Olle Korsgrens projekt inom diabetesforskning
1.1 Pancreatic inflammation in T1D
Previous studies of the pancreas from individuals with diabetes have shown that the phenomenon of insulitis in humans is discrete, only affects a part of all islets, and is very heterogeneously distributed in the pancreas. T cells are often found at the interface between the islet and the exocrine tissue (also called "peri-insulitis"), the T cells less frequently invade the islet. The mechanism governing this is not known. Our group has previously shown that a large proportion of the infiltrating T cells are of a tissue-resident memory phenotype. These T cells lack characteristics of classic cytotoxic T cells. The exocrine tissue of the pancreas is also affected by T1D, and frequent leukocyte infiltration in the exocrine tissue has been reported. The pancreas seems to be affected by inflammation in a 'patchy' pattern, with intense inflammation in some regions while other regions are apparently unaffected. We want to investigate this phenomenon more closely by, among other things, looking at:
- Periductal fibrosis and how it can affect endocrine progenitor cells.
- How the beta cells are destroyed and what effect the gut microbiome has in T1D.
1.2 Single-cell transcriptomics on cells extracted with LCM
Previous reports of single beta-cell transcriptomics have been based on tissue that has been degraded by proteolytic enzymes and without information on the original location of the analyzed cells. We want to use Laser Capture Microdissection (LCM) to analyze the transcriptome of single cells. For example, insulin-positive cells from different locations in the pancreas can be extracted from individuals with and without T1D. This will increase our understanding of the dynamics of the human beta cell mass and potentially reveal important mechanisms of how beta cells are lost in T1D.
1.3 Spatial transcriptomics on pancreatic tissue
NanoString GeoMx® Digital Spatial Profiler (DSP) allows analysis of the transcriptome (covering 18 000 genes) in single cell types on FFPE-sections stained with 4 immunofluorescence markers. The method utilized a hybridization technology where the user specifically chooses regions of interest, where the stained cells are analyzed separately. In this project, nanoString GeoMx® Digital Spatial Profiler (DSP) will be used to characterize cells in different regions of the T1D pancreas, especially in regions with and without remaining beta cell-containing islets. The purpose of this is to discover factors that may contribute to beta-cell protection/loss in these areas.
1.4 Mass spectrometry on isolated islands
The aim of this project is to characterize the proteome of the islets of Langerhans. The islets consist of several different endocrine cell types; for example, beta cells, alpha cells, delta cells, pp cells and epsilon cells that produce insulin, glucagon, somatostatin, pancreatic polypeptide and ghrelin respectively. Beta cells corresponds to approximately 60% of the total islet mass, alpha cells represent up to 30% while the remaining cell types make up a smaller amount of the total islet endocrine mass. We are interested in characterizing the proteome of these different cell types.
1.5 Linage-tracing med hjälp av en lentivirusvektor
Med hjälp av en lentivirusvektor, kan individuella betaceller (liksom andra celltyper) märkas in och följas genom olika experimentella uppställningar. Öar kommer att isoleras och dissocieras till singelceller, varefter individuella betaceller kommer att märkas in av ett fluorescerande protein (GFP). Efterföljande odling av öarna i olika förhållanden för att exempelvis efterlikna en diabetisk profil (högt glukos och/eller fettkoncentrationer) gör det möjligt för oss att undersöka hur detta påverkar betacellerna.
2.1, 2.2 Transplantation of isolated islets to cure patients with the most severe TID, experimental and clinical studies
Together with The Nordic Network For Clinical Islet Transplantation, continuous work is carried out to develop and improve the method of isolating and transplanting pancreatic islets.