scholarly journals Inherited IL-18BP deficiency in human fulminant viral hepatitis

2019 ◽  
Vol 216 (8) ◽  
pp. 1777-1790 ◽  
Author(s):  
Serkan Belkaya ◽  
Eleftherios Michailidis ◽  
Cecilia B. Korol ◽  
Mohammad Kabbani ◽  
Aurélie Cobat ◽  
...  
Keyword(s):  
Viral Hepatitis ◽  
Cell Activation ◽  
Hepatitis A Virus ◽  
Nk Cell ◽  
Single Gene ◽  
Loss Of Function ◽  
Homozygous State ◽  
Inborn Errors ◽  
Fulminant Viral Hepatitis

Fulminant viral hepatitis (FVH) is a devastating and unexplained condition that strikes otherwise healthy individuals during primary infection with common liver-tropic viruses. We report a child who died of FVH upon infection with hepatitis A virus (HAV) at age 11 yr and who was homozygous for a private 40-nucleotide deletion in IL18BP, which encodes the IL-18 binding protein (IL-18BP). This mutation is loss-of-function, unlike the variants found in a homozygous state in public databases. We show that human IL-18 and IL-18BP are both secreted mostly by hepatocytes and macrophages in the liver. Moreover, in the absence of IL-18BP, excessive NK cell activation by IL-18 results in uncontrolled killing of human hepatocytes in vitro. Inherited human IL-18BP deficiency thus underlies fulminant HAV hepatitis by unleashing IL-18. These findings provide proof-of-principle that FVH can be caused by single-gene inborn errors that selectively disrupt liver-specific immunity. They also show that human IL-18 is toxic to the liver and that IL-18BP is its antidote.

scholarly journals Dual T cell– and B cell–intrinsic deficiency in humans with biallelic RLTPR mutations

2016 ◽  
Vol 213 (11) ◽  
pp. 2413-2435 ◽  
Author(s):  
Yi Wang ◽  
Cindy S. Ma ◽  
Yun Ling ◽  
Aziz Bousfiha ◽  
Yildiz Camcioglu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Ex Vivo ◽  
Cell Phenotype ◽  
Loss Of Function ◽  
Inborn Errors

Combined immunodeficiency (CID) refers to inborn errors of human T cells that also affect B cells because of the T cell deficit or an additional B cell–intrinsic deficit. In this study, we report six patients from three unrelated families with biallelic loss-of-function mutations in RLTPR, the mouse orthologue of which is essential for CD28 signaling. The patients have cutaneous and pulmonary allergy, as well as a variety of bacterial and fungal infectious diseases, including invasive tuberculosis and mucocutaneous candidiasis. Proportions of circulating regulatory T cells and memory CD4+ T cells are reduced. Their CD4+ T cells do not respond to CD28 stimulation. Their CD4+ T cells exhibit a "Th2" cell bias ex vivo and when cultured in vitro, contrasting with the paucity of "Th1," "Th17," and T follicular helper cells. The patients also display few memory B cells and poor antibody responses. This B cell phenotype does not result solely from the T cell deficiency, as the patients’ B cells fail to activate NF-κB upon B cell receptor (BCR) stimulation. Human RLTPR deficiency is a CID affecting at least the CD28-responsive pathway in T cells and the BCR-responsive pathway in B cells.

Adrenal tumors provide insight into the role of cortisol in NK cell activity

2021 ◽  
Author(s):  
Andrew E. Greenstein ◽  
Mouhammed Amir Habra ◽  
Subhagya A. Wadekar ◽  
Andreas Grauer
Keyword(s):  
Immune Response ◽  
Nk Cells ◽  
Cell Activation ◽  
Nk Cell ◽  
Phase 1 ◽  
Cell Activity ◽  
The Cancer Genome Atlas ◽  
Adrenal Tumors ◽  
Steroid Synthesis

Elevated glucocorticoid (GC) activity may limit tumor immune response and immune checkpoint inhibitor (ICI) efficacy. Adrenocortical carcinoma (ACC) provides a unique test case to assess correlates of GC activity, as approximately half of ACC patients exhibit excess GC production (GC+). ACC multi-omics were analyzed to identify molecular consequences of GC+ and assess the rationale for combining the glucocorticoid receptor (GR) antagonist relacorilant with an ICI. GC status, mRNA expression, and DNA mutation and methylation data from 71 adrenal tumors were accessed via The Cancer Genome Atlas. Expression of 858 genes differed significantly between GC- and GC+ ACC cases. KEGG pathway analysis showed higher gene expression of 3 pathways involved in steroid synthesis and secretion in GC+ cases. Fifteen pathways, most related to NK cells and other immune activity, showed lower expression. Hypomethylation was primarily observed in the steroid synthesis pathways. Tumor-infiltrating CD4+ memory (P=.003), CD8+ memory (P=.001), and NKT-cells (P=.014) were depleted in GC+ cases; tumor-associated neutrophils were enriched (P=.001). Given the pronounced differences between GC+ and GC- ACC, the effects of cortisol on NK cells were assessed in vitro (NK cells from human PBMCs stimulated with IL-2 or IL-12/15). Cortisol suppressed, and relacorilant restored, NK cell activation, proliferation, and direct tumor cell killing. Thus, GR antagonism may increase the abundance and function of NK and other immune cells in the tumor microenvironment, promoting immune response in GC+ ACC and other malignancies with GC+. This hypothesis will be tested in a phase 1 trial of relacorilant + ICI.

scholarly journals SARS-CoV-2 Spike 1 Protein Controls Natural Killer Cell Activation via the HLA-E/NKG2A Pathway

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1975 ◽  
Author(s):  
Daria Bortolotti ◽  
Valentina Gentili ◽  
Sabrina Rizzo ◽  
Antonella Rotola ◽  
Roberta Rizzo
Keyword(s):  
Epithelial Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Cell Activation ◽  
Nk Cell ◽  
Killer Cell ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Spike Proteins

Natural killer cells are important in the control of viral infections. However, the role of NK cells during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has previously not been identified. Peripheral blood NK cells from SARS-CoV and SARS-CoV-2 naïve subjects were evaluated for their activation, degranulation, and interferon-gamma expression in the presence of SARS-CoV and SARS-CoV-2 spike proteins. K562 and lung epithelial cells were transfected with spike proteins and co-cultured with NK cells. The analysis was performed by flow cytometry and immune fluorescence. SARS-CoV and SARS-CoV-2 spike proteins did not alter NK cell activation in a K562 in vitro model. On the contrary, SARS-CoV-2 spike 1 protein (SP1) intracellular expression by lung epithelial cells resulted in NK cell-reduced degranulation. Further experiments revealed a concomitant induction of HLA-E expression on the surface of lung epithelial cells and the recognition of an SP1-derived HLA-E-binding peptide. Simultaneously, there was increased modulation of the inhibitory receptor NKG2A/CD94 on NK cells when SP1 was expressed in lung epithelial cells. We ruled out the GATA3 transcription factor as being responsible for HLA-E increased levels and HLA-E/NKG2A interaction as implicated in NK cell exhaustion. We show for the first time that NK cells are affected by SP1 expression in lung epithelial cells via HLA-E/NKG2A interaction. The resulting NK cells’ exhaustion might contribute to immunopathogenesis in SARS-CoV-2 infection.

scholarly journals NK-cell activation is associated with increased HIV transcriptional activity following allogeneic hematopoietic cell transplantation

2018 ◽  
Vol 2 (12) ◽  
pp. 1412-1416
Author(s):  
Louise E. Hogan ◽  
Christian Körner ◽  
Kristen Hobbs ◽  
Camille R. Simoneau ◽  
Cassandra Thanh ◽  
...  
Keyword(s):  
Cell Death ◽  
Transcriptional Activity ◽  
Cell Activation ◽  
Hematopoietic Cell Transplantation ◽  
Nk Cell ◽  
Killer Cell ◽  
Graft Versus Host ◽  
Key Points ◽  
Hiv 1

Key Points Graft-versus-host effects may lead to HIV-1 reactivation and cell death of infected pre-HCT CD4+ T cells. Natural killer cell activation correlates with in vitro HIV-1 transcriptional activity in the setting of HCT.

Imlifidase Inhibits HLA Antibody-Mediated NK Cell Activation and Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) In Vitro

2019 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Shili Ge ◽  
Maggie Chu ◽  
Jua Choi ◽  
Sabrina Louie ◽  
Ashley Vo ◽  
...  
Keyword(s):  
Cell Activation ◽  
Nk Cell ◽  
Dependent Cell ◽  
Hla Antibody

scholarly journals Tumor-Related Exosomes Contribute to Tumor-Promoting Microenvironment: An Immunological Perspective

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Wuzhen Chen ◽  
Jingxin Jiang ◽  
Wenjie Xia ◽  
Jian Huang
Keyword(s):  
T Cell ◽  
Cell Activation ◽  
Nk Cell ◽  
Immune Surveillance ◽  
Suppressor Cells ◽  
Effector T Cell ◽  
T Cell Apoptosis ◽  
And Function

Exosomes are a kind of cell-released membrane-form structures which contain proteins, lipids, and nucleic acids. These vesicular organelles play a key role in intercellular communication. Numerous experiments demonstrated that tumor-related exosomes (TEXs) can induce immune surveillance in the microenvironment in vivo and in vitro. They can interfere with the maturation of DC cells, impair NK cell activation, induce myeloid-derived suppressor cells, and educate macrophages into protumor phenotype. They can also selectively induce effector T cell apoptosis via Fas/FasL interaction and enhance regulatory T cell proliferation and function by releasing TGF-β. In this review, we focus on the TEX-induced immunosuppression and microenvironment change. Based on the truth that TEXs play crucial roles in suppressing the immune system, studies on modification of exosomes as immunotherapy strategies will also be discussed.

scholarly journals No IL-18BP? Avoid HAV

2019 ◽  
Vol 216 (8) ◽  
pp. 1728-1729 ◽  
Author(s):  
Michael S. Diamond
Keyword(s):  
Natural Killer Cell ◽  
Viral Hepatitis ◽  
Natural Killer ◽  
Cell Activation ◽  
Killer Cell ◽  
Affected Child ◽  
Fulminant Viral Hepatitis ◽  
Natural Killer Cell Activation

Fulminant viral hepatitis occurs in a very small number of infected individuals. Until now, the basis for this phenotype has remained unknown. In this issue of JEM, Belkaya et al. (https://doi.org/10.1084/jem.20190669) identify a deletion in the IL18BP gene in a severely affected child that results in excessive natural killer cell activation and uncontrolled killing of hepatocytes.

Natural-killer cells and dendritic cells: “l'union fait la force”

Blood ◽  
2005 ◽  
Vol 106 (7) ◽  
pp. 2252-2258 ◽  
Author(s):  
Thierry Walzer ◽  
Marc Dalod ◽  
Scott H. Robbins ◽  
Laurence Zitvogel ◽  
Eric Vivier
Keyword(s):  
Dendritic Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Cell Activation ◽  
Nk Cell ◽  
Interleukin 12 ◽  
Cell Contact ◽  
Ifn Γ

AbstractSeveral recent publications have focused on the newly described interactions between natural-killer (NK) cells and dendritic cells (DCs). Activated NK cells induce DC maturation either directly or in synergy with suboptimal levels of microbial signals. Immature DCs appear susceptible to autologous NK-cell-mediated cytolysis while mature DCs are protected. NK-cell-induced DC activation is dependent on both tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ) secretion and a cell-cell contact involving NKp30. In vitro, interleukin-12 (IL-12)/IL-18, IL-15, and IFN-α/β production by activated DCs enhance, in turn, NK-cell IFN-γ production, proliferation, and cytotoxic potential, respectively. In vivo, NK-cell/DC interactions may occur in lymphoid organs as well as in nonlymphoid tissues, and their consequences are multiple. By inducing DC activation, NK-cell activation induced by tumor cells can indirectly promote antitumoral T-cell responses. Reciprocally, DCs activated through Toll-like receptors (TLRs) induce potent NK-cell activation in antiviral responses. Thus, DCs and NK cells are equipped with complementary sets of receptors that allow the recognition of various pathogenic agents, emphasizing the role of NK-cell/DC crosstalk in the coordination of innate and adaptive immune responses.

A family with Papillon-Lefèvre syndrome reveals a requirement for cathepsin C in granzyme B activation and NK cell cytolytic activity

Blood ◽  
2006 ◽  
Vol 107 (9) ◽  
pp. 3665-3668 ◽  
Author(s):  
Josephine L. Meade ◽  
Erika A. de Wynter ◽  
Peter Brett ◽  
Saghira Malik Sharif ◽  
C. Geoffrey Woods ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cell Function ◽  
Nk Cell ◽  
Granzyme B ◽  
Interleukin 2 ◽  
Target Cells ◽  
Loss Of Function ◽  
Cathepsin C ◽  
Cytolytic Function

Activation of granzyme B, a key cytolytic effector molecule of natural killer (NK) cells, requires removal of an N-terminal pro-domain. In mice, cathepsin C is required for granzyme processing and normal NK cell cytolytic function, whereas in patients with Papillon-Lefèvre syndrome (PLS), loss-of-function mutations in cathepsin C do not affect lymphokine activated killer (LAK) cell function. Here we demonstrate that resting PLS NK cells do have a cytolytic defect and fail to induce the caspase cascade in target cells. NK cells from these patients contain inactive granzyme B, indicating that cathepsin C is required for granzyme B activation in unstimulated human NK cells. However, in vitro activation of PLS NK cells with interleukin-2 restores cytolytic function and granzyme B activity by a cathepsin C-independent mechanism. This is the first documented example of a human mutation affecting granzyme B activity and highlights the importance of cathepsin C in human NK cell function.

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