Universidad del Desarrollo

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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
;
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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Autoantibodies against type I IFNs in humans with alternative NF-κB pathway deficiency
(2023)
Tom Le Voyer
;
Audrey V. Parent
;
Xian Liu
;
Axel Cederholm
;
Adrian Gervais
<jats:title>Abstract</jats:title><jats:p>Patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1) caused by autosomal recessive AIRE deficiency produce autoantibodies that neutralize type I interferons (IFNs)<jats:sup>1,2</jats:sup>, conferring a predisposition to life-threatening COVID-19 pneumonia<jats:sup>3</jats:sup>. Here we report that patients with autosomal recessive NIK or RELB deficiency, or a specific type of autosomal-dominant NF-κB2 deficiency, also have neutralizing autoantibodies against type I IFNs and are at higher risk of getting life-threatening COVID-19 pneumonia. In patients with autosomal-dominant NF-κB2 deficiency, these autoantibodies are found only in individuals who are heterozygous for variants associated with both transcription (p52 activity) loss of function (LOF) due to impaired p100 processing to generate p52, and regulatory (IκBδ activity) gain of function (GOF) due to the accumulation of unprocessed p100, therefore increasing the inhibitory activity of IκBδ (hereafter, p52<jats:sup>LOF</jats:sup>/IκBδ<jats:sup>GOF</jats:sup>). By contrast, neutralizing autoantibodies against type I IFNs are not found in individuals who are heterozygous for <jats:italic>NFKB2</jats:italic> variants causing haploinsufficiency of p100 and p52 (hereafter, p52<jats:sup>LOF</jats:sup>/IκBδ<jats:sup>LOF</jats:sup>) or gain-of-function of p52 (hereafter, p52<jats:sup>GOF</jats:sup>/IκBδ<jats:sup>LOF</jats:sup>). In contrast to patients with APS-1, patients with disorders of NIK, RELB or NF-κB2 have very few tissue-specific autoantibodies. However, their thymuses have an abnormal structure, with few AIRE-expressing medullary thymic epithelial cells. Human inborn errors of the alternative NF-κB pathway impair the development of AIRE-expressing medullary thymic epithelial cells, thereby underlying the production of autoantibodies against type I IFNs and predisposition to viral diseases.</jats:p>
3Scopus© Citations 90
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Inborn errors of OAS–RNase L in SARS-CoV-2–related multisystem inflammatory syndrome in children
(2023)
Danyel Lee
;
Jérémie Le Pen
;
Ahmad Yatim
;
Beihua Dong
;
Yann Aquino
<jats:p> Multisystem inflammatory syndrome in children (MIS-C) is a rare and severe condition that follows benign COVID-19. We report autosomal recessive deficiencies of <jats:italic>OAS1</jats:italic> , <jats:italic>OAS2</jats:italic> , or <jats:italic>RNASEL</jats:italic> in five unrelated children with MIS-C. The cytosolic double-stranded RNA (dsRNA)–sensing OAS1 and OAS2 generate 2′-5′-linked oligoadenylates (2-5A) that activate the single-stranded RNA–degrading ribonuclease L (RNase L). Monocytic cell lines and primary myeloid cells with OAS1, OAS2, or RNase L deficiencies produce excessive amounts of inflammatory cytokines upon dsRNA or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stimulation. Exogenous 2-5A suppresses cytokine production in OAS1-deficient but not RNase L–deficient cells. Cytokine production in RNase L–deficient cells is impaired by MDA5 or RIG-I deficiency and abolished by mitochondrial antiviral-signaling protein (MAVS) deficiency. Recessive OAS–RNase L deficiencies in these patients unleash the production of SARS-CoV-2–triggered, MAVS-mediated inflammatory cytokines by mononuclear phagocytes, thereby underlying MIS-C. </jats:p>
11Scopus© Citations 137

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