Journal of Clinical Immunology最新文献

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.

Purpose: Immunodysregulation, Polyendocrinopathy, Enteropathy, and X-linked (IPEX) syndrome is a rare autoimmune disorder caused by mutations in the FOXP3 gene. Patients with IPEX frequently present with severe dermatitis, diabetes, and enteropathy. This study explores the efficacy of Dupilumab (an anti-IL-4Rα monoclonal antibody) in treating persistent, severe dermatitis in an IPEX patient refractory to conventional treatments like sirolimus.

Methods: We conducted a clinical case study of a 2-year-old IPEX patient with refractory dermatitis. Whole-exome sequencing (WES) confirmed the FOXP3 mutation. Skin biopsies were analyzed for inflammatory gene expression by RNA sequencing and immunohistochemistry to characterize inflammatory pathways. Immune cell phenotyping was performed using flow cytometry pre- and post-treatment in peripheral blood mononuclear cells (PBMCs). The patient was treated with Dupilumab alongside sirolimus and prednisone. Clinical improvements were evaluated using the Eczema Area and Severity Index (EASI) score.

Results: Immunohistochemistry revealed elevated IL-13 expression. RNA sequencing of skin samples revealed upregulation of both Th1- and Th2-related genes, suggesting a dual inflammatory phenotype in IPEX dermatitis. The patient exhibited significant clinical improvement after 8 months of sustained Dupilumab therapy, with the EASI decreasing from 24.8 to 0.4. Flow cytometry demonstrated a reduction in Th1 and Th2 cell subsets post-treatment, accompanied by an increase in Treg and Th3 cell populations as well as enhanced expression of immunosuppressive markers such as CTLA-4 and CD39.

Conclusion: Dupilumab appears promising as a therapeutic option for managing refractory dermatitis in IPEX, particularly by attenuating Th1/Th2 inflammation and promoting regulatory responses mediated by Treg and Th3 cells.

Purpose: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is successful in pediatric patients with inborn errors of immunity (IEI), but its use in adults is complicated by pre-existing organ damage and increased risk of treatment-related mortality. Ex vivo graft engineering using αβTCR/CD19 depletion has shown promising safety profiles in pediatric IEI, yet evidence in adults is limited. We assessed the feasibility and outcomes of αβTCR/CD19-depleted allo-HSCT in adults with IEI, focusing on engraftment, immune reconstitution, and clinical outcomes.

Methods: We included 9 adults with IEI and 1 with VEXAS (age 21-51). IEIs included CTLA4HI, APDS, DOCK8, ALPS, DADA2, CVID2, and HA20, with Immune Deficiency and Dysregulation Activity (IDDA) scores of 17-92. αβTCR/CD19-depleted allografts from related, unrelated or haplo-identical donors were used after antithymocyte globulin (ATG) and myeloablative conditioning (thiotepa, melphalan, and fludarabine). Post-transplant immunoprophylaxis included mycophenolate mofetil; 4/10 patients received additional transplant-associated immunosuppression.

Results: All patients achieved primary engraftment. One patient with secondary rejection successfully underwent a second allo-HSCT. 5 patients developed grade 2-4 acute GvHD; no chronic GvHD was observed. One patient with GvHD died from COVID-19. All remaining 9 patients were successfully tapered off immunosuppression and showed improved IDDA scores. At 6 months NK, γδT, B and CD8 + T cells normalized; CD4 + numbers reached 149 cells/µl at 1 year. Most patients were successfully vaccinated and could stop immunoglobulin substitution.

Conclusion: In conclusion, ex vivo graft engineering using αβTCR/CD19 depletion was feasible in adults with IEI. Clinical outcomes are encouraging, but need to be confirmed in larger studies.

Purpose: 22q11.2 Deletion Syndrome has been primarily described as a disorder of T cell production secondary to thymic hypoplasia. However, there is great complexity in the clinical picture with infections, autoimmunity, and inflammation occurring. Emerging evidence suggests that qualitative T cell dysfunction occurs, and the goal of this study was to utilize single-cell RNA-seq to better define altered gene expression patterns to inform on the mechanisms associated with recurrent infections.

Methods: We utilized single-cell RNA-seq to define distinct populations in 22q11.2 Deletion Syndrome (N = 13) and controls (N = 11) as well as within a subcohort of patients with 22q11.2 Deletion Syndrome and recurrent infections.

Results: When we analyzed differentially expressed genes, we identified a signature of type I interferons across all cell types. Within the T cell compartment, and particularly within the follicular helper T cells, we identified a senescence signature. The alterations found in T cells were most substantial in the patients with recurrent infection.

Conclusions: While T cell numbers can often normalize in patients with 22q11.2 Deletion Syndrome, our data indicate significantly altered function as defined by differentially expressed genes and aligned with what is known about T cell senescence. The effect was greatest in the patients with recurrent infection. This would be expected to impact T cell function and may account for ongoing symptoms, reduced B cell maturation, and possibly the risk of immune dysregulation.

Behçet's disease (BD) is a chronic inflammatory disorder characterized by recurrent oral aphthous ulcers, genital ulcers, skin lesions, and uveitis. Recent genetic studies have identified monogenic diseases with phenotypes resembling BD, including RELA-associated inflammatory disease (RAID), Haploinsufficiency of A20 (HA20), and otulipenia. The RelA gene encodes the RELA protein, which is involved in the nuclear factor kappa B (NF-κB) signaling pathway that regulates the transcription of genes associated with cell survival, apoptosis, and immune responses. In RAID, dysfunction of the NF-κB pathway leads to reduced cell survival and symptoms of BD, such as recurrent fever, chronic mucocutaneous ulceration, arthralgia, and colitis. Herein, we report a pediatric patient who presented with recurrent, severe oral and genital ulcers from the age of five years and was diagnosed with RAID following a documented RelA gene mutation. The patient responded to a combination of corticosteroids, colchicine and methotrexate. RAID should be considered in the differential diagnosis of patients with early onset recurrent fever and mucosal ulcerations.