bims-actimu Biomed News
on Actinopathies in inborn errors of immunity
Issue of 2025–06–29
three papers selected by
Elodie Busch, University of Strasbourg



  1. EClinicalMedicine. 2025 Jun;84 103271
       Background: Wiskott-Aldrich Syndrome (WAS) is characterized by eczema, infections, and severe bleeding, but may also include autoimmunity and malignancy. Subjects with X-linked thrombocytopenia (XLT) can display a mild phenotype, although severe complications may occur at any age. WAS and XLT are caused by mutations of the WAS gene. However, retrospective studies have shown conflicting results about their genotype-phenotype correlation and their relative risk of complications.
    Methods: To evaluate the outcome of patients with WAS or XLT, since January 2004, patients with identified WAS mutations were enrolled in the WAS/XLT IPINet registry at diagnosis and annually evaluated until December 2018 by participating AIEOP-IPINet centers; data were prospectively collected by each participating center throughout a web-based centralized system and then retrieved from the registry for the analysis. This prospective study enrolled 117 patients (according to Zhu criteria, 92 were affected by WAS and 25 by XLT) with appropriate hematological features and documented WAS mutation.
    Findings: The median follow-up was 6 years (range 1-30 years), resulting in 1110 patient years. At diagnosis, only the patients with WAS presented invasive infections, such as sepsis, meningitis, cerebral abscesses, herpetic infections, and candida infections, while patients with XLT did not present invasive infections. The most common autoimmune manifestations in patients with WAS were hemolytic anemia (20%) and vasculitis (9.3%), inflammatory bowel disease (5%), arthritis (4%), nephropathy (2%), and coeliac disease (1%). Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) was performed in 71 (61%), autologous hematopoietic stem cell gene therapy (HSC-GT) in 10 (8.5%), splenectomy in 16 (14%) patients, while 26 patients (22%) received none of these therapies. The overall survival at 25-year follow-up was 75% for patients with WAS after HSCT. Considering the cut-off date year 2000, it improved to >80%. Patients with WAS treated by haploidentical HSCT with αβTCRT-/CD19 B-cell depletion or gene therapy showed 100% survival at 5 years. The overall survival rate at the 20-year follow-up of the 25 patients with XLT was 83% but with a cumulative incidence of 100% and 19% of infections and autoimmunity, respectively, at the 15-year follow-up.
    Interpretation: The evidence of the heterogeneity of WAS and XLT outcomes could be instrumental to draw updated recommendations for the management of the patients affected by these rare conditions. It would be desirable to expand the tools to estimate the risk of infectious and autoimmune events in patients with XLT and the impact of their treatment, including HSCT over time.
    Funding: This study was funded by the European Union-Next Generation EU-NRRP M6C2-Investment 2.1 Enhancement and strengthening of biomedical research in the NHS, Ministero della Salute (PNRR-MR1-2022-12376594). A.S., A.A., P.C., F.F., C.M.P., C.F., D.L., G.S., M.D., M.C., P.A., B.A., P.F. are part of the European Reference Network on Rare Primary Immunodeficiency, Autoinflammatory and Autoimmune Diseases (ERN-RITA, project 739543).
    Keywords:  Disease-related events; Management; Overall survival; Wiskott-Aldrich syndrome; X-linked thrombocytopenia
    DOI:  https://doi.org/10.1016/j.eclinm.2025.103271
  2. Sci Immunol. 2025 Jun 26. eadt9239
      Immune cells navigate through complex tissue architectures by extensive cellular deformation, low adhesion, and high cell velocities. Loss-of-function mutations in Dedicator of Cytokinesis 8 (Dock8) are associated with immunodeficiency as immune cells becoming entangled during migration through dense environments, but their migration on two-dimensional surfaces remains entirely intact. Here we investigated the specific cytoskeletal defect of Dock8-deficient activated T cells and describe a central pool of F-actin in wild-type murine and human T cells that is absent in Dock8 knockout T cells. The appearance of the central actin pool is mechanoresponsive and emerges only when cells are very confined. We identified mammalian sterile 20-like (Mst1) as a necessary component in this mechanosensitive pathway in addition to Dock8, allowing for cell shape integrity and survival during migration through complex environments. Our work shows that loss of the central actin pool results in greater nuclear deformation, accrual of DNA damage, and premature cell senescence.
    DOI:  https://doi.org/10.1126/sciimmunol.adt9239
  3. Curr Opin Cell Biol. 2025 Jun 25. pii: S0955-0674(25)00103-6. [Epub ahead of print]95 102565
      Arp2/3 complex is a central actin filament generator driving numerous motile processes in cells. It was originally isolated from Acanthamoeba approx. 30 years ago. It is highly conserved throughout eukaryotic life and composed of 7 subunits, two of which are actin related proteins, ARP2 and ARP3. Since then the modalities of its regulation were continuously unraveled, bringing about a large number of proteins that affect its activity. We here set out to briefly review our current knowledge and identify open questions that demand answers and add new twists, advancing our understanding to reflect physiological complexity.
    DOI:  https://doi.org/10.1016/j.ceb.2025.102565