Single Cell Transcriptomic Classification of Inflammatory Skin Disease

Grantee: Jeffrey Cheng, Associate Professor, The Regents of the University of California San Francisco

Amount: DKK 3,999,960

Grant category: Research grants in open competition

Year: 2022

Geography: USA

Jeffrey Cheng’s project aims to improve our understanding and discrimination of chronic atypical skin rashes which do not fit into well-defined clinical categories. Jeffrey along with his team will approach this by first mapping gene expression variations on a single cell level for a number of prototypical rash types. This will allow them to create a framework to identify variations that can discriminate between well characterized rash types, which each have different treatment regimens. While they have already done this for rashes with atopic dermatitis- and psoriasis-like features, this project will add information about rashes with features common to cutaneous sarcoidosis and lupus erythematosus. Based on these findings, Jeffrey aims to establish a more accessible approach to classify these rashes by assessing tissue samples for presence of disease-relevant proteins.

If successful, Jeffrey and his team will provide important guidance for optimal classification and subsequent treatment of otherwise indeterminant rashes.

Molecular genetics of recalcitrant warts

Grantee: Hassan Vahidnezhad, Assistant Professor, Thomas Jefferson University

Amount: DKK 2,131,526

Grant category: Research grants in open competition

Year: 2022

Geography: USA

This project led by Hassan Vahidnezhad aims to elucidate the mechanisms behind skin warts that do not resolve automatically.

Warts are very common, approximately present in 20-35% of the general population. While they typically disappear within a few months, some linger and may be hard to get rid of. These persistent warts are caused by infection with Human Papilloma Virus (HPV) in persons where the immune response is insufficient due to genetic defects. Particularly, defects in T cells are suspected as a causation, but exactly how the warts are formed and how they persist is to a large degree unknown.

Hassan and his team seek to identify the genetic and molecular causes of recalcitrant warts, which will not only better the understanding of the skin’s immunological response to HPV infection, but may also provide diagnostic, prognostic and therapeutic improvements for patients with recalcitrant warts.

The role of eosinophils in atopic dermatitis skin inflammation and itch

Grantee: Nathan Archer Ph.D., Assistant Professor, Johns Hopkins School of Medicine

Amount: DKK 3,783,727

Grant category: Research grants in open competition

Year: 2022

Geography: USA

This project led by Dr. Nathan Archer investigates the interplay between bacterial colonization and a specific immune cell, the eosinophil, in development of atopic dermatitis (AD).

AD is a very common skin disease, particularly amongst young people, and the associated healthcare costs in the U.S. alone are estimated at USD 5.2 billion. Thus, there is a strong incentive to better understand the disease to improve its treatment.

The cause of AD is still unclear, but one interesting observation is that a specific type of immune cell, the eosinophil, infiltrates the affected areas and correlates with disease severity. The role of these eosinophils in AD remains unknown, but initial observations by Dr. Archer and his team point to a link between skin colonization of a specific bacteria, Staphylococcus aureus, and the observed infiltration – which may lead to both inflammation and itch. This bacteria-immune cell interaction is unusual, and Dr. Archer and his team will investigate the observed interaction in detail, with an aim to provide novel therapeutic targets for the treatment of AD.

Adherens Junction Dysfunction in Hidradenitis Suppurativa

Grantee: Amanda Nelson, Assistant Professor, The Pennsylvania State University

Amount: DKK 3,996,947

Grant category: Research grants in open competition

Year: 2022

Geography: USA

Amanda Nelson’s project investigates the role of two proteins, E-cadherin and p120, in the relatively common inflammatory skin disease Hidradenitis Suppurativa (HS), which is characterized by skin lesions that cause intense pain, odor, drainage and scarring.

The cause of HS remains unclear, and this limits the current treatment options. The current hypothesis is that there is a blockage in the hair follicle unit, which triggers the immune response. Amanda and her team have found that E-cadherin and p120, both important for skin integrity, are lost in HS-affected skin, and their project seeks to understand how this loss may contribute to the hair follicle breakdown and subsequent inflammation. If the link is proven it may provide novel approaches for treatment of HS.

Development of predictive psoriasis response endotypes using single cell transcriptomics in ustekinumab responders versus non-responders

Grantee: Kevin Cooper, Professor, University Hospitals Cleveland Medical Center

Amount: DKK 3,653,532

Grant category: Research grants in open competition

Year: 2021

Geography: USA

Among the biological treatments approved for the treatment of psoriasis, is ustekinumab, which is a monoclonal antibody targeting the shared p40 subunit of two cytokines, IL12 and IL23.

This project aims to improve psoriasis treatment by understanding why some psoriasis patients respond well to treatment with ustekinumab (responders) and others do not (non-responders). Interestingly, some non-responders to ustekinumab still respond well to inhibition of the IL23 pathway alone via the unique p19 subunit.

The pattern of differentially expressed genes among responders and non-responders may enable prediction of which intervention will be most beneficial for the individual patient. The plan is to compare single-cell transcriptomic analyses from both responders and non-responders to identify treatment response-linked gene expression patterns, so-called ‘endotypes’.

One size does not fit all for these biological therapeutics, and the goal is for the research to contribute to the development of a ‘companion diagnostic’, which is a diagnostic test used as a companion to a therapeutic drug to determine its applicability to a specific person, and thereby to personalized medicine in psoriasis.

Melanocyte stem cell lineage determination and plasticity

Grantee: Deborah Lang, Associate Professor, Boston University School of Medicine

Amount: DKK 3,583,404

Grant category: Research grants in open competition

Year: 2021

Geography: USA

Melanocytes are pigment-producing skin cells. They serve as an excellent model for stem cell research because they are easily obtainable from the skin and have the potential to be modified into other types of cells. The aims of this project are to define molecular events that promote stem cell maintenance and to test if melanocyte stem cells can be transformed into other cell types (such as nerves).

Deborah Lang has created a unique transgenic mouse model that fluorescently marks melanocyte stem cells.  This model is an innovative and powerful tool to visualize and isolate pure stem cells without contaminating non-stem cells. The Lang lab, along with Andrey Sharov and other collaborators at Boston University, will investigate gene expression in the stem cells, and how these stem cells change into pigment-producing melanocytes. Further, the team will test the ability of the melanocyte stem cells to turn in to other cells, such as neurons and neuron-like cells.

This project will provide new insights into melanocyte stem cell function and flexibility to become other cell types. The potential long-term impact of this project is that it will provide insight on normal melanocyte function, melanocyte dysfunction and pathology, and stem cell therapy.

Positional Information and Repair of Skin Injury

Grantee: Peter Reddien, Professor, Whitehead Institute, Cambridge

Amount: DKK 2,498,235

Grant category: Research grants in open competition

Year: 2021

Geography: USA

The project aims to investigate if an untapped potential for true skin regeneration exists in vertebrates not known to have the capacity to regrow skin tissue. If indeed such capacity exists and if it can be reactivated it may be possible to regenerate fully functional skin without any scarring.

Peter Reddien and his team at Whitehead Institute will look at the so-called “regional identity” of new cells which is central to regeneration in many animals capable of regeneration. They will use sophisticated techniques like single-cell RNA sequencing and spatial transcriptomics to compare factors and signaling pathways central to development in skin. Mouse skin – a vertebrate not known to be able to regenerate – and skin from a special regenerative salamander (axolotl) are used as models.

Peter Reddien’s research project is a basic skin science project with a novel approach to understanding the skin’s potential for regeneration.

Immunomodulatory porous biomaterials for skin regeneration

Grantee: Philip Scumpia, Assistant Professor, University of California – Los Angeles, CA

Amount: DKK 3,885,333

Grant category: Research grants in open competition

Year: 2021

Geography: USA

This project predicts in situ/local immunomodulatory biomaterials as a novel therapeutic approach to engineer regenerative wound healing and limit scarring.

Local tissue engineering represents a promising approach to regenerate tissue, however, immunologic barriers to restore tissue strength and function must be overcome. In previous studies, Philip Scumpia has shown that by simply inducing an adaptive immune response from a novel synthetic biomaterial that mimics the natural porosity and other characteristics of the skin, it is possible to provide the inductive signals to regenerate hair follicles and sebaceous glands in small murine cutaneous wounds.

In this project, it is proposed to identify the cells and the signals from the innate and adaptive immune system responsible for switching profibrotic signals in the wound environment to regenerative signals. This will be achieved by combining novel, pro-regenerative biomaterial formulations with loss-of-function studies of cells and factors of the immune system. Single-cell RNA-sequencing, multiplexed immunofluorescent microscopy, and bioinformatics analyses will be applied to directly assess biomaterial-to-cell and cell-to-cell interactions at the molecular level.

If successful, the project may help identify key players in regenerative wound healing, which would be of great importance.

Sodium intake and storage in the skin

Grantee: Katrina Abuabara, Associate Professor, University of California – San Francisco, CA

Amount: DKK 3,965,534

Grant category: Research grants in open competition

Year: 2021

Geography: USA

The rapid increase in prevalence of AD suggests that environmental factors play an important role, but which environmental drivers are most important and the mechanism by which they impact AD is unclear. Large epidemiological studies suggest that changing diets are an important contributor. Dietary sodium intake warrants additional investigation because studies have shown high rates of sodium storage in the skin and that high sodium concentrations can trigger inflammatory responses involved in AD.

To study this, Katrina Abuabara will enroll 30 participants and employ a novel Magnetic Resonance Imaging (MRI) technique that has been shown to accurately quantify skin sodium concentration to examine whether a low-sodium diet can decrease skin sodium concentration and improve AD severity. The study presents a strong statistical analysis plan to identify key parameters for a future full-scale clinical trial.

If sodium restriction proves to be beneficial, it could lead to actionable impact on AD patients as a cost-effective, low-risk intervention that could be implemented in low resource settings.

Keratinocyte contributions to inflammatory skin disease – Desmoglein 1 loss as a model

Grantee: Kathleen Green, Professor, Northwestern University - Illinois

Amount: DKK 3,025,870

Grant category: Research grants in open competition

Year: 2020

Geography: USA

The aim of this project is to study how the loss of a cell-cell adhesion protein called Desmoglein 1 helps drive activation of the immune system in inflammatory skin diseases.

The skin’s outermost layer, the epidermis, is made up of closely connected skin cells and plays a critical role in establishing an efficient barrier between the human body and the environment. Failure of this barrier in infectious, inflammatory and genetic skin diseases leads to clinical appearances driven by the interplay between the epidermis and the immune system.

Essential to establishing this epidermal barrier is a member of the desmosomal cadherin family of intercellular adhesion molecules, Desmoglein 1, whose best-known function is to connect neighboring skin cells together.  Professor Green and her team at Northwestern University, along with the group of Dr. Eran Cohen-Barak, Ha’Emek Medical Center Afula, Israel, are studying Desmoglein 1 functions that transcend their roles as ‘cell glue’. Their data suggest that loss of this protein increases immune responses and that the pathways activated are similar to those observed in inflammatory skin diseases like psoriasis.

Dr. Green and her team will use Desmoglein 1 deficient mice and Desmoglein 1 deficient human cells and tissues to determine the extent to which lack of this protein contributes to inflammatory skin diseases and to define molecular pathways that connect Desmoglein 1 to the immune system.