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Cheng-Lung Ku

Publications and source records attributed to Cheng-Lung Ku.

16 recordsLinked to original sources
PubMed2024

Neutralizing IFN-γ autoantibodies are rare and pathogenic in HLA-DRB1*15:02 or 16:02 individuals.

BACKGROUNDWeakly virulent environmental mycobacteria (EM) can cause severe disease in HLA-DRB1*15:02 or 16:02 adults harboring neutralizing anti-IFN-γ autoantibodies (nAIGAs). The overall prevalence of nAIGAs in the general population is unknown, as are the penetrance of nAIGAs in HLA-DRB1*15:02 or 16:02 individuals and the proportion of patients with unexplained, adult-onset EM infections carrying nAIGAs.METHODSThis study analyzed the detection and neutralization of anti-IFN-γ autoantibodies (auto-Abs) from 8,430 healthy individuals of the general population, 257 HLA-DRB1*15:02 or 16:02 carriers, 1,063 patients with autoimmune disease, and 497 patients with unexplained severe disease due to EM.RESULTSWe found that anti-IFN-γ auto-Abs detected in 4,148 of 8,430 healthy individuals (49.2%) from the general population of an unknown HLA-DRB1 genotype were not neutralizing. Moreover, we did not find nAIGAs in 257 individuals carrying HLA-DRB1* 15:02 or 16:02. Additionally, nAIGAs were absent in 1,063 patients with an autoimmune disease. Finally, 7 of 497 patients (1.4%) with unexplained severe disease due to EM harbored nAIGAs.CONCLUSIONThese findings suggest that nAIGAs are isolated and that their penetrance in HLA-DRB1*15:02 or 16:02 individuals is low, implying that they may be triggered by rare germline or somatic variants. In contrast, the risk of mycobacterial disease in patients with nAIGAs is high, confirming that these nAIGAs are the cause of EM disease.FUNDINGThe Laboratory of Human Genetics of Infectious Diseases is supported by the Howard Hughes Medical Institute, the Rockefeller University, the St. Giles Foundation, the National Institutes of Health (NIH) (R01AI095983 and U19AIN1625568), the National Center for Advancing Translational Sciences (NCATS), the NIH Clinical and Translational Science Award (CTSA) program (UL1 TR001866), the French National Research Agency (ANR) under the "Investments for the Future" program (ANR-10-IAHU-01), the Integrative Biology of Emerging Infectious Diseases Laboratory of Excellence (ANR-10-LABX-62-IBEID), ANR-GENMSMD (ANR-16-CE17-0005-01), ANR-MAFMACRO (ANR-22-CE92-0008), ANRSECTZ170784, the French Foundation for Medical Research (FRM) (EQU201903007798), the ANRS-COV05, ANR GENVIR (ANR-20-CE93-003), and ANR AI2D (ANR-22-CE15-0046) projects, the ANR-RHU program (ANR-21-RHUS-08-COVIFERON), the European Union's Horizon 2020 research and innovation program under grant agreement no. 824110 (EASI-genomics), the Square Foundation, Grandir - Fonds de solidarité pour l'enfance, the Fondation du Souffle, the SCOR Corporate Foundation for Science, the Battersea & Bowery Advisory Group, William E. Ford, General Atlantic's Chairman and Chief Executive Officer, Gabriel Caillaux, General Atlantic's Co-President, Managing Director, and Head of business in EMEA, and the General Atlantic Foundation, Institut National de la Santé et de la Recherche Médicale (INSERM) and of Paris Cité University. JR was supported by the INSERM PhD program for doctors of pharmacy (poste d'accueil INSERM). JR and TLV were supported by the Bettencourt-Schueller Foundation and the MD-PhD program of the Imagine Institute. MO was supported by the David Rockefeller Graduate Program, the Funai Foundation for Information Technology (FFIT), the Honjo International Scholarship Foundation (HISF), and the New York Hideyo Noguchi Memorial Society (HNMS).

Adult↗
PubMed2006

IRAK4 and NEMO mutations in otherwise healthy children with recurrent invasive pneumococcal disease.

BACKGROUND: About 2% of childhood episodes of invasive pneumococcal disease (IPD) are recurrent, and most remain unexplained. OBJECTIVE: To report two cases of otherwise healthy, unrelated children with recurrent IPD as the only clinical infectious manifestation of an inherited disorder in nuclear factor-kappaB(NF-kappaB)-dependent immunity. RESULTS: One child carried two germline mutations in IRAK4, and had impaired cellular responses to interleukin (IL)1 receptor and toll-like receptor (TLR) stimulation. The other child carried a hemizygous mutation in NEMO, associated with a broader impairment of NF-kappaB activation, with an impaired cellular response to IL-1R, TLR and tumour necrosis factor receptor stimulation. The two patients shared a narrow clinical phenotype, associated with two related but different genotypes. CONCLUSIONS: Otherwise healthy children with recurrent IPD should be explored for underlying primary immunodeficiencies affecting the IRAK4-dependent and NEMO-dependent signalling pathways.

Anti-Bacterial Agents↗
PubMed2006

X-linked susceptibility to mycobacteria is caused by mutations in NEMO impairing CD40-dependent IL-12 production.

Germline mutations in five autosomal genes involved in interleukin (IL)-12-dependent, interferon (IFN)-gamma-mediated immunity cause Mendelian susceptibility to mycobacterial diseases (MSMD). The molecular basis of X-linked recessive (XR)-MSMD remains unknown. We report here mutations in the leucine zipper (LZ) domain of the NF-kappaB essential modulator (NEMO) gene in three unrelated kindreds with XR-MSMD. The mutant proteins were produced in normal amounts in blood and fibroblastic cells. However, the patients' monocytes presented an intrinsic defect in T cell-dependent IL-12 production, resulting in defective IFN-gamma secretion by T cells. IL-12 production was also impaired as the result of a specific defect in NEMO- and NF-kappaB/c-Rel-mediated CD40 signaling after the stimulation of monocytes and dendritic cells by CD40L-expressing T cells and fibroblasts, respectively. However, the CD40-dependent up-regulation of costimulatory molecules of dendritic cells and the proliferation and immunoglobulin class switch of B cells were normal. Moreover, the patients' blood and fibroblastic cells responded to other NF-kappaB activators, such as tumor necrosis factor-alpha, IL-1beta, and lipopolysaccharide. These two mutations in the NEMO LZ domain provide the first genetic etiology of XR-MSMD. They also demonstrate the importance of the T cell- and CD40L-triggered, CD40-, and NEMO/NF-kappaB/c-Rel-mediated induction of IL-12 by monocyte-derived cells for protective immunity to mycobacteria in humans.

Adolescent↗
PubMed2006

The NEMO mutation creating the most-upstream premature stop codon is hypomorphic because of a reinitiation of translation.

Amorphic mutations in the NF- kappa B essential modulator (NEMO) cause X-dominant incontinentia pigmenti, which is lethal in males in utero, whereas hypomorphic mutations cause X-recessive anhidrotic ectodermal dysplasia with immunodeficiency, a complex developmental disorder and life-threatening primary immunodeficiency. We characterized the NEMO mutation 110_111insC, which creates the most-upstream premature translation termination codon (at codon position 49) of any known NEMO mutation. Surprisingly, this mutation is associated with a pure immunodeficiency. We solve this paradox by showing that a Kozakian methionine codon located immediately downstream from the insertion allows the reinitiation of translation. The residual production of an NH(2)-truncated NEMO protein was sufficient for normal fetal development and for the subsequent normal development of skin appendages but was insufficient for the development of protective immune responses.

Amino Acid Sequence↗
PubMed2006

A fast procedure for the detection of defects in Toll-like receptor signaling.

OBJECTIVES: Inborn defects in Toll-like receptor signaling are recently described primary immunodeficiencies that predispose affected children to life-threatening infections. Patients with interleukin-1 receptor-associated kinase-4 deficiency are prone to invasive pneumococcal disease, and patients with UNC-93B deficiency are prone to herpes simplex virus encephalitis. These genetic disorders are underdiagnosed, partly because diagnosis currently requires expensive and time-consuming techniques available at only a few specialized centers worldwide. We, therefore, aimed to develop a cheap and fast test for the detection of defects in Toll-like receptor signaling. PATIENTS AND METHODS: We used flow cytometry to evaluate the cleavage of membrane-bound L-selectin on granulocytes in 38 healthy controls and in 7 patients with genetically defined Toll-like receptor signaling defects (5 patients with interleukin-1 receptor-associated kinase-4 deficiency and 2 patients with UNC-93B deficiency), on activation with various Toll-like receptor agonists. RESULTS: Impaired L-selectin shedding was observed with granulocytes from all of the interleukin-1 receptor-associated kinase-4-deficient patients on activation with agonists of Toll-like receptors 1/2, 2/6, 4, 7, and 8 and with granulocytes from all of the UNC-93B-deficient patients on activation with agonists of Toll-like receptors 7 and 8. All of the healthy controls responded to these stimuli. CONCLUSIONS: The assessment of membrane-bound L-selectin cleavage on granulocytes by flow cytometry may prove useful for the detection of primary immunodeficiencies in the Toll-like receptor pathway, such as interleukin-1 receptor-associated kinase-4 deficiency and UNC-93B deficiency. This procedure is cheap and rapid. It may, therefore, be suitable for routine testing worldwide in children with invasive pneumococcal disease and in patients with herpes simplex encephalitis.

Child↗
PubMed2005

Septicemia without sepsis: inherited disorders of nuclear factor-kappa B-mediated inflammation.

Septicemia is a life-threatening condition that may lead to sepsis and even septic shock. This cascade is usually accompanied by a pronounced inflammatory response, leading to high body temperature and elevated levels of laboratory markers of inflammation. However, this response can be significantly diminished in children with inherited disorders of nuclear factor (NF)-kappa B-mediated immunity. Three disease-causing genes involved in NF-kappa B activation have been identified: NEMO, IKBA, and IRAK4. Patients with anhidrotic ectodermal dysplasia and immunodeficiency, which is caused by mutations in NEMO and IKBA, have sparse hair, dry skin, and conical teeth and are at increased risk of severe infections caused by pyogenic bacteria and atypical mycobacteria. Patients with interleukin-1 receptor-associated kinase-4 deficiency are at increased risk of invasive disease due to pyogenic bacteria. An underlying defect in NF- kappa B activation should be suspected in children with bacterial septicemia accompanied by mild signs of inflammation.

Ectodermal Dysplasia↗
PubMed2005

NEMO mutations in 2 unrelated boys with severe infections and conical teeth.

X-linked recessive anhidrotic ectodermal dysplasia with immunodeficiency is a developmental and immunologic disorder caused by mutations in nuclear factor-kappaB essential modulator (NEMO), which is essential for nuclear factor-kappaB activation. Early in life, affected boys present a typical appearance, with hypotrichosis or atrichosis, hypohidrosis or anhidrosis, and hypodontia or anodontia with conical incisors. They are also susceptible to various microorganisms, mostly pyogenic bacteria and mycobacteria. Here we report 2 unrelated boys, aged 6 and 11 years, who have novel mutations in NEMO and present conical incisors and hypodontia as their sole and long-unrecognized developmental anomaly. One child had isolated recurrent pneumococcal disease, whereas the other had multiple infections. Our observations indicate that conical incisors should prompt the search for NEMO mutations in boys with unusual infectious diseases.

Anodontia↗
PubMed2005

Human TLR-7-, -8-, and -9-mediated induction of IFN-alpha/beta and -lambda Is IRAK-4 dependent and redundant for protective immunity to viruses.

Five TLRs are thought to play an important role in antiviral immunity, sensing viral products and inducing IFN-alpha/beta and -lambda. Surprisingly, patients with a defect of IRAK-4, a critical kinase downstream from TLRs, are resistant to common viruses. We show here that IFN-alpha/beta and -lambda induction via TLR-7, TLR-8, and TLR-9 was abolished in IRAK-4-deficient blood cells. In contrast, IFN-alpha/beta and -lambda were induced normally by TLR-3 and TLR-4 agonists. Moreover, IFN-beta and -lambda were normally induced by TLR-3 agonists and viruses in IRAK-4-deficient fibroblasts. We further show that IFN-alpha/beta and -lambda production in response to 9 of 11 viruses tested was normal or weakly affected in IRAK-4-deficient blood cells. Thus, IRAK-4-deficient patients may control viral infections by TLR-3- and TLR-4-dependent and/or TLR-independent production of IFNs. The TLR-7-, TLR-8-, and TLR-9-dependent induction of IFN-alpha/beta and -lambda is strictly IRAK-4 dependent and paradoxically redundant for protective immunity to most viruses in humans.

Fibroblasts↗
PubMed2005

Autosomal-dominant primary immunodeficiencies.

The vast majority of known primary immunodeficiencies (PIDs) are autosomal or X-linked recessive Mendelian traits. Only four classical primary immunodeficiencies are thought to be autosomal-dominant, three of which still lack a well-defined genetic etiology: isolated congenital asplenia, isolated chronic mucocutaneous candidiasis, and hyper IgE syndrome. The large deletions on chromosome 22q11.2 associated with Di George syndrome suggest that this disease may be dominant but not Mendelian, possibly involving several genes. The clinical and genetic features of six novel autosomal-dominant primary immunodeficiencies have however been described in recent years. These primary immunodeficiencies are caused by germline mutations in seven genes: ELA2, encoding a neutrophil elastase, and GFI1, encoding a regulator of ELA2 (mutations associated with severe congenital neutropenia); CXCR4, encoding a chemokine receptor (warts, hypogammaglobulinemia, infections and myelokathexis syndrome); LCRR8, encoding a key protein for B-cell development (agammaglobulinemia); IFNGR1, encoding the ligand-binding chain of the interferon-gamma receptor; STAT1, encoding the signal transducer and activator of transcription 1 downstream from interferon-gammaR1 (Mendelian susceptibility to mycobacterial diseases); and IKBA, encoding IkappaBalpha, the inhibitor alpha of NF-kappaB (anhidrotic ectodermal dysplasia with immunodeficiency). These recent data suggest that many more autosomal-dominant PIDs are likely to be identified in the near future.

Genes, Dominant↗
PubMed2005

Inherited disorders of human Toll-like receptor signaling: immunological implications.

In vitro nine of 10 known human Toll-like receptors (TLRs) are engaged by well-defined chemical agonists that mimic microbial compounds, raising the possibility that human TLRs play a critical role in protective immunity in vivo. We thus review here the recently described human primary immunodeficiencies caused by germline mutations in genes encoding molecules involved in cell signaling downstream from TLRs. Subjects with anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) carry either X-linked recessive hypomorphic mutations in NEMO or autosomal dominant hypermorphic mutations in IKBA. Their cells show a broad defect in nuclear factor-kappaB (NF-kappaB) activation, with an impaired, but not abolished response to a large variety of stimuli including TLR agonists. EDA-ID patients show developmental anomalies of skin appendages and a broad spectrum of infectious diseases. Patients with autosomal recessive amorphic mutations in IRAK4 present a purely immunological syndrome and more restricted defects, with specific impairment of the Toll and interleukin-1 receptor (TIR)-interleukin-1 receptor-associated kinase (IRAK) signaling pathway. In these subjects, the NF-kappaB- and mitogen-activated protein kinase-mediated induction of inflammatory cytokines in response to TIR agonists is impaired. The patients present a narrow range of pyogenic bacterial infections that become increasingly rare with age. Altogether, these data suggest that human TLRs play a critical role in host defense. However, they do not provide compelling evidence, as even the infectious phenotype of patients with mutations in IRAK4 may result from impaired signaling via receptors other than TLRs. Paradoxically, these experiments of nature raise the possibility that the entire set of human TLRs is largely redundant in protective immunity in vivo.

Animals↗
PubMed2005

Heritable defects of the human TLR signalling pathways.

Recently, three human primary immunodeficiencies associated with impaired TLR signalling were described. Anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID), either X-linked recessive or autosomal dominant, is caused by hypomorphic mutations in NEMO or hypermorphic mutation in IKBA, respectively, both involved in nuclear factor-kappaB (NF-kappaB) activation. These patients present with abnormal development of ectoderm-derived structures and suffer from a broad spectrum of infectious diseases. In vitro studies of the patients' cells showed an impaired, but not abolished, NF-kappaB activation in response to a large set of stimuli, including TLR agonists. More recently, patients with autosomal recessive amorphic mutations in IRAK4 have been reported, presenting no developmental defect and a more restricted spectrum of infectious diseases, mostly caused by pyogenic encapsulated bacteria, principally, but not exclusively Gram-positive. In vitro studies carried out with these patients' cells showed a specific impairment of the Toll-interleukin-1 receptor (TIR)-interleukin-1 receptor associated kinase (IRAK) signalling pathway. NF-kappaB- and mitogen activated protein kinase (MAPK) pathways are impaired in response to all TIR agonists tested. These data, therefore, suggest that TLRs play a critical role in host defence against pyogenic bacteria, but may be dispensable or redundant for immunity to most other infectious agents in humans.

Ectodermal Dysplasia↗
PubMed2004

Bacillus Calmette Guerin triggers the IL-12/IFN-gamma axis by an IRAK-4- and NEMO-dependent, non-cognate interaction between monocytes, NK, and T lymphocytes.

The IL-12/IFN-gamma axis is crucial for protective immunity to Mycobacterium in humans and mice. Our goal was to analyze the relative contribution of various human blood cell subsets and molecules to the production of, or response to IL-12 and IFN-gamma. We designed an assay for the stimulation of whole blood by live M. bovis Bacillus Calmette-Guerin (BCG) alone, or BCG plus IL-12 or IFN-gamma, measuring IFN-gamma and IL-12 levels. We studied patients with a variety of specific inherited immunodeficiencies resulting in a lack of leukocytes, or T, B, and/or NK lymphocytes, or polymorphonuclear cells, or a lack of expression of key molecules such as HLA class II, CD40L, NF-kappaB essential modulator (NEMO), and IL-1 receptor-associated kinase-4 (IRAK-4). Patients with deficiencies in IL-12p40, IL-12 receptor beta1 chain (IL-12Rbeta1), IFN-gammaR1, IFN-gammaR2, and STAT-1 were used as internal controls. We showed that monocytes were probably the main producers of IL-12, and that NK and T cells produced similar amounts of IFN-gamma. NEMO and IRAK-4 were found to be important for IL-12 production and subsequent IFN-gamma production, while a lack of CD40L or HLA class II had no major impact on the IL-12/IFN-gamma axis. The stimulation of whole blood by live BCG thus triggers the IL-12/IFN-gamma axis by an IRAK-4- and NEMO-dependent, non-cognate interaction between monocytes, NK, and T lymphocytes.

Adult↗
PubMed2004

Inherited disorders of NF-kappaB-mediated immunity in man.

The transcription factors of the NF-kappaB family play an important role in immunity to infection in animal models. Three human primary immunodeficiencies associated with impaired NF-kappaB signaling were recently described. X-linked recessive anhidrotic ectodermal dysplasia with immunodeficiency (XL-EDA-ID) is caused by hypomorphic mutations in the gene encoding NEMO/IKKgamma, the regulatory subunit of the IkappaB-kinase (IKK) complex. Autosomal dominant EDA-ID (AD-EDA-ID) is caused by a hypermorphic mutation in the gene encoding the inhibitory protein IkappaBalpha. Autosomal recessive immunodeficiency without EDA is caused by mutations in the gene encoding IRAK-4, a kinase acting upstream from the IKK complex in the TIR signaling pathway. The description of the infectious phenotypes associated with these genetic defects has initiated the forward genetic dissection of NF-kappaB-mediated immunity in man.

Animals↗
PubMed2003

Pyogenic bacterial infections in humans with IRAK-4 deficiency.

Members of the Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) superfamily share an intracytoplasmic Toll-IL-1 receptor (TIR) domain, which mediates recruitment of the interleukin-1 receptor-associated kinase (IRAK) complex via TIR-containing adapter molecules. We describe three unrelated children with inherited IRAK-4 deficiency. Their blood and fibroblast cells did not activate nuclear factor kappaB and mitogen-activated protein kinase (MAPK) and failed to induce downstream cytokines in response to any of the known ligands of TIR-bearing receptors. The otherwise healthy children developed infections caused by pyogenic bacteria. These findings suggest that, in humans, the TIR-IRAK signaling pathway is crucial for protective immunity against specific bacteria but is redundant against most other microorganisms.

Alleles↗
PubMed2003

Primary immunodeficiencies associated with pneumococcal disease.

PURPOSE OF REVIEW: Streptococcus pneumoniae may cause disease in patients with a variety of primary immunodeficiencies. However, no previous review has dealt with the issue of which primary immunodeficiencies predispose affected individuals to pneumococcal disease. We thus reviewed the medical literature on cases of S. pneumoniae infection in patients with primary immunodeficiency diseases, with a particular emphasis on invasive pneumococcal disease. RECENT FINDINGS: Primary immunodeficiency diseases comprise over 100 conditions, each associated with a variety of infections. Patients at high risk for pneumococcal disease include most if not all B-cell defects (whether due to an intrinsic B-cell anomaly or an impaired T-cell help), deficiencies of early components of the classical pathway of complement and C3 deficiency, congenital asplenia, anhidrotic ectodermal dysplasia with immunodeficiency (caused by impaired NF-kappaB activation), and interleukin-1 receptor associated kinase-4 deficiency. Patients with other complement deficiencies (alternative and third pathway) and hyperimmunoglobulin E syndrome show a lower risk, whereas patients with other known primary immunodeficiencies, such as phagocytic disorders, do not appear to be particularly vulnerable to S. pneumoniae. SUMMARY: Antibody- and complement-mediated opsonization, splenic macrophages and interleukin-1 receptor associated kinase-4- and nuclear factor kappaB-mediated immune responses are crucial for protective immunity to S. pneumoniae. This information is useful, not only in increasing our understanding of human immunity to S. pneumoniae, but also in the diagnostic investigation of patients with pneumococcal disease.

B-Lymphocytes↗