Journal: JCI Insight
Article Title: PhIP-Seq uncovers marked heterogeneity in acute rheumatic fever autoantibodies
doi: 10.1172/jci.insight.196619
Figure Lengend Snippet: ( A ) Volcano plot of differential autoantibody reactivity (PhIP-Seq peptides) between ARF cases and healthy controls. Significant peptides (using DESeq2, adjusted P < 0.05) colored by average binding magnitude, nonsignificant by sample density. Number of peptides significantly elevated in ARF cases compares with healthy controls is indicated; 118 peptides mapping to 81 proteins. Dashed lines indicate thresholds for significance and no change; enriched targets PPP1R12B and COL1A1 labeled. Total magnitude indicated by red scale; ARF significantly elevated magnitude compared with healthy controls by 1-sided Wilcoxon’s test. P = 0.018, r = 0.35. ( B ) GO pathway enrichment for ARF-associated autoantigens ( P < 0.01, 81 proteins represented by 118 peptides in A ). Dot size reflects protein count per pathway; fill color indicates enrichment strength. Outlines denote GO categories: Cellular Component (blue), Biological Process (green). Highlighted pathways include Sarcomere and Heart Morphogenesis. Full pathway analysis results with enrichment metrics for all GO terms are provided in . ( C ) Heart muscle expression of ARF-enriched targets (Human Protein Atlas). Upper panel: RNA expression ordered from low to high; tile borders indicate multiple (green) or single (gray) peptide hits. Lower panel: Protein expression by immunohistochemistry; tile borders indicate staining reliability (enhanced, red; supported, orange; approved, pink; uncertain, gray). Red arrows highlight PPP1R12B and COL1A1. ( D ) Subcellular localization and secretion prediction (Human Protein Atlas). Upper panel: Localization across cellular compartments (purple = presence); borders show reliability. Lower panel: Secreted proteins prediction (violet = predicted secreted). Main locations shaded if proteins predicted secreted as main location. PPP1R12B and COL1A1 indicated by red arrows.
Article Snippet: Recombinant antigens were either obtained commercially — human COL1A1 ( NM_000088 , Origene) and PPP1R12B ( NM_032104 , Origene) — or produced recombinantly using Expi293 cells as the expression host and purified using standard nickel affinity and size exclusion chromatography (CD226; NM_006566 , Callaghan Innovation).
Techniques: Binding Assay, Labeling, Immunopeptidomics, Expressing, RNA Expression, Immunohistochemistry, Staining