Las células guardianes residentes de la piel y su papel en la respuesta inmune. Parte 1 / Cells resident guardians of the skin and its role in the immune response

La piel constituye la primera barrera del sistema inmune contra potenciales agentes patógenos y nocivos externos. Evidencia importante sugiere que las células inmunológicas requieren de funciones conjuntas con los queratinocitos, para alertar y ensamblar una respuesta inmune adecuada, que incluye la formación del sistema de alerta denominado inflamosoma. Adicionalmente, nuevos fenotipos funcionales de células presentadoras de antígenos (CPA) en la piel como las células dendríticas han demostrado tener gran importancia en ensamblar la respuesta inmune incluso mayor que las células T circulantes. La primera entrega de este artículo describe la funcionalidad de los queratinocitos y las células dendriticas en la piel, para en la segunda parte discriminar sus roles juntos a los linfocitos T y las fallas de la regulación durante las interacciones en la formaión del inflamosoma.

Human skin is the first shield which provides essential protection of the human body from injury and infection. Important evidence reinforces the importance of keratinocytes as sensors of danger through alert systems such as the inflammasome and key components in the appropriate immune response. In addition, newly identified antigen-presenting cells (APCs), as dendritic cells, have demonstrated to have a key role of assembling the immune response even major than circulating T cells in skin. The first part of this review focuses on dissecting the functional role of keratinocytes and dendritic cells in skin in order to, in the second part, analyze their roles and interactions together with the T lymphocytes during the inflammasome formation.

Melanocitos en vitíligo y melanoma: una lección entre autoinmunidad e inmunidad tumoral / Melanocytes in vitiligo and melanoma: a lesson between autoimmunity and tumor immunity

Clásicamente, el vitiligo ha sido definido como una enfermedad de la piel en la cual los melanocitos (MC) son erradicados de una epidermis lesionada por células T autorreactivas con la presencia de moléculas del sistema inmune y otros componentes no inmunológicos que resultan en la pérdida de pigmento y lesiones cutáneas en el paciente. Anteriormente, la ausencia y daño en los MC ha sido asociado a mayor riesgo de cáncer de piel incluyendo melanoma. Sin embargo, en vitiligo se ha identificado la presencia de melanocitos 'no pigmentados', similar a individuos albinos, que aparentemente confieren mayor resistencia para el desarrollo de melanoma en estas personas. Estos hechos aparentemente contradictorios se complican aún más cuando los antigenos de los MC reconocidos por el sistema inmune durante la respuesta autoinmune o en la inmunidad antitumoral son los mismos en ambas enfermedades. Un análisis de las similitudes y diferencias entre la respuesta inmune contra MC observada en vitiligo y su rol en la inmunidad tumoral observada en melanoma, podría llevar a entender mejor el rol de estas células y al futuro desarrollo de nuevas terapias para ambas enfermedades.

Classically, vitiligo has been defined as a skin disease in which melanocytes (MC) are eradicated from lesional epidermis by MC- reactive T cells, as well as other non-immune and immune components, resulting in disfiguring loss of pigmento Moreover, the absence 01' damage on MC has frequently been associated to a major risk to develop skin cancer including melanoma. However, patients with vitiligo have also shown 'non-pigmented' MC in epidermis similar to individuals with albinism, and these cells are apparently conferring resistance of developing melanoma. These seemingly contradictory facts are further complicated because, the MC antigens which are immunologically recognized are shared for both diseases producing fairly different results. An analysis of the similarities and differences between the autoimmunity observed in vitiligo and the tumour immunity observed in melanoma might lead to a better understanding of the MC roles and the development of new therapies for both diseases.

Mastocitos y basófilos y sus nuevas funciones en inmunología / Mast cells and basophils: its new functions in immunity

Los mastocitos y basófilos han demostrado tener múltiples funciones dentro del sistema inmune. Además de su clásico rol de respuesta inflamatoria en contra de alérgenos también se les ha visto participando en respuestas directas contra diversos agentes infecciosos. Diversas funciones in vivo de estas células han permanecido poco conocidas debido a la usencia de modelos animales que puedan investigar su desarrollo y su real importancia durante salud y enfermedad. Sin embargo, recientes estudios han podido caracterizar y aislar las células precursoras de estos linajes, y así entender nuevas funciones efectoras que eran desconocidas in vivo. Esta revisión brinda conceptos básicos e importantes del desarrollo y la acción efectora de estas células enfatizando conceptos inmunológicos necesarios para la comprensión de los mecanismos de enfermedad en diversos estados patológicos.

Mast cells and basophils have demonstrated to have both beneficial and detrimental functions for the immune system. Additionally to their classic role in pro-inflammatory responses to allergens, they are also involved directly in immunity against different pathogens. Because there are few anima/s models developed to investigate these cells in vivo, their functions during health and disease remain poorly understood. This review gives a short glance in the development and functional status of mast cells and basophils focusing on immunology concepts necessary to get a major understanding of the mechanisms of disease in different pathological states.

Determination of low bacterial concentrations in hyperarid Atacama soils: comparison of biochemical and microscopy methods with real-time quantitative PCR.

Hyperarid Atacama soils are reported to contain significantly reduced numbers of microbes per gram of soil relative to soils from other environments. Molecular methods have been used to evaluate microbial populations in hyperarid Atacama soils; however, conflicting results across the various studies, possibly caused by this low number of microorganisms and consequent biomass, suggest that knowledge of expected DNA concentrations in these soils becomes important to interpreting data from any method regarding microbial concentrations and diversity. In this paper we compare the number of bacteria per gram of Atacama Desert soils determined by real-time quantitative polymerase chain reaction with the number of bacteria estimated by the standard methods of phospholipids fatty acid analysis, adenine composition (determined by liquid chromatography - time-of-flight mass spectrometry), and SYBR-green microscopy. The number determined by real-time quantitative polymerase chain reaction as implemented in this study was several orders of magnitude lower than that determined by the other three methods and probably underestimates the concentrations of soil bacteria, most likely because of soil binding during the DNA extraction methods. However, the other methods very possibly overestimate the bacteria concentrations owing to desiccated, intact organisms, which would stain positive in microscopy and preserve both adenine and phospholipid fatty acid for the other methods.

Actin cytoskeleton participation in the onset of IL-1beta induction of an invasive mesenchymal-like phenotype in epithelial MCF-7 cells.

BACKGROUND: Interleukin 1 beta (IL-1beta) and other inflammatory cytokines are reported to induce phenotypic changes in epithelial breast cancer tumor cells related to increased invasiveness. Mechanisms involved in the process are not well understood. METHODS: The noninvasive breast cancer epithelial cell line MCF-7 was used to investigate the IL-1beta-induced phenotype. Live cells expressing EGFP-actin were monitored for cell morphology changes and actin cytoskeleton dynamics by time-lapse video microscopy in the presence of IL-1beta and specific inhibitors of actin signaling pathways. Chemotaxis, invasion of Matrigel, MMP activity and expression of S100A4 in cells treated with IL-1beta were assessed by migration assays, zymograms and immunoblots. RESULTS: Exposure to IL-1beta specifically induced a change in MCF-7 cells from a typical epithelial morphology into elongated cells, showing numerous dynamic actin-rich lamellae and peripheral ruffles characteristic of fibroblasts. These cells could scatter from compact cell colonies and respond to chemoattractants such as the homing-associated chemokine CXCL-12. Pharmacological blockage of actin signaling pathways and negative mutants of RhoGTPases revealed that actin reorganization and enhanced motility are regulated via PI3K/Rac 1 activation. IL-1beta-stimulated cells expressed the metastasis promoter S100A4, increased secretion of active MMP-9 and MMP-2 and invasion of extracellular matrix proteins. CONCLUSIONS: IL-1beta induces a PI3K/Rac 1-regulated reorganization of the actin cytoskeleton of MCF-7 cells that is required for cell scattering, elongation and migration. The enhanced motility is accompanied by expression of protein markers correlated with invasive behavior.

Expresión de factores inflamatorios e incremento del grosor mediointimal en preeclampsia: evidencia de riesgo arteriosclerótico materno y neonatal / Expression of inflammatory factors and increasing of the intima-media thickness in pre-eclampsia: Evidence of maternal and neonatal arteriosclerotic risk

Introducción La preeclampsia es una afección caracterizada por daño vascular sistémico producido por factores liberados desde la placenta. Entre esos factores hay radicales libres de oxígeno, factores de crecimiento y citocinas inflamatorias producto de ciclos de hipoxia placentaria. Aunque hay evidencia de disfunción endotelial durante la preeclampsia, no la hay de cambios estructurales en la vasculatura periférica materna ni de la expresión de factores patológicos que se podría considerar de riesgo arteriosclerótico. Métodos Comparamos las concentraciones plasmáticas del factor de crecimiento de endotelio vascular y de su receptor soluble sFlt-1 entre 16 gestantes sanas y 24 con preeclampsia a término mediante pruebas de ELISA, relacionamos la expresión de los factores inducibles por hipoxia y CD40L mediante RT-PCR y Western blot de células endoteliales de la arteria humeral materna, y medimos el grosor mediointimal (GMI) y la vasodilatación mediada por flujo (DMF) mediante ultrasonografía vascular periférica. Se consideró un valor de p < 0,05 como estadísticamente significativo. Resultados Las pacientes preeclámpsicas presentaron elevadas concentraciones plasmáticas de sVEGFR-1/sFlt-1, lo que correlaciona directamente con la expresión de HIF-2a y CD40L en células endoteliales, mientras que HIF-1a se encontró disminuido significativamente. Curiosamente, el GMI se encontró incrementado en las gestantes preeclámpsicas, hecho que coincide con una disminución marcada en la DMF. Conclusiones Nuestros resultados demuestran que moléculas involucradas en la fisiopatología de la arteriosclerosis se encuentran incrementadas en la vasculatura periférica con un significativo engrosamiento de la íntima arterial de pacientes con preeclampsia, lo que predispone a una enfermedad arteriosclerótica materna tras el parto que puede ser extrapolada a un futuro riesgo neonatal (AU)

Introduction. Pre-eclampsia is a pathological condition characterized by vascular damage produced by systemic factors released from the placenta. These factors include oxygen free radicals, growth factors and inflammatory cytokines that are products released by the placenta during hypoxia cycles. Although, there is evidence of endothelial dysfunction during preeclampsia, there is no evidence of structural changes in the maternal peripheral vasculature or expression of pathological factors which could be considered as arteriosclerotic risk. Methods. We compared the plasma levels of vascular endothelial growth factor and its soluble receptor sVEGFR-1/sFlt-1 between 16 healthy pregnant women and 24 with pre-eclampsia at term, using the ELISA test. We correlated the expression of hypoxia-inducible factors and theCD40L by RT -PCR and Western blot of endothelial cells of the maternal brachial artery, and measured the Intima-Media- Thickness (IMT) and Flow-Mediated Vasodilation (FMD) by peripheral vascular ultrasound. A P value < 0.05 was considered as statistically significant. Results. The pre-eclamptic women had highlevels of plasma sVEGFR-1/sFlt-1, which directly correlated with the expression of HIF-2a andCD40L in endothelial cells, whereas HIF-1a was significantly diminished. Curiously, the IMT was increased in pregnant women with pre-eclampsia, coinciding with a marked decrease in the FMD. Conclusions. Our results demonstrate that molecules involved in the pathophysiology of atherosclerosis are increased in the peripheral vasculature, with a significant thickening of the arterial intima of patients with pre-eclampsia, a condition that predisposes to maternal arteriosclerosis and could be extrapolated to a future neonatal risk (AU)

Effect of pro-inflammatory cytokine stimulation on human breast cancer: implications of chemokine receptor expression in cancer metastasis.

Interactions between tumour cells and microenvironments may affect their growth and metastasis formation. In search for a better understanding of the role of cellular mediators in the progression of cancer, we investigated the effect of pro-inflammatory cytokines IL-1, IL-6, TNF-alpha and IFN-gamma on the regulation of expression of chemokine receptors CXCR4, CXCR2, CX3CR1, CCR9, and CCR5 in the human breast cancer cell line MCF-7. Our results showed that IL-1 increased CXCR4 expression whereas TNF-alpha increased CX3CR1, CCR9 and CCR5. Interestingly, this regulation was not homogeneous, emphasizing the inherent heterogeneity in cancer that may be responsive to specific inflammatory microenvironments.

Efecto de la terapia temprana con L-arginina en el crecimiento intrauterino restringido en la preclampsia. Estudio aleatorizado en mujeres latinoamericanas / Effect of early L-arginine therapy on intrauterine growth restriction in preeclampsia. A randomized controlled trial in Latin-American women

Objetivo: Evaluar el beneficio de la administración temprana de L-arginina en la preeclampsia en el riesgo relativo del crecimiento fetal. Pacientes y métodos: Se aleatorizó a 100 mujeres con preeclampsia a recibir L-arginina o placebo hasta el día del parto. Se comparó a 96 infantes nacidos de gestantes preeclámpticas (50 con tratamiento y 46 sin tratamiento) y con 50 infantes nacidos de gestantes sanas para evaluar el riesgo relativo de crecimiento intrauterino restringido (CIR) y el efecto de L-arginina en éste. El peso al nacer relacionado con la edad gestacional se comparó con curvas de crecimiento respectivas. Los infantes más pequeños del percentil 10 fueron clasificados como CIR. Se utilizaron las pruebas de la U de Mann-Whitney, ANOVA de la χ2 para evaluar las diferencias estadísticas significativas (p < 0,05) entre los grupos. Resultados: No hubo diferencias entre los grupos con preeclampsia antes del estudio. La preeclampsia se asoció en el 21% de los casos al CIR. El riesgo de CIR fue 5 veces más alto en infantes nacidos de preeclámpticas sin terapia de L-arginina comparado con los controles (riesgo relativo [RR] = 5,0; intervalo de confianza [IC], 1,5-16,2) y 2 veces más alto en infantes nacidos de preeclámpticas en tratamiento con L-arginina (RR = 2,0; IC del 95%, 1,9-7,6). Los estudios del perfil biofísico fetal y la puntuación en la prueba de Apgar al nacer demostraron mejoras estadísticamente significativas con el uso de L-arginina en la preeclampsia (p < 0,05). Conclusión: El crecimiento fetal mejora significativamente con la terapia de L-arginina administrada de forma temprana en gestantes con preeclampsia (AU)

Objective: To assess the benefit of early L-arginine administration in preeclampsia on the relative risk to fetal growth. Patients and methods: One-hundred women with preeclampsia were randomized to receive either L-arginine or placebo until the day of delivery. To evaluate the relative risk of intrauterine growth restriction (IUGR) and the effect of L-arginine on this process, 96 live singleton infants of women with preeclampsia (50 with treatment and 46 without treatment) were compared; these infants were also compared with a further 50 control infants of healthy women. Gestational age-related birth weight was compared using standard growth curves. Infants smaller than the 10th percentile were classified as IUGR. The Mann-Witney U-test, ANOVA, and chi-square test were used to evaluate statistically significant differences (P<.05) between the groups. Results: No significant differences were found between the groups with preeclampsia before randomization. Preeclampsia was associated with a 21% reduction in birth weight. The risk of IUGR was five times higher in infants born after preeclampsia without L-arginine therapy than in control pregnancies (RR = 5.0; 95%IC: 1.5-16.2) and was two times higher in infants born after preeclampsia with L-arginine therapy (RR = 2.0; 95% CI: 1.9-7.6). The fetal biophysical profile and Apgar score were significantly more favorable in the L-arginine group (P<.05). Conclusion: Fetal growth markedly improves with early L-arginine therapy in women with preeclampsia (AU)

Valores de proteinuria y daño vascular en gestantes sanas, preeclámpticas y con hipertensión no proteinúrica, evaluados por ultrasonografía vascular / Levels of proteinuria and vascular damage in healthy pregnant, preeclamptic, and non-proteinuric hypertensive women, assessed by vascular ultrasonography

Objetivo: Comparar si la ultrasonografía vascular esmás eficaz en diagnosticar daño vascular que laproteinuria.Sujetos y métodos: A 40 gestantes sanas (GS), 35preeclámpticas (GP) y 35 con hipertensión inducidapor el embarazo, sin proteinuria (GNP), de loshospitales Yanahuara y Nacional del Sur, EsSalud, enArequipa, Perú, se les midieron los valores de presiónarterial y proteinuria, y se les realizó unaultrasonografía vascular para evaluar la dilataciónmediada por flujo (DMF). Se realizaron comparacionesentre los 3 grupos mediante las pruebas de ANOVA oKruskal-Wallis, dependiendo de su distribución normalo no, respectivamente; se consideró estadísticamentesignificativo a un valor de p < 0,05.Resultados: Se obtuvieron valores de proteinuria de0,05 g/24 h; 2,57 g/24 h y 0,21 g/24 h, y valores deDMF de 0,66, 0,25 y 0,45 mm para los grupos GS,GP y GNP, respectivamente. La comparación delDMF entre grupos mostró diferencias significativaspara cada grupo (p < 0,01), pero en el caso de laproteinuria los valores del grupo GNP aúnpertenecen a rangos considerados normales(< 0,03 g/24 h). No se encontró relación entre laDMF y proteinuria.Conclusiones: La DMF evaluada por ultrasonografíadetecta una alteración vascular, inclusive en elgrupo de gestantes con hipertensión inducida delembarazo sin proteinuria

Objective: To compare the effectiveness of vascularultrasonography and proteinuria in diagnosingsystemic vascular damage.Subjects and methods: Forty healthy pregnantwomen, 35 with preeclampsia, and 35 with nonproteinurichypertension in the Yanahuara andNacional del Sur hospitals in Arequipa (Peru)underwent measurement of blood pressure,proteinuria, and ultrasonographic studies in thehumeral artery to obtain their flow-mediated dilation(FMD). Comparisons between the three groups weremade using ANOVA or Kruskal-Wallis tests,depending on whether the distribution was normalor non-normal, respectively. Values of P<0.05 wereconsidered statistically significant.Results: Proteinuria values were 0.05 g/24 h, 2.57g/24 h and 0.21 g/24 h while FMD values showedmean values of 0.66mm, 0.25mm, and 0.45mm forhealthy pregnant women, women with preeclampsiaand women with non-proteinuric hypertension,respectively. Comparison of FMD among groupsshowed significant differences among the groups(P<.01). However, proteinuria values in the groupwith non-proteinuric hypertension were within thenormal range (<0.03 g/24 h). No relation was foundbetween FMD and proteinuria.Conclusions: Ultrasonographic evaluation of FMDdetected vascular damage even in the group ofpregnant women with pregnancy-induced hypertensionwithout proteinuria