically relevant anti-CD20 Abs rituximab and obinutuzumab. Bulk RNA sequencing revealed that KIR2DS2high NK cells have upregulation of NK-mediated cytotoxicity, translation, and FCGR gene pathways. We developed a novel single-cell RNA-sequencing technique to identify KIR2DS2+ NK cells, and this confirmed that KIR2DS2 is associated with enhanced NK cell–mediated cytotoxicity. This study provides evidence that KIR2DS2 marks a population of NK cells primed for anticancer activity and indicates that KIR2DS2 is an attractive target for NK-based therapeutic strategies.
Publisher: Frontiers Media SA
Date: 15-06-2021
DOI: 10.3389/FIMMU.2021.665312
Abstract: Langerhans cells (LCs) reside in the epidermis as a dense network of immune system sentinels, coordinating both immunogenic and tolerogenic immune responses. To determine molecular switches directing induction of LC immune activation, we performed mathematical modelling of gene regulatory networks identified by single cell RNA sequencing of LCs exposed to TNF-alpha, a key pro-inflammatory signal produced by the skin. Our approach delineated three programmes of LC phenotypic activation (immunogenic, tolerogenic or ambivalent), and confirmed that TNF-alpha enhanced LC immunogenic programming. Through regulon analysis followed by mutual information modelling, we identified IRF1 as the key transcription factor for the regulation of immunogenicity in LCs. Application of a mathematical toggle switch model, coupling IRF1 with tolerance-inducing transcription factors, determined the key set of transcription factors regulating the switch between tolerance and immunogenicity, and correctly predicted LC behaviour in LCs derived from different body sites. Our findings provide a mechanistic explanation of how combinatorial interactions between different transcription factors can coordinate specific transcriptional programmes in human LCs, interpreting the microenvironmental context of the local tissue microenvironments.
Publisher: Public Library of Science (PLoS)
Date: 16-03-2015
Publisher: Springer Science and Business Media LLC
Date: 10-03-2014
Publisher: Elsevier BV
Date: 2010
Publisher: Public Library of Science (PLoS)
Date: 08-01-2015
Publisher: Cold Spring Harbor Laboratory
Date: 24-08-2022
DOI: 10.1101/2022.08.23.505054
Abstract: FFPE (formalin-fixed, paraffin-embedded) tissue archives are the largest repository of clinically annotated human specimens. Despite numerous advances in technology, current methods for sequencing of FFPE-fixed single-cells are slow, labour intensive, insufficiently sensitive and have a low resolution, making it difficult to fully exploit their enormous research and clinical potential. Here we introduce single nuclei pathology sequencing (snPATHO-Seq), a sensitive and efficient high-throughput platform to profile the transcriptome of single nuclei extracted from formalin-fixed paraffin-embedded (FFPE) s les. snPATHO-Seq combines an optimised nuclei extraction protocol from archival s les with 10x Genomics probe-based technology targeting the whole transcriptome. We performed direct comparison of the Fixed RNA Profiling (FRP) and established 3’ single cell RNA-Sequencing (scRNA-Seq) workflows through a comprehensive bioinformatics analysis of matched fresh and fixed s les derived from the LNCaP prostate cancer cell line. FRP detected 2.1 times more transcripts in the fixed s le than the 3’ kit did in the fresh s le. Low mitochondrial genes detection using the FRP was translated into 99.9 percent of cells passing the QC filters, compared to 81.6 percent of cells using the v3.1 chemistry. We then optimized snPATHO-Seq and applied it to a human breast cancer metastasis to the liver collected at autopsy and preserved in FFPE, a particularly challenging s le type. Remarkably, at 28,000 reads/cell snPATHO-Seq was able to detect a median of 1850 genes/cell and 3,216 UMI counts/cell. Comparison of snPATHO-Seq with spatial transcriptomics data (10x Genomics Visium FFPE v1) derived from an adjacent section of the same s le revealed a strong correlation, validating the accuracy of the snPATHO-Seq data. Gene expression data from snPATHO-Seq was used to predict cell type composition within each spatial transcriptomic location via deconvolution. Overall, snPATHO-Seq enables high quality and sensitivity snRNA-Seq from preserved tissue s les, unlocking the vast archives of FFPE tissues and thereby allowing extensive retrospective clinical genomic studies.
Publisher: Springer Science and Business Media LLC
Date: 17-09-2013
Publisher: Elsevier BV
Date: 09-2008
Publisher: Springer Science and Business Media LLC
Date: 28-01-2016
Publisher: Public Library of Science (PLoS)
Date: 29-06-2016
Publisher: Frontiers Media SA
Date: 15-11-2019
Publisher: American Society for Clinical Investigation
Date: 17-09-2020
Publisher: Frontiers Media SA
Date: 20-09-2022
DOI: 10.3389/FIMMU.2022.892254
Abstract: Human epidermal Langerhans cells (LCs) maintain immune homeostasis in the skin. To examine transcriptional programming of human primary LCs during homeostasis, we performed scRNA-seq analysis of LCs before and after migration from the epidermis, coupled with functional assessment of their regulatory T cell priming capabilities. The analysis revealed that steady-state LCs exist in a continuum of maturation states and upregulate antigen presentation genes along with an immunoregulatory module including the genes IDO1 , LGALS1 , LAMTOR1, IL4I , upon their migration. The migration-induced transition in genomic state is accompanied by the ability of LCs to more efficiently prime regulatory T cell responses in co-culture assays. Computational analyses of the scRNAseq datasets using SCENIC and Partial Information Decomposition in Context identified a set of migration-induced transcription factors including IRF4, KLF6 and RelB as key nodes within a immunoregulatory gene regulatory network. These findings support a model in which efficient priming of immunoregulatory responses by LCs is dependent on coordinated upregulation of a migration-coupled maturation program with a immunoregulation-promoting genomic module.
Publisher: Cold Spring Harbor Laboratory
Date: 10-10-2019
DOI: 10.1101/800631
Abstract: Single-cell transcriptomics has sensitivity limits that restrict low abundance transcript identification, affects clustering and introduce artefact. Here, we describe Constellation DropSeq (C-DropSeq), a molecular transcriptome filter that delivers two orders of magnitude sensitivity gains by maximising read utility while reducing sequencing depth and costs. The simple and powerful method is broadly compatible with library preparation routines and was demonstrated by identifying and characterizing the activation of rare dendritic cell sub-populations.
Publisher: Elsevier BV
Date: 2010
Publisher: Springer Science and Business Media LLC
Date: 27-06-2016
DOI: 10.1038/NG.3588
Publisher: Elsevier BV
Date: 2010
Publisher: Springer Science and Business Media LLC
Date: 12-04-2016
Publisher: Elsevier BV
Date: 11-2018
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Andres Felipe Vallejo.