A Spatial Atlas of Human Gastro-Intestinal Acute Gvhd Reveals Epithelial and Immune Dynamics Underlying Disease Pathophysiology

• Published in: Blood 2024-11, Vol.144 (Supplement 1), p.4813-4813
• Main Authors: Milo, Idan, Azulay, Nofar, Bussi, Yuval, Ben Uri, Raz, Keidar-Haran, Tal, Eldar, Michal, Elhanani, Ofer, Harnik, Yotam, Yakubovsky, Oran, Nachmany, Ido, Salame, Tomer, Bertheau, Philippe, Michonneau, David, Socie, Gerard, Keren, Leeat
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2024-198175

Intro Acute graft versus host disease (aGVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (aHSCT). Alloreactive donor T cells are driving factor in GVHD development in the gut, but knowledge of the role that additional donor and host cells play in this process is limited. Here, we leveraged Multiplexed Ion Beam Imaging by Time of Flight (MIBI-TOF), to generate comprehensive spatial maps of healthy and GVHD-afflicted duodenum at single cell resolution. Methods We profiled biopsies taken from 57 GVHD patients and 10 healthy controls and measured by MIBI-TOF the spatial expression of 40 proteins, designated to delineate distinct epithelial cells, stromal cells and immune cells in the gut. Overall, we acquired 256 high-dimensional images, each depicting the spatial expression of forty proteins in situ. To map single cell identity and function we segmented individual cells and classified them using a deep-learning pipeline. Altogether, we identified 32 cell populations, including populations of epithelial cells (enterocytes, goblet, endocrine, and Paneth cells), various immune populations among them CD4 and CD8 T cells, T regulatory cells (Tregs), plasma cells, B cells, neutrophils, macrophages, mast cells and several stromal populations. Results First, we interrogated the composition and spatial distribution of immune cells in normal duodenum. We found that plasma cells, macrophages and CD4+ T cells were the most frequent immune cell types, with prevalences of 30%, 27% and 20%, respectively. Following them were CD8+ T cells (8%), other cells, such as neutrophils and Tregs appeared at low prevalence (< 2% each). The lamina propria was enriched with plasma cells, macrophages and CD4+ T cells, whereas CD8+ and double negative T cells were the predominant populations inside the epithelium. Then we explored the effects of GVHD on the structure of the gut epithelium. GVHD patients exhibited increased fibrosis, alterations in crypt morphology, loss of Paneth cells, and accumulation of endocrine cells in the crypts. These alterations were correlated with pathological staging. To investigate the local immunological processes in GVHD, we analyzed the immune composition in GVHD patients and controls. We found that GVHD was characterized by a significant decrease in plasma cells and CD4+ T cells. Patients with severe clinical gut staging disclosed infiltration of additional immune cells including neutrophils, Tregs, macrophages and CD8+ T