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1.
Animals (Basel) ; 11(3)2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33806270

RESUMEN

Soy protein concentrate improves nutrient utilization and growth performance compared to soybean meal, and diets with a low crude protein (CP) level decreases diarrhoea. The objectives were to (1) test a low CP diet based on different soy products, and (2) to test a very-low CP diet (15.1%) with amino acids (AA) on diarrhoea and productivity. A total of 5,635 weaned pigs (~28 days), were assigned to five dietary treatments; PC (positive control): Standard CP levels (192, 189, 191 g/kg CP) with 2500 ppm ZnO; NC (negative control): Same as PC without ZnO; SP (Soy protein concentrate): Low CP levels (176, 174, 191 g/kg CP); SB (Soybean meal): Low CP levels (177, 176, 191 g/kg CP); and XLA (X-low CP + AA): Very low CP levels (154, 151, 191 g/kg CP) with AA. The PC and XLA diets reduced diarrhoea by 41 and 61%, respectively, compared to the NC group, while no difference between SB and SP were observed. The XLA diet reduced feed intake and daily gain compared with PC and NC, where SP, SB, and XLA had a poorer feed conversion compared with PC. Conclusively, the SP and SB low-protein diets did not reduce diarrhoea or growth performance, whereas the XLA diet decreased both diarrhoea and performance.

2.
Animals (Basel) ; 10(6)2020 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-32580422

RESUMEN

A well-balanced gut microbiome is associated with improved health outcomes, but to date, the GM of IUGR piglets have only been sparsely investigated. Here, we investigated GM composition, color of colon content, and blood parameters of 20 IUGR and 20 normal 24-day-old piglets. No significant differences were detected in colon microbiota composition between IUGR and the normal piglets with respect to alpha and beta diversity measures. The colon content of these piglets displayed three colors: brown, black, and yellow. Interestingly, the color of the colon content varied with microbial community composition, with significant differences in the relative abundance of taxa belonging to Fusobacteria and Treponema. Fusobacteria were most abundant in yellow fecal samples, with a mean relative abundance around 5.6%, whereas this was 0.51% within brown and 0.02% for the black fecal samples. Fusobacteria positively correlated with total blood protein, albumin, and triglycerides. Contrarily, Treponema was at 0.9% the most abundant in black fecal samples, while present at 0.1% of relative abundance in brown fecal samples and 0.01% in yellow samples, correlating positively with blood iron content. This study indicates that colon/fecal content color can be used as indicator for specific GM and metabolite signatures.

3.
Angew Chem Int Ed Engl ; 59(39): 17192-17196, 2020 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-32524693

RESUMEN

Light-induced transitions between the trans and cis isomer of triazatriangulenium-based azobenzene derivatives on Au(111) surfaces were observed directly by scanning tunneling microscopy, allowing atomic-scale studies of the photoisomerization kinetics. Although the azobenzene units in these adlayers are free-standing and spaced at uniform distances of 1.26 nm, their photoswitching depends on the isomeric state of the surrounding molecules and, specifically, is accelerated by neighboring cis isomers. These collective effects are supported by ab initio calculations indicating that the electronic excitation preferably localizes on the n-π* state of trans isomers with neighboring cis azobenzenes.

4.
Phys Chem Chem Phys ; 22(24): 13378-13389, 2020 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-32391539

RESUMEN

The orientation of diatomic molecular impurities in crystals is a classic problem in physics, whose analysis started in the early 1930s with Pauling's pioneering studies and has extended to the present day. In the present work, we investigate the orientation of a superoxide ion (O2-), which is known to be oriented in the 1 1 0 direction when replacing a halide ion in alkali halide rock salt lattices. The unpaired electron of the superoxide, whose ground state is degenerate (2Πg), is oriented in the 0 0 1 direction for sodium halides while it is oriented in the 1 1[combining macron] 0 direction for potassium and rubidium halides. We performed density functional theory (DFT) calculations to describe the full adiabatic potential energy surface (APES) of this complex system for the first time with ab initio methods. We are focused on four alkali halide lattices, namely NaCl, NaBr, KCl, and KBr. We show that DFT, at the generalized gradient approximation (GGA) and meta-GGA levels, is able to reproduce all the experimental features for potassium halides. However, for sodium halides, although the DFT predicts the correct unpaired electron orientation, the forecasted APES energy minimum for the molecular orientation is found to be close to the 1 1 3/4 orientation, in contrast to the experimental 1 1 0 orientation. The difference in energy between the 1 1 3/4 and 1 1 0 orientation is less than 10 meV, which points out the subtleness of the considered problem. In addition to assessing the DFT accuracy and limitations to treat these systems, we also paid special attention to analyze the geometry distortions of the host lattice for the high symmetry orientations of the superoxide ion, i.e., 1 0 0, 1 1 0 and 1 1 1. In the case of the 1 1 0 molecular orientation, we find a strong dependence on the distance between the alkali ions in the 0 0 1 direction and the superoxide ion upon the unpaired electron orientation. This fact explains why the orientation of the unpaired electron is different in sodium vs. potassium halides. In the case of the 1 0 0 and 1 1 1 molecular orientations, we analyze the Jahn-Teller vibronic coupling to find an unusually large vibronic centrifugal term in the latter.

5.
Phys Chem Chem Phys ; 22(25): 14376, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32458892

RESUMEN

Correction for 'Density functional theory study of superoxide ions as impurities in alkali halides' by Alexander S. Tygesen et al., Phys. Chem. Chem. Phys., 2020, DOI: 10.1039/d0cp00719f.

6.
Sci Total Environ ; 670: 1226-1239, 2019 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-31018437

RESUMEN

The present article assesses the environmental profile of a real-scale anaerobic-digestion plant that has been developed in France. The system utilises 13652 t of different types of feedstock related to food industry, agriculture, etc. The study is based on Life Cycle Assessment (LCA) according to Global Warming Potential (GWP), Cumulative Energy Demand (CED), ReCiPe midpoint/endpoint and USEtox. The life-cycle inventory includes real data from various sources of waste as well as the transportation distances. By considering the impact of both anaerobic digestion and transportation for the whole system, the following findings have been found: 6430 t CO2.eq (GWP 100a); 67194 GJprim (CED); 231100 Pts (ReCiPe endpoint single-score: Human health), 146932 Pts (ReCiPe endpoint single-score: Ecosystems), 171568 Pts (ReCiPe endpoint single-score: Resources). Furthermore, USEtox results, for the whole system and by taking into account both anaerobic digestion and transportation, show that based on: 1) Human toxicity/cancer, anaerobic-digestion phase has around 21 times higher value comparing to transportation, 2) Ecotoxicity, anaerobic-digestion phase presents about 77 times higher value than transportation. Regarding the impact of both phases (anaerobic digestion; transportation) per t of waste or per MWh of electricity, the findings show values of 0.5-0.6 t CO2.eq per t of feedstock (or digestate) or per MWh of electricity produced (not net). A separate subsection with comparisons of the present findings with literature studies about LCA of anaerobic-digestion plants has been included. In general, a good agreement has been observed. Moreover, comparisons of the impact of the electricity produced by means of the present biogas system with the impact of conventional electricity mixes of several countries are presented and discussed, proving the environmental benefits of the proposed anaerobic-digestion plant.


Asunto(s)
Contaminantes Atmosféricos/análisis , Biocombustibles/análisis , Gases de Efecto Invernadero/análisis , Anaerobiosis , Reactores Biológicos , Francia
7.
Chemistry ; 24(66): 17497-17505, 2018 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-30257037

RESUMEN

Glycolipids as constituents of cell membranes play an important role in cell membrane functioning. To enable the structural modification of membranes on demand, embedding of photosensitive glycolipid mimetics was envisioned and novel amphiphilic glycolipid mimetics comprising a photoswitchable azobenzene unit were synthesized. In this study, the photochromic properties of these glycolipid mimetics were analyzed by means of UV/Vis spectroscopy and reversible photoswitching. The glycolipids were based on a racemic glycerolipid derivative to be comparable in DPPC (dipalmitoylphosphatidylcholine) phospholipid membrane monolayers. Carbohydrate head groups were altered between a ß-glucoside and a ß-lactosyl unit, as well as acyl chain lengths between C12 and C16, resulting in altered photoswitching. Langmuir isotherms showed that photoswitching of Langmuir films comprising the synthetic photosensitive glycoamphiphiles was successful.

8.
Chemphyschem ; 17(12): 1870-4, 2016 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-27016909

RESUMEN

Triazatriangulenium (TATA) platforms have been used to prepare highly ordered, self-assembled monolayers of free- and vertically standing imines on Au(111) surfaces. Upon irradiation, the imines undergo trans-cis isomerization and a fast thermal reaction (t1/2 =0.58 s at 20 °C) back to the more stable trans form. It is known that the photochemical reaction proceeds through rotation of the C=N bond and the thermochemical reaction through inversion at the N atom. The imine motors, therefore, should be able to induce a net displacement of particles above the surface similar to cilia epithelia in nature.


Asunto(s)
Materiales Biomiméticos/química , Biomimética , Cilios/química , Colorantes Fluorescentes/química , Iminas/química , Pirenos/química , Materiales Biomiméticos/síntesis química , Colorantes Fluorescentes/síntesis química , Oro/química , Estructura Molecular , Pirenos/síntesis química , Propiedades de Superficie
9.
J Pediatric Infect Dis Soc ; 5(1): 76-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26908493

RESUMEN

Incidence rates for varicella and herpes zoster were similar in patients with juvenile idiopathic arthritis receiving etanercept/methotrexate (n = 85, 184.9 patient-years [PY]) or methotrexate alone (n = 71, 199.4 PY); no complicated varicella or herpes zoster cases were reported; herpes labialis incidence was higher in patients receiving etanercept/methotrexate versus methotrexate alone (0.38 vs. 0.24 PY).


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Juvenil/tratamiento farmacológico , Varicela/epidemiología , Etanercept/uso terapéutico , Herpes Labial/epidemiología , Herpes Zóster/epidemiología , Metotrexato/uso terapéutico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Niño , Preescolar , Quimioterapia Combinada , Femenino , Humanos , Incidencia , Masculino , Ciudad de Roma/epidemiología
10.
J Immunol ; 194(4): 1417-21, 2015 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-25595774

RESUMEN

Triggering receptor expressed on myeloid cells (TREM)-1 is an orphan receptor implicated in innate immune activation. Inhibition of TREM-1 reduces sepsis in mouse models, suggesting a role for it in immune responses triggered by bacteria. However, the absence of an identified ligand has hampered a full understanding of TREM-1 function. We identified complexes between peptidoglycan recognition protein 1 (PGLYRP1) and bacterially derived peptidoglycan that constitute a potent ligand capable of binding TREM-1 and inducing known TREM-1 functions. Interestingly, multimerization of PGLYRP1 bypassed the need for peptidoglycan in TREM-1 activation, demonstrating that the PGLYRP1/TREM-1 axis can be activated in the absence of bacterial products. The role for PGLYRP1 as a TREM-1 activator provides a new mechanism by which bacteria can trigger myeloid cells, linking two known, but previously unrelated, pathways in innate immunity.


Asunto(s)
Citocinas/inmunología , Inmunidad Innata/inmunología , Glicoproteínas de Membrana/inmunología , Neutrófilos/inmunología , Receptores Inmunológicos/inmunología , Humanos , Inmunoprecipitación , Ligandos , Resonancia por Plasmón de Superficie , Receptor Activador Expresado en Células Mieloides 1
11.
J Am Chem Soc ; 136(32): 11248-51, 2014 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-25053445

RESUMEN

The controlled attachment of chromophores to metal or semiconducting surfaces is a prerequisite for the construction of photonic devices and artificial surface-based light-harvesting systems. We present an approach to mount porphyrins in ordered monolayers on Au(111) by self-assembly and verify it, employing STM, absorption spectroscopy, and quantum chemical calculations. The usual adsorption geometry of planar chromophores, flat on the surface or densely packed edge-on, is prevented by mounting the porphyrins upright on a molecular platform. An ethynyl unit as spacer and pivot joint provides almost free azimuthal rotation of the unsubstituted porphin. However, rotation of the larger triphenylporphyrin unit is sterically restricted: because the diameter of the substituted porphyrin is larger than the distance to its next neighbors, the phenyl substituents of neigboring molecules interact by dispersion force, which leads to an alignment of the azimuthal rotators.


Asunto(s)
Oro/química , Porfirinas/química , Adsorción , Dimerización , Ensayo de Materiales , Metales/química , Microscopía de Túnel de Rastreo , Fotones , Teoría Cuántica , Semiconductores , Espectrofotometría Ultravioleta , Propiedades de Superficie
12.
Environ Sci Technol ; 48(13): 7669-76, 2014 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-24873631

RESUMEN

Ammonia-rich substrates inhibit the anaerobic digestion (AD) process and constitute the main reason for low energy recovery in full-scale reactors. It is estimated that many full-scale AD reactors are operating in ammonia induced "inhibited steady-state" with significant losses of the potential biogas production yield. To date there are not any reliable methods to alleviate the ammonia toxicity effect or to efficiently digest ammonia-rich waste. In the current study, bioaugmentation as a possible method to alleviate ammonia toxicity effect in a mesophilic continuously stirred-tank reactor (CSTR) operating under "inhibited steady state" was tested. A fast growing hydrogenotrophic methanogen (i.e., Methanoculleus bourgensis MS2(T)) was bioaugmented in the CSTR reactor at high ammonia levels (5 g NH4(+)-N L(-1)). A second CSTR reactor was used as control with no bioaugmentation. The results derived from this study clearly demonstrated a 31.3% increase in methane production yield in the CSTR reactor, at steady-state, after bioaugmentation. Additionally, high-throughput 16S rRNA gene sequencing analysis showed a 5-fold increase in relative abundance of Methanoculleus spp. after bioaugmentation. On the contrary to all methods used today to alleviate ammonia toxicity effect, the tested bioaugmentation process performed without interrupting the continuous operation of the reactor and without replacing the ammonia-rich feedstock.


Asunto(s)
Amoníaco/metabolismo , Metano/biosíntesis , Animales , Archaea/clasificación , Archaea/genética , Biodegradación Ambiental , Biocombustibles/microbiología , Reactores Biológicos/microbiología , Bovinos , Ácidos Grasos Volátiles/análisis , Variación Genética , Concentración de Iones de Hidrógeno , Estiércol , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie
13.
Langmuir ; 30(42): 12457-64, 2014 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-24649803

RESUMEN

Colloidal polymer particles are an important class of materials finding use in both everyday and basic research applications. Tailoring their composition, shape, and functionality is of key importance. In this article, we describe a new class of shape-tunable core-shell microparticles. They are composed of a cross-linked polystyrene (PS) core and a poly(methyl methacrylate) (PMMA) shell of varying thickness. In the first step, we prepared highly cross-linked PS cores, which are subsequently transferred into a nonpolar dispersant. They serve as the seed dispersion for a nonaqueous dispersion polymerization to generate the PMMA shell. The shape of the particles can subsequently be manipulated. After the shell growth stage, the spherical PS/PMMA core-shell colloids exhibit an uneven and wrinkled surface. An additional tempering procedure allows for smoothing the surface of the core-shell colloids. This results in polymer core-shell particles with a perfectly spherical shape. In addition to this thermal smoothing of the PMMA shell, we generated a selection of shape-anisotropic core-shell particles using a thermomechanical stretching procedure. Because of the unique constitution, we can selectively interrogate molecular vibrations in the PS core or the PMMA shell of the colloids using nonlinear optical microscopy techniques. This is of great interest because no photobleaching occurs, such that the particles can be tracked in real space over long times.

14.
Br J Nutr ; 106(6): 852-61, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21676273

RESUMEN

Uterine infections during pregnancy predispose to pre-term birth and postnatal morbidity, but it is unknown how prenatal bacterial exposure affects maturation of the immature gut. We hypothesised that a prenatal exposure to gram-negative lipopolysaccharide (LPS) has immunomodulatory effects that improve resistance towards necrotising enterocolitis (NEC) in pre-term neonates. At approximately 85 % gestation, pig fetuses were injected intramuscularly with saline or LPS (0·014 mg/kg), or intra-amniotically with LPS (0·4 mg/kg). Pigs were delivered by caesarean section 3-5 d later and fed colostrum (C) or formula (F) for 48 h. Gut indices did not differ between pigs injected intramuscularly with saline or LPS, and these groups were therefore pooled into two control groups according to diet (control-F, n 32 and control-C, n 11). Control-F pigs showed reduced villus heights, mucosal structure, gut integrity, digestive enzymes, elevated NEC incidence (38 v. 0 %, P < 0·05) and several differentially expressed immune-related genes, relative to control-C pigs. Compared with the control-F and control-C groups, values in formula-fed pigs given intra-amniotic LPS formula (n 17) were intermediate for villus height, enzyme activities, intestinal permeability and NEC incidence (18 %, P = 0·2 relative to control-F), and numbers of differentially expressed immune genes. In conclusion, prenatal exposure of the fetal gut to Gram-negative bacteria may modulate the immediate postnatal response to an enteral diet and colonising bacteria.


Asunto(s)
Enterocolitis Necrotizante/prevención & control , Lipopolisacáridos/metabolismo , Alimentación Animal , Animales , Dieta , Enterocolitis Necrotizante/embriología , Escherichia coli/metabolismo , Femenino , Mucosa Intestinal/metabolismo , Intestinos/embriología , Exposición Materna , Permeabilidad , Embarazo , Preñez , Porcinos , Factores de Tiempo
15.
Neuroscience ; 167(4): 1168-74, 2010 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-20302919

RESUMEN

Damages to the nervous system are the primarily cause of neuropathy and chronic pain. Current pharmacological treatments for neuropathic pain are not able to prevent or revert morphological and molecular consequences of tissue injury. On the other hand, many neurotrophins, like nerve growth factor (NGF), paired off restorative effects with hyperalgesia. Interestingly, the glial cell line-derived neurotrophic factors GDNF and Artemin (ARTN) seem to support neuron survival and to normalize abnormal pain behaviour. In the present research protein levels of NGF, GDNF and ARTN were evaluated in a rat model of peripheral neuropathy, the chronic constriction injury (CCI). NGF was increased by CCI in the ipsilateral dorsal root ganglia (DRG), in the spinal cord and in the periaqueductal grey matter (PAG). On the contrary, ARTN was decreased bilaterally in DRG, spinal cord and PAG. GDNF levels decreased in ipsilateral DRG, whereas the constriction did not modify its expression in the central nervous system districts. Repeated treatments with the antihyperalgesic and neuroregenerative compound acetyl-l-carnitine (ALCAR; 100 mgkg(-1) i.p. twice daily for 15 days) was able to prevent the increase of NGF levels. In conditions of pain relief ALCAR normalized peripheral and central alterations of GDNF and ARTN levels. Characteristically, sham animals that underwent the same ALCAR treatment, showed increased levels of ARTN both in the DRG and in the spinal cord. These data offer a new point of view on the mechanism of the antihyperalgesic as well as the neuroprotective effect of ALCAR.


Asunto(s)
Acetilcarnitina/farmacología , Analgésicos/farmacología , Factores de Crecimiento Nervioso/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Fármacos Neuroprotectores/farmacología , Dolor/metabolismo , Enfermedades del Sistema Nervioso Periférico/metabolismo , Animales , Constricción Patológica/complicaciones , Ganglios Espinales/metabolismo , Masculino , Dolor/etiología , Umbral del Dolor , Sustancia Gris Periacueductal/metabolismo , Enfermedades del Sistema Nervioso Periférico/etiología , Ratas , Ratas Sprague-Dawley , Nervio Ciático/lesiones , Médula Espinal/metabolismo
16.
Clin Immunol ; 134(2): 158-68, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19880352

RESUMEN

Natural killer (NK) cells may be protective in HIV infection and are inhibited by killer cell immunoglobulin-like receptors (KIRs) interacting with MHC class I molecules, including HLA-C. Retention of HLA-C despite downregulation of other MHC class I molecules on HIV infected cells might protect infected cells from NK cell recognition in vitro. To assess the role of inhibitory HLA-C ligands in the capacity of NK cells to recognize autologous infected T cells, we measured NK cell degranulation in vitro in viremic patients, controllers with low viremia, and healthy donors. No difference in NK cell response to uninfected compared to HIV-1(IIIB) infected targets was observed. Activation of NK cells was regulated by KIRs, because NK cell degranulation was increased by 1-7F9, a human antibody that binds KIR2DL1/L2/L3 and KIR2DS1/S2, and this effect was most pronounced in KIR haplotype B individuals.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Infecciones por VIH/inmunología , Células Asesinas Naturales/inmunología , Activación de Linfocitos/inmunología , Receptores KIR/inmunología , Adulto , Femenino , Genotipo , Infecciones por VIH/genética , Antígenos HLA-C/genética , Antígenos HLA-C/inmunología , Humanos , Células Jurkat , Células Asesinas Naturales/virología , Activación de Linfocitos/genética , Masculino , Persona de Mediana Edad , Receptores KIR/genética , Viremia
17.
Eur J Immunol ; 40(3): 813-23, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20039300

RESUMEN

Missing-self-reactivity can be mimicked by blocking self-specific inhibitory receptors on NK cells, leading to increased rejection of syngeneic tumor cells. Using a mouse model, we investigated whether Ab-mediated blocking of inhibitory receptors, to a degree where NK cells rejected syngeneic tumor cells, would still allow self-tolerance toward normal syngeneic cells. Ly49C/I inhibitory receptors on C57BL/6 (H-2(b)) NK cells were blocked with F(ab')(2) fragments of the mAb 5E6. Inhibitory receptor blockade in vivo caused rejection of i.v. inoculated fluorescence-labeled syngeneic lymphoma line cells but not of syngeneic spleen cells, BM cells or lymphoblasts. The selective rejection of tumor cells was NK cell-dependent and specifically induced by Ly49C/I blockade. Moreover, selective tumor rejection was maintained after treatment with 5E6 F(ab')(2) for 9 wk, arguing against the induction of NK cell anergy or autoreactivity during this time. Combination therapy using 5E6 F(ab')(2) together with high dose IL-2 treatment further increased lymphoma cell rejection. In addition, combination therapy reduced growth of melanoma cell line tumors established by s.c. inoculation 3 days before start of treatment. Our results demonstrate that inhibitory receptor blockade does not result in attack on normal cells, despite potent reactivity against MHC class I-expressing tumors.


Asunto(s)
Inmunoterapia/métodos , Interleucina-2/inmunología , Células Asesinas Naturales/inmunología , Subfamilia A de Receptores Similares a Lectina de Células NK/antagonistas & inhibidores , Neoplasias Experimentales/inmunología , Autotolerancia/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Separación Celular , Citometría de Flujo , Fragmentos Fab de Inmunoglobulinas/inmunología , Fragmentos Fab de Inmunoglobulinas/uso terapéutico , Interleucina-2/uso terapéutico , Células Asesinas Naturales/efectos de los fármacos , Linfoma/terapia , Ratones , Subfamilia A de Receptores Similares a Lectina de Células NK/inmunología , Neoplasias Experimentales/terapia , Autotolerancia/efectos de los fármacos
19.
Proc Natl Acad Sci U S A ; 106(31): 12879-84, 2009 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-19561305

RESUMEN

Natural killer (NK) cells are lymphocytes of the innate immune system able to recognize and kill tumors lacking self-MHC class I molecules. This "missing-self" recognition is mediated by the lack of engagement of MHC class I-specific inhibitory NK cell receptors that include the killer cell Ig-like receptors (KIR) in humans and Ly49 molecules in mice. A promising immunotherapeutic strategy against MHC class I(+) cancer cells is to block NK cell inhibitory receptors using monoclonal antibodies (mAb). However, interactions between MHC class I molecules and their inhibitory receptors are also required for the acquisition of NK cell functional competence, a process referred as to "education." In addition, inhibitory receptors are involved in self-tolerance on educated NK cells. Here, we developed a preclinical mouse model in which all NK cells are educated by a single transgenic inhibitory receptor, human KIR2DL3, through the engagement with its HLA-Cw3 ligand. This approach revealed that NK cells could be reprogrammed to control the development of mouse syngenic tumors in vivo. Moreover, in vivo anti-KIR mAb treatment induced the killing of HLA(+) target cells without breaking self-tolerance. Finally, the long-term infusion of anti-KIR mAb neither abolished NK cell education nor tumor cell recognition. Therefore, these results strongly support the use of inhibitory receptor blockade in cancer patients.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antígenos HLA-C/fisiología , Células Asesinas Naturales/inmunología , Neoplasias Experimentales/terapia , Receptores KIR2DL3/fisiología , Autotolerancia , Animales , Línea Celular , Humanos , Inmunidad Innata , Ratones , Ratones Endogámicos C57BL , Neoplasias Experimentales/inmunología , Receptores KIR2DL3/inmunología
20.
Eur J Neurosci ; 26(4): 820-7, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17714181

RESUMEN

Peripheral neuropathies are widespread disorders induced by autoimmune diseases, drug or toxin exposure, infections, metabolic insults or trauma. Nerve damage may cause muscle weakness, altered functionalities and sensitivity, and a chronic pain syndrome characterized by allodynia and hyperalgesia. Pathophysiological mechanisms related to neuropathic disease are associated with mitochondrial dysfunctions that lead to the activation of the apoptotic cascade. In a model of peripheral neuropathy, obtained by the loose ligation of the rat sciatic nerve (CCI), we describe a nerve apoptotic state that encompasses the release of cytochrome C in the cytosol, the activation of caspase 3, and the fragmentation of the genome. Animal treatment with acetyl-L-carnitine (ALCAR), but not with L-carnitine (L-Carn) or Gabapentin, prevents apoptosis induction. ALCAR reduces cytosolic cytochrome C and caspase 3 active fragments expression in a significant manner with respect to saline treatment. Accordingly, ALCAR treatment impairs caspase 3 protease activity, as demonstrated by reduced levels of cleaved PARP. Finally, ALCAR decreases the number of piknotic nuclei. This protection correlates with the induction of X-linked inhibitor apoptosis protein (XIAP). Taken together these results show that CCI is a valuable model to investigate neuropathies-related apoptosis phenomena and that ALCAR is able to prevent regulated cell death in the damaged sciatic nerve.


Asunto(s)
Acetilcarnitina/farmacología , Apoptosis/efectos de los fármacos , Nootrópicos/farmacología , Enfermedades del Sistema Nervioso Periférico/patología , Animales , Western Blotting , Caspasa 3/metabolismo , Citocromos c/metabolismo , Citosol/metabolismo , Fragmentación del ADN , Hiperalgesia/fisiopatología , Etiquetado Corte-Fin in Situ , Masculino , Degeneración Nerviosa/patología , Poli(ADP-Ribosa) Polimerasas/biosíntesis , Poli(ADP-Ribosa) Polimerasas/genética , Ratas , Ratas Sprague-Dawley , Neuropatía Ciática/patología
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