Fig. 7: Spatial proteomics reveals that peri-epithelial immune microenvironments are uniquely enriched in innate immune populations nearest to junctional keratinocytes.
From: Single-cell and spatially resolved interactomics of tooth-associated keratinocytes in periodontitis
a The orientation of periodontal tissues is critical to show tooth-facing (sulcular, junctional epithelial keratinocytes; SK/JKs) and oral-facing (gingival margin, GM; attached gingiva, AG; and alveolar mucosa, AM) attachments for highly multiplexed immunofluorescence (mIF) assays of periodontitis. b By doing this in sequential sections, we first confirmed orientation and noted highly localized inflammatory profiles near tooth-facing epithelial keratinocytes. As discovered in the initial analysis (Fig. 2), tooth-facing SKs and JKs uniquely express Keratin 19 (KRT19) in every cell type, highlighting the transition zone. An initial analysis of Tier 1 cell assignments using mIF (PhenoCycler Fusion; Akoya Biosciences) revealed adaptive immune foci concentrated near SKs and more diverse, innate immune populated foci near JKs. Cell segmentation was performed using StarDist. c The 33-antibody assay revealed more heterogeneity at the cell type and cell state level, including peri-sulcular tertiary lymphoid structures (TLS, yellow) defined by T cell, B cell, and dendritic cell mixed aggregates. Antibodies are grouped and zoomed-in regions from a periodontitis sample are featured. d Spatial analysis of peri-epithelial regions was broken into four specific regions as before, highlighting the innate (MPO, CD68, HLA-DR) to adaptive (CD4, CD8) cell transition. e Segmented immune cells were assigned identities in health and disease across the four regions. f Periodontitis displayed more diverse heterogeneity considering the whole tissue. g However, cell–cell interactions among immune cells revealed diverse enrichment of immune cell types in peri-junctional and peri-sulcular immune foci in periodontitis. Abbreviations: Antibodies (see Methods); also see Fig. 1 legend. Scale bars: (b, d) 250 μm, (c) 50 μm. Illustration from (a) created with BioRender.com. For this figure, n = 6 for tissues: 3 health, 3 periodontitis).
