National Institute of Allergy and Infectious Diseases (NIAID)

Generation of reactive oxygen species (ROS) by the phagocyte NADPH oxidase is a critical and highly conserved antimicrobial function of myeloid immune cells such as neutrophils and monocytes. ROS production must be tightly regulated to ensure constant readiness for immune defence, while restraining inappropriate activation. A lack of ROS from this complex results in the devastating inborn error of immunity chronic granulomatous disease (CGD), characterised by recurrent infection but also autoinflammation and autoimmunity. Common hypomorphic variation in the genes encoding components of the phagocyte NADPH oxidase also drives pre-disposition to common autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Excess ROS production can, however, result in   Understanding how ROS is tightly regulated is important for the development of rational therapeutics immune-mediated diseases.

Despite the elucidation of the NADPH oxidase complex structure and function, upstream regulators of ROS production remain largely undiscovered due to a lack of robust biological model systems. The Thomas Lab characterised EROS |(Essential for Reactive Oxygen Species) as an indispensable regulator of ROS generation but we believe that there are many more. Recent developments in CRISPR-Cas9 technology now allows both the introduction of precise edits (homology-directed repair, HDR) and genome-wide forward genetic screening by introducing knockout (CRISPRko) libraries. This may identify therapeutic targets in inflammatory disease. We will use CRISPR-HDR methods to endogenously tag key components of the NADPH oxidase complex with fluorescent proteins to generate reporter lines for iterative selection by flow cytometry. By screening these at genome-wide scale with CRISPRko libraries and sorting cells based on component expression, followed by functional screens using fluorescent ROS probes, we will elucidate upstream regulators of the complex expression and function. The function of these novel regulators can then be investigated and validated using primary and immortalised cells, structural biology, and selective mutagenesis. Interrogation of publicly available genomic datasets will guide ‘hit’ selection and possible therapeutic relevance.

Asthma is a common, complex, and chronic disease that is characterized by inflammation of the airways, airway hyperresponsiveness, and bronchospasms. It has major health disparities, and unfortunately populations that bear the greatest burden of disease are minimally represented in genomics research. The Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA) seeks to discover genes and mechanisms conferring risk to asthma in populations of African ancestry, utilizing multi-omic data. A multi-omics approach in nasal epithelium using RNASeq and DNA methylation in CAAPA led to the confirmation of well-known T2 mechanisms in asthma risk, but also identified novel wound healing and medication response signatures, providing new information about the biological mechanisms underlying asthma in the underrepresented African ancestry populations. We have a greatly expanded opportunity including serum proteomics, RNASeq on PBMCs, and additional DNA methylation to test if an expanded systems biology / integrative omics approach can further refine axes of dysregulation in CAAPA and develop models to predict asthma endotypes that are derived off ‘local’ and ‘systemic’ signatures of asthma pertaining to the nasal epithelium and serum/PBMCs, respectively. 

Asthma is a common, complex, and chronic disease that is characterized by inflammation of the airways, airway hyperresponsiveness, and bronchospasms. It has major health disparities, and unfortunately populations that bear the greatest burden of disease are minimally represented in genomics research. The Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA) seeks to discover genes and mechanisms conferring risk to asthma in populations of African ancestry, utilizing multi-omic data. A multi-omics approach in nasal epithelium using RNASeq and DNA methylation in CAAPA led to the confirmation of well-known T2 mechanisms in asthma risk, but also identified novel wound healing and medication response signatures, providing new information about the biological mechanisms underlying asthma in the underrepresented African ancestry populations. We have a greatly expanded opportunity including serum proteomics, RNASeq on PBMCs, and additional DNA methylation to test if an expanded systems biology / integrative omics approach can further refine axes of dysregulation in CAAPA and develop models to predict asthma endotypes that are derived off ‘local’ and ‘systemic’ signatures of asthma pertaining to the nasal epithelium and serum/PBMCs, respectively. 

Asthma is a common, complex, and chronic disease that is characterized by inflammation of the airways, airway hyperresponsiveness, and bronchospasms. It has major health disparities, and unfortunately populations that bear the greatest burden of disease are minimally represented in genomics research. The Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA) seeks to discover genes and mechanisms conferring risk to asthma in populations of African ancestry, utilizing multi-omic data. A multi-omics approach in nasal epithelium using RNASeq and DNA methylation in CAAPA led to the confirmation of well-known T2 mechanisms in asthma risk, but also identified novel wound healing and medication response signatures, providing new information about the biological mechanisms underlying asthma in the underrepresented African ancestry populations. We have a greatly expanded opportunity including serum proteomics, RNASeq on PBMCs, and additional DNA methylation to test if an expanded systems biology / integrative omics approach can further refine axes of dysregulation in CAAPA and develop models to predict asthma endotypes that are derived off ‘local’ and ‘systemic’ signatures of asthma pertaining to the nasal epithelium and serum/PBMCs, respectively. 

The aberrant modification status of proteins is universally recognized as a crucial component of disease. In order to develop therapeutic agents to combat disease, we need to understand the role that posttranslational modifications (PTMs) play within pathological systems. Focusing on infectious diseases using mutant cell lines, mouse models and patient data, we will study the link between PTM status and subcellular location which has been so far poorly captured in the majority of experimental workflows. The knowledge of the PTM affecting relocalization of the protein and, in turn, its function, will be pivotal to the correct drug design. This project combines development of state of the art quantitative proteomics methodologies, computational workflows and whole cell modelling which will be used to decipher the mechanism of immunity to infection and propose new ways of treatment. 

La Crosse virus (LACV), a member of the Bunyaviridae family, is a mosquito-borne pathogen that is leading cause of paediatric encephalitis in North America. Most cases of LACV infection are asymptomatic. However, the virus can cause severe disease when it infects the central nervous system: approximately 1% of LACV neuroinvasive disease cases are fatal, and it causes neurological sequelae including epilepsy and cognitive abnormalities in a further 6-15% of cases. LACV neuroinvasive disease is most common in children under the age of 16.

LACV is an enveloped virus with a tripartite, negative-sense RNA genome consisting of small (S), medium (M), and large (L) segments. The M segment encodes the glycoproteins Gn and Gc that are present on the surface of virus particles. These glycoproteins recognise receptors on the surface of suitable host cells and catalyse the membrane fusion that allows entry of the viral genome into the host cell, the essential first step of the infection cycle. The cell surface receptor(s) of LACV have not been characterised, limiting our understanding of which cells can be infected and of why children but not adults suffer severe LACV neuroinvasive disease.

We have performed an unbiased protein-based screen to identify human cell surface proteins that bind the surface glycoproteins of LACV. We identified that LACV binds to receptors of the Notch signalling pathway. This result is highly significant because Notch receptors are regulators of neuronal development, helping determine whether neural progenitor cells differentiate into neurons or glial cells. Biochemical and biophysical experiments using purified components have confirmed that LACV binds these receptors with high affinity, and we have a high-confidence structural prediction of the interaction between LACV and these cell surface receptors.

This project will define the molecular interactions between LACV and its cell surface receptors at atomic resolution, using a combination of structural biology, biochemical and biophysical techniques. We will exploit this information to generate structurally informed mutations that disrupt these interactions, allowing us to test the functional consequences of Notch receptor binding for LACV infection and neuropathogenesis. Students undertaking this project will gain experience of biochemistry, biophysics, structural biology and molecular virology, with the opportunity to perform virus infection experiments in a high-containment environment. They will also advance our knowledge of an important paediatric disease, potentially identifying new strategies to prevent LACV infection or minimise the subsequent neurological sequelae.

The Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that control diverse signalling pathways affecting gene-transcription, cellular adhesion and trafficking, autophagy and metabolism via the generation of PIP3. While some of these readouts are controlled by the evolutionarily conserved PI3K-AKT-FOXO, PI3K-AKT-mTOR axes, there is a diverse network of PI3K effectors that are less well studied, especially in lymphocytes, but which nonetheless can have profound effects on lymphocyte biology. We have recently used CRISPR/Cas9 to perform a targeted screen of PI3K effectors by generating a library that specifically targets PIP3-binding proteins. Screening for genes that affect T cell adhesion, we identified RASA3 as a key protein linking PI3K to the activation of the integrin LFA-1 and found that RASA3 is critical for T cell migration, homeostasis and responses to immunization (Johansen et al Sci Signaling 2022; Trend Immunol 2023; Front Immunol. 2021). We have now generated extended CRISPR/Cas9 libraries that target the entire PI3K-ome (including the kinases, phosphatases and all known effector proteins). Potential projects include designing and implementing new screens for downstream readouts of PI function, including autophagy, endocytosis, regulation of humoral immunity in vivo or other readouts, and/or understanding how RASA3 and Kindlin3 regulate T cell function and the signaling pathways. Interestingly, while RASA3 and Kindlin3 are both regulated by PIP3, they have opposite effects on LFA1 activity.  We will use advanced imaging technologies to determine the differential effects of PI3K signalling on these two proteins.

Innate immune responses are the first line of defense against viral infection, but their inappropriate activation can cause autoinflammatory disease. The Best and Modis groups study how the host senses viruses, mounts sufficiently sensitive yet specific responses, and how this balance can be perturbed for example by disease mutations. Our work focuses largely on the roles of two key families of viral restriction factors, the TRIMs and RIG-I-like receptors (RLRs). We integrate an exceptionally broad spectrum of approaches, from in vivo work in high and maximum contain laboratories to state-of-the-art electron microscopy. This uniquely positions us to obtain a more complete understanding of virus-host interactions under physiological conditions with mechanistic insights in atomic-level detail.  

This PhD project will focus on unravelling important insights into how RNA viruses are detected and targeted by their hosts. The aims of this project will apply our full complement of approaches, including electron microscopy, biochemical and cell-based assays, and in vivo work as needed to obtain a detailed mechanistic understanding of the contributions of virus-host interactions to antiviral innate immunity and virus pathogenesis. Our long-term goal is to use contribute to the design of novel therapeutics, such as antivirals, vaccine adjuvants, or immunomodulatory therapeutics, with potential applications in the treatment of infection, autoinflammatory disorders and cancer.

Our teams at the NIAID Rocky Mountain Laboratories and University of Cambridge are strongly committed to fostering a supportive and inclusive work environment in which trainees can thrive and experience the thrill of scientific discovery.

References:
Chiramel AI, Meyerson NR, McNally KL, Broeckel RM, Montoya VR, Méndez-Solís O, Robertson SJ, Sturdevant GL, Lubick KJ, Nair V, Youseff BH, Ireland RM, Bosio CM, Kim K, Luban J, Hirsch VM, Taylor RT, Bouamr F, Sawyer SL, Best SM (2019) TRIM5α Restricts Flavivirus Replication by Targeting the Viral Protease for Proteasomal Degradation. Cell Rep 27:3269  PMC8666140

Yu Q, Herrero del Valle A, Singh R, Modis Y (2021) MDA5 autoimmune disease variant M854K prevents ATP-dependent structural discrimination of viral and cellular RNA. Nat Commun 12:6668  PMCID: PMC8602431

Stoll GA, Pandiloski N, Douse CH, Modis Y (2022) Structure and functional mapping of the KRAB-KAP1 repressor complex. EMBO J 41:e111179  PMC9753469

Shannon JG, Sturdevant GL, Rosenke R, Anzick SL, Forte E, Preuss C, Baker CN, Harder JM, Brunton C, Munger S, Bruno DP, Lack JB, Leung JM, Shamsaddini A, Gardina P, Sturdevant DE, Sun J, Martens C, Holland SM, Rosenthal NA, Best SM (2023) Genetically diverse mouse models of SARS-CoV-2 infection reproduce clinical variation in type I interferon and cytokine responses in COVID-19. Nat Commun 14:4481  PMC10368652

Monoclonal antibodies have emerged in recent years as powerful tools to guide vaccine design and potentially to directly prevent infectious disease. Plasmodium falciparum, which causes malaria, is a relatively unexplored pathogen in this area, with only a few major vaccine candidates dominating the field despite the thousands of proteins expressed by the parasite. This project aims to isolate, characterize and determine the structures of human monoclonal antibodies against known and novel P. falciparum blood-stage antigens using cutting-edge technology. This collaborative project combines the expertise of the Tan lab in isolating human monoclonal antibodies against infectious pathogens and the expertise of the Higgins lab in solving crystal structures of antibody-antigen complexes to identify new sites of vulnerability on parasites at high resolution.

Potential subprojects include: Extending methods for pangenome annotation and analysis to eukaryotic pathogens (e.g. https://www.biorxiv.org/content/10.1101/2023.01.24.524926v1).

Developing adaptive sampling and hybrid enrichment techniques for pathogen/bacteria/host sequencing (see https://www.nature.com/articles/s41587-022-01580-z.)  

Linking strain/variant transmission with pathogen
genetic determinants and host epidemiology. (see: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8552050/ and https://www.science.org/doi/full/10.1126/scitranslmed.abg4262)

Globally, HIV and schistosomiasis are leading causes of death due to infectious diseases. Despite available interventions, the infections remain uncontrolled in low-income settings causing acute and chronic morbidities. Intestinal schistosomiasis is caused by a parasitic blood fluke, most commonly of the species Schistosoma mansoni, and is predominantly found in sub-Saharan Africa. Chronic infections lead to advanced disease including liver fibrosis, portal hypertension, upper gastrointestinal tract bleeding, and severe anaemia. In the context of coinfections, severe clinical outcomes including death may be likely due to immune failure, interactions related to general fibrosis, and responses to starting antiretroviral therapy. In this project, you will have the opportunity to work with cutting-edge statistical and big data approaches alongside state-of-the art immunology to examine disease progression in the context of schistosome and HIV coinfections in arguably some of the poorest settings worldwide.

The group of Associate Prof. Chami studies schistosomiasis evaluating transmission, clinical outcomes, and treatment strategies, especially for liver fibrosis, in the SchistoTrack Cohort with the Uganda Ministry of Health. This Cohort is the largest individual-based cohort tracking individuals prospectively in the context of schistosomiasis. At Oxford, students can get exposure to computational, big data approaches to clinical epidemiology and field experience in global health research.

The group of Dr. Sereti studies HIV immune pathogenesis with a focus on inflammatory complications related to HIV and coinfections. Studies on biomarkers and how they may assist in identifying early people with HIV who may develop inflammatory and other adverse complications is currently an active area of investigation in the lab as they can also inform disease pathogenesis and new targeted interventions.

At the NIH, students can get experience in immunology research (wet lab) with optional exposure to complicated cases within a clinical setting.

Globally, HIV and schistosomiasis are leading causes of death due to infectious diseases. Despite available interventions, the infections remain uncontrolled in low-income settings causing acute and chronic morbidities. Intestinal schistosomiasis is caused by a parasitic blood fluke, most commonly of the species Schistosoma mansoni, and is predominantly found in sub-Saharan Africa. Chronic infections lead to advanced disease including liver fibrosis, portal hypertension, upper gastrointestinal tract bleeding, and severe anaemia. In the context of coinfections, severe clinical outcomes including death may be likely due to immune failure, interactions related to general fibrosis, and responses to starting antiretroviral therapy. In this project, you will have the opportunity to work with cutting-edge statistical and big data approaches alongside state-of-the art immunology to examine disease progression in the context of schistosome and HIV coinfections in arguably some of the poorest settings worldwide.

The group of Associate Prof. Chami studies schistosomiasis evaluating transmission, clinical outcomes, and treatment strategies, especially for liver fibrosis, in the SchistoTrack Cohort with the Uganda Ministry of Health. This Cohort is the largest individual-based cohort tracking individuals prospectively in the context of schistosomiasis. At Oxford, students can get exposure to computational, big data approaches to clinical epidemiology and field experience in global health research.

The group of Dr. Sereti studies HIV immune pathogenesis with a focus on inflammatory complications related to HIV and coinfections. Studies on biomarkers and how they may assist in identifying early people with HIV who may develop inflammatory and other adverse complications is currently an active area of investigation in the lab as they can also inform disease pathogenesis and new targeted interventions.

At the NIH, students can get experience in immunology research (wet lab) with optional exposure to complicated cases within a clinical setting.

There is a pressing need to improve the understanding of morbidity for schistosomiasis. These parasitic blood flukes afflict over 250 million people worldwide with over 700 million people at risk. For Schistosoma mansoni (a species that causes the intestinal form of schistosomiasis), untreated individuals can develop severe or functional morbidities such as enlarged livers/spleens, periportal fibrosis, oesophageal varices, anaemia, and chronic gut inflammation. The onset and progression of these morbidities is a complex interplay of host genetics and immune response, environmental factors, coinfections, and social determinants. This project is an exciting opportunity to combine work in immunology with epidemiology, providing opportunities to apply computational approaches, experimentally test mechanistic hypotheses found in humans in mice, and gain fieldwork experience in global health research. The candidate will gain skills in both wet lab work and fieldwork in Uganda. You will join multidisciplinary labs at the NIH-NIAID and Oxford.

Multipotent self-renewing hematopoietic stem cells (HSCs) support life-long blood system homeostasis and play essential roles in human disease and its therapy. HSC transplantation is an important cell therapy for a range of hematological diseases including immunodeficiencies, beta-globinopathies, and blood cancers. Through their ability for self-renewal and multipotency, HSCs can reconstitute the hematopoietic system following transplantation. Most HSC transplants are performed using allogeneic HSCs but there is also a growing interest in the development and use of autologous HSC transplantation gene therapies for a range of non-malignant blood diseases. A major unresolved question in the field is what regulates the fitness of an HSC. High fitness HSCs display durable and balanced blood system reconstitution activities. By contrast, low fitness HSCs have weak or biased activities. The accumulation of low fitness HSCs is thought to contribute to various disease pathologies and their use in HSC transplantation can result in engraftment failure. Building on research interests in the Muljo lab at the NIH and the Wilkinson lab at the University of Oxford, this project will focus on characterizing transcriptional and post-transcriptional mechanisms regulating HSC fitness. Biological mechanisms identified here will be used to devise new strategies to enhance life-long hematopoietic system health and to improve the safety and efficacy of HSC transplantation therapies.
 

Recent publications:

Wang, S., Chim, B., Su, Y., Khil, P., Wong, M., Wang, X., Foroushani, A., Smith, P. T., Liu, X., Li, R., Ganesan, S., Kanellopoulou, C., Hafner, M. and S. A. Muljo. Enhancement of LIN28B-induced hematopoietic reprogramming by IGF2BP3. Genes & Development, 33: 1048–1068. DOI: 10.1101/gad.325100.119.

Wilkinson, A.C., Ishida, R., Kikuchi, M., Sudo, K., Morita, M., Crisostomo, R.V., Yamamoto, R., Loh, K.M., Nakamura, Y., Watanabe, M., Nakauchi, H. and S. Yamazaki. (2019). Long-term ex vivo haematopoietic-stem-cell expansion allows nonconditioned transplantation. Nature, 571: 117–121. DOI: 10.1038/s41586-019-1244-x.

Haney, M.S., Shankar, A., Hsu, I., Miyauchi, M., Palovics, R., Khoo, H.M., Igarashi, K.J., Bhadury, J., Munson, C., Mack, P.K., Tan, T., Wyss-Coray, T., Nakauchi, H., Wilkinson, A.C. Large-scale in vivo CRISPR screens identify SAGA complex members as a key regulators of HSC lineage commitment and aging. bioRxiv 2022. DOI: 10.1101/2022.07.22.501030

Immunity and immune-tolerance at mucosal and other barrier surfaces is vital for host survival and homeostasis with antibodies or immunoglobulins (Ig) playing a key role. However, the specific roles of B cell sub-types, particularly, the innate-like B-1 cell subset is poorly understood. The surgeon James Rutherford Morrison (1906) called the omentum in the peritoneal cavity the "abdominal policeman" and it promotes gut IgA production by peritoneal B-1 cells. IgA is the most abundantly produced antibody isotype and is known to be important for mucosal immunity. It is estimated that ~50% of IgA is derived from B-1 cells. In addition, B-1 cells are thought to be important because they make T cell-independent “natural” IgM circulating in our blood, and they can rapidly respond to mucosal perturbations such as an infection. By contrast, it will take conventional B-2 cells weeks to mount a germinal center (GC) reaction and generate antibodies that have undergone T cell-dependent affinity maturation and isotype switching. Textbooks currently do not entertain the possibility that B-1 cells can also participate in GC reactions. This project aims to challenge such an assumption. After all, B-1 cells in the gut mucosa and probably other mucosal tissues can undergo class switch recombination to IgA. However, the differentiation program that leads to this distinct pathway of IgA production is not well understood: for example, it is unknown if this process occurs outside or within GCs in mucosa-associated lymphoid tissues (MALT). Expertise on B-1 cells in the Muljo lab and the GC reaction in the Turner lab will be combined to explore this potentially paradigm-shifting research. Both wet-bench and bioinformatic research opportunities are available.

Students will learn about the fundamentals of transcriptional; epigenetic and post-transcriptional regulation; immunometabolism; in vivo CRISPR screening; CRISPR editing in primary B cells; and systems immunology. The combination of classical immunological techniques and cutting-edge, multi-disciplinary approaches will enable important discoveries to define the in vivo biology of B-1 cells. Ultimately, we seek novel insights that can be translated to inform vaccine design targeted to activate B-1 cells and/or therapeutics to inhibit their activity when necessary.
 

Recent publications:

Turner, D. J., Saveliev, A., Salerno, F., Matheson, L. S., Screen, M., Lawson, H., Wotherspoon, D., Kranc, K. R., and Turner, M. (2022). A functional screen of RNA binding proteins identifies genes that promote or limit the accumulation of CD138+ plasma cells. eLife, 11, e72313. PMID: 35451955; DOI: 10.7554/eLife.72313.

Osma-Garcia, I.C., Capitan-Sobrino, D., Mouysset, M., Bell, S.E., Lebeurrier, M., Turner, M. and Diaz-Muñoz, M.D. (2021). The RNA-binding protein HuR is required for maintenance of the germinal centre response. Nature Communications, 12(1):6556. PMID: 34772950; DOI: 10.1038/s41467-021-26908-2.

Wang, S., Chim, B., Su, Y., Khil, P., Wong, M., Wang, X., Foroushani, A., Smith, P. T., Liu, X., Li, R., Ganesan, S., Kanellopoulou, C., Hafner, M. and S. A. Muljo. (2109). Enhancement of LIN28B-induced hematopoietic reprogramming by IGF2BP3. Genes & Development, 33: 1048-1068. PMID: 31221665; DOI: 10.1101/gad.325100.119.

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.

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. 

We have the largest world-wide collection of patients suffering from rare-inherited immunodeficiency that have been whole-genome sequenced (1500+ cases). Using established analytical expertise the candidate will use novel methods to interrogate and filter potential genetic mutations, we will identify novel candidate genetic loci in patients grouped by disease phenotype or familial relationship. Candidate genetic loci will be investigated using CRISPR-editing of patient derived material (lymphoblastoid, fibroblast and iPS cell lines). Confirmatory studies at mRNA, protein and functional level will be carried out to validate the link between variant and disease.

The inflammasome consists of a cytosolic NOD-like receptor, an adaptor molecule (ASC) and an effector molecules caspase 1.  Once activated the inflammasome processes inflammatory cytokines such as interleukin 1 beta (IL1B) and IL18 as well as driving an aggressive form of cell death (pyroptosis).  Inflammasomme protein complexes are central to sustaining inflammation in acute diseases (like COVID-19 associated ARDS) or chronic conditions (such as Alzheimer’s Disease, Parkinson’s, diabetes, arthritis).  Patients with rare autoactivating mutations in the NLR proteins have basally active inflammasomes leading to severe autoinflammatory syndromes. How inflammasome complexes form within the cell, particularly in patients with autoactivating mutations in NLRs are poorly understood.  

The aims of this project are as follows:
1.      Identify the molecular mechanisms by which the gain of function mutations causes constitutive activation of the NLRs
2.      Determine why gain of function mutations in different NLRs (NLRP3 and NLRC4) result in differences in inflammasome cytokine production with NLRP3 biased towards IL1B and NLRC4 towards IL18
3.      Visualise how gain of function mutations alter inflammasome formation by visualising the protein complexes at super resolution and atomic resolution

This project will study how the inflammasome forms using state of the art microscopy techniques including live super resolution imaging and cyroelectron microscopy tomography.  The consequences of the gain of function mutations on inflammasome formation will be studied using these techniques in cell lines where the key proteins are tagged and the gain of function mutations introduced by CRISPR/Cas9 (many of which are already available within the laboratory).  This work will be extended to consider cells from patients with these diseases to map back the biology and the imaging onto the cell line models.   

This collaborative project between Dr. Steven Holland’s laboratory at the NIH and Dr. Lalita Ramakrishnan’s lab at the University of Cambridge will seek to understand the mechanistic basis of human susceptibility to environmental mycobacteria that are nonpathogenic to most people but can cause serious disease in individuals with specific immune deficiencies. Dr. Holland runs an international referral service that takes care of a unique cohort of patients with genetic susceptibility to nontuberculous mycobacterial infections. In the lab, they are mapping these susceptibilities and have found then to map to distinct immune genes, e.g., IRF8 and GATA-2, myeloid growth factors, IL-12R, the GTPase Rac2, to name only a few. 

Dr. Ramakrishnan’s group has pioneered the optically transparent and genetically tractable zebrafish as a model for mycobacterial pathogenesis. The use of the zebrafish has enabled discoveries about TB immunopathogenesis and the genetic basis of susceptibility to TB which has led to the discovery of a variety of inexpensive, approved drugs that can be used to treat TB, often in a patient genotype-directed manner. They have also used the zebrafish to understand the mechanism of leprosy neuropathy.

Through this joint project, the two labs will work together to harness the power of the zebrafish to understand the molecular and cellular basis of the human susceptibilities identified by Holland. The student will move between humans and fish (and Bethesda and Cambridge) to uncover fundamental mechanisms of mycobacterial disease pathogenesis while acquiring mastery over the disciplines immunology, infectious diseases, genetics, molecular biology and cell biology.

Apicomplexan pathogens are highly-adapted intracellular parasites of humans causing disease including malaria, toxoplasmosis and cryptosporidiosis. These parasites actively confront, subvert and defend themselves against host immune attack using a complex suite of parasite surface and secreted proteins that hijack immune signalling pathways. Moreover, transmission and generation of genetic novelty occurs in definitive hosts where differentiation into sexual parasite forms occurs. Relatively little is known, however, of the molecules and processes that drive these events, particularly during the sexual stages of parasite development. This project will use new methods in in vitro culture of sexual development in Toxoplasma, advanced methods for global spatial characterisation of parasite cell proteomes in order to identify specific proteins thought to be implicated in these interactions, and then utilise CRISPR/cas9 mutagenesis tools to engineer pools of strains deficient in these specific proteins. By assaying mutant pools both in vitro, and through the definitive host we will identify proteins and processes required for sexual stage conversion.

*This project is available for the 2021 Oxford-NIH Pilot Programme*

Some of the most globally impactful diseases are caused by emerging and re-emerging viral pathogens. We have a long-standing collaboration with Vincent Munster at the NIH, investigating disease pathogenesis and developing vaccines against a number of outbreak pathogens.
 
This project represents an opportunity to join this world-class team to advance these works, investigating the mechanisms of disease, deriving correlates of protection, testing new therapeutic interventions and deriving structural determinants of disease through collaboration with Prof. Thomas Bowden.

Influenza A virus imposes a significant socio-economic burden on humanity.  Vaccination is effective in only 60% of individuals, even under optimal circumstances.  The difficulty stems from the remarkable ability of influenza A virus to evade existing immunity.  IAV’s error prone polymerase enables the rapid antigenic evolution of the two virion surface glycoproteins, neuraminidase (NA) and hemagglutinin (HA).  Since the most potent antibodies (Abs) at neutralizing viral infectivity are directed the HA and NA globular domains, amino acid substitutions in these regions enable IAV to evade Ab-based immunity.  The project focuses on understanding the “immunodominance” of Ab responses to HA and NA in humans.  Immunodominance describes the strong tendency of the immune response to respond to complex antigens in a hierarchical manner, with higher ranking, “immunodominant” antigens potentially suppressing (“immunodominating”) responses to “subdominant” antigens.  By focusing responses on single antigenic sites, it is likely responsible for enabling influenza A virus to evade immunity by allowing the virus to sequentially alter its antigenicity.

Leishmaniasis is an important disease caused by protozoan parasites that are transmitted by infected sand fly bites in tropical and subtropical regions.  Depending on the strain of Leishmania, disease forms in humans range from localized, self-limiting cutaneous lesions to visceralizing infections that are fatal in the absence of treatment.   The specific contribution of parasite genotype to disease outcome remains largely unknown. Taking advantage of a recently revealed sexual cycle that occurs during Leishmania development in the insect vector, our goal is to generate a series of hybrids between cutaneous and visceral strains that will be phenotyped in mouse models of cutaneous and visceral leishmaniasis.  Each hybrid will be subjected to whole genome DNA and RNA-sequencing to follow parental allele, structural variation, including chromosome somy, gene expression, and epigenetic differences that associate with disease outcome.  Experimental approaches will involve genetic manipulation of the parasite, DNA and RNAseq analysis, single cell genomics, and the application of various computational/bioinformatics methods developed to facilitate QTL and GWAS studies that identify linkage between genes and phenotypes. 

In this project you will use state-of-the-art viral sequencing data, combined with epidemiological data and mathematical modeling, to create an integrated understanding of HIV transmission. HIV places an enormous burden on global health. Implementing treatment and interventions can save millions of lives, but to do this effectively requires us to be able to predict the outcome of interventions, and to be able to accurately assess how well they are working once implemented. For HIV, these efforts are hampered by long durations of infections, and rapid within-host viral evolution during infection, meaning the virus an individual is infected with is unlikely to be the same as any viruses they go on to transmit.
 
For this project, you will identify individuals enrolled in the Rakai Community Cohort Project, based in Uganda, who are part of possible transmission chains, and for whom multiple blood samples are available throughout infection and at the time of transmission. These samples will be sequenced using state-of-the-art technology developed at the University of Oxford enabling the sequencing of thousands of whole virus genomes per sample, without the need to break the viral genomes into short fragments (whole-haplotype deep sequencing). Using this data, you will comprehensively characterize viral diversity during infection and at the point of transmission.

Key questions you will tackle are:
 
- Do ‘founder-like’ viruses (similar to those that initiated infection) persist during chronic infection?
- Is there a consistent pattern of evolution towards population consensus virus?
- Are ‘founder-like’ viruses, or ‘consensus-like’ viruses more likely to be transmitted?
- Does the transmission of drug-resistant virus depend on the history of the transmitting partner?

*This project is available for the 2021 Oxford-NIH Pilot Programme*

Understanding HIV incidence at a population level is critical for monitoring the epidemic and understanding the impact of interventions. Using full length sequencing of HIV we are developing models for estimating incidence based on viral diversity which increases with time in the infected host. Using data from longitudinal cohorts we will develop these models and then apply them to large population based interventions to determine their impact.  Experimental approaches include next-generation sequencing, phylogenetic analysis, modelling and statistical methodologies.

The impact of proteins and their modification on disease states is now being recognized as crucial, but there are knowledge gaps that have to be filled to develop therapeutic agents to combat disease. Focusing on infectious diseases using mutant cell lines, mouse models and patient data we will study the link between PTM status and subcellular location which has been so far poorly captured in the majority of experimental workflows. The knowledge of the PTM affecting relocalization of the protein and, in turn, its function, may be pivotal to the correct drug design. This project combines development of state of the art quantitative proteomics methodologies, computational workflows and whole cell modelling which will be used to decipher the mechanism of immunity to infection and propose new ways of treatment.

The metabolic repertoire of immune cells – which encompasses metabolic enzymes/pathways, the available nutrient sensors and metabolic checkpoint kinases, and the epigenetic programming of metabolic genes – directly enables and modulates specific immune functions. Capitalizing on a large cohort of patients suffering from rare genetic immunodeficiency that have been whole-genome sequenced, our goal is to delineate the genetic and molecular basis of how cellular metabolism regulates immune-function in human health and disease states. Experimental approaches will involve genomics, molecular biology, cell biology, immunology, and biochemistry with an aim to elucidating mechanisms that lead to new treatment approaches to inborn diseases of immunity.

Malaria remains an important global health problem; with increasing drug resistance and the lack of an effective vaccine, new therapies are needed and should be based on a rigorous understanding of parasite biology. Our NIAID lab has used a multidisciplinary approach to discover and characterize the three known ion channels in bloodstream malaria parasites. Through academic and pharmaceutical collaborations, we have also found potent inhibitors that are being pursued as new antimalarial drugs. Research projects will be tailored to the interests of the trainee and expertise available in possible collaborator labs. These projects may utilize molecular biology including CRISPR and heterologous expression, structural biology including cryoEM, biochemical methods including electrophysiology, epigenetics, and high-throughput screening for drug discovery.  These and other methods are actively used in the lab. Dr. Desai has collaborators at Oxford, Cambridge, and Wellcome Sanger, depending on project.

Hematopoiesis is a finely tuned process by which mature blood cells of multiple lineages are constantly generated throughout life from hematopoietic stem cells. In humans, definitive hematopoiesis commences in the fetal liver (FL) at around five weeks of gestation, and remains the main site of hematopoiesis throughout fetal life. Hematopoiesis in the bone marrow (BM) starts around 11-12 weeks of gestation, but does not take over as the primary site of hematopoiesis until just after birth. Recent evidence suggests that fetal hematopoiesis is distinct from postnatal hematopoiesis in many ways. Most of these studies have been done on mouse models, but whether these differences exist in, or are a true reflection of hematopoiesis in the human setting, remains to be determined. We, and others have begun to investigate unique features of human fetal hematopoiesis and this project will determine fetal specific programmes that change through ontogeny. This may depend on the physiological processes or demands of that particular developmental stage, and/or in response to specific microenvironmental cues. This research is clinically relevant since the transplantation of hematopoietic stem cells from donors of different ages vary in their regenerative and differentiation potential. Studying hematopoiesis throughout the human lifespan may be important not only to understand normal developmental processes, but also to understand the pathogenesis of postnatal haematological diseases that may have their origins in fetal life. Research by the Roy laboratory particularly focuses on properties of fetal cells that contribute to leukemia initiation in utero and how these might change after birth, and we have recently developed a unique infant acute lymphocytic leukemia (ALL) model. We are particularly interested in ‘oncofetal’ genes that might define the biology of infant and childhood leukemias; and whether they can be manipulated for therapeutic interventions.

*This project is available for the 2021 Oxford-NIH Pilot Programme*

Monoclonal antibodies have emerged in recent years as powerful tools to guide vaccine design and potentially to directly prevent infectious disease. Plasmodium falciparum, which causes malaria, is a relatively unexplored pathogen in this area, with only a few major vaccine candidates dominating the field despite the thousands of proteins expressed by the parasite. This project aims to isolate, characterize and determine the structures of human monoclonal antibodies against known and novel P. falciparum blood-stage antigens using cutting-edge technology. This collaborative project combines the expertise of the Tan lab in isolating human monoclonal antibodies against infectious pathogens and the expertise of the Higgins lab in solving crystal structures of antibody-antigen complexes to identify new sites of vulnerability on parasites at high resolution.

*This project is available for the 2021 Oxford-NIH Pilot Programme*

A previous infection with one of the four dengue viruses increases future risk of severe dengue disease, including hemorrhagic fever, upon infection with a different dengue virus. For this reason, dengue viruses 1-4 are challenging vaccine targets because sub-protective vaccines can increase risk the disease vaccines are designed to prevent. In the Viral Epidemiology and Immunity Unit (Chief, Dr. Katzelnick), we aim to identify correlates of natural and vaccine protection and antibody-dependent enhancement in order to develop better next generation vaccines, extend the longevity of vaccine-induced immunity, and characterize how vaccines may affect viral evolution and transmission.  Our work combines immunology, virology, and epidemiology, including close collaborations with research teams leading longitudinal cohort and vaccine studies in Nicaragua, Sri Lanka, Thailand, Ecuador, the Philippines, and other sites. Specific projects include studying quaternary ‘super-antibodies', which bind epitopes across viral envelope proteins, and testing whether these antibodies provide enduring protection against dengue and other viral diseases. We will also study antigenic evolution away from existing immunity for flaviviruses and coronaviruses. Dr. Katzelnick was part of the NIH OxCam program (2012-2016) and is open to collaborating with research groups at both Oxford and Cambridge to mentor Ph.D. students.