Jinx, an MCMV susceptibility phenotype caused by disruption of Unc13d: a mouse model of type 3 familial hemophagocytic lymphohistiocytosis

Mouse cytomegalovirus (MCMV) susceptibility often results from defects of natural killer (NK) cell function. Here we describe Jinx, an N-ethyl-N-nitrosourea–induced MCMV susceptibility mutation that permits unchecked proliferation of the virus, causing death. In Jinx homozygotes, activated NK cells and cytotoxic T lymphocytes (CTLs) fail to degranulate, although they retain the ability to produce cytokines, and cytokine levels are markedly elevated in the blood of infected mutant mice. Jinx was mapped to mouse chromosome 11 on a total of 246 meioses and confined to a 4.60–million basepair critical region encompassing 122 annotated genes. The phenotype was ascribed to the creation of a novel donor splice site in Unc13d, the mouse orthologue of human MUNC13-4, in which mutations cause type 3 familial hemophagocytic lymphohistiocytosis (FHL3), a fatal disease marked by massive hepatosplenomegaly, anemia, and thrombocytopenia. Jinx mice do not spontaneously develop clinical features of hemophagocytic lymphohistiocytosis (HLH), but do so when infected with lymphocytic choriomeningitis virus, exhibiting hyperactivation of CTLs and antigen-presenting cells, and inadequate restriction of viral proliferation. In contrast, neither Listeria monocytogenes nor MCMV induces the syndrome. In mice, the HLH phenotype is conditional, which suggests the existence of a specific infectious trigger of FHL3 in humans.

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Histopathologic Correlates of Familial Hemophagocytic Lymphohistiocytosis Isolated to the Central Nervous System

Journal of Neuropathology & Experimental Neurology ◽

10.1093/jnen/nly094 ◽

2018 ◽

Vol 77 (12) ◽

pp. 1079-1084 ◽

Cited By ~ 8

Author(s):

Isaac H Solomon ◽

Hojun Li ◽

Leslie A Benson ◽

Lauren A Henderson ◽

Barbara A Degar ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Hemophagocytic Lymphohistiocytosis ◽

Cell Function ◽

Nk Cell ◽

Systemic Disease ◽

Cytotoxic T Cell ◽

Compound Heterozygous ◽

Hematopoietic Stem ◽

Familial Hemophagocytic Lymphohistiocytosis

AbstractFamilial hemophagocytic lymphohistiocytosis (HLH) is an immune hyperactivation syndrome caused by mutations in genes associated with cytotoxic T-cell and NK-cell function. While neurological manifestations frequently accompany systemic inflammation at initial presentation, isolated central nervous system (CNS) involvement is rare, and the histological correlates are not well described. We present 3 patients (ages 5, 6, and 7 years) with CNS-isolated familial HLH, who presented with a variety of neurological symptoms and underwent brain biopsies for multifocal enhancing supratentorial and infratentorial lesions. Biopsy slides from all 3 patients revealed similar findings: perivascular lymphocytes, predominantly CD3+ T-cells (CD4>CD8) with occasional intramural infiltration of small vessels; scattered histiocytes without hemophagocytosis; parenchymal and leptomeningeal inflammation varying from mild and focal to severe and sheet-like with associated destructive lesions. There was no evidence of demyelination, neoplasia, or infection. Genetic testing identified compound heterozygous mutations in PRF1 (Patients 1 and 2) and UNC13D (Patient 3), with no evidence of systemic disease except decreased NK-cell function. All 3 patients were treated with hematopoietic stem cell transplantation with marked improvement of symptoms. These findings combined with the poor outcomes associated with delayed diagnosis and lack of aggressive treatment highlight the need to consider HLH in the differential diagnosis of inflammatory brain lesions.

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Natural Killer Cell Function Tests by Flowcytometry-Based Cytotoxicity and IFN-γ Production for the Diagnosis of Adult Hemophagocytic Lymphohistiocytosis

International Journal of Molecular Sciences ◽

10.3390/ijms20215413 ◽

2019 ◽

Vol 20 (21) ◽

pp. 5413 ◽

Cited By ~ 4

Author(s):

Lee ◽

Kim ◽

Lee ◽

Park ◽

Choi ◽

...

Keyword(s):

Natural Killer ◽

Hemophagocytic Lymphohistiocytosis ◽

Cell Function ◽

Nk Cell ◽

Cell Phenotype ◽

Cytotoxicity Test ◽

Serum Cytokine ◽

Function Tests ◽

Cytokine Levels ◽

Nk Cytotoxicity

Although natural killer (NK) cell function is a hallmark of hemophagocytic lymphohistiocytosis (HLH), there is no standard method or data on its diagnostic value in adults. Thus, we performed a single-center retrospective study of 119 adult patients with suspected HLH. NK cell function was determined using both flowcytometry-based NK-cytotoxicity test (NK-cytotoxicity) and NK cell activity test for interferon-gamma (NKA-IFNγ). NK cell phenotype and serum cytokine levels were also tested. Fifty (42.0%) HLH patients showed significantly reduced NK cell function compared to 69 non-HLH patients by both NK-cytotoxicity and NKA-IFNγ (p < 0.001 and p = 0.020, respectively). Agreement between NK-cytotoxicity and NKA-IFNγ was 88.0% in HLH patients and 58.0% in non-HLH patients. NK-cytotoxicity and NKA-IFNγ assays predicted HLH with sensitivities of 96.0% and 92.0%, respectively. The combination of NKA-IFNγ and ferritin (>10,000 µg/L) was helpful for ruling out HLH, with a specificity of 94.2%. Decreased NK-cytotoxicity was associated with increased soluble IL-2 receptor levels and decreased CD56dim NK cells. Decreased NKA-IFNγ was associated with decreased serum cytokine levels. We suggest that both NK-cytotoxicity and NKA-IFNγ could be used for diagnosis of HLH. Further studies are needed to validate the diagnostic and prognostic value of NK cell function tests.

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682. Correction of CTLs Cytotoxic Function Defect by SIN-lentiviral Mediated Expression of Munc13-4 in Type 3 Familial Hemophagocytic Lymphohistiocytosis

Molecular Therapy ◽

10.1016/s1525-0016(16)33490-6 ◽

2016 ◽

Vol 24 ◽

pp. S270

Author(s):

Tayebeh-Shabi Soheili ◽

Ida Ricciardelli ◽

Julie Riviere ◽

Amandine Durand ◽

Els Verhoeyen ◽

...

Keyword(s):

Hemophagocytic Lymphohistiocytosis ◽

Familial Hemophagocytic Lymphohistiocytosis ◽

Function Defect ◽

Type 3 ◽

Cytotoxic Function

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Jinx, an MCMV susceptibility phenotype caused by disruption of Unc13d: a mouse model of type 3 familial hemophagocytic lymphohistiocytosis

Journal of Experimental Medicine ◽

10.1084/jem.20062447020108c ◽

2008 ◽

Vol 205 (3) ◽

pp. 737-737

Author(s):

Karine Crozat ◽

Kasper Hoebe ◽

Sophie Ugolini ◽

Nancy A. Hong ◽

Edith Janssen ◽

...

Keyword(s):

Mouse Model ◽

Hemophagocytic Lymphohistiocytosis ◽

Familial Hemophagocytic Lymphohistiocytosis ◽

Type 3

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Defective cytotoxic lymphocyte degranulation in syntaxin-11–deficient familial hemophagocytic lymphohistiocytosis 4 (FHL4) patients

Blood ◽

10.1182/blood-2007-02-074468 ◽

2007 ◽

Vol 110 (6) ◽

pp. 1906-1915 ◽

Cited By ~ 205

Author(s):

Yenan T. Bryceson ◽

Eva Rudd ◽

Chengyun Zheng ◽

Josefine Edner ◽

Daoxin Ma ◽

...

Keyword(s):

Nk Cells ◽

Hemophagocytic Lymphohistiocytosis ◽

Nk Cell ◽

Severe Disease ◽

Target Cells ◽

Loss Of Function ◽

Cytotoxic Lymphocyte ◽

Familial Hemophagocytic Lymphohistiocytosis ◽

Genes Encoding ◽

Syntaxin 11

Abstract Familial hemophagocytic lymphohistiocytosis (FHL) is typically an early onset, fatal disease characterized by a sepsislike illness with cytopenia, hepatosplenomegaly, and deficient lymphocyte cytotoxicity. Disease-causing mutations have been identified in genes encoding perforin (PRF1/FHL2), Munc13-4 (UNC13D/FHL3), and syntaxin-11 (STX11/FHL4). In contrast to mutations leading to loss of perforin and Munc13-4 function, it is unclear how syntaxin-11 loss-of-function mutations contribute to disease. We show here that freshly isolated, resting natural killer (NK) cells and CD8+ T cells express syntaxin-11. In infants, NK cells are the predominant perforin-containing cell type. NK cells from FHL4 patients fail to degranulate when encountering susceptible target cells. Unexpectedly, IL-2 stimulation partially restores degranulation and cytotoxicity by NK cells, which could explain the less severe disease progression observed in FHL4 patients, compared with FHL2 and FHL3 patients. Since the effector T-cell compartment is still immature in infants, our data suggest that the observed defect in NK-cell degranulation may contribute to the pathophysiology of FHL, that evaluation of NK-cell degranulation in suspected FHL patients may facilitate diagnosis, and that these new insights may offer novel therapeutic possibilities.

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Analysis of natural killer–cell function in familial hemophagocytic lymphohistiocytosis (FHL): defective CD107a surface expression heralds Munc13-4 defect and discriminates between genetic subtypes of the disease

Blood ◽

10.1182/blood-2006-04-015693 ◽

2006 ◽

Vol 108 (7) ◽

pp. 2316-2323 ◽

Cited By ~ 122

Author(s):

Stefania Marcenaro ◽

Federico Gallo ◽

Stefania Martini ◽

Alessandra Santoro ◽

Gillian M. Griffiths ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Hemophagocytic Lymphohistiocytosis ◽

Cytokine Production ◽

Nk Cell ◽

Killer Cell ◽

Target Cells ◽

Familial Hemophagocytic Lymphohistiocytosis ◽

Control Subjects ◽

Healthy Control

Abstract Natural killer (NK) cells from patients with familial hemophagocytic lymphohistiocytosis because of PRF1 (FHL2, n = 5) or MUNC13-4 (FHL3, n = 8) mutations were cultured in IL-2 prior to their use in various functional assays. Here, we report on the surface CD107a expression as a novel rapid tool for identification of patients with Munc13-4 defect. On target interaction and degranulation, FHL3 NK cells displayed low levels of surface CD107a staining, in contrast to healthy control subjects or perforin-deficient NK cells. B-EBV cell lines and dendritic cell targets reveal the FHL3 NK-cell defect, whereas highly susceptible tumor targets were partially lysed by FHL3 NK cells expressing only trace amounts of Munc13-4 protein. Perforin-deficient NK cells were completely devoid of any ability to lyse target cells. Cytokine production induced by mAb-crosslinking of triggering receptors was comparable in patients and healthy control subjects. However, when cytokine production was induced by coculture with 721.221 B-EBV cells, FHL NK cells resulted in high producers, whereas control cells were almost ineffective. This could reflect survival versus elimination of B-EBV cells (ie, the source of NK-cell stimulation) in patients versus healthy control subjects, thus mimicking the pathophysiologic scenario of FHL.

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