Fig 2: Defective TFh cells in HBV T mothers. (A) Sequential gating strategy of CD4+CXCR5+TFh cells and ICOS+TFh cells and dot plot graph showing the percentage frequencies of TFh cells and ICOS+TFh cells in mothers and newborns. (B) Serum IL‐21 levels in mothers. (C) Frequencies of IFN‐γ‐ and IL‐17A‐producing HBV‐specific CD4+CXCR5+ TFh cells in mothers and newborns. Horizontal short bars indicate the mean ± SEM. P < 0.05 is considered significant and represented as *P < 0.05, **P < 0.01, and ***P < 0.001. (D) Spearman's rank correlation showing the scattered diagram of TFh cells and HBV DNA. (E,F) ROC analysis of TFh cells for the transmission of HBV in mothers and newborns showing cutoff, % area under the curve, and P value.

Fig 3: CRISPR/CAS9-based deletion of accessible, promoter-connected genomic regions harboring SLE variants influences TFH gene expression.a, CRISPR–CAS9 targeting of the 136 bp OCR near the TREH gene harboring the rs527619 (r2 = 0.51) and rs71041848 (r2 = 0.44) SLE proxy SNPs and captured interacting with the CXCR5 promoter leads to increased CXCR5 expression (blue histogram) by Jurkat cells compared to cells transduced with a CTRL-gRNA+CAS9 (pink histogram). b CRISPR–CAS9 targeting of the 213 bp OCR containing the rs4385425 SLE proxy (r2 = 0.99) to rs11185603 and captured interacting with the IKZF1 promoter leads to increased IKZF1 (Ikaros) expression (blue histogram) by Jurkat cells compared to cells transduced with a CTRL-gRNA+CAS9 (pink histogram). c CRISPR–CAS9 targeting of the LPP SLE proxies rs34631447 (r2 = 1.0) and rs79044630 (r2 = 0.8) captured interacting with the BCL6 promoter abrogates IFNg-induced BCL-6 expression (orange histogram) compared to cells transduced with a CTRL-gRNA+CAS9 (blue histogram). The red histogram shows BCL-6 expression by unstimulated Jurkat cells. Graphs in a–c depict biological replicate (circles) and mean (bars) fluorescence intensities (upper panels) and biological replicate (circles) and mean (bars) percent positive cells (lower panels) ±SEM (error bars) for CXCR5, Ikaros, and BCL-6 in control gRNA-tranduced vs. targeted cells. All data are representative of three independent experiments. See Supplementary Fig. 7 for design and validation of CRISPR/CAS9-mediated deletion and mutation. Source data are provided as a Source Data file.

Fig 4: SLE variant-to-gene mapping implicates drug targets for modulation of TFH function.a The interactomes of SLE proxies rs11552449 (r2 = 0.97), rs71368520 (r2 = 0.5), and rs71368521 (r2 = 0.5) implicate HIPK1 and MINK1. b Purified naive CD4+ T cells cultured under neutral (Tact) or TFH-skewing (TFH) conditions show increased expression of PD-1 and CXCR5, as well as BCL-6 (c). d HIPK1 mRNA expression by in vitro-differentiated TFH cells transduced with scrambled Lenti-shRNA or Lenti-HIPK-1 shRNA. e shRNA-mediated knock-down of HIPK1 inhibits IL-21 secretion by TFH cells. A HIPK inhibitory drug causes dose-dependent inhibition of IL-21 production (f) and expression of several SLE-associated gene (g) by TFH cells. All data in e and f are mean ± SEM and are representative of three independent experiments. Data in g depict the mean (columns) ± SEM (error bars) normalized gene expression by three individual donor T cell cultures (circles). Statistical significance of the effect of HIPK inhibition was determined by t-test (two-tailed). P values are: BACH2, 0.01; SPRED2, 0.02; IL2RB, 0.03; ARID5B, 0.03; PD1, 0.04; IL6R, 0.04; PTPN22, 0.05; IL21, 0.06. Source data are provided as a Source data file.

Fig 5: IL21-AS1 is positively associated with IL-2 expression and activated Tfr cells. A The relative mRNA expression levels of IL21-AS1, IL2, and IL21 were analyzed in the isolated PBMCs of patients with SLE (n = 53). Correlation of IL21-AS1 level with IL2 and IL21 in patients with SLE. B, C PBMCs were isolated from the peripheral blood of patients with SLE (n = 29), and they were analyzed using flow cytometry without incubation and qPCR. B Gating strategy was employed to identify Tfh (CD4+CXCR5+Foxp3-), Tfr (CD4+CXCR5+Foxp3+), Tconv (CD4+CXCR5-Foxp3-), PD-1hi Tfh (CD4+CXCR5+Foxp3-PD-1hi), Tph (CD4+CXCR5-Foxp3-PD-1hi), rTfr (CD4+CXCR5+CD45RA+Foxp3lo), aTfr (CD4+CXCR5+CD45RA-Foxp3hi), and ns-Tfr (CD4+CXCR5+CD45RA-Foxp3lo) cells. C Correlation of IL21-AS1 level with the percentage of PD-1hi Tfh cell, Tph cell, Tfr cell subsets, and aTfr/PD-1hi Tfh ratio in patients with SLE (n = 29). Data symbols represent individual subjects; Spearman’s test was used for the correlation analysis between two variables of interest