Molecular body map of human skin: the key for understanding human skin diseases

Grantee: Maria Kasper, Principal Investigator, Karolinska Institutet, Stockholm

Amount: DKK 3,949,807

Grant category: Research Grants in open competition

Year: 2019

Geography: Sweden

Skin is the largest human organ and contains an intricate variety of cell types that assure tissue architecture and proper skin function, such as thermoregulation and hair growth.

An imbalance of cell types and/or molecular signalling often results in disease. Across the body, skin composition differs in thickness, hair growth, sebaceous and sweat gland density, microbiota exposure and disease susceptibility.

However, a molecular understanding of how cell types and genetic programs vary with skin regions, and molecular alterations in disease, is currently lacking.

Previously, my lab pioneered the use of single-cell RNA-seq (scRNA-seq) in mouse skin by generating a comprehensive molecular and spatial atlas of epithelial and mesenchymal cells during hair growth and rest (Joost et al. 2016; Joost et al. 2019). Building upon our expertise, we will molecularly dissect human skin, initially through a body map that spans various body sites of healthy donors, to identify cell types and sub types in human skin and also to investigate important cell type differences and alterations compared to mouse skin. Subsequently, the body map will be the foundation for molecular analyses of skin diseases, including immune-triggered psoriasis.

A carefully constructed and annotated human skin atlas, with spatial and molecular precision, would have enormous value for the scientific community and propel our molecular understanding of skin in health and disease.

Mechanisms involved in decreased cutaneous immunity during ageing: reversal by Vitamin D pre-treatment

Grantee: Arne Akbar, Professor of Immunology, University College London

Amount: DKK 4,478,517

Grant category: Research Grants in open competition

Year: 2019

Geography: United Kingdom

There is a sterile inflammatory response to needle challenge driven by recruitment of inflammatory monocytes to the skin in old humans. This inflammatory response negatively correlates with cutaneous immunity after injection of varicella zoster virus antigens into the skin. Inhibition of the inflammation associated with the injury response, with a p38-MAPkinase inhibitor, reduced inflammatory monocyte recruitment and significantly enhanced antigen-specific immunity.

The aim of this project is to understand how inflammation and inflammatory monocytes inhibit antigen-specific T cells in the skin of old human volunteers.

The following experimental questions will be addressed: 1) Which cells are responsible for the inflammatory response to needle injury and how does the interaction between the infiltrating monocytes and other inflammatory populations amplify the response? 2) How are the inflammatory monocytes recruited to the site of challenge in the skin? 3) How do the recruited monocytes inhibit antigen-specific immunity in vivo in the old? 4) Using biobanked skin biopsy samples before and after the same older subjects have been treated with Vitamin D, we will determine gene expression signatures of how this treatment enhances cutaneous antigen-specific immunity.

These investigations will identify ways to enhance the immunity of older humans to vaccination and also infection and malignancy.

A multi-pronged approach to decipher the role of melanosomal transporters in human pigmentation

Grantee: David M Sabatini, Professor of Biology, Whitehead Institute of Biomedical Research

Amount: DKK 2,666,588

Grant category: Research Grants in open competition

Year: 2019

Geography: USA

Dozens of genes are known to be involved in human pigmentation. Many of these genes encode proteins with well-understood functions, such as in melanocyte development, melanin biosynthesis, and the biogenesis and trafficking of specialized melanin-containing organelles called melanosomes.

Yet, we do not know the molecular function of a class of pigmentation genes encoding putative transport proteins that localize to the melanosome. Identifying their substrates would represent a significant advance in our understanding of how melanin synthesis is regulated and how variants in these genes result in differences in human pigmentation.

Based on a method we developed to rapidly and specifically isolate melanosomes, termed MelanoIP, we can capture melanosomes in minute time-scales such that their labile metabolic contents are preserved for quantitative analysis.

Using this technology, we have performed a comparative study of melanosomal metabolites from cells with several pigment genes disrupted, including the putative melanosomal transporter encoding genes Slc45a2, Oca2, and Mfsd12, which has revealed potential substrates. In this proposal, we will define the substrates of these transporters using MelanoIP, metabolite profiling, and organellar uptake screens.

We will also perform follow-up biochemical analysis of each transporter and its naturally occurring genetic variants. Our unique combination of rigorous approaches will inform our understanding of how melanosomal transporters regulate melanin synthesis, and uncover the molecular basis of how mutations in these melanosomaltransport genes lead to human pigment variation.

Knowledge gained from this study will inform the development of interventions for modulating pigmentation and treating pigmentation pathologies.

Establishing the keratinocyte stem cell basis for skin field cancerisation and squamous cell carcinoma

Grantee: Girish Patel, Honorary Senior Lecturer, Cardiff University

Amount: DKK 3,935,737

Grant category: Research Grants in open competition

Year: 2019

Geography: United Kingdom

Epithelial tissues, the environmental barriers of our bodies, are constantly exposed to cancer causing agents. As such carcinoma, the cancer of epithelial tissues, are the most common form of cancer accounting for 85% of all cancers and 78% of all cancer associated deaths.

Many carcinomas arise from a pre-cancerous transformation, known as intraepithelial neoplasia or field cancerisation (FC), within which multiple carcinoma can develop.

By studying skin FC in a mouse model of human papillomavirus 8 infection (K14-HPV8-CER), we have uncovered specific expansion of only the Lrig1 hair follicle junctional zone keratinocyte stem cells (HFJZKSC) driven by ΔNp63 expression, which is the basis for skin FC 1-3.

These findings raised two important fundamental questions:

  1. How does HPV8 induce Lrig1 KSC expansion? The background for this proposal and ongoing work (Leo Foundation grant 2017, LF17070).
  2. Are Lrig1 derived cells responsible for squamous cell carcinoma (SCC)? The basis for this Leo grant proposal.

The current Leo Foundation grant allowed us to identify E6 as the HPV8 protein responsible for Lrig1 KSC expansion through activation of the STAT3 intracellular signalling pathway.

Therefore, we are now positioned for a follow-on grant to determine whether Lrig1 derived cells are responsible for FC associated SCC. Herein we aim to:

1) confirm that Lrig1 HFJZKSC proliferation is responsible KSC expansion into the infundibulum and adjoining interfollicular epidermis

2) test the hypothesis that Lrig1 HFJZKSC progeny give rise to papilloma and SCC

3) determine whether STAT3 mediate HFJZKSC expansion occurs in human skin FC.

Role of Skin Stem Cells in Psoriasis and Atopic Dermatitis

Grantee: George Murphy, Professor, Brigham & Women’s Hospital, Boston

Amount: DKK 3,988,427

Grant category: Research Grants in open competition

Year: 2019

Geography: USA

This two-year proposal is based on the hypothesis that skin stem cells are critically involved in the pathogenesis of psoriasis and atopic dermatitis.

In previous work, the three principal investigators have identified a cytokeratin 15-expressing stem cell niche at the tips of epidermal rete ridges, discovered immunomodulatory dermal mesenchymal stem cells, and defined an epigenetic mark that regulates skin stem cell behavior.

During the past year that was funded by the LEO Foundation, we have provided data that supports epidermal stem cell participation in human and experimental psoriasis and begun to probe the genetic and epigenetic underpinnings of this phenomenon.

We now propose to advance these findings to determine mechanistic commonalities in stem cell behavior that may unify the pathogenesis of psoriasis and atopic dermatitis. Specifically, the proposal focuses on epidermal and dermal stem cells in the context of innovative experimental models, human biospecimens to test relevance, and epigenetic modifiers that may be transformative in normalizing stem cell aberrations responsible for the initiation and propagation of these two prevalent, pernicious, and potentially preventable skin diseases.

Implementation of novel 3-bounce 2-pass ATR FTIR spectroscopy into the Skin Testing for Atopic dermatitis (STAR) study

Grantee: Dr Simon G. Danby, Independent Research Fellow, The University of Sheffield Medical School

Amount: DKK 390,506

Grant category: Research Grants in open competition

Year: 2018

Geography: United Kingdom

With this grant, the group led by Simon G. Danby seeks a potentially important technological addition to the ongoing A longitudinal investigation of skin barrier development from birth and the validation of early predictors of Atopic dermatitis (AD) risk: the skin testing for atopic dermatitis risk (STAR) trial (see Grants 2017).

This addition may prove valuable to the group’s envisioned paradigm shift – from management of established AD to primary prevention of the condition.

More specifically, the group will include enhanced ATR-FTIR spectroscopy to quantify biomarkers of skin barrier condition and AD severity in newborns. While existing spectroscopy works in adults and children, its sensitivity has been proven unsatisfactory when measuring newborns.

Working with the equipment manufacturer, the group has developed a solution that increases sensitivity 6-fold. This increase can help better prediction of the risk of AD in the newborn and thus enable targeted emollient intervention right from birth – potentially leading to a reduction of the incidence of the condition as increasing evidence suggests that topical emollient therapy can prevent the initial onset of AD by 50%.

AD is a very common chronic inflammatory skin condition affecting around 20% of children worldwide. The disease often heralds development of allergic diseases such as food allergy, asthma, and allergic rhinitis.

Project Group

Prof. Michael J. Cork and Mr J. Chittock, The University of Sheffield, United Kingdom

Dame Prof. Tina Lavender and Dr Alison Cooke, The University of Manchester, United Kingdom

GWA studies on common dermatological diseases

Grantee: Professor Gregor B. Jemec, Department of Dermatology, Zealand University Hospital, Roskilde, and Assoc. Professor Ole B. V. Pedersen, Department of Clinical Immunology, Næstved Hospital

Amount: DKK 5,770,000

Grant category: Research Grants in open competition

Year: 2018

Geography: Denmark

In this study, the group led by Professor Gregor Jemec of Roskilde Hospital has set out to identify new genes for the development of a long line of common dermatological conditions, including deep skin infections, warts, fungal infections, and eczema.

Many of these common skin diseases are still poorly understood and the treatments often insufficient. A study of the genetics of these disorders will help increase the understanding of the pathogenic mechanisms. The study will have its origin in Denmark and be based on unique national biobanks, national registries, and with extensive genetic analyses done in collaboration with deCODE Genetics, Iceland.

This is possible due to the growing number of Danish large-scale biobanks as well as biobank based scientific studies suited for further genetic studies. The largest genetic study in Denmark is the Danish Blood Donor Study (DBDS) in which the genome wide association (GWA) arrays have been analysed on 110,000 research participants.

In addition to this cohort, Jemec’s group is currently pursuing genetic testing on the Copenhagen Hospital Biobank (CHB) that includes samples from around 350,000 patients. Both of these biobanks have established a collaboration with deCODE Genetics, Iceland – one of the leading genetic research centers in the world.

 

Project Group

Henrik Ullum, Professor, Department of Clinical Immunology, Rigshospitalet

Søren Brunak, Professor, Center for Protein Research (CPR), Copenhagen University

Simon Francis Thomsen, Professor, Department of Dermatology, Bispebjerg Hospital

Claus Zachariae, Professor, Department of Dermatology, Gentofte Hospital

 

International affiliations

Ingileif Jonsdottir, Professor, deCODE Genetics, Iceland

Errol Prens, Professor, Department of Dermatology, Erasmus University, Rotterdam, Netherlands

Christos Zouboulis, Professor, Department of Dermatology, Brandenburg Medical School Theodor Fontane, Dessau, Germany

Fully Synthetic Lincosamides to Combat Multidrug-Resistant Skin Infections

Grantee: Prof. Dr. Andrew G. Myers, Amory Houghton Professor of Chemistry Harvard University, Cambridge, MA

Amount: DKK 3,108,110

Grant category: Research Grants in open competition

Year: 2018

Geography: USA

Many common skin infections are caused by the Gram-positive bacterial species Staphylococcus aureus and Streptococcus pyogenes. The infections lead to conditions ranging in severity from minor folliculitis to life threatening skin reactions. If not managed successfully, they may escalate into lethal systemic infections.

Commonly, these diseases are treated with clindamycin, a prototypical member of the wide-ranging so-called lincosamide antibiotic class. Its clinical importance is underlined by the World Health Organization’s listing of it as an essential medicine. In the past decades, however, prevalence of in particular lincosamide resistant Staphylococci and Streptococci has risen sharply. The rise threatens to diminish clindamycin’s usability in the future, even render it obsolete.

In the course of this project, the team led by Andrew G. Myers of Havard University, will seek to address this growing unmet medical need by synthetic discovery efforts focused on the lincosamide class.

The team’s preliminary results indicate that new lincosamides uncovered in this fashion are able to address the contemporary resistance threats: Many of the compounds designed, synthesised, and evaluated by the team to date have shown themselves active against multidrug-resistant clinical isolates of Staphylococci and Streptococci, and at the same time they demonstrate favourable pharmacokinetic and safety profiles.

The team expects that it can uncover new candidates displaying expanded spectra of action against MDR and Gram-negative bacteria. The expected results can then be used to advance refined lead candidates capable of demonstrating efficacy in in vivo murine models of skin infection, and thus yield substantial promise for further clinical development of actual treatments.

 

Project group

Dr. Amarnath Pisipati, Postdoctoral microbiologist

Matthew J. Mitcheltree, PhD student, chemistry

Ioana Moga, PhD student, chemistry

Katherine J. Silvestre, PhD student, chemistry

 

International affiliation

The Institut Pasteur, Annecy, France – International Course on Antibiotics and Resistance (ICARe), Organizing Committee, Core Faculty

In vivo model of human melanoma using a novel crest chimera system

Grantee: Dr. Rudolf Jaenisch, Member, Whitehead Institute and Professor, Department of Biology, Massachusetts Institute of Technology, MA

Amount: DKK 2,476,836

Grant category: Research Grants in open competition

Year: 2018

Geography: USA

Two major challenges when using mouse models to model human cancers such as melanoma are that the human tumor cells transplanted to mice 1) represent the end-stage of the disease and 2) that the host animals are usually immunocompromised.

Thus, these models fail to actually show development of the disease and they fail to display the ongoing interaction between melanoma cells and the immune system as the disease progresses.

To curb these two shortcomings, the team led by Rudolf Jaenisch of Massachusetts Institute of Technology, has set out to create an experimental model system that will make it possible to study initiation, progression, and manifestation of human melanoma in immune competent host animals.

Their basis is generation of human-mouse neural crest chimeras – where mice embryos are introduced with human neural crest cells carrying the genetic dispositions alleged to lead to development of the particular cancer – and their goal is a model that has the potential to show how melanoma cells evade the immune system.

Given a positive outcome, this innovative project can help devise strategies to improve the effectiveness of current immunotherapies, to test novel immunotherapies, and to identify novel targets in melanoma treatment.

 

Project group

Malkiel Cohen, Postdoctoral researcher

Kristin Andrykovich, Graduate Assistant

Development of biomarkers and models for wound infection

Grantee: Mariena van der Plas, University of Copenhagen, Faculty of Health and Medical Sciences, Department of Pharmacy

Amount: DKK 2,745,375

Grant category: Research Grants in open competition

Year: 2018

Geography: Denmark

Proper wound healing is a fundamental survival mechanism and dysfunctions cause significant disease, such as seen in infections after burns, trauma and surgery, as well as in non-healing ulcers.

Currently, the prevalence of non-healing wounds is estimated to be over 40 million worldwide, a number projected to rise with 6-9% annually, due to aging of the population and the increasing incidence of diseases that contribute to nonhealing ulcer development, such as obesity and diabetes.

There is a great and unmet need for novel treatments for improved healing, and thus better predictors for wound healing outcomes are essential. Given the importance of innate immunity and microbial interactions for development of impaired wound healing, the aim of this project is to define novel prognostic and diagnostic biomarkers for assessment of wound healing and infection risk.

For this purpose, we will use state-of-the-art techniques for peptidomics mass spectrometry. This unique approach, without the classical trypsin digestion of the samples, will give actual insight in processes occurring in the wound bed, e.g. enzymatic activity, infection, inflammation, and angiogenesis, instead of just reporting the presence of a protein, independent of the state it is in.

Furthermore, we will set up biological models for validation of biomarkers, as well as novel treatments. Together, the outcomes of these studies have the potential to improve diagnostic evaluations of wounds, and will enable us to develop novel treatment concepts for early prevention of infection, leading to improved healing results for large and significant patient groups.