A Map of Human Type 1 Diabetes Progression by Imaging Mass Cytometry

Abstract

Highlights d Highly multiplexed imaging of pancreas tissues from human donors with T1D d Islet evolution through T1D progression inferred from snapshot data d The phenotype of b cells is altered prior to b cell destruction d T cell recruitment depends on both disease stage and islet profile

Single-cell RNA sequencing of murine islets shows high cellular complexity at all stages of autoimmune diabetes

“…Recent studies applied advanced imaging mass cytometry techniques to compare the human pancreas in T1D patients and in control individuals. Changes were found in islet structure and size, vascularization, and levels of various immune cells, as well as progressive cell loss preceded by infiltration of cytotoxic and helper T cells in the pancreatic islets (Damond et al, 2019; Wang et al, 2019). However, the analysis of stages during T1D progression is complicated for multiple reasons, particularly the late manifestation of the disease and limited availability of samples.…”

Islet–immune interactions in type 1 diabetes: the nexus of beta cell destruction

“…Single cell assays such as mass cytometry (CyTOF), along with other new methods designed to profile the proteome at high resolution and with minimal cell input [108,109], can offer insights into cellular heterogeneity but cannot discern cell-cell interactions or orientation within the native tissue environment (Table 3). In contrast, Imaging Mass Cytometry (IMC), which facilitates visualization of tissue sections labeled with antibodies conjugated to rare metal isotopes using high-resolution laser ablation and time-of-flight mass spectrometry, allows for high-parameter in situ data acquisition without the compensation issues plaguing traditional immunofluorescence analyses [110,111] (Table 3). Simultaneous detection of 36 parameters from a single tissue section by IMC coupled with analysis of pseudotime dynamics indicated that β-cells lose identifying markers such as insulin, proinsulin, IAPP, and protein tyrosine phosphatase receptor type N (PTPRN) prior to their destruction [111], potentially indicating a direct role for β-cells in inciting their own destruction by autoreactive T cells.…”

“…In contrast, Imaging Mass Cytometry (IMC), which facilitates visualization of tissue sections labeled with antibodies conjugated to rare metal isotopes using high-resolution laser ablation and time-of-flight mass spectrometry, allows for high-parameter in situ data acquisition without the compensation issues plaguing traditional immunofluorescence analyses [110,111] (Table 3). Simultaneous detection of 36 parameters from a single tissue section by IMC coupled with analysis of pseudotime dynamics indicated that β-cells lose identifying markers such as insulin, proinsulin, IAPP, and protein tyrosine phosphatase receptor type N (PTPRN) prior to their destruction [111], potentially indicating a direct role for β-cells in inciting their own destruction by autoreactive T cells. Additionally, intra-and peri-islet T cell numbers were negatively correlated with disease duration and residual β-cell mass, with new-onset T1D donors possessing the highest degree of infiltration, regardless of the presence of β-cells (defined as islet cells expressing both Pancreatic And Duodenal Homeobox 1 (PDX1) and NKX6-1) [111].…”

“…Simultaneous detection of 36 parameters from a single tissue section by IMC coupled with analysis of pseudotime dynamics indicated that β-cells lose identifying markers such as insulin, proinsulin, IAPP, and protein tyrosine phosphatase receptor type N (PTPRN) prior to their destruction [111], potentially indicating a direct role for β-cells in inciting their own destruction by autoreactive T cells. Additionally, intra-and peri-islet T cell numbers were negatively correlated with disease duration and residual β-cell mass, with new-onset T1D donors possessing the highest degree of infiltration, regardless of the presence of β-cells (defined as islet cells expressing both Pancreatic And Duodenal Homeobox 1 (PDX1) and NKX6-1) [111]. Similarly, Wang et al observed increased Granzyme B + macrophages and CD8 + T cells in pancreas tissues from T1D donors, with β-cell containing islets (defined by expression of insulin, NKX6.1 and PDX1) enriched in CD8 + T cells and CD20 + B cells [112], likely identifying islets that are actively being targeted by autoreactive immune cells.…”

“…Single cell transcriptomics/ proteomics Assess expression of candidate genes and their protein products for paired cell genotype/ phenotype data, as well as adaptive immune cell repertoire analysis [104] Single cell ATAC-sequencing Investigate the contribution of dysregulated gene networks, particularly in candidate loci, to immune or β-cell function [106,107] CyTOF Following labeling with metal tagged antibodies, deep phenotyping of single cell suspensions can be performed [110] IMC By applying metal tagged antibodies to fixed tissue sections, deep phenotyping of cells can be performed in situ [111,112] Laser capture microdissection Identify differentially expressed genes and proteins to develop disease-predictive biomarkers or targeted therapeutics [108] nanoPOTS Identify novel post-translational modifications within a single islet and the proteomic basis for islet heterogeneity [109] CODEX Examine disease-related tissue and cell subset reorganization, as well as perform multiplexed deep phenotyping [113] Tissue clearing (e.g. X-CLARITY, PARS) Visualization of intact morphology, vasculature, innervation, and extracellular matrix [114] RNA single-molecule FISH Identify the dynamics of candidate gene and checkpoint molecule expression in all subsets present in the tissue microenvironment, examine how they influence cell phenotype and function [115] Microphysiological Systems Introduce targeted therapeutics or innate and adaptive immune cells to assess their contribution to disease development/treatment [116] Investigate the underlying cause of the islet anti-viral immune signature Examine the role of hybrid insulin peptides (HIPs), defective ribosomal products (DRiPs) and neoantigens in β-cell stress or destruction Tissue Slice Profile live immune and endocrine cells across the pancreas in the native tissue environment [24] Assess the role of chemokines and adhesion molecules Determine which cells are directly pathogenic vs bystander or tissue resident cells *nanoPOTS = Nanodroplet processing in one pot for trace samples; PARS = Perfusion-assisted agent release in situ; ATAC = Assay for Transposase Accessible Chromatin; CyTOF = Cytometry time of flight; IMC = Imaging mass cytometry.…”