Epstein-Barr virus (EBV) infection in humans is a major trigger of malignant and nonmalignant B cell proliferations. CD27 is a co-stimulatory molecule of T cells, and inherited CD27 deficiency is ...characterized by high susceptibility to EBV infection, though the underlying pathological mechanisms have not yet been identified. In this study, we report a patient suffering from recurrent EBV-induced B cell proliferations including Hodgkin's lymphoma because of a deficiency in CD70, the ligand of CD27. We show that EBV-specific T lymphocytes did not expand properly when stimulated with CD70-deficient EBV-infected B cells, whereas expression of CD70 in B cells restored expansion, indicating that CD70 on B cells but not on T cells is required for efficient proliferation of T cells. CD70 was found to be up-regulated on B cells when activated and during EBV infection. The proliferation of T cells triggered by CD70-expressing B cells was dependent on CD27 and CD3 on T cells. Importantly, CD27-deficient T cells failed to proliferate when stimulated with CD70-expressing B cells. Thus, the CD70-CD27 pathway appears to be a crucial component of EBV-specific T cell immunity and more generally for the immune surveillance of B cells and may be a target for immunotherapy of B cell malignancies.
Abstract
Autoinflammatory disease is an ‘inborn error of immunity’, resulting in systemic inflammation. Cryopyrin-associated periodic syndrome (CAPS) is a prototypical autoinflammatory disease caused ...by gain-of-function mutations in the NLRP3 (NLR family pyrin domain containing 3) gene; these mutations activate the NLRP3 inflammasome, resulting in overproduction of IL-1β. The first case of CAPS caused by somatic NLRP3 mosaicism was reported in 2005 after identification of variant small peaks by Sanger sequencing. An international collaborative study revealed that the majority of mutation-negative CAPS cases are due to low-level NLRP3 mosaicism, suggesting that central nervous system involvement in somatic mosaicism patients is milder than in genotype-matched heterozygous patients. Recent advances in next-generation sequencing have expanded the number of NLRP3 somatic mosaicism cases and identified a new entity called ‘late-onset CAPS with myeloid-specific NLRP3 mosaicism’; however, no mosaic-specific clinical features have been identified/confirmed yet. With respect to NLRP3 mosaicism in CAPS, a prospective longitudinal study on the variant genotype, its allele frequency and its tissue distribution (along with a comprehensive clinical phenotype) would provide better understanding of NLRP3 mosaicism, resulting in more appropriate patient care and genetic counseling.
Mosaicism in CAPS
Purpose
Pathogenic
MEFV
variants cause pyrin-associated autoinflammatory diseases (PAADs), which include familial Mediterranean fever (FMF), FMF-like disease, and pyrin-associated autoinflammation ...with neutrophilic dermatosis (PAAND). The diagnosis of PAADs is established by clinical phenotypic and genetic analyses. However, the pathogenicity of most
MEFV
variants remains controversial, as they have not been functionally evaluated. This study aimed to establish and validate a new functional assay to evaluate the pathogenicity of
MEFV
variants.
Methods
We transfected THP-1 monocytes with 32
MEFV
variants and analyzed their effects on cell death with or without stimulation with
Clostridium difficile
toxin A (TcdA) or UCN-01. These variants were classified using hierarchical cluster analysis. Macrophages were obtained from three healthy controls and two patients with a novel homozygous
MEFV
P257L
variant, for comparison of IL-1β secretion using a cell-based assay and a novel THP-1-based assay.
Results
Disease-associated
MEFV
variants induced variable degrees of spontaneous or TcdA/UCN-01-induced cell death in THP-1. Cell death was caspase-1 dependent and was accompanied by ASC speck formation and IL-1β secretion, indicating that pathogenic
MEFV
variants induced abnormal pyrin inflammasome activation and subsequent pyroptotic cell deaths in this assay. The
MEFV
variants (
n
= 32) exhibiting distinct response signatures were classified into 6 clusters, which showed a good correlation with the clinical phenotypes. Regarding the pathogenicity of
MEFV
P257L
variants, the results were consistent between the cell-based assay and the THP-1-based assay.
Conclusion
Our assay facilitates a rapid and comprehensive assessment of the pathogenicity of
MEFV
variants and contributes to a refined definition of PAAD subtypes.
Objective
Coatomer subunit alpha (COPA) syndrome, also known as autoinflammatory interstitial lung, joint, and kidney disease, is caused by heterozygous mutations in COPA. We identified a novel COPA ...variant in 4 patients in one family. We undertook this study to elucidate whether and how the variant causes manifestations of COPA syndrome by studying these 4 patients and by analyzing results from a gene‐targeted mouse model.
Methods
We performed whole‐exome sequencing in 7 family members and measured the type I interferon (IFN) signature of the peripheral blood cells. We analyzed the effects of COPA variants in in vitro experiments and in Copa mutant mice that were generated.
Results
We identified a heterozygous variant of COPA (c.725T>G, p.Val242Gly) in the 4 affected members of the family. The IFN score was high in the members carrying the variant. In vitro analysis revealed that COPA V242G, as well as the previously reported disease‐causing variants, augmented stimulator of interferon genes (STING)–induced type I IFN promoter activities. CopaV242G/+ mice manifested interstitial lung disease and STING‐dependent elevation of IFN‐stimulated gene expression. In CopaV242G/+ dendritic cells, the STING pathway was not constitutively activated but was hyperactivated upon stimulation, leading to increased type I IFN production.
Conclusion
V242G, a novel COPA variant, was found in 4 patients from one family. In gene‐targeted mice with the V242G variant, interstitial lung disease was recapitulated and augmented responses of the STING pathway, leading to an increase in type I IFN production, were demonstrated.
To collect clinical information and
mutation data on patients with Blau syndrome and to evaluate their prognosis.
Fifty patients with
mutations were analysed. The activity of each
mutant was ...evaluated in HEK293 cells by reporter assay. Clinical information was collected from medical records through the attending physicians.
The study population comprised 26 males and 24 females aged 0-61 years. Thirty-two cases were sporadic, and 18 were familial from 9 unrelated families. Fifteen different mutations in
were identified, including 2 novel mutations (p.W490S and D512V); all showed spontaneous nuclear factor kappa B activation, and the most common mutation was p.R334W. Twenty-six patients had fever at relatively early timepoints in the disease course. Forty-three of 47 patients had a skin rash. The onset of disease in 9 patients was recognised after BCG vaccination. Forty-five of 49 patients had joint lesions. Thirty-eight of 50 patients had ocular symptoms, 7 of which resulted in blindness. After the diagnosis of Blau syndrome, 26 patients were treated with biologics; all were antitumour necrosis factor agents. Only 3 patients were treated with biologics alone; the others received a biologic in combination with methotrexate and/or prednisolone. None of the patients who became blind received biologic treatment.
In patients with Blau syndrome, severe joint contractures and blindness may occur if diagnosis and appropriate treatment are delayed. Early treatment with a biologic agent may improve the prognosis.
Dried blood spots (DBS) are widely used for screening biomolecular profiles, including enzymatic activities. However, detection of minor proteins in DBS by liquid chromatography–mass spectrometry ...(LC-MS/MS) without pre-enrichment remains challenging because of the coexistence of large quantities of hydrophilic proteins. In this study, we address this problem by developing a simple method using sodium carbonate precipitation (SCP). SCP enriches hydrophobic proteins from DBS, allowing substantial removal of soluble proteins. In combination with SCP, we used quantitative LC-MS/MS proteome analysis in a data-independent acquisition mode (DIA) to enhance the sensitivity and quantification limits of proteome analysis. As a result, identification of 1977 proteins in DBS is possible, including 585 disease-related proteins listed in the Online Mendelian Inheritance in Man.
Impaired proteasome activity due to genetic variants of certain subunits might lead to proteasome-associated autoinflammatory syndromes (PRAAS). Here we report a de novo heterozygous missense variant ...of the PSMB9 proteasome subunit gene in two unrelated Japanese infants resulting in amino acid substitution of the glycine (G) by aspartic acid (D) at position 156 of the encoded protein β1i. In addition to PRAAS-like manifestations, these individuals suffer from pulmonary hypertension and immunodeficiency, which are distinct from typical PRAAS symptoms. The missense variant results in impaired immunoproteasome maturation and activity, yet ubiquitin accumulation is hardly detectable in the patients. A mouse model of the heterozygous human genetic variant (Psmb9
) recapitulates the proteasome defects and the immunodeficiency phenotype of patients. Structurally, PSMB9 G156D interferes with the β-ring-βring interaction of the wild type protein that is necessary for 20S proteasome formation. We propose the term, proteasome-associated autoinflammatory syndrome with immunodeficiency (PRAAS-ID), to indicate a separate category of autoinflammatory diseases, similar to, but distinct from PRAAS, that describes the patients in this study.
Next, the IL-1β secretion from macrophages derived from monocytes in vitro (peripheral blood–derived macrophages PB-MPs) was evaluated. Because TcdA stimulation alone did not induce IL-1β secretion ...from PB-MPs (data not shown), PB-MPs were primed with LPS before TcdA stimulation. ...by examining both cell types from the same patients, we revealed the overall picture of the cytokine responses of monocytes and macrophages from patients with FMF. Induced pluripotent stem cell (iPSC) technology provides the opportunity to analyze the effect of genetic variants free from the influence of medication or differences in genetic background. ...we evaluated whether macrophages derived from patients' iPSCs (iPSC-derived macrophages iPS-MPs) recapitulated the phenotype of PB-MPs from patients with FMF. iPSC lines from 3 patients with FMF with the M694I and E148Q MEFV variants were established (patients 6-8; see Fig E2 and Table E1 in this article's Online Repository at www.jacionline.org) and differentiated into iPS-MPs (see Fig E3 in this article's Online Repository at www.jacionline.org). iPS-MPs with the M694I mutation recapitulated the enhanced pyrin inflammasome activation of PB-MPs, leading to increased IL-1β secretion (Fig 2, A), ASC speck formation (Fig 2, B), and cell death, which was dependent on MEFV expression (see Fig E4 in this article's Online Repository at www.jacionline.org). ...we applied our newly established method to 2 additional MEFV variants, T577N and N679H, which were identified in 2 families in which autoinflammatory disease with dominant inheritance was suspected.
PDF
