RESUMEN
Human interleukin (IL) 1 receptor-associated kinase 4 (IRAK-4) deficiency is a recently discovered primary immunodeficiency that impairs Toll/IL-1R immunity, except for the Toll-like receptor (TLR) 3- and TLR4-interferon (IFN)-alpha/beta pathways. The clinical and immunological phenotype remains largely unknown. We diagnosed up to 28 patients with IRAK-4 deficiency, tested blood TLR responses for individual leukocyte subsets, and TLR responses for multiple cytokines. The patients' peripheral blood mononuclear cells (PBMCs) did not induce the 11 non-IFN cytokines tested upon activation with TLR agonists other than the nonspecific TLR3 agonist poly(I:C). The patients' individual cell subsets from both myeloid (granulocytes, monocytes, monocyte-derived dendritic cells [MDDCs], myeloid DCs [MDCs], and plasmacytoid DCs) and lymphoid (B, T, and NK cells) lineages did not respond to the TLR agonists that stimulated control cells, with the exception of residual responses to poly(I:C) and lipopolysaccharide in MDCs and MDDCs. Most patients (22 out of 28; 79%) suffered from invasive pneumococcal disease, which was often recurrent (13 out of 22; 59%). Other infections were rare, with the exception of severe staphylococcal disease (9 out of 28; 32%). Almost half of the patients died (12 out of 28; 43%). No death and no invasive infection occurred in patients older than 8 and 14 yr, respectively. The IRAK-4-dependent TLRs and IL-1Rs are therefore vital for childhood immunity to pyogenic bacteria, particularly Streptococcus pneumoniae. Conversely, IRAK-4-dependent human TLRs appear to play a redundant role in protective immunity to most infections, at most limited to childhood immunity to some pyogenic bacteria.
Asunto(s)
Infecciones Bacterianas/inmunología , Infecciones Bacterianas/metabolismo , Quinasas Asociadas a Receptores de Interleucina-1/deficiencia , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , Receptores Toll-Like/metabolismo , Adolescente , Adulto , Infecciones Bacterianas/patología , Diferenciación Celular/inmunología , Células Cultivadas , Niño , Preescolar , Citocinas/biosíntesis , Citocinas/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Lactante , Quinasas Asociadas a Receptores de Interleucina-1/genética , Leucocitos/citología , Leucocitos/inmunología , Leucocitos/metabolismo , Masculino , Mutación/genética , Células Mieloides/inmunología , Células Mieloides/metabolismo , Linaje , Receptores Toll-Like/agonistasRESUMEN
BACKGROUND: Children with germline mutations in Toll-like receptor 3 (TLR3), UNC93B1, TNF receptor-associated factor 3, and signal transducer and activator of transcription 1 are prone to herpes simplex virus-1 encephalitis, owing to impaired TLR3-triggered, UNC-93B-dependent, IFN-α/ß, and/or IFN-λ-mediated signal transducer and activator of transcription 1-dependent immunity. OBJECTIVE: We explore here the molecular basis of the pathogenesis of herpes simplex encephalitis in a child with a hypomorphic mutation in nuclear factor-κB (NF-κB) essential modulator, which encodes the regulatory subunit of the inhibitor of the Iκß kinase complex. METHODS: The TLR3 signaling pathway was investigated in the patient's fibroblasts by analyses of IFN-ß, IFN-λ, and IL-6 mRNA and protein levels, by quantitative PCR and ELISA, respectively, upon TLR3 stimulation (TLR3 agonists or TLR3-dependent viruses). NF-κB activation was assessed by electrophoretic mobility shift assay and interferon regulatory factor 3 dimerization on native gels after stimulation with a TLR3 agonist. RESULTS: The patient's fibroblasts displayed impaired responses to TLR3 stimulation in terms of IFN-ß, IFN-λ, and IL-6 production, owing to impaired activation of both NF-κB and IRF-3. Moreover, vesicular stomatitis virus, a potent IFN-inducer in human fibroblasts, and herpes simplex virus-1, induced only low levels of IFN-ß and IFN-λ in the patient's fibroblasts, resulting in enhanced viral replication and cell death, as reported for UNC-93B-deficient fibroblasts. CONCLUSION: Herpes simplex encephalitis may occur in patients carrying NF-κB essential modulator mutations, due to the impairment of NF-κB- and interferon regulatory factor 3-dependent-TLR3-mediated antiviral IFN production.
Asunto(s)
Encefalitis por Herpes Simple/inmunología , Quinasa I-kappa B/metabolismo , Factor 3 Regulador del Interferón/metabolismo , Mutación , FN-kappa B/metabolismo , Receptor Toll-Like 3/inmunología , Preescolar , Encefalitis por Herpes Simple/genética , Encefalitis por Herpes Simple/virología , Fibroblastos/inmunología , Fibroblastos/metabolismo , Humanos , Quinasa I-kappa B/genética , Transducción de Señal , Simplexvirus/inmunología , Receptor Toll-Like 3/metabolismoRESUMEN
PURPOSE: We characterized the innate immune response to intravesical bacillus Calmette-Guerin therapy using a systems approach based on proteomic and cytometric screens. MATERIALS AND METHODS: Blood and urine were collected from patients receiving intravesical bacillus Calmette-Guerin therapy before, and 2 and 4 hours after bacillus Calmette-Guerin treatment, at the first and third instillation. Proteomic and cytometry based screens were performed. RESULTS: Molecular analyte profiling revealed a prime/boost pattern to the innate response to intravesical bacillus Calmette-Guerin. We identified 36 statistically significant changes in the proteins induced during the third instillation compared to the initial treatment. These analytes were classified into 3 categories of 1) plasma proteins that leaked into the urine, 2) cytokines/chemokines produced locally during the first hours of inflammation and 3) other innate molecules that modulate the bladder microenvironment. To characterize the marked increase in the inflammatory response after multiple treatments we evaluated the cells present in the urine and again a prime/boost response was revealed. For the locally produced analytes it was possible to define the cell source(s) and, thus, provide a first generation map of what occurs during the initial phase of bacillus Calmette-Guerin therapy. CONCLUSIONS: This study provides in vivo information concerning the ability of bacillus Calmette-Guerin to sensitize the tissue microenvironment to enhance innate responses and establishes a framework for improving vaccination strategies while decreasing adverse events.
Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Vacuna BCG/administración & dosificación , Citometría de Flujo , Proteómica , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Administración Intravesical , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo , Neoplasias de la Vejiga Urinaria/sangre , Neoplasias de la Vejiga Urinaria/orinaRESUMEN
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.
Asunto(s)
Quinasa I-kappa B/genética , Quinasas Asociadas a Receptores de Interleucina-1/genética , Infecciones Neumocócicas/genética , Infecciones Neumocócicas/inmunología , Streptococcus pneumoniae/inmunología , Antibacterianos/uso terapéutico , Formación de Anticuerpos , Ceftriaxona/uso terapéutico , Niño , Preescolar , ADN Complementario , Exones , Humanos , Quinasa I-kappa B/metabolismo , Síndromes de Inmunodeficiencia/genética , Interleucina-1/inmunología , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , Intrones , Masculino , FN-kappa B/inmunología , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/patología , Vacunas Neumococicas/inmunología , Reacción en Cadena de la Polimerasa , Recurrencia , Transducción de Señal , Streptococcus pneumoniae/químicaRESUMEN
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.
Asunto(s)
Displasia Ectodérmica/genética , FN-kappa B/genética , Síndrome de Respuesta Inflamatoria Sistémica/genética , Humanos , Inflamación , Quinasas Asociadas a Receptores de Interleucina-1/deficiencia , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , FN-kappa B/inmunología , Sepsis/diagnóstico , Síndrome de Respuesta Inflamatoria Sistémica/diagnóstico , Síndrome de Respuesta Inflamatoria Sistémica/inmunologíaRESUMEN
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.
Asunto(s)
Displasia Ectodérmica/genética , Displasia Ectodérmica/inmunología , Síndromes de Inmunodeficiencia/genética , Síndromes de Inmunodeficiencia/inmunología , Glicoproteínas de Membrana/fisiología , Receptores de Superficie Celular/fisiología , Transducción de Señal/inmunología , Enfermedades Genéticas Ligadas al Cromosoma X/inmunología , Humanos , Glicoproteínas de Membrana/agonistas , Modelos Inmunológicos , Mutación , FN-kappa B/metabolismo , Receptores de Superficie Celular/agonistas , Receptores de Interleucina-1/fisiología , Transducción de Señal/genética , Receptores Toll-LikeRESUMEN
MyD88 is a key downstream adapter for most Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 deficiency in mice leads to susceptibility to a broad range of pathogens in experimental settings of infection. We describe a distinct situation in a natural setting of human infection. Nine children with autosomal recessive MyD88 deficiency suffered from life-threatening, often recurrent pyogenic bacterial infections, including invasive pneumococcal disease. However, these patients were otherwise healthy, with normal resistance to other microbes. Their clinical status improved with age, but not due to any cellular leakiness in MyD88 deficiency. The MyD88-dependent TLRs and IL-1Rs are therefore essential for protective immunity to a small number of pyogenic bacteria, but redundant for host defense to most natural infections.
Asunto(s)
Infecciones Bacterianas/genética , Infecciones Bacterianas/inmunología , Factor 88 de Diferenciación Mieloide/deficiencia , Adolescente , Animales , Línea Celular Transformada , Niño , Preescolar , Citocinas/metabolismo , Susceptibilidad a Enfermedades , Femenino , Eliminación de Gen , Humanos , Inmunidad Innata , Masculino , Ratones , Mutación Missense , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Infecciones Neumocócicas/genética , Infecciones Neumocócicas/inmunología , Infecciones por Pseudomonas/genética , Infecciones por Pseudomonas/inmunología , Receptores de Interleucina-1/inmunología , Receptores de Interleucina-1/metabolismo , Transducción de Señal , Infecciones Estafilocócicas/genética , Infecciones Estafilocócicas/inmunología , Receptores Toll-Like/inmunología , Receptores Toll-Like/metabolismo , TransfecciónRESUMEN
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.