Jinx, an MCMV susceptibility phenotype caused by disruption of Unc13d: a mouse model of type 3 familial hemophagocytic lymphohistiocytosis
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PROVIDER: S-EPMC2275393 | biostudies-literature | 2008 Mar
REPOSITORIES: biostudies-literature
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Project description: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.
| S-EPMC2118559 | biostudies-literature
Project description:Hemophagocytic lymphohistiocytosis (HLH) are basically a heterogenous group of clinical syndromes, characterised by activation and non-malignant proliferation of benign histiocytes i.e. lymphocytes and macrophages, leading to a cytokine storm that accounts for the fever, organomegaly and multi-organ dysfunction. Two types of HLH are described, either due to known genetic defect (familial HLH/FHL) or due to some acquired cause either infection or rheumatological diseases. Here we present a case of a 3 months old baby, admitted with fever, hepatosplenomegaly and cytopenia and ultimately was diagnosed to be a case of Familial HLH type 3 due to defect in UNC13D gene as a result of compound heterozygous for two nonsense mutation resulting in the Munc13-4 protein defect.
| S-EPMC4925480 | biostudies-literature
Project description:Familial hemophagocytic lymphohistiocytosis type 3 (FHL3) is a rare disease caused by mutations to the UNC13D gene and the subsequent absence or decreased activity of the Munc13-4 protein. Munc13-4 is essential for the exocytosis of perforin and granzyme containing granules from cytotoxic cells. Without it, these cells are able to recognize an immunological insult but are unable to execute their cytotoxic functions. The result is a hyperinflammatory state that, if left untreated, is fatal. At present, the only curative treatment is hematopoietic stem cell transplantation (HSCT), but eligibility and response to this treatment are largely dependent on the ability to control inflammation before HSCT. In this study, we describe an optimized lentiviral vector that can restore Munc13-4 expression and degranulation capacity in both transduced FHL3 patient T cells and transduced hematopoietic stem cells from the FHL3 (Jinx) disease model.
| S-EPMC7310202 | biostudies-literature
Project description:BackgroundHemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by some clinical signs (e.g., non-remitting fever, hepatosplenomegaly) and laboratory findings (e.g., cytopenia, increased ferritin level, hypofibrinogenemia, lipid disorders, coagulopathy, and multiple organ failure). Depending on the etiology, HLH is divided into familial (i.e., primary) and acquired (i.e., secondary) forms. Familial HLH (FHL), an autosomal recessive condition, is classified into five subtypes based on underlying genetic defects. The PRF1, STX11, UNC13D, HPLH1, and STXBP2 are the most well-known genes of this type which are related to granule-mediated cytotoxic T and Natural killer (NK) cells. The treatment is based on the HLH-2004 protocol.Case presentationThe current report presents two cases of HLH with presentations different from each other and previously reported cases. Case 1 was a 15-month-old boy with fever, skin rash, splenomegaly, and bicytopenia, raised triglyceride levels, AST (aspartate transaminase), and ALT (alanine aminotransferase), normal ferritin, and abundant hemophagocytic cell in bone marrow aspiration. He was diagnosed with HLH and received HLH protocol as treatment. The patient had a homozygous intronic mutation; NM_199242: c.2448-13G > A in UNC13D. The associated disease was Familial Hemophagocytic Lymphohistiocytosis 3 (FHL3). Case 2, a 37-day-old female presented with fever, a history of neonatal cholestasis, and huge hepatosplenomegaly. Her whole-exome sequencing report manifested that the patient had the same mutation as case 1. Unfortunately, both patients passed away.ConclusionThe sequencing of the entire UNC13D gene (coding and non-coding regions) is an applicable and valuable diagnostic procedure for the detection of deep intronic splicing variants and large inversions in patients with atypical manifestations of HLH (such as normal ferritin or triglyceride and cholesterol).
| S-EPMC9675162 | biostudies-literature
Project description:BACKGROUND: Familial hemophagocytic lymphohistiocytosis is a fatal disease characterized by immune dysregulation from defective function of cytotoxic lymphocytes. Three causative genes have been identified for this autosomal recessive disorder (PRF1, UNC13D, and STX11). We investigated the molecular genetics of familial hemophagocytic lymphohistiocytosis in Korea. DESIGN AND METHODS: Pediatric patients who fulfilled the HLH-2004 criteria were recruited from the Korean Registry for Histiocytosis. Molecular genetic studies were performed on the patients' DNA samples by direct sequencing of all coding exons and flanking sequences of PRF1, UNC13D, and STX11. RESULTS: Forty patients were studied and familial hemophagocytic lymphohistiocytosis mutations were identified in nine; eight patients had UNC13D mutations (89%) and one had a mutation in PRF1. No patient had a STX11 mutation. Notably, four patients had only one UNC13D mutant allele, suggesting that the other mutation was missed by conventional direct sequencing. All UNC13D mutations were deleterious in nature. One known splicing mutation, c.754-1G>C, was recurrent, accounting for 58% of all the mutant alleles (7/12). Five UNC13D mutations were novel (p.Gln98X, p.Glu565SerfsX7, c.1993-2A>G, c.2367+1G>A, and c.2954+5G>A). The one patient with PRF1 mutation was homozygous for a frameshift mutation (p.Leu364GlufsX93), which was previously reported to be the most frequent PRF1 mutation in Japan. CONCLUSIONS: This is the first investigation on the molecular genetics of familial hemophagocytic lymphohistiocytosis in Korea. The data showed that UNC13D is the predominant causative gene in the Korean population. The identification of mutations missed by conventional sequencing would better delineate the mutation spectrum and help to establish the optimal molecular diagnostic strategy for familial hemophagocytic lymphohistiocytosis in Korea, which might need an RNA-based screening strategy.
| S-EPMC2857192 | biostudies-literature
Project description: Not available
| S-EPMC2857182 | biostudies-literature
Project description:AbstractCurrent hemophagocytic lymphohistiocytosis 2004 (HLH-2004)-based diagnostic criteria for familial hemophagocytic lymphohistiocytosis (FHL) are based on expert opinion. Here, we performed a case-control study to test and possibly improve these criteria. We also developed 2 complementary expert opinion-based diagnostic strategies for FHL in patients with signs/symptoms suggestive of HLH, based on genetic and cellular cytotoxicity assays. The cases (N = 366) were children aged <16 years with verified familial and/or genetic FHL (n = 341) or Griscelli syndrome type 2 (n = 25); 276 from the HLH-94/HLH-2004 databases and 90 from the Italian HLH Registry. All fulfilled the HLH-94/HLH-2004 patient inclusion criteria. Controls were 374 children with systemic-onset juvenile idiopathic arthritis (sJIA) and 329 + 361 children in 2 cohorts with febrile infections that could be confused with HLH and sepsis, respectively. To provide complete data sets, multiple imputations were performed. The optimal model, based on 17 variables studied, revealed almost similar diagnostic thresholds as the existing criteria, with accuracy 99.1% (sensitivity 97.1%; specificity 99.5%); the original HLH-2004 criteria had accuracy 97.4% (sensitivity 99.0%; specificity 97.1%). Because cellular cytotoxicity assays here constitute a separate diagnostic strategy, HLH-2004 criteria without natural killer (NK)-cell function was also studied, which showed accuracy 99.0% (sensitivity, 96.2%; specificity, 99.5%). Thus, we conclude that the HLH-2004 criteria (without NK-cell function) have significant validity in their current form when tested against severe infections or sJIA. It is important to exclude underlying malignancies and atypical infections. In addition, complementary cellular and genetic diagnostic guidelines can facilitate necessary confirmation of clinical diagnosis.
| S-EPMC11619794 | biostudies-literature
Project description:Background Familial hemophagocytic lymphohistiocytosis (FLH) is an autosomal recessive disorder of immune regulation that leads to a hyperinflammatory syndrome. Fetal onset FHL is extremely rare and is considered to be the most severe form of FHL. Case We report a preterm case of FHL that presented as hydrops fetalis. The infant was treated with a chemotherapy regimen based on the HLH-2004 protocol from the third day of life. However, he had persistent cytopenia and died on the 18th day of life due to bacteremia. The detection of defective perforin expression in the patient's natural killer cells and mutations in the PRF1 gene resulted in a molecular diagnosis of FHL. Conclusion We suggest that early diagnosis and the development of an appropriate immunosuppressive strategy that can induce and maintain remission until hematopoietic stem cell transplantation can be performed are required to improve the outcomes of fetal onset FHL.
| S-EPMC4502624 | biostudies-other
Project description:Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory disease characterized by familial and acquired forms. Here, we present the case of a 26-year-old male patient with relapsed/refractory peripheral T-cell lymphoma and concurrent HLH. Whole-exon sequencing revealed germline mutations associated with HLH, including those in critical genes such as CD27 and UNC13D and other germline heterozygous variants (NOTCH2, NOTCH3, IL2RA, TYK2, AGL, CFD, and F13A1). CD107a analyses consistently demonstrated impaired degranulation of cytotoxic T-lymphocytes and natural killer (NK) cells. Examination of the patient's family pedigree revealed that his father and mother harbored UNC13D and CD27 mutations, respectively; his brother carried the same CD27 heterozygous mutation. However, none of them manifested the disease. Despite the missense mutation of CD27 (c.779C>T; p.Pro260Leu) lacking previous documentation in databases, comprehensive analysis suggested non-pathogenic mutations in the CD27 variant, indicating minimal impact on T- and NK-cell functions. These results ultimately supported the option of hematopoietic stem cell transplantation (HSCT) as a successful curative therapeutic approach. As of this report, the patient has remained free of lymphoma and quiescent HLH 15.2 months post-HSCT. This study underscores the efficacy of genetic tests in identifying significant mutations and confirming their etiologies, providing an early basis for treatment decisions and the selection of suitable transplant donors.
| S-EPMC10771736 | biostudies-literature
Project description:Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that causes systemic inflammation which can progress to multiorgan failure and death. Symptoms and signs commonly seen in HLH include high fever, hepatosplenomegaly, pancytopenia, and hypertriglyceridemia. This report describes the 8-month clinical course of a 17-year-old male with G6PD deficiency who presented with intermittent high fever of unknown origin for 8 months accompanied by pancytopenia and bilateral lower limb weakness. A pathogenic homozygous missense mutation (c.1081A > T p.(Arg361Trp)) in the PRF1 gene was detected by whole exome sequencing (WES). The brain and the whole spine MRI showed leptomeningeal enhancement at different levels involving both the brain and the spine. Therefore, a diagnosis of familial HLH type 2 with CNS involvement was confirmed. Accordingly, treatment with dexamethasone, cyclosporin, and etoposide in addition to intrathecal methotrexate and hydrocortisone was given. The patient showed a dramatic response with significant neurological improvement of the bilateral lower limb weakness. Genetic analysis has helped the patient's family with appropriate genetic counselling. This case highlights the importance of immediate treatment with immunosuppressants and the high clinical suspicion of physicians regarding HLH in areas where consanguinity is common.
| S-EPMC8731261 | biostudies-literature