Fig 1: In vitro differentiation and activation of tonsillar FRC subsets.a–c, Bulk cultured primary tonsillar fibroblast of patients with OSA were stimulated with the indicated recombinant proteins for 48 h. a, FN1 mRNA fold change measured by quantitative PCR with reverse transcription (RT-qPCR), n = 8 (Medium, TGF-ß1, LIGHT), n = 7 (FGF2), n = 6 (TGF-ß1 + LIGHT, FGF2 + LIGHT) and n = 5 (TGF-ß3). b, IL-6 concentration in culture supernatants. c, Flow cytometric analysis of ICAM1 surface expression displayed as fold change of mean fluorescence intensity (MFI). b,c, n = 8 (Medium, TGF-ß1, LIGHT, FGF2) and n = 6 (TGF-ß3, TGF-ß1 + LIGHT, FGF2 + LIGHT). d, Representative flow cytometric plots depicting the sorting strategy for TRCs and PI16+ RCs from human palatine tonsils according to the indicated markers, where CD34 was used as a surrogate marker for PI16+ RCs based on the scRNA-seq analysis of tonsillar FRCs. e, PI16 mRNA expression after in vitro expansion of sorted TRCs and PI16+ RCs from n = 5 patients with OSA or tonsillitis. f,g, Sorted TRCs and PI16+ RCs from n = 5 adult patients with OSA or tonsillitis were cultured and stimulated with indicated recombinant proteins for 48 h. f, Flow cytometric analysis of relative increase in cell counts. g, Flow cytometric analysis of ICAM1 mean fluorescence intensity (MFI). a-c,f-g, Box extends from 25th to 75th percentile, median is indicated and whiskers show the minimum and maximum values. Q values were calculated with the Kruskal-Wallis (a-c,f) or Friedman (g) test and Benjamini, Krieger and Yekutieli correction for multiple comparisons.