Explore the vast range of titles available.

Patients with Wiskott–Aldrich syndrome (WAS) lacking a human leukocyte antigen-matched donor may benefit from gene therapy through the provision of gene-corrected, autologous hematopoietic stem/progenitor cells. Here, we present comprehensive, long-term follow-up results (median follow-up, 7.6 years) (phase I/II trial no. NCT02333760 ) for eight patients with WAS having undergone phase I/II lentiviral vector-based gene therapy trials (nos. NCT01347346 and NCT01347242 ), with a focus on thrombocytopenia and autoimmunity. Primary outcomes of the long-term study were to establish clinical and biological safety, efficacy and tolerability by evaluating the incidence and type of serious adverse events and clinical status and biological parameters including lentiviral genomic integration sites in different cell subpopulations from 3 years to 15 years after gene therapy. Secondary outcomes included monitoring the need for additional treatment and T cell repertoire diversity. An interim analysis shows that the study meets the primary outcome criteria tested given that the gene-corrected cells engrafted stably, and no serious treatment-associated adverse events occurred. Overall, severe infections and eczema resolved. Autoimmune disorders and bleeding episodes were significantly less frequent, despite only partial correction of the platelet compartment. The results suggest that lentiviral gene therapy provides sustained clinical benefits for patients with WAS. Long-term monitoring of patients with Wiskott–Aldrich syndrome following lentiviral gene therapy shows a safe profile and a reduction in the frequency of autoimmune manifestations and bleeding events, despite incomplete platelet reconstitution.

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency with severe platelet abnormalities and complex immunodeficiency. Although clinical gene therapy approaches using lentiviral vectors have produced encouraging results, full immune and platelet reconstitution is not always achieved. Here we show that a CRISPR/Cas9-based genome editing strategy allows the precise correction of WAS mutations in up to 60% of human hematopoietic stem and progenitor cells (HSPCs), without impairing cell viability and differentiation potential. Delivery of the editing reagents to WAS HSPCs led to full rescue of WASp expression and correction of functional defects in myeloid and lymphoid cells. Primary and secondary transplantation of corrected WAS HSPCs into immunodeficient mice showed persistence of edited cells for up to 26 weeks and efficient targeting of long-term repopulating stem cells. Finally, no major genotoxicity was associated with the gene editing process, paving the way for an alternative, yet highly efficient and safe therapy. In recent years, hematopoietic stem cells gene editing has emerged as a promising tool to treat blood disorders. Here the authors develop a CRISPR/Cas9-based genome editing strategy that allows the precise correction of Wiskott-Aldrich Syndrome in vitro and in vivo with high efficiency.

Purpose Wiskott-Aldrich syndrome (WAS) is an X-linked genetic disorder characterized by distinctive features including microthrombocytopenia, eczema and recurrent infections. In the present study we report clinical, immunological and molecular spectrum of 41 WAS patients diagnosed over last five years. Methods Clinical and family history was collected from case records. Comprehensive immunological assessments including lymphocyte subset analysis, and flow cytometry based evaluation of WAS protein (WASP) expressions were performed in patients along with evaluation of carrier status in mothers. Genetic analysis was carried out with either Sanger sequencing or targeted exome sequencing. Results The patients included in this study presented at a median age of 9.5 months, with two adult cases. Clinical manifestations encompassed thrombocytopenia, eczema, bleeding, diarrhea, respiratory tract infections, CMV infection, and malignancy. Immunological phenotype revealed T cell lymphopenia, B cell lymphopenia, and elevated IgE levels. Flow cytometry analysis of WASP was performed in 36 cases out of which 68.42% demonstrated complete absent expression while others showed reduced expression. Genetic analysis highlighted that the majority of mutations affect the WH1 domain of WASP while both adult patients showed intronic mutations. Molecular Dynamics analysis conducted for the novel variants P398R and G33R showed an average RMSD (Å) higher than that of the wild type, indicating greater structural perturbations in WASP. Conclusion In the present study we have documented 56.09% novel WAS mutations in Indian cohort. Notably, the application of flow cytometry has emerged as a valuable and efficient diagnostic tool for identifying these WAS patients.

Key Points Wiskott–Aldrich Syndrome protein (WASP) is an important regulator of the actin cytoskeleton in haematopoietic cells. WASP-deficiency gives rise to the human disease Wiskott–Aldrich Syndrome (WAS), an X-linked primary immunodeficiency. Constitutively active mutations of WASP have recently been described to give rise to a distinct human disease: X-linked neutropenia. WASP activity is attenuated by multiple signalling pathways downstream of surface receptors. Conformational change, phosphorylation and degradation are important mechanisms. Although WASP does not seem to have a key role in haematopoiesis, WASP confers selective advantage for many mature haematopoietic cell types and is emerging as a key regulator of lymphocyte homeostasis. WASP is required for a diverse range of cell functions in innate and adaptive immune cells. These relate both to the role of WASP in cytoskelatal rearrangement and as an intrinsic signalling molecule. Autoimmunity is an important feature of WAS which is poorly understood. Recent studies suggest that defective regulatory T cell function is an important component. Insights into the basic mechanisms of WASP-associated disease are advancing our understanding of immune regulation with wider application, and this allows the potential for future therapeutic benefit. As a key regulator of the actin cytoskeleton, Wiskott–Aldrich syndrome protein (WASP) is involved in diverse immune responses, including leukocyte migration and activation. This Review describes how various mutations in mice and humans have led us to a greater appreciation of the many immunological functions of WASP. The Wiskott–Aldrich syndrome protein (WASP) is an important regulator of the actin cytoskeleton that is required for many haematopoietic and immune cell functions, including effective migration, phagocytosis and immune synapse formation. Loss of WASP activity leads to Wiskott–Aldrich syndrome, an X-linked disease that is associated with defects in a broad range of cellular processes, resulting in complex immunodeficiency, autoimmunity and microthrombocytopenia. Intriguingly, gain of function mutations cause a separate disease that is mainly characterized by neutropenia. Here, we describe recent insights into the cellular mechanisms of these two related, but distinct, human diseases and discuss their wider implications for haematopoiesis, immune function and autoimmunity.

Purpose Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency characterized by eczema, microthrombocytopenia, and recurrent infections. This study evaluates the frequency of clinical manifestations and overall outcomes in WAS patients, comparing those who received hematopoietic stem cell transplantation (HSCT) with those who did not. Methods Thirty-eight boys with a definite diagnosis of WAS were retrospectively evaluated in the Immunology, Asthma, and Allergy Research Institute registry in Tehran from 2006 to 2023. Results The median ages at symptom onset, diagnosis, and delay to diagnosis were 3.5, 7.5, and 4.5 months, respectively. The clinical presentations include allergies in 38 (100%), infection in 37 (97.4%), hemorrhage in 36 (94.7%), autoimmunity in 14 (36.8%), and malignancies or myelodysplasia syndrome in 3 (7.9%) patients. Although microthrombocytopenia is a hallmark of WAS, 34.4% of our cases had normal platelet size. The WAS gene analysis in 36 of 38 patients identified six novel mutations. Sixteen patients underwent HSCT. Disease-free survival was reported in 10 (62.5%) of them, whereas 6 (37.5%) of them were deceased. The mortality rate in non-transplant patients was 15/22 (68.2%). Conclusion Most WAS patients experienced atopy, recurrent infections, and bleeding. Moreover, autoimmunity and malignancies have increased relative to the general population. Moreover, the mortality rate is high, especially among those who did not receive HSCT. Keeping in mind that thrombocytopenia alongside eczema and/or infection in a male infant can be the presentation of this fatal disease. Early diagnosis and treatment could be lifesaving and prevent severe morbidities.

Wiskott–Aldrich syndrome (WAS) is caused by mutations in the WAS gene and is characterized by immunodeficiency, eczema and microthrombocytopenia. The molecular link between WAS mutations and microthrombocytopenia is unknown. Profilin1 (Pfn1) is a key actin-regulating protein that, besides actin, interacts with phosphoinositides and multiple proline-rich proteins, including the WAS protein (WASp)/WASp-interacting protein (WIP) complex. Here we report that mice with a megakaryocyte/platelet-specific Pfn1 deficiency display microthrombocytopenia due to accelerated turnover of platelets and premature platelet release into the bone marrow. Both Pfn1-null mouse platelets and platelets isolated from WAS patients contained abnormally organized and hyperstable microtubules. These results reveal an unexpected function of Pfn1 as a regulator of microtubule organization and point to a previously unrecognized mechanism underlying the platelet formation defect in WAS patients. Patients with mutations in the gene encoding the cytoskeleton regulator WAS have platelet defects. Here the authors show that the WAS-binding protein, Profilin1, is essential for platelet formation in mice, and that its deficiency reproduces the bleeding disorder of patients with WAS mutations.

Wiskott-Aldrich syndrome (WAS) is a rare x-linked monogenic immunodeficiency disease, caused by the mutation of WAS gene encoding WAS protein (WASp). Previous findings in WAS patients show B cell perturbations in the periphery, characterized by diminished B-cell numbers and phenotype abnormalities, including reduced frequency of classical CD27 + memory B cells (MBCs), accompanied by an unusual expansion of atypical CD21low MBCs. The mechanism underlying these abnormalities in MBCs developmental pathway has not been completely dissected. In this study, WASp knock-out mice undergone with acute lymphocytic choriomeningitis virus (LCMV) infection was used as a model to investigate the effects of WASp deficiency on the differentiation of MBCs and the possible mechanisms. We found that by day 11 after infection, the proportion of classical IgG2c + MBCs was dramatically decreased, this was accompanied by a corresponding increase in the proportion of atypical CD21low MBCs. Using single-cell RNA sequencing (scRNA-seq), we also identified WASp deficiency promoted the formation of atypical MBCs during acute viral infection. Remarkably, our study revealed a marked reduction of WASp expression in atypical MBCs. Overall, our data show that WASp is differentially expressed in MBCs subsets, and manipulates the fate of MBCs during acute LCMV infection.

The authors report the long-term (up to 3 years) correction of the Wiskott–Aldrich syndrome in two patients through retroviral infection of CD34+ hematopoietic cells after busulfan-induced transient myelosuppression. The Wiskott–Aldrich syndrome (WAS) is a complex primary immunodeficiency disorder that is characterized by recurrent infections, thrombocytopenia, eczema, and autoimmunity 1 , 2 and caused by mutations in WAS . 3 Its gene product, WAS protein (WASP), is a key regulator of actin polymerization in hematopoietic cells, with domains involved in signaling, cell locomotion, and immunologic-synapse formation. 4 The complex biologic features of this disease result from multiple dysfunctions in different subgroups of leukocytes, including defective function of T and B cells, disturbed formation of the NK-cell immunologic synapse, and impaired migratory responses in all leukocyte subgroups. 4 , 5 Severe WAS leads to an early . . .

Non-small-cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer which is the deadliest type of cancer for both men and women. Previous studies already showed that cell-intrinsic loss of WASp causes B cell tolerance and WASp deficiency in T helper (T H ) cells is linked to negative effects on cytokine gene transcription necessary for T H 1 differentiation. In the current study, we investigated the molecular mechanisms involved in WASp-mediated epigenetic regulation of B cell differentiation during NSCLC. Our ChIP-qPCR data suggest the less percentage enrichment of the B cell differentiating factors (Ikaros, Pax5, PU.1, BATF) and WASp across the WAS gene in the B cells of NSCLC patients in comparison with normal healthy donors and overexpression of WASp showed the reverse effects. WASp-depleted B cells while co-culturing with respective PBMCs isolated from normal healthy donors and NSCLC patients, we observed upregulation of T H 2-, T H 17-, and Treg-specific cytokines (IL4, ILI7A, IL10) & transcription factors (GATA3, RORC, FOXP3) and downregulation of T H 1-specific cytokine (IFNγ) & transcription factor (TBX21). Our study showed that the overexpression of WASp resulted into upregulation of B cell differentiating factors, tumor suppressor protein (p53), histone methylation marker (H3K4me3) with concomitant downregulation of tumor-promoting factors (Notch 1, β-Catenin, DNAPKcs) and histone deacetylation marker (HDAC2) and increase in percentage cytotoxicity of NSCLC-specific cells (A549). Successful overexpression of WASp not only helps in epigenetic regulation of B cell differentiation but also supports tumor suppression in NSCLC. Thus, WASp can be targeted for therapeutic intervention of NSCLC. Graphical abstract

The actin nodule is a novel F-actin structure present in platelets during early spreading. However, only limited detail is known regarding nodule organization and function. Here we use electron microscopy, SIM and dSTORM super-resolution, and live-cell TIRF microscopy to characterize the structural organization and signalling pathways associated with nodule formation. Nodules are composed of up to four actin-rich structures linked together by actin bundles. They are enriched in the adhesion-related proteins talin and vinculin, have a central core of tyrosine phosphorylated proteins and are depleted of integrins at the plasma membrane. Nodule formation is dependent on Wiskott–Aldrich syndrome protein (WASp) and the ARP2/3 complex. WASp −/− mouse blood displays impaired platelet aggregate formation at arteriolar shear rates. We propose actin nodules are platelet podosome-related structures required for platelet–platelet interaction and their absence contributes to the bleeding diathesis of Wiskott–Aldrich syndrome. During early platelet spreading a novel F-actin structure forms, called the actin nodule. Here Poulter et al. demonstrate that actin nodule formation depends on WASp and the Arp2/3 complex, and using super-resolution microscopy they show that nodules bear a structural resemblance to podosomes.