T cell-fibroblast interactive cell atlas in systemic sclerosis: Role of T cell exhaustion in tissue fibrosis

Concept

In recent years, accumulating evidence suggests that exhausted T cells (Tex) are of paramount importance for the maintenance of immunological self-tolerance and immune homeostasis. Tex are characterized by high expression of co-inhibitory receptors (CiR), and their key role is supported by the worsening of autoimmune diseases after depletion, or inhibition of, co-inhibitory molecules in mice, as well as in man. In this project, we plan to examine SSc cohorts, fibroblast cultures with antibodies to co inhibitory molecules by using techniques of  flowcytometry, ELISA,  PCR studies. Measurements and analysis of changes to matrix proteins and inflammatory proteins.

Facts and figures

Project lead
M Aspari
Aarhus University
au611635@uni.au.dk
FOREUM research grant: €50'000
2019–2020

Meet the team

M Aspari
Aarhus University
B Deleuran
Aarhus University
D Abraham
University College London
Stinne Greisen
Stinne Greisen Department of Biomedicine, Aarhus University
Voon H. Ong
UCL Medical School, Royal Free Campus
Christopher P. Denton
UCL Medical School, Royal Free Campus

Objectives

The purpose of this project is to examine T cell exhaustion and their role in the outcome of dSSc, with the focus on CiR and their ligands. Fibroblasts play a crucial role in the pathogenesis of dSSc, this project will also elucidate how TEX and CiR are regulated in co-cultures with T cell and autologous dSSc fibroblasts.

Additionally, their levels will be compared to well-known disease parameters and pseudo-parameters in dSSc. To establish the role of T cell exhaustion in SSc.

Interim Results

ELISA

ResultsThe mean of sPD-1 level was increased (136pg/ml) among dcSSc patients in comparison to healthy controls. Comparison of sPD-1 levels in patients on DMARDs with those without treatment demonstrated significant effect of immunosuppressive therapies, with mean sPD-1 95.1 pg/ml among patients on DMARD compared to 216.7 pg/ml among those on no treatment (p=0.0178). There was association between sPD-1 and mRss (p=0.04) and FVC (p=0.04).

Mean sLAG-3 levels were significantly lower among dcSSc patients (394.6 pg/ml) vs healthy controls (740.8 pg/ml, p=0.0001). sLAG-3 was inversely associated with disease duration (p=0.04). There was a trend for association between sLAG-3 and mRss, with higher levels of sLAG-3 seen in patients with higher skin score (p=0.06),and between sLAG-3 levels and presence of tendon friction rubs (TFR) (mean sLAG-3 366.3 ng/ml among patient without TFR and 531.5 ng/ml among those with TFR, p=0.08). There was highly significant difference in the sTIM-3 levels between healthy controls (mean 4721.9 ng/ml) and dcSSc patients (8728.0 ng/ml, p<0.0001).  There was a trend for association between anti-Scl70 (ATA) positivity and sTIM-3 levels (p=0.0944). Hb levels showed significant association with sTIM-3, with higher Hb levels associated with lower sTIM-3 levels (p=0.02).

FLOWCYTOMETRY

Pilot flowcytometry studies showed that the  proportion of CD4+ T cells expressing PD1 were markedly increased in SSc patients compared to healthy volunteers and Rheumatoid Arthritis patients. There was increased expression of both TIGIT and TIM3 in the CD4+ T cells. (Figure 1 ) Similarly, the co-expression of these receptors on the CD4+ T cell population was elevated compared to healthy volunteers. (figure 2)

Patient Voice

The experimental nature of our research proposal limits the potential contribution of patient research partners. However, A project taskforce will be setup at Aarhus University based on EULAR recommendations during the course of this project . This taskforce would consist of both patients and doctors involved in the project. Regular meetings and consultations with patients will be held as part of the taskforce’s schedule. Patient input in terms of both sample collection and suggestions will be taken into consideratio.

Publications

EULAR Abstracts

2020

  • AB0151: Preliminary results show an increased expression of coinhibitory receptors in Systemic Sclerosis

Go to EULAR Abstract Archive