Abstract: TH-PO654
Single Cell RNAseq Analysis of Kidney Transplant Biopsies Demonstrates a Role for Endothelial Cell CCL23 in Antibody Mediated Rejection
Session Information
- Transplantation: Basic
November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2001 Transplantation: Basic
Authors
- Malone, Andrew F., Washington University in St Louis, St Louis, Missouri, United States
- Leckie-Harre, Aidan, Washington University in St Louis, St Louis, Missouri, United States
Background
Antibody mediated rejection (AMR) remains one of the major causes of allograft failure and our understanding of this disease process is poor. Macrophages are thought to play an important role in the alloimmune reaction including AMR. We performed single cell RNAseq on biopsies from transplant patients to examine the effects of endothelial cell ligand expression on macrophages in AMR.
Methods
The 10X Genomics platform was used to make libraries which were sequenced to a depth of ~50k reads/cell. Gene-cell matrices were obtained from CellRanger and the downstream analysis were done using R and Seurat. The effect of ligand expression on target cells was analyzed using nichenetr. nichenetr predicts ligand-receptor interaction based on known target cell gene activity in response to ligand activity. This study had IRB approval.
Results
15375 cells in total from 5 kidney transplant biopsy samples (3 AMR and 2 non-AMR) were included in the final integrated analysis using UMAP. All major kidney cell types were identified including macrophages. Endothelial cells (EC) were subclustered into 4 subgroups, IFNg_EC, PTC_EC, GEC_EC, and angiogenic_EC. The ligand with the greatest prediction score (0.958) for target cell (macrophage) gene activity in the rejection niche was CCL23 acting through CCR1 receptor. CCL23 was differentially expressed in IFNg_EC cells in AMR (compared to other ECs and non-rejecting ECs).
Conclusion
A target gene activity approach to ligand-receptor analysis using single cell RNAseq of human kidney transplant biopsies suggests CCL23 expression from endothelial cells interacts with macrophages in AMR. Therefore, CCL23 may mediate macrophage recruitment to the kidney allograft in AMR.
Funding
- NIDDK Support