ANKRD55 is a key regulator of T cell inflammation in multiple sclerosis
Chuyu Wu, Meiling Jiang, Xue Yang, Yixuan Liu, Bin Huang, Yi Guo, Runjing Cao, Zhihui Cui, Guozhen Deng, Weiyan Wang, Mengdi Guo, Zhiyong Lin, Jiahui Fan, Lin-ming Zhang, Lorenzo Di Cesare Mannelli, Tao Pang, Chenhui Wang, Cun-Jin Zhang
Chuyu Wu, Meiling Jiang, Xue Yang, Yixuan Liu, Bin Huang, Yi Guo, Runjing Cao, Zhihui Cui, Guozhen Deng, Weiyan Wang, Mengdi Guo, Zhiyong Lin, Jiahui Fan, Lin-ming Zhang, Lorenzo Di Cesare Mannelli, Tao Pang, Chenhui Wang, Cun-Jin Zhang
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Research Article Autoimmunity Immunology

ANKRD55 is a key regulator of T cell inflammation in multiple sclerosis

Abstract

Multiple sclerosis (MS) is a progressive, chronic, and highly disabling neuroinflammatory disorder characterized by demyelination and T cell–driven inflammation. Pathogenic T cells play a central role in MS, but effective therapeutic targeting remains challenging. Here, we identified ankyrin repeat domain–containing protein 55 (ANKRD55) as a key regulator of T cell function by single-cell transcriptomic analysis of cerebrospinal fluid and blood from MS patients. ANKRD55 was predominantly expressed in CD4+ T cells in both compartments. Genetic ablation of Ankrd55 led to a robustly reduced disease severity and neuroinflammation in experimental autoimmune encephalomyelitis (EAE), a widely used animal model for MS. Furthermore, T cell–specific deficiency of Ankrd55 significantly impaired Th1 polarization and Th17 differentiation, reducing EAE pathogenicity. Mechanistically, we found that Ankrd55 deficiency disrupted T cell receptor (TCR) signaling integrity. We demonstrated that ANKRD55 regulates the formation of the immune synapse, an essential prerequisite for TCR activation, by interacting with subunits of the chaperonin-containing TCP1 (CCT) complex and modulating its activity, enhancing its assembly by competing with CCT5 for binding to TCP1, CCT3, and CCT6. This facilitates proper microtubule organization and TCR activation. These findings establish ANKRD55 as a critical regulator of TCR signaling and highlight its therapeutic potential in pathogenic T cell–driven autoimmune diseases.

Authors

Chuyu Wu, Meiling Jiang, Xue Yang, Yixuan Liu, Bin Huang, Yi Guo, Runjing Cao, Zhihui Cui, Guozhen Deng, Weiyan Wang, Mengdi Guo, Zhiyong Lin, Jiahui Fan, Lin-ming Zhang, Lorenzo Di Cesare Mannelli, Tao Pang, Chenhui Wang, Cun-Jin Zhang

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Figure 7

ANKRD55 affects CCT complex assembly by competing with CCT5 binding to CCT1/3/6, thus promoting immune synapse formation and TCR activation.

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ANKRD55 affects CCT complex assembly by competing with CCT5 binding to C...
(A and B) α-Tubulin immunoblotting in lysates and pellet determined by microtubule sedimentation assay in Jurkat cells with TCP1 (A) or ANKRD55 (B) knocked down. (C) TCP1 degradation rate analyzed via immunoblot after cycloheximide (CHX; 70 μM) treatment for 0–48 hours in control and Jurkat cells overexpressing ANKRD55. (D–F) Co-IP detection of interactions between CCT5 and TCP1 (D), CCT3 (E), or CCT6 (F) at varying concentrations of ANKRD55 in HEK293T. (G) Immunofluorescence analysis of immune synapse formation between Jurkat and Raji cells. Jurkat cells were prelabeled with CMAC. Raji cells were stimulated with SEE for 30 minutes. The 2 cell types were then cocultured for 30 minutes. Cells were stained with antibodies against ANKRD55, TCP1, pericentrin, and α-tubulin to visualize protein localization at the immune synapse. Scale bars: 2 μm. BF, bright-field; CMAC, CellTracker blue fluorescent probe. (H) Flow cytometry–based immune synapse (IS) pattern analysis. (I and J) Raji cells (APCs) stained with CFSE and stimulated with SEE for 30 minutes at 37°C and Jurkat cells (T cells) stained with CMTPX. T cell conjugation with APCs after 20 minutes of contact was analyzed by flow cytometry. Conjugate percentages were determined for Jurkat cells with ANKRD55 or TCP1 knocked down (I) and pretreatment with HSF1A (50 μM) for 2 hours (J). (K) Mean clinical score of EAE in mice injected intraperitoneally with PBS or HSF1A (20 mg/mL) (n = 7 or 8 mice per group), induced by active immunization with MOG35–55. (L) Immunoblot analysis of TCR signaling in Jurkat cells. Cells included vector control, a stable ANKRD55-overexpressing cell line, and ANKRD55-overexpressing cells pretreated with HSF1A (50 μM, 2 hours). All groups were stimulated on plates coated with anti-CD3 and anti-CD28. Lysates were collected at the indicated time points (1, 2, 15, and 30 minutes) and probed for TCR signaling–associated proteins. (M) H&E and Luxol fast blue (LFB) staining of spinal cord sections at the peak of EAE disease. Arrows indicate areas of demyelination. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, by 2-way ANOVA with Tukey’s multiple-comparison test. Data are shown as mean ± SEM.