ECCO Fellowship Grant Study Synopsis: Sulak Anandabaskaran
Sulak Anandabaskaran, ECCO Fellowship Grant Awardee
Defining the Role of invariant Natural Killer T (iNKT) Cells in Perianal Fistula
© Sulak Anandabaskaran
Background & aim of research
Perianal fistulising Crohn’s Disease (pCD) is associated with poor outcomes and impaired quality of life. It remains difficult to manage despite medical and surgical advancements, likely due to poor understanding of the underlying immunology. Previous multiparameter flow cytometry work in our lab on immune cells isolated from peripheral blood and fistula curettage samples showed expansion of iNKT cells in perianal fistula compared to peripheral blood. Furthermore, iNKTs have been suggested to have a potential role in key processes in fistula pathogenesis, namely epithelial-to-mesenchymal transition and extracellular matrix degradation. The role of iNKTs in inflammation remains poorly defined and their function in human IBD is largely unexplored. Therefore, in this experiment we aim to further define their role in the pathogenesis of perianal fistula.
Methodology/experiments that will be used
Paired fistula curettage and peripheral blood will be collected from pCD patients (n=15) undergoing examination under anaesthesia (EUA) at St Mark’s Hospital and used for experimental optimisation, deep phenotyping at a single cell resolution and organoid co-culture experiments. iNKT cells will be comprehensively identified by staining with a combination of T-cell receptors (TCRs), including the iNKT TCR (Vα24-Jα18) and a CD1d tetramer, which currently constitutes the most comprehensive definition of an iNKT cell. Following optimised staining parameters, iNKT cells will undergo fluorescence-activated cell sorting for downstream experiments.
Anticipated main impact
We believe that this project will help us to further understand whether iNKT cells are universally involved in the pathogenesis of Crohn’s perianal fistulae and, if so, to elucidate the significance of such involvement. By understanding the cellular and cytokine pathways alongside these iNKT cells, we will be able to look forward to novel, targeted medical therapies for pCD.
We anticipate that the experimental optimisation and sample collection will be carried out from January to October/November 2022. Following this, we expect to carry out “Omics” data analysis for a further 3–6 months, until May 2023, and then to finish manuscript write-up by December 2023.