Aiolos promotes CXCR3 expression on Th1 cells via positive regulation of IFN-γ/STAT1 signaling
Melissa R. Leonard, … , Jacob S. Yount, Kenneth J. Oestreich
Melissa R. Leonard, … , Jacob S. Yount, Kenneth J. Oestreich
Published November 19, 2024
Citation Information: JCI Insight. 2025;10(1):e180287. https://doi.org/10.1172/jci.insight.180287.
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Research Article Immunology Infectious disease

Aiolos promotes CXCR3 expression on Th1 cells via positive regulation of IFN-γ/STAT1 signaling

Abstract

CD4+ T helper 1 (Th1) cells coordinate adaptive immune responses to intracellular pathogens, including viruses. Key to this function is the ability of Th1 cells to migrate within secondary lymphoid tissues, as well as to sites of inflammation, which relies on signals received through the chemokine receptor CXCR3. CXCR3 expression is driven by the Th1 lineage-defining transcription factor T-bet and the cytokine-responsive STAT family members STAT1 and STAT4. Here, we identify the Ikaros zinc finger (IkZF) transcription factor Aiolos (Ikzf3) as an additional positive regulator of CXCR3 both in vitro and in vivo using a murine model of influenza virus infection. Mechanistically, we found that Aiolos-deficient CD4+ T cells exhibited decreased expression of key components of the IFN-γ/STAT1 signaling pathway, including JAK2 and STAT1. Consequently, Aiolos deficiency resulted in decreased levels of STAT1 tyrosine phosphorylation and reduced STAT1 enrichment at the Cxcr3 promoter. We further found that Aiolos and STAT1 formed a positive feedback loop via reciprocal regulation of each other downstream of IFN-γ signaling. Collectively, our study demonstrates that Aiolos promotes CXCR3 expression on Th1 cells by propagating the IFN-γ/STAT1 cytokine signaling pathway.

Authors

Melissa R. Leonard, Devin M. Jones, Kaitlin A. Read, Srijana Pokhrel, Jasmine A. Tuazon, Robert T. Warren, Jacob S. Yount, Kenneth J. Oestreich

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Figure 1

CXCR3 expression is reduced on Aiolos-deficient Th1 cells.

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CXCR3 expression is reduced on Aiolos-deficient Th1 cells. (A) Published...
(A) Published RNA-Seq data (GSE203065) from in vitro–generated WT and Ikzf3–/– Th1 cells were assessed for differentially expressed genes (DEGs). A volcano plot displays gene expression changes at day 3. Genes are color-coded: no significant changes (gray), upregulated genes with > 1.5-fold change with P < 0.05 (red), downregulated genes with > 1.5-fold change with P < 0.05 (blue), and selected genes of interest (turquoise). (B) Schematic of Th1 cell culturing system. Naive CD4+ T cells were stimulated with anti-CD3/CD28 (α-CD3/CD28) under Th1-polarizing conditions (IL-12, α-IL-4). On day 3, cells were harvested or removed from stimulation and placed into fresh Th1 conditions with IL-2 for an additional 2 days. (C) At day 3, transcript analysis was performed via quantitative reverse transcription PCR (qRT-PCR). Transcript was normalized to Rps18 and presented as fold-change compared with WT control (n = 10 biological replicates from 10 independent experiments, mean ± SEM; ****P < 0.0001, 2-tailed unpaired Student’s t test). (D) Representative flow cytometric analysis for CXCR3 on day 3 Th1 cells. Data displayed as median fluorescence intensity (MFI) fold-change compared with WT controls (n = 6 biological replicates from 6 independent experiments, mean ± SEM; ***P < 0.001, 2-tailed unpaired Student’s t test). (E) At day 5, transcript analysis was performed as in C (n = 9 biological replicates from 9 independent experiments, mean ± SEM; ****P < 0.0001, 2-tailed unpaired Student’s t test). Note: Cxcr3 and Ikzf3 transcript data presented here are the same as in Figure 5B. (F) Representative flow cytometric analysis for CXCR3 on day 5 Th1 cells. Data displayed as MFI fold-change compared with WT controls (n = 5 biological replicates from 5 independent experiments, mean ± SEM; ****P < 0.0001, 2-tailed unpaired Student’s t test).