Research Opportunities

The Rayon’s lab (www.rayonlab.org) overall aim at the Babraham Institute in Cambridge is to investigate the molecular and metabolic pathways that control biological timing and lifespan. To answer these questions, we work with mouse and human stem cells and embryos and employ a variety of quantitative and genomic techniques. We are looking for applicants that are curious about evolution, developmental biology and embryonic stem cells.

We are interested in the following topics:
1.    Understanding the regulation of enhancer timing. We want to test the existence of species-specific enhancers and their dynamics.
2.    Exploiting genetic variation to investigate dynamics of regulatory networks in stem cell models.  
3.    To develop a high-content imaging assay to screen for modulators of timing. Develop a screen to explore if epigenetic, metabolic, and turnover factors impact the pace of differentiation.

A background on cell culture or molecular biology, as well as skills in bioinformatics or computational approaches would be useful, but ample opportunities for training will be provided.

Virus infection of brain stem cells represents a major global health concern, but also offers treatment possibilities in neurodegenerative diseases and in malignant brain tumours. For example, Zika Virus targets SOX2+ neural progenitors in the developing brain to cause microcephaly in babies born to mothers infected during pregnancy; likewise, it targets SOX2+ glioma stem cells in the most common and lethal malignant brain tumour, glioblastoma (GBM) (https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4135719). Stem cells have been shown to exploit a distinct set of antiviral mechanisms compared to somatic cells (https://doi.org/10.1016/j.cell.2017.11.018), and viral permissivity varies widely between example developing brain and glioblastoma stem cell populations. Understanding and manipulating the cell-intrinsic mechanisms underpinning antiviral resistance in brain stem cells will inform approaches to protect and exploit neural stem cell function and to ablate cancer stem cells in GBM.

This project will seek to understand and modify viral permissivity and antiviral defence mechanisms in developing brain and brain tumours, focusing on stem cell intrinsic pathways. In the first place we will  address the hypothesis that immune selection pressure on glioma stem cells during tumour development results in expansion of a mesenchymal/injury-response cell population (https://www.cell.com/cell/pdf/S0092-8674(21)00351-2.pdf) refractory to virus infection, then proceed to examine underlying mechanisms.

You will be working with human patient-derived and mouse defined mutation glioma cell models, treated with viruses and viral mimetic compounds. You will be assaying transcriptional identity and responses using qPCR and RNA sequencing, immunofluorescence and RNA smFISH, and cytokine secretion using immunoassays. The lab has access to the state-of-the-art Cambridge Stem Cell Institute imaging, FACS, sequencing and bioinformatic facilities, and to additional specialist facilities (e.g. imaging mass cytometry) in the CRUK Cancer Institute next door. We will validate results in mice in vivo and/or slice cultures prepared from  human developing brain and patient brain tumour tissue, models we have established and use routinely in the lab.

The bacterial cell envelope comprises the cell wall and either one or two membranes. The cell envelope is of major interest in infection biology because it is the site at which pathogenic bacteria interact with their host organism. In particular, bacterial virulence proteins must be transported across the cell envelope to affect the host.

We aim to understand the molecular mechanisms by which proteins, nucleic acids, and mechanical force are transferred across and along the cell envelope in processes of biomedical importance. The project is to undertake structure-led studies of  the dedicated nanomachines that carry out these processes. The NCI part of the collaboration will involve structural analysis, primarily by cryoEM. The Oxford part of the collaboration will concentrate on complementary mechanistic work using biochemical, genetic, and live cell single molecule imaging methods. Our groups  have collaborated for more than 15 years on projects including the transport of folded proteins across the bacterial inner and outer membranes (Tat protein transport system and Type 9 Secretion System), lipoprotein export, DNA transport during horizontal gene transfer (conjugation and natural competence), and gliding motility.

Our group is interested in uncovering and understanding key mechanisms of disease that affect cardiac muscle function. We have a particular interest in understanding how regulation of cardiac muscle contraction is altered in common acquired and inherited cardiovascular diseases. We do this by using cutting edge techniques in cellular imaging, employing human induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs), and CRISPR/Cas-9 to understand human cardiovascular disease in the dish.
 

We have two key focuses in the lab:

1. Understanding how inherited heart conditions including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) alter cardiomyocyte function. We do this by using CRISPR Cas-9 genome engineering in combination with iPSC-CMs to screen how HCM and DCM causing variants cause disease. We can then use these systems to screen novel therapeutics in the dish. We have designed multiple techniques to make these analyses feasible and rapidly deployable: SarcTrack and CalTrack.
    
2.  Investigate the processes that alter cardiac muscle function in acquired cardiac diseases including myocardial infarction, atrial fibrillation, and heart failure. We are able to use biochemical techniques twinned with fluorescent imaging to assess how cardiac myosin states are altered in disease tissues. This technology allows us to uncover key disease mechanisms that alter heart muscle function, allowing insight into these common heart muscle diseases. 
    

We have multiple key collaborations within the University of Oxford and internationally. Together we focus on pushing the boundaries of understanding in acquired and inherited cardiovascular disorders of the heart muscle. Within the group we have an inclusive and diverse set of researchers who have a wide range of cutting-edge expertise. Within the wider lab environment and our collaboration network we have over 20 researchers in this area.
 

Scientific training opportunities in the lab include but are not limited to:
 

1. Induced pluripotent stem cell culture
2. Techniques for iPSC to cardiomyocyte differentiation
3. CRISPR/Cas-9 genome engineering
4. PCR and genetic sequencing
5. A wide range of standard fluorescent microscopy and confocal microscopy
6. Phenotyping of cardiomyocyte function with fluorescent probes and genetically encoded protein tags
7. RNA sequencing and qPCR
8. Western blotting and phosphoprotein blotting techniques
9. Drug screening using live cell microscopy

Transferrable skills include but are not limited to:
 

1. Learning to interact with MatLab and other computing packages for automating and simplifying data analysis.
2. Using genome viewers and associated software for designing and executing CRISPR/Cas-9 engineering.

References:

1.  Hypertrophic cardiomyopathy mutations in MYBPC3 dysregulate myosin Science Translational Medicine 2019
2. Myosin Sequestration Regulates Sarcomere Function, Cardiomyocyte Energetics, and Metabolism, Informing the Pathogenesis of Hypertrophic Cardiomyopathy Circulation 2020
3. SarcTrack An Adaptable Software Tool for Efficient Large-Scale Analysis of Sarcomere Function in hiPSC-Cardiomyocytes Circulation Research 2019
4. CalTrack: High-Throughput Automated Calcium Transient Analysis in Cardiomyocytes Circulation Research 2021
5. Common genetic variants and modifiable risk factors underpin hypertrophic cardiomyopathy susceptibility and expressivity Nature Genetics 2021

Retroviruses, flaviviruses and coronaviruses are important pathogens capable of causing serious human disease. To replicate and disseminate infection, these viruses hijack host cell machinery, including organelles such as the endoplasmic reticulum, the Golgi apparatus, lipid droplets and the nucleus to generate progeny virions. Sensors within the innate immune system detect virus-induced membrane reorganization, identify virus weak spots, and influence disease progression in this complex virus-host interplay. This project focuses on the innate immune response that specifically targets virus replication and translation complexes (RTCs) anchored at the membrane of cell host organelles. RTCs isolated from these sites will be studied using molecular and cell biology, in combination with bioinformatics, structural biology and high resolution imaging to design novel antiviral interventions.

Emerging evidence suggests an exciting link between metabolism, chromatin and transcription. Metabolism can regulate post-translational modifications of histones which in turn regulate transcription of target genes. Highly proliferative cancer cells re-wire their metabolism to fuel growth, and in turn modify histones to alter gene expression. Identifying mechanisms by which cancer cells re-wire their metabolism and gene expression will identify key vulnerabilities to target using small molecule therapeutics.

Our recent work at NIH has demonstrated links between histone lactylation, gene expression and cancer metabolism (histone lactylation depends on elevated cellular lactate, the end product of glycolysis – a preferred metabolic pathway in cancer). Work in Cambridge has further linked the molecular chaperone HSP90 with gene expression and metabolism in the context of cancer. Harnessing the complementary strengths in the two labs at NIH and Cambridge, the collaborative work will delineate molecular pathways linking small-molecule therapeutics targeting the chaperone HSP90 with cancer metabolism and with specific small-molecule inhibitors of glycolysis. The data we obtain delineating the metabolic dependence of gene expression in cancer will uncover novel and exciting treatment strategies to treat cancers’ metabolic vulnerabilities.

The laboratory investigates the interactions between episodic memory formation and brain dynamics during sleep. How are memories strengthened (‘consolidated’) overnight? What is the role of specific brain rhythms during sleep? Can we use sleep to experimentally control the extent of forgetting? To tackle these questions, a range of techniques including intracranial EEG, scalp EEG, MEG, fMRI, non-invasive brain stimulation (NIBS), and behavioural testing are used.

Since 2018, several studies have reported “germline-somatic interactions” across cancer types. However, such studies demonstrate extensive heterogeneity in defining the germline and somatic features involved or the specific mechanism of interaction (including predicted protein changes, cell lines/CRISPR screens, and immune system-associated phenotypes), and effectively none evaluate results clinically. We hypothesize that pan-cancer or breast-cancer-specific germline-somatic interactions will demonstrate associations with therapy in the metastatic setting. To test this, we will compile reported (a) germline-somatic variant interactions from papers and (b) datasets with individual-level treatment information and test the associations between these interactions and treatment response in metastatic breast cancer.

Multisensory learning helps an individual learn through more than one sense. However, the underlying neural mechanism is unclear. In this study we aim to pursue this question in a spatial learning regime. We will focus on the medial entorhinal cortex (MEC), which plays a critical role in spatial learning and the dysfunction of which is closely related to Alzheimer’s disease. We will record neural dynamics of the MEC using two-photon imaging approach when mice navigate in virtual environments, in which multisensory spatial information will be precisely delivered. The goal of the project is to deeply understand how the neural response of the MEC contributes to multisensory learning.

The formation of infectious HIV-1 particles requires the incorporation of Env glycoproteins during the assembly process, with Env mediating binding of newly released virions to target cells and subsequent entry via fusion between viral and target-cell membranes. The interaction between the MA domain of Gag and gp41 of Env plays a central role in Env incorporation into virions and in the activation of Env fusion activity, yet this interaction remains poorly understood at the biochemical and structural levels. In addition, recent structures of the MA lattice in both immature and mature HIV-1 particles implicate a maturation-induced rearrangement of MA the lattice. This opens the possibility that MA-gp41 interactions are dynamic, and change during the maturation process.

We aim to apply an array of biochemical, structural, super-resolution imaging, and virological approaches that will interrogate the MA/gp41 interaction and will provide novel insights into the mechanism and dynamics of Env incorporation into HIV-1 particles. A set of informative mutants, which display stabilized MA-MA and/or MA-gp41 interactions, will be used for structural studies,. Cryo-ET analysis of intact mature and immature virions will be performed to obtain structural data that will complement the information obtained with the MA/Gag assemblies. Predictions regarding potential sites of MA-MA and MA-gp41 interactions obtained from these structural studies will be tested in Env incorporation and virus replication assays. This combination of structural, biochemical, and virological studies will help to elucidate the mechanism of Env incorporation into HIV-1 particles and the subsequent process of particle maturation.

Human immunodeficiency virus type 1 (HIV-1) is the causative agent behind acquired immunodeficiency syndrome (AIDS) that currently has no cure or vaccine. While antiviral treatments are effective, the rise of drug-resistant strains has become a growing concern. HIV-1 primarily infects the immune system, targeting CD4+ T cells and macrophages and is a lentivirus known to be able to infect non-dividing cells, requiring it to exploit nuclear import mechanisms. This process is dependent on the viral capsid. The HIV capsid is a conical structure that houses the genomic material of the virus. It needs to be metastable in order to be protective while allowing timely disassembly (termed uncoating) to release its genome. The dynamics of the capsid nuclear import and uncoating are still unknown and are modulated by host dependency and restriction factors.

We aim to apply multi-imaging modalities to investigate uncoating and nuclear import of HIV. These will include super-resolution fluorescence microscopy (including the newest MINFLUX technology), Focused Ion Beam and Scanning electron microscopy (cryoFIB/SEM), cryo-electron microscopy and cryo-electron tomography (cryoEM/ET). The viral core and host factors will be fluorescently tagged, and infection will be monitored from viral attachment to nuclear import. The sample will be cryo-preserved and imaged by cryoEM/ET and cryoFIB/SEM. The combination of these imaging techniques, paired with molecular biology and virology tools, will yield unparalleled knowledge of the HIV infection process within the native cells, providing the framework for development of novel therapeutics targeting HIV infection in the future.

We are interested in a variety of topics related to “Deciphering cellular heterogeneity in tumor microenvironment using single cell data”, “Functional characterization of tumor infiltrating T cells”, “Links between embryonic development and cancer”, “Functional characterization of non-coding somatic mutations”, and “Methods for single cell omics”. These projects involve non-trivial  methods development as well as sophisticated data analysis but the focus is always on the biological question. Our lab is involved in several collaborations with immunologists and cancer biologists.

Our group focuses on how human health is affected by the normal microorganisms that live on our skin (collectively termed the microbiome). Our emphasis is on eczema (also called atopic dermatitis or AD), which is an inflammatory disease of the skin associated with reduced quality of life and high risk of developing asthma, allergic rhinitis, and food allergies. Recent work has uncovered that the skin microbiome is significantly different between healthy controls and patients with AD and that early commensal diversity may protect against development of AD. These realizations suggest that the skin microbiome contributes to AD presentation through both harmful and protective pathways. Our group identified a species of bacteria from normal healthy skin, called Roseomonas mucosa, which showed promising features in cell culture and mouse models that suggested the bacteria might be able to treat patients with eczema. We have since transitioned into a clinical trial using Roseomonas mucosa as a topical treatment for eczema. 

The posterior Lateral Line primordium is a group of about a hundred cells that migrates under the skin, from the ear to the tip of the tail, periodically forming and depositing sensory organs called neuromasts, to spearhead formation of the zebrafish Lateral Line sensory system. In recent years, this relatively simple and accessible system has emerged as an attractive model for understanding various aspects of morphogenesis in the developing embryo, including the guidance of cell migration, tissue patterning and organ formation. The goal is to use a combination of cellular, molecular, genetic and biomechanical manipulations coupled with live imaging, image processing and the development of multi-scale computational models to understand the self-organization of cell-fate, morphogenesis and migration of the lateral line primordium. Specific focus will be on developing tools and methods for investigating, imaging, quantifying and modelling the mechanics of collective migration, morphogenesis of epithelial rosettes and the intercellular and intracellular signaling networks that coordinate lateral line primordium development.

I founded a new ultra-high field (7T) MRI physics group in Cambridge in autumn 2017. We develop cutting-edge methods for studying the human brain and body using Cambridge’s state-of-the-art Siemens Terra 7T MRI scanner. My group have active collaborations with clinicians in clinical neurosciences, psychiatry, oncology, and cardiology (Papworth), and with experts in cognitive neuroscience. I welcome PhD students to join the group. The following are areas of strong interest from our community, which would be suitable to develop a PhD project in discussion with me.

(i) Developing new spectroscopic imaging pulse sequences to map neurochemical profiles across the whole brain in a single scan. We have hardware available to apply these methods to study metabolites containing 1H (e.g. NAA, creatine, GABA, GSH) or 31P (e.g. PCr, ATP, in vivo pH mapping) or 13C (e.g. labelled glucose or succinate).
(ii) Developing new methods for neuroimaging, particularly for imaging blood flow in small vessel disease, or for rapid, motion-corrected fMRI in deep brain nuclei.
(iii) Developing new metabolic imaging methods for use in the human body. These would use a new multinuclear (1H and 31P) whole-body coil being built for me by Tesla Dynamic Coils (Netherlands). This could be developed in collaboration with colleagues at Papworth and Radiology for studies in the heart.
(iv) Imaging of metabolism by 2H deuterium metabolic imaging (DMI).