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1.
J Infect Dis ; 214(12): 1876-1883, 2016 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-27683816

RESUMEN

BACKGROUND: Neutrophils have been proposed as important contributors to the hyperinflammatory responses that are associated with severe invasive Streptococcus pyogenes infections. In particular, streptococcal surface proteins have been implicated as potent neutrophil activators. Here we explore the impact of streptococcus-secreted factors on neutrophil activation and degranulation. METHODS: Primary human neutrophils were exposed to supernatants prepared from cultures of invasive S. pyogenes strains of varying serotypes in the stationary growth phase. Neutrophil activation was assessed by measurement of secreted resistin, an azurophilic granule marker, and by determination of the secretome profile, using mass spectrometry. RESULTS: Marked variation in resistin release and the neutrophil secretome profile were observed following exposure to different strains. A high resistin response was triggered exclusively by SpeB-negative strains, suggesting that at least 1 stimulatory factor is susceptible to SpeB proteolytic degradation. Further analysis, including proteomics and stimulation analyses, identified phosphoglycerate kinase as a stimulatory factor for neutrophils. CONCLUSIONS: Taken together, results of this study reveal a novel secreted streptococcal factor that, in the absence of SpeB, can trigger neutrophil activation and degranulation. This finding is of interest in light of reports of hypervirulent SpeB-negative S. pyogenes variants present during invasive infections.


Asunto(s)
Degranulación de la Célula , Activación Neutrófila , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Fosfoglicerato Quinasa/metabolismo , Streptococcus pyogenes/enzimología , Streptococcus pyogenes/inmunología , Células Cultivadas , Voluntarios Sanos , Humanos , Espectrometría de Masas , Resistina/análisis
2.
Proc Natl Acad Sci U S A ; 111(35): E3735-44, 2014 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-25136085

RESUMEN

Narcolepsy is a chronic sleep disorder, likely with an autoimmune component. During 2009 and 2010, a link between A(H1N1)pdm09 Pandemrix vaccination and onset of narcolepsy was suggested in Scandinavia. In this study, we searched for autoantibodies related to narcolepsy using a neuroanatomical array: rat brain sections were processed for immunohistochemistry/double labeling using patient sera/cerebrospinal fluid as primary antibodies. Sera from 89 narcoleptic patients, 52 patients with other sleep-related disorders (OSRDs), and 137 healthy controls were examined. Three distinct patterns of immunoreactivity were of particular interest: pattern A, hypothalamic melanin-concentrating hormone and proopiomelanocortin but not hypocretin/orexin neurons; pattern B, GABAergic cortical interneurons; and pattern C, mainly globus pallidus neurons. Altogether, 24 of 89 (27%) narcoleptics exhibited pattern A or B or C. None of the patterns were exclusive for narcolepsy but were also detected in the OSRD group at significantly lower numbers. Also, some healthy controls exhibited these patterns. The antigen of pattern A autoantibodies was identified as the common C-terminal epitope of neuropeptide glutamic acid-isoleucine/α-melanocyte-stimulating hormone (NEI/αMSH) peptides. Passive transfer experiments on rat showed significant effects of pattern A human IgGs on rapid eye movement and slow-wave sleep time parameters in the inactive phase and EEG θ-power in the active phase. We suggest that NEI/αMSH autoantibodies may interfere with the fine regulation of sleep, contributing to the complex pathogenesis of narcolepsy and OSRDs. Also, patterns B and C are potentially interesting, because recent data suggest a relevance of those brain regions/neuron populations in the regulation of sleep/arousal.


Asunto(s)
Autoanticuerpos/sangre , Encéfalo/inmunología , Encéfalo/patología , Narcolepsia/inmunología , Narcolepsia/patología , Sueño/fisiología , Adolescente , Adulto , Animales , Autoanticuerpos/inmunología , Colchicina/análogos & derivados , Colchicina/farmacología , Electroencefalografía , Globo Pálido/inmunología , Globo Pálido/patología , Hipocampo/inmunología , Hipocampo/patología , Humanos , Inmunoglobulina G/sangre , Interneuronas/inmunología , Interneuronas/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neocórtex/inmunología , Neocórtex/patología , Proteínas del Tejido Nervioso/metabolismo , Bulbo Olfatorio/inmunología , Bulbo Olfatorio/patología , Ratas , Ratas Wistar , Adulto Joven
3.
Acta Paediatr ; 103(10): 1000-8, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24861898

RESUMEN

UNLABELLED: At birth, the foetus makes the transition from the uterus to a world full of microbes. The newborn baby needs protection against potential invading pathogens and needs to establish a normal microbiota. CONCLUSION: Antimicrobial peptides and proteins are key effector molecules of innate immunity and are also important immunomodulators. Their presence in the cells and tissues of the uterus, foetus and the neonate indicates an important role in immunity during pregnancy and in early life.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/fisiología , Feto/inmunología , Inmunidad Innata , Recién Nacido/inmunología , Femenino , Humanos , Enfermedades del Recién Nacido/inmunología , Periodo Posparto , Embarazo
4.
Mol Pain ; 10: 12, 2014 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-24521084

RESUMEN

BACKGROUND: Somatostatin (SST) and some of its receptor subtypes have been implicated in pain signaling at the spinal level. In this study we have investigated the role of SST and its sst2A receptor (sst2A) in dorsal root ganglia (DRGs) and spinal cord. RESULTS: SST and sst2A protein and sst2 transcript were found in both mouse and human DRGs, sst2A-immunoreactive (IR) cell bodies and processes in lamina II in mouse and human spinal dorsal horn, and sst2A-IR nerve terminals in mouse skin. The receptor protein was associated with the cell membrane. Following peripheral nerve injury sst2A-like immunoreactivity (LI) was decreased, and SST-LI increased in DRGs. sst2A-LI accumulated on the proximal and, more strongly, on the distal side of a sciatic nerve ligation. Fluorescence-labeled SST administered to a hind paw was internalized and retrogradely transported, indicating that a SST-sst2A complex may represent a retrograde signal. Internalization of sst2A was seen in DRG neurons after systemic treatment with the sst2 agonist octreotide (Oct), and in dorsal horn and DRG neurons after intrathecal administration. Some DRG neurons co-expressed sst2A and the neuropeptide Y Y1 receptor on the cell membrane, and systemic Oct caused co-internalization, hypothetically a sign of receptor heterodimerization. Oct treatment attenuated the reduction of pain threshold in a neuropathic pain model, in parallel suppressing the activation of p38 MAPK in the DRGs CONCLUSIONS: The findings highlight a significant and complex role of the SST system in pain signaling. The fact that the sst2A system is found also in human DRGs and spinal cord, suggests that sst2A may represent a potential pharmacologic target for treatment of neuropathic pain.


Asunto(s)
Ganglios Espinales/patología , Receptores de Somatostatina/metabolismo , Ciática/metabolismo , Ciática/patología , Células Receptoras Sensoriales/metabolismo , Somatostatina/metabolismo , Animales , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Lateralidad Funcional/genética , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Glutamato Descarboxilasa/genética , Proteínas Fluorescentes Verdes/deficiencia , Proteínas Fluorescentes Verdes/genética , Humanos , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/etiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Persona de Mediana Edad , Octreótido/uso terapéutico , Oligopéptidos/farmacología , Umbral del Dolor/efectos de los fármacos , Umbral del Dolor/fisiología , Transporte de Proteínas/efectos de los fármacos , Transporte de Proteínas/genética , Receptores de Somatostatina/antagonistas & inhibidores , Receptores de Somatostatina/deficiencia , Receptores de Somatostatina/genética , Ciática/complicaciones , Ciática/tratamiento farmacológico , Células Receptoras Sensoriales/efectos de los fármacos , Somatostatina/genética
5.
PLoS One ; 8(1): e53876, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23326523

RESUMEN

Postpartum, infants have not yet established a fully functional adaptive immune system and are at risk of acquiring infections. Hence, newborns are dependent on the innate immune system with its antimicrobial peptides (AMPs) and proteins expressed at epithelial surfaces. Several factors in breast milk are known to confer immune protection, but which the decisive factors are and through which manner they work is unknown. Here, we isolated an AMP-inducing factor from human milk and identified it by electrospray mass spectrometry and NMR to be lactose. It induces the gene (CAMP) that encodes the only human cathelicidin LL-37 in colonic epithelial cells in a dose- and time-dependent manner. The induction was suppressed by two different p38 antagonists, indicating an effect via the p38-dependent pathway. Lactose also induced CAMP in the colonic epithelial cell line T84 and in THP-1 monocytes and macrophages. It further exhibited a synergistic effect with butyrate and phenylbutyrate on CAMP induction. Together, these results suggest an additional function of lactose in innate immunity by upregulating gastrointestinal AMPs that may lead to protection of the neonatal gut against pathogens and regulation of the microbiota of the infant.


Asunto(s)
Antiinfecciosos/química , Inmunidad Innata , Mucosa Intestinal , Intestinos , Lactosa/química , Leche Humana , Antiinfecciosos/inmunología , Antiinfecciosos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/metabolismo , Línea Celular , Células Epiteliales , Homeostasis/inmunología , Homeostasis/fisiología , Humanos , Mucosa Intestinal/metabolismo , Intestinos/inmunología , Intestinos/microbiología , Lactosa/inmunología , Lactosa/aislamiento & purificación , Leche Humana/química , Leche Humana/inmunología , Leche Humana/microbiología , Monocitos/química , Monocitos/citología
6.
PLoS Pathog ; 6(7): e1001010, 2010 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-20661475

RESUMEN

Bacterial growth in multicellular communities, or biofilms, offers many potential advantages over single-cell growth, including resistance to antimicrobial factors. Here we describe the interaction between the biofilm-promoting components curli fimbriae and cellulose of uropathogenic E. coli and the endogenous antimicrobial defense in the urinary tract. We also demonstrate the impact of this interplay on the pathogenesis of urinary tract infections. Our results suggest that curli and cellulose exhibit differential and complementary functions. Both of these biofilm components were expressed by a high proportion of clinical E. coli isolates. Curli promoted adherence to epithelial cells and resistance against the human antimicrobial peptide LL-37, but also increased the induction of the proinflammatory cytokine IL-8. Cellulose production, on the other hand, reduced immune induction and hence delayed bacterial elimination from the kidneys. Interestingly, LL-37 inhibited curli formation by preventing the polymerization of the major curli subunit, CsgA. Thus, even relatively low concentrations of LL-37 inhibited curli-mediated biofilm formation in vitro. Taken together, our data demonstrate that biofilm components are involved in the pathogenesis of urinary tract infections by E. coli and can be a target of local immune defense mechanisms.


Asunto(s)
Catelicidinas/fisiología , Fimbrias Bacterianas/inmunología , Escherichia coli Uropatógena/inmunología , Adulto , Proteínas Bacterianas , Biopelículas/crecimiento & desarrollo , Línea Celular , Celulosa/metabolismo , Niño , Células Epiteliales/microbiología , Femenino , Humanos , Inmunidad , Interleucina-8/biosíntesis , Masculino , Infecciones Urinarias/etiología , Infecciones Urinarias/microbiología
7.
J Clin Invest ; 118(10): 3491-502, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18787642

RESUMEN

In acute inflammation, infiltrating polymorphonuclear leukocytes (also known as PMNs) release preformed granule proteins having multitudinous effects on the surrounding environment. Here we present what we believe to be a novel role for PMN-derived proteins in bacterial phagocytosis by both human and murine macrophages. Exposure of macrophages to PMN secretion markedly enhanced phagocytosis of IgG-opsonized Staphylococcus aureus both in vitro and in murine models in vivo. PMN secretion activated macrophages, resulting in upregulation of the Fcgamma receptors CD32 and CD64, which then mediated the enhanced phagocytosis of IgG-opsonized bacteria. The phagocytosis-stimulating activity within the PMN secretion was found to be due to proteins released from PMN primary granules; thorough investigation revealed heparin-binding protein (HBP) and human neutrophil peptides 1-3 (HNP1-3) as the mediators of the macrophage response to PMN secretion. The use of blocking antibodies and knockout mice revealed that HBP acts via beta2 integrins, but the receptor for HNP1-3 remained unclear. Mechanistically, HBP and HNP1-3 triggered macrophage release of TNF-alpha and IFN-gamma, which acted in an autocrine loop to enhance expression of CD32 and CD64 and thereby enhance phagocytosis. Thus, we attribute what may be a novel role for PMN granule proteins in regulating the immune response to bacterial infections.


Asunto(s)
Bacterias/inmunología , Proteína Asociada a Proteínas Relacionadas con Receptor de LDL/metabolismo , Macrófagos/inmunología , Macrófagos/microbiología , Neutrófilos/metabolismo , Fagocitosis , alfa-Defensinas/metabolismo , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Humanos , Interferón gamma/metabolismo , Macrófagos/citología , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/microbiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Peritonitis/fisiopatología , Receptores de IgG/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismo
8.
Front Biosci ; 13: 3760-7, 2008 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-18508470

RESUMEN

Neutrophil granules contain several antimicrobial peptides (AMPs) that are important effector molecules of innate immunity. In mammals, the main families of these peptides are the cathelicidins and defensins. Several defensins have been characterized in humans, while there is only one human cathelicidin, designated LL-37. This peptide is stored in specific granules of neutrophils in an inactive proform, which is processed extracellularly to the mature active peptide LL-37 and the propart cathelin after neutrophil degranulation. Apart from exhibiting a broad antimicrobial spectra, it is now evident that LL-37 possesses several additional functions that are related to host defense. Examples of such functions are chemotactic, endotoxin neutralizing, angiogenic and wound healing activities. These effects of LL-37 reveal a role as a mediator between innate and adaptive immunity. This review is giving an overview of the different immunological effects exerted by LL-37 and the physiological significance of these functions in immunity.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/fisiología , Neutrófilos/fisiología , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/farmacología , Quimiotaxis/efectos de los fármacos , Endotoxinas/metabolismo , Células Epiteliales/fisiología , Escherichia coli/efectos de los fármacos , Humanos , Lipopolisacáridos/farmacología , Mamíferos , Neisseria gonorrhoeae/efectos de los fármacos , Salmonella typhimurium/efectos de los fármacos
9.
Pediatr Res ; 61(5 Pt 1): 530-6, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17413858

RESUMEN

Antimicrobial peptides (AMP) produced throughout our body are important effectors in the defense barrier of innate immunity. Here, we have analyzed antimicrobial activity and polypeptide composition of meconium versus neonatal feces to address the development of antimicrobial defense of the neonatal gut. Extracts of meconium exhibited antimicrobial activity against Bacillus megaterium, Escherichia coli, and group B streptococci (GBS) but not against the yeast Candida albicans. Extracts of neonatal feces were found to possess low activity against E. coli, GBS, and C. albicans. However, the anti-B. megaterium activity was higher in the fecal extracts than in meconium. All activities were reduced or abolished when salt was added to the antimicrobial assay. The AMP cathelicidin LL-37, alpha-defensin HNP-1-2, alpha-defensin HD 5, and lysozyme were identified in both meconium and fecal extracts. In addition, HNP-3 and a fragment of azurocidin were found in meconium, whereas the holoprotein azurocidin was detected in feces. In meconium, histones H2A and H4 were isolated and identified by their antimicrobial activity. Notably, LL-37 and lysozyme were found at significantly higher levels in feces than in meconium. Our findings reveal that meconium and feces contain AMP, acting in the defense of the neonatal gut, and may be implicated in the control of the initial colonization.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/análisis , Heces/química , Tracto Gastrointestinal , Meconio/química , Proteínas Sanguíneas/análisis , Proteínas Portadoras/análisis , Femenino , Tracto Gastrointestinal/química , Tracto Gastrointestinal/microbiología , Edad Gestacional , Humanos , Recién Nacido , Masculino , Fragmentos de Péptidos/análisis , Embarazo
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