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TGFβ links EBV to multisystem inflammatory syndrome in children
(Springer Science and Business Media LLC, 2025-03-12)
Carl Christoph Goetzke
;
Mona Massoud
;
Stefan Frischbutter
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Gabriela Maria Guerra
;
Marta Ferreira-Gomes
<jats:title>Abstract</jats:title> <jats:p>In a subset of children and adolescents, SARS-CoV-2 infection induces a severe acute hyperinflammatory shock<jats:sup>1</jats:sup> termed multisystem inflammatory syndrome in children (MIS-C) at four to eight weeks after infection. MIS-C is characterized by a specific T cell expansion<jats:sup>2</jats:sup> and systemic hyperinflammation<jats:sup>3</jats:sup>. The pathogenesis of MIS-C remains largely unknown. Here we show that acute MIS-C is characterized by impaired reactivation of virus-reactive memory T cells, which depends on increased serum levels of the cytokine TGFβ resembling those that occur during severe COVID-19 (refs. <jats:sup>4,5</jats:sup>). This functional impairment in T cell reactivity is accompanied by the presence of TGFβ-response signatures in T cells, B cells and monocytes along with reduced antigen-presentation capabilities of monocytes, and can be reversed by blocking TGFβ. Furthermore, T cell receptor repertoires of patients with MIS-C exhibit expansion of T cells expressing TCRVβ21.3, resembling Epstein–Barr virus (EBV)-reactive T cell clones capable of eliminating EBV-infected B cells. Additionally, serum TGFβ in patients with MIS-C can trigger EBV reactivation, which is reversible with TGFβ blockade. Clinically, the TGFβ-induced defect in T cell reactivity correlates with a higher EBV seroprevalence in patients with MIS-C compared with age-matched controls, along with the occurrence of EBV reactivation. Our findings establish a connection between SARS-CoV-2 infection and COVID-19 sequelae in children, in which impaired T cell cytotoxicity triggered by TGFβ overproduction leads to EBV reactivation and subsequent hyperinflammation.</jats:p>
Scopus© Citations 4 2
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Multiomics dissection of human RAG deficiency reveals distinctive patterns of immune dysregulation but a common inflammatory signature
(American Association for the Advancement of Science (AAAS), 2025-01-10)
Marita Bosticardo
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Kerry Dobbs
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Ottavia M. Delmonte
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Andrew J. Martins
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Francesca Pala
<jats:p> Human recombination-activating gene (RAG) deficiency can manifest with distinct clinical and immunological phenotypes. By applying a multiomics approach to a large group of <jats:italic>RAG</jats:italic> -mutated patients, we aimed at characterizing the immunopathology associated with each phenotype. Although defective T and B cell development is common to all phenotypes, patients with hypomorphic <jats:italic>RAG</jats:italic> variants can generate T and B cells with signatures of immune dysregulation and produce autoantibodies to a broad range of self-antigens, including type I interferons. T helper 2 (T <jats:sub>H</jats:sub> 2) cell skewing and a prominent inflammatory signature characterize Omenn syndrome, whereas more hypomorphic forms of RAG deficiency are associated with a type 1 immune profile both in blood and tissues. We used cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) analysis to define the cell lineage–specific contribution to the immunopathology of the distinct RAG phenotypes. These insights may help improve the diagnosis and clinical management of the various forms of the disease. </jats:p>
Scopus© Citations 2 1
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Absent B cells, agammaglobulinemia, and hypertrophic cardiomyopathy in folliculin-interacting protein 1 deficiency
(2021)
Francesco Saettini
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POLI HARLOWE, MARIA CECILIA BERTA
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Jaime Vengoechea
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Sonia Bonanomi
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Julio C. Orellana
<jats:title>Abstract</jats:title> <jats:p>Agammaglobulinemia is the most profound primary antibody deficiency that can occur due to an early termination of B-cell development. We here investigated 3 novel patients, including the first known adult, from unrelated families with agammaglobulinemia, recurrent infections, and hypertrophic cardiomyopathy (HCM). Two of them also presented with intermittent or severe chronic neutropenia. We identified homozygous or compound-heterozygous variants in the gene for folliculin interacting protein 1 (FNIP1), leading to loss of the FNIP1 protein. B-cell metabolism, including mitochondrial numbers and activity and phosphatidylinositol 3-kinase/AKT pathway, was impaired. These defects recapitulated the Fnip1−/− animal model. Moreover, we identified either uniparental disomy or copy-number variants (CNVs) in 2 patients, expanding the variant spectrum of this novel inborn error of immunity. The results indicate that FNIP1 deficiency can be caused by complex genetic mechanisms and support the clinical utility of exome sequencing and CNV analysis in patients with broad phenotypes, including agammaglobulinemia and HCM. FNIP1 deficiency is a novel inborn error of immunity characterized by early and severe B-cell development defect, agammaglobulinemia, variable neutropenia, and HCM. Our findings elucidate a functional and relevant role of FNIP1 in B-cell development and metabolism and potentially neutrophil activity.</jats:p>
Scopus© Citations 28 2
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Evaluation of the Immune Response Induced by CoronaVac 28-Day Schedule Vaccination in a Healthy Population Group
(2022)
Alejandro Escobar
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Felipe E. Reyes-López
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Mónica L. Acevedo
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Luis Alonso-Palomares
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Fernando Valiente-Echeverría
<jats:p>CoronaVac vaccine from Sinovac Life Science is currently being used in several countries. In Chile, the effectiveness of preventing hospitalization is higher than 80% with a vaccination schedule. However, to date, there are no data about immune response induction or specific memory. For this reason, we recruited 15 volunteers without previous suspected/diagnosed COVID-19 and with negative PCR over time to evaluate the immune response to CoronaVac 28 and 90 days after the second immunization (dpi). The CoronaVac administration induces total and neutralizing anti-spike antibodies in all vaccinated volunteers at 28 and 90 dpi. Furthermore, using ELISpot analysis to assay cellular immune responses against SARS-CoV-2 spike protein, we found an increase in IFN-gamma- and Granzyme B-producing cells in vaccinated volunteers at 28 and 90 dpi. Together, our results indicate that CoronaVac induces a robust humoral immune response and cellular immune memory of at least 90 dpi.</jats:p>
23Scopus© Citations 19

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