Panel A: A scatter plot shows the relationship between allele frequency and alphamissense score for various IL23R variants. The x-axis represents allele frequency on a logarithmic scale, and the y-axis represents the alphamissense score. Different symbols and colors indicate various types of variants, including isomorphic, likely pathogenic, loss of function (LOF), and hypomorphic variants. Panel B: A line graph illustrates the specific binding of IL-23-TAMRA to NLuc IL23R G300V/IL-12R1. The x-axis represents the concentration of IL23-TMR in nanomoles, and the y-axis represents the specific binding (BRET ratio). The graph shows a saturable binding curve with a low maximum BRET window. Panel C: Three bar graphs compare the BRET ratio of different IL-23R variants to wildtype IL-23R. The x-axis lists the different IL-23R variants, and the y-axis represents the BRET ratio. Statistical significance is indicated with asterisks, showing differences between variants. Panel D: A Western blot image shows the phosphorylation of STAT3 (pSTAT3) after stimulation with IL-23 in EBV-B cell lines from healthy donors and various IL23R homozygotes. The blot includes bands for pSTAT3 (Y705), STAT3, and beta-Actin as a loading control. Panel E: A pedigree chart displays the genetic and clinical information of kindreds studied. Symbols represent individuals, with different shades indicating clinical phenotypes. Genotypes are indicated below each symbol, and arrows point to the index case in each family.
Population genetics and impact of hypomorphic IL23R variants on IL-23 binding. (A) AlphaMissense/MAF (right) graphs for all homozygous IL23R LOF variants described in previous studies (red) (Martinez-Barricarte et al., 2018; Philippot et al., 2023), from the general population (gray dots), and other homozygous variants found in our in-house cohort (black triangles). The four hypomorphic variants are presented in different colors. MSC, mutation significance cutoff score with a 99% CI. CADD, combined annotation-dependent depletion. (B) Same graph as Fig. 2 C with an adjusted y axis, illustrating the saturable binding of IL-23–TAMRA to NLuc IL23R G300V/IL-12Rβ1, but with a low maximum BRET window. (C) HEK cells were transiently transfected with N-terminal NanoLuciferase-tagged versions of the WT or variants of the IL-23 receptor (NLuc IL-23R, NLuc IL-23R R381Q, NLuc IL-23R G300V, NLuc IL-23R G149R, or NLuc IL-23R L372F) and N-terminal HaloTag IL-12Rβ1. Emitted luminescence and fluorescence emissions were measured with a BMG PheraStar FS. The data shown are the mean ± SEM from five independent experiments performed in triplicate wells. Statistical significance was determined by one-way ANOVA with Tukey’s post hoc analysis for multiple comparisons with **P < 0.01, ***P < 0.001. (D) Western blot of pSTAT3 after the stimulation with 1 ng/ml or 10 ng/ml IL-23 stimulation of EBV–B cell from healthy controls (green), IL23RR381Q/R381Q (violet), IL23RG300V/G300V (orange), IL23RG149R/G149R, and IL23R LOF (red) homozygotes. IFN-α stimulation was used as a positive control. The representative of at least two independent experiment is showed. (E) Pedigrees of the kindreds studied in this report. The gene and variants are indicated above the kindreds. The clinical phenotype of each symptomatic patient is indicated by different shaded shapes, as described at the bottom of the figure. Symbols linked with a double line indicate consanguinity. The genotype is indicated under each symbol, with M corresponding to the variant found in each kindred. Arrows indicate the index case in each family. E?: Unavailable clinical or genotype information. Source data are available for this figure: SourceData FS2.