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Background: Cell migration is essential for the immune system and is frequently analyzed in adult non-pregnant animals but poorly explored in pregnant animals. However, a physiologic increased size in the spleen and periaortic lymph nodes had been reported in pregnant mice. Methods: Using a mouse model, we transferred PKH26-stained thymocytes and splenocytes from pregnant or non-pregnant animals to receptor mice in the presence or absence of pregnancy. Percentage of PKH-26 cells and Mean Fluorescence Intensity were calculated. Non-parametric ANOVA analysis was performed. Results: We detected that the percentage of PKH26+ thymocytes in the spleen, lymph nodes, and peripheral blood is higher in females than in males (p = 0.039). Our results showed a similar frequency of thymocytes and splenocytes from pregnant and non-pregnant mice located in receptor lymphoid organs (p > 0.05). Also, the location of marked cells was similar during the perinatal period (p > 0.05). Conclusions: The mobility of thymocytes and splenocytes in pregnant and non-pregnant mice is similar. Therefore, we suggest that the larger size of the spleen and periaortic lymph nodes noted previously in pregnant mice could result from the retention of leukocytes in the secondary lymphoid organs.
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Tumors have high requirements in terms of nutrients and oxygen. Angiogenesis is the classical mechanism for vessel formation. Tumoral vascularization has the function of nourishing the cancer cells to support tumor growth. Vasculogenic mimicry, a novel intratumoral microcirculation system, alludes to the ability of cancer cells to organize in three-dimensional (3D) channel-like architectures. It also supplies the tumors with nutrients and oxygen. Both mechanisms operate in a coordinated way; however, their functions in breast cancer stem-like cells and their regulation by microRNAs remain elusive. In the present study, we investigated the functional role of microRNA-204 (miR-204) on angiogenesis and vasculogenic mimicry in breast cancer stem-like cells. Using flow cytometry assays, we found that 86.1% of MDA-MB-231 and 92% of Hs-578t breast cancer cells showed the CD44+/CD24- immunophenotype representative of cancer stem-like cells (CSCs). The MDA-MB-231 subpopulation of CSCs exhibited the ability to form mammospheres, as expected. Interestingly, we found that the restoration of miR-204 expression in CSCs significantly inhibited the number and size of the mammospheres. Moreover, we found that MDA-MB-231 and Hs-578t CSCs efficiently undergo angiogenesis and hypoxia-induced vasculogenic mimicry in vitro. The transfection of precursor miR-204 in both CSCs was able to impair the angiogenesis in the HUVEC cell model, which was observed as a diminution in the number of polygons and sprouting cells. Remarkably, miR-204 mimics also resulted in the inhibition of vasculogenic mimicry formation in MDA-MB-231 and Hs-578t CSCs, with a significant reduction in the number of channel-like structures and branch points. Mechanistically, the effects of miR-204 were associated with a diminution of pro-angiogenic VEGFA and ß-catenin protein levels. In conclusion, our findings indicated that miR-204 abrogates the angiogenesis and vasculogenic mimicry development in breast cancer stem-like cells, suggesting that it could be a potential tool for breast cancer intervention based on microRNA replacement therapies.
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BACKGROUND: Intravenous immunoglobulin (IVIG) can suppress the inflammatory response in adults, but its role in pregnant women and newborns is poorly studied. While the adult immune system is considered mature, it is immature in neonates and suppressed in pregnancy. Since the immune response differs in these 3 groups, the use of IVIG could differentially modulate the immune response. OBJECTIVES: We aimed to explore the effect of IVIG on myeloid blood cells from non-pregnant women, pregnant women and newborns. MATERIAL AND METHODS: Whole blood from healthy donors was incubated with lipopolysaccharide (LPS) and/or IVIG. After 0 h, 24 h and 48 h of culture, Fc-gamma receptor (CD16, CD32 and CD64) expression, monocyte and neutrophil bacterial phagocytosis, and cytokine and chemokine concentrations were determined in the supernatant. RESULTS: The baseline expression of monocyte CD16 was higher in newborns than in adult women, but the expression of CD32 and CD64 was similar between groups. Furthermore, LPS and IVIG stimulation, together or separately, did not change Fc-gamma receptor expression in monocytes or neutrophils and did not modify their phagocytosis capacity. On the other hand, IVIG did not downregulate the proinflammatory cytokine response induced by LPS in any group. Interestingly, IVIG induced a strong interleukin 8 (IL-8) response in neonates but not in non-pregnant or pregnant women. CONCLUSIONS: Our results show that IVIG did not induce changes in Fc-gamma receptor expression, phagocytic ability, or the cytokine response to LPS in blood cells from neonates, non-pregnant or pregnant women. However, IVIG induced a strong IL-8 response in neonates that could improve immunity.
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Neutrophils infiltrate several types of cancer; however, whether their presence is associated with disease progression remains controversial. Here, we show that colon tumors overexpress neutrophil chemoattractants compared to healthy tissues, leading to their recruitment to the invasive margin and the central part of colon tumors. Of note, tumor-associated neutrophils expressing tumor necrosis factor α, which usually represents an antitumoral phenotype, were predominantly located in the invasive margin. Tumor-associated neutrophils from the invasive margin displayed an antitumoral phenotype with higher ICAM-1 and CD95 expression than neutrophils from healthy adjacent tissues. A higher neutrophil/lymphocyte ratio was found at later stages compared to the early phases of colon cancer. A neutrophil/lymphocyte ratio ≤3.5 predicted tumor samples had significantly more neutrophils at the invasive margin and the central part. Moreover, tumor-associated neutrophils at the invasive margin of early-stage tumors showed higher ICAM-1 and CD95 expression. Coculture of colon cancer cell lines with primary neutrophils induced ICAM-1 and CD95 expression, confirming our in situ findings. Thus, our data demonstrate that tumor-associated neutrophils with an antitumoral phenotype characterized by high ICAM-1 and CD95 expression infiltrate the invasive margin of early-stage colon tumors, suggesting that these cells can combat the disease at its early courses. The presence of tumor-associated neutrophils with antitumoral phenotype could help predict outcomes of patients with colon cancer.
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Neoplasias del Colon , Neutrófilos , Humanos , Neutrófilos/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Neoplasias del Colon/patología , FenotipoRESUMEN
The difficulty in predicting fatal outcomes in patients with coronavirus disease 2019 (COVID-19) impacts the general morbidity and mortality due to severe acute respiratory syndrome-coronavirus 2 infection, as it wears out the hospital services that care for these patients. Unfortunately, in several of the candidates for prognostic biomarkers proposed, the predictive power is compromised when patients have pre-existing comorbidities. A cohort of 147 patients hospitalized for severe COVID-19 was included in a descriptive, observational, single-center, and prospective study. Patients were recruited during the first COVID-19 pandemic wave (April-November 2020). Data were collected from the clinical history whereas immunophenotyping by multiparameter flow cytometry analysis allowed us to assess the expression of surface markers on peripheral leucocyte. Patients were grouped according to the outcome in survivors or non-survivors. The prognostic value of leucocyte, cytokines or HLA-DR, CD39, and CD73 was calculated. Hypertension and chronic renal failure but not obesity and diabetes were conditions more frequent among the deceased patient group. Mixed hypercytokinemia, including inflammatory (IL-6) and anti-inflammatory (IL-10) cytokines, was more evident in deceased patients. In the deceased patient group, lymphopenia with a higher neutrophil-lymphocyte ratio (NLR) value was present. HLA-DR expression and the percentage of CD39+ cells were higher than non-COVID-19 patients but remained similar despite the outcome. Receiver operating characteristic analysis and cutoff value of NLR (69.6%, 9.4), percentage NLR (pNLR; 71.1%, 13.6), and IL-6 (79.7%, 135.2 pg/mL). The expression of HLA-DR, CD39, and CD73, as many serum cytokines (other than IL-6) and chemokines levels do not show prognostic potential, were compared to NLR and pNLR values.
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COVID-19 , Humanos , COVID-19/complicaciones , Estudios Prospectivos , Interleucina-6 , Pandemias , Pronóstico , Biomarcadores , Neutrófilos , Antígenos HLA-DR , Estudios RetrospectivosRESUMEN
The differential contribution of monocyte subsets expressing the C-C chemokine receptor 2 (CCR2) to subclinical atherosclerosis in girls and boys is unclear. In this pilot study, we compared classical, intermediate, and nonclassical monocyte subsets expressing CCR2 in 33 obese children of both sexes aged 8 to 16 divided by carotid intima-media thickness (IMT), considering values above the 75th percentile (p75) as abnormally high IMT. Obesity was defined as body mass index above the 95th percentile according to age and sex. Flow cytometry analyses revealed that boys but not girls with IMT ≥ p75 displayed increased CCR2+ cell percentage and CCR2 expression in the three monocyte subsets, compared to boys with IMT < p75. The CCR2+ cell percentage and CCR2 expression in the three monocyte subsets significantly correlated with increased IMT and insulin resistance in boys but not girls, where the CCR2+ nonclassical monocyte percentage had the strongest associations (r = 0.73 and r = 0.72, respectively). The role of CCR2+ monocyte subpopulations in identifying an abnormally high IMT shows a marked sexual dimorphism, where boys seem to be at higher subclinical atherosclerosis risk than girls.
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The 3D organotypic cultures, which depend on the growth of cells over the extracellular matrix (ECM) used as a scaffold, can better mimic several characteristics of solid cancers that influence tumor biology and the response to drug therapies. Most of our current knowledge on cancer is derived from studies in 2D cultures, which lack the ECM-mediated microenvironment. Moreover, the role of miRNAs that is critical for fine-tuning of gene expression is poorly understood in 3D cultures. The aim of this study was to compare the miRNA expression profiles of breast cancer cells grown in 2D and 3D conditions. On an on-top 3D cell culture model using a basement membrane matrix enriched with laminin, collagen IV, entactin, and heparin-sulfate proteoglycans, the basal B (Hs578T) and luminal (T47D) breast cancer cells formed 3D spheroid-like stellate and rounded mass structures, respectively. Morphological changes in 3D cultures were observed as cell stretching, cell-cell, and cell-ECM interactions associated with a loss of polarity and reorganization on bulk structures. Interestingly, we found prolongations of the cytoplasmic membrane of Hs578T cells similar to tunneled nanotubes contacting between neighboring cells, suggesting the existence of cellular intercommunication processes and the possibility of fusion between spheroids. Expression profiling data revealed that 354 miRNAs were differentially expressed in 3D relative to 2D cultures in Hs578T cells. Downregulated miRNAs may contribute to a positive regulation of genes involved in hypoxia, catabolic processes, and focal adhesion, whereas overexpressed miRNAs modulate genes involved in negative regulation of the cell cycle. Target genes of the top ten modulated miRNAs were selected to construct miRNA/mRNA coregulation networks. Around 502 interactions were identified for downregulated miRNAs, including miR-935/HIF1A and miR-5189-3p/AKT that could contribute to cell migration and the response to hypoxia. Furthermore, the expression levels of miR-935 and its target HIF1A correlated with the expression found in clinical tumors and predicted poor outcomes. On the other hand, 416 interactions were identified for overexpressed miRNAs, including miR-6780b-5p/ANKRD45 and miR-7641/CDK4 that may result in cell proliferation inhibition and cell cycle arrest in quiescent layers of 3D cultures. In conclusion, 3D cultures could represent a suitable model that better resembles the miRNA transcriptional programs operating in tumors, with implications not only in the understanding of basic cancer biology in 3D microenvironments, but also in the identification of novel biomarkers of disease and potential targets for personalized therapies in cancer.
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Cellular senescence is more than a proliferative arrest in response to various stimuli. Senescent cells (SC) participate in several physiological processes, and their adequate removal is essential to maintain tissue and organism homeostasis. However, SC accumulation in aging and age-related diseases alters the tissue microenvironment leading to deterioration. The immune system clears the SC, but the specific scenarios and mechanisms related to recognizing and eliminating them are unknown. Hence, we aimed to evaluate the existence of three regulatory signals of phagocytic function, CD47, major histocompatibility complex class I (MHC-I), and calreticulin, present in the membrane of SC. Therefore, primary fibroblasts were isolated from CD1 female mice lungs, and stress-induced premature senescence (SIPS) was induced with hydrogen peroxide. Replicative senescence (RS) was used as a second senescent model. Our results revealed a considerable increment of CD47 and MHC-I in RS and SIPS fibroblasts. At the same time, no significant changes were found in calreticulin, suggesting that those signals might be associated with evading immune system recognition and thus averting senescent cells clearance.
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Antígenos CD1/metabolismo , Antígeno CD47/metabolismo , Senescencia Celular/fisiología , Fibroblastos/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Pulmón/metabolismo , Animales , Calbindina 2/metabolismo , Senescencia Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Femenino , Fibroblastos/citología , Peróxido de Hidrógeno/toxicidad , Ratones , Cultivo Primario de CélulasRESUMEN
Increasing evidence has demonstrated that oxidized low-density lipoproteins (oxLDL) and lipopolysaccharide (LPS) enhance accumulation of interleukin (IL)-1 beta-producing macrophages in atherosclerotic lesions. However, the potential synergistic effect of native LDL (nLDL) and LPS on the inflammatory ability and migration pattern of monocyte subpopulations remains elusive and is examined here. In vitro, whole blood cells from healthy donors (n = 20) were incubated with 100 µg/mL nLDL, 10 ng/mL LPS, or nLDL + LPS for 9 h. Flow cytometry assays revealed that nLDL significantly decreases the classical monocyte (CM) percentage and increases the non-classical monocyte (NCM) subset. While nLDL + LPS significantly increased the number of NCMs expressing IL-1 beta and the C-C chemokine receptor type 2 (CCR2), the amount of NCMs expressing the CX3C chemokine receptor 1 (CX3CR1) decreased. In vivo, patients (n = 85) with serum LDL-cholesterol (LDL-C) >100 mg/dL showed an increase in NCM, IL-1 beta, LPS-binding protein (LBP), and Castelli's atherogenic risk index as compared to controls (n = 65) with optimal LDL-C concentrations (≤100 mg/dL). This work demonstrates for the first time that nLDL acts in synergy with LPS to alter the balance of human monocyte subsets and their ability to produce inflammatory cytokines and chemokine receptors with prominent roles in atherogenesis.
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Receptor 1 de Quimiocinas CX3C/genética , LDL-Colesterol/farmacología , Interleucina-1beta/genética , Lipopolisacáridos/farmacología , Monocitos/efectos de los fármacos , Receptores CCR2/genética , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/inmunología , Adolescente , Adulto , Proteína C-Reactiva/genética , Proteína C-Reactiva/inmunología , Receptor 1 de Quimiocinas CX3C/inmunología , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Linaje de la Célula/efectos de los fármacos , Linaje de la Célula/inmunología , HDL-Colesterol/sangre , Sinergismo Farmacológico , Femenino , Citometría de Flujo , Expresión Génica , Voluntarios Sanos , Humanos , Interleucina-1beta/inmunología , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/inmunología , Persona de Mediana Edad , Monocitos/citología , Monocitos/inmunología , Cultivo Primario de Células , Receptores CCR2/inmunología , Triglicéridos/sangreRESUMEN
Breast cancer is an aggressive disease with a high incidence in women worldwide. Two decades ago, a controversial hypothesis was proposed that cancer arises from a subpopulation of "tumor initiating cells" or "cancer stem cells-like" (CSC). Today, CSC are defined as small subset of somatic cancer cells within a tumor with self-renewal properties driven by the aberrant expression of genes involved in the maintenance of a stemness-like phenotype. The understanding of the underlying cellular and molecular mechanisms involved in the maintenance of CSC subpopulation are fundamental in the development and persistence of breast cancer. Nowadays, the hypothesis suggests that genetic and epigenetic alterations give rise to breast cancer stem cells (bCSC), which are responsible for self-renewal, tumor growth, chemoresistance, poor prognosis and low survival in patients. However, the prominence of bCSC, as well as the molecular mechanisms that regulates and promotes the malignant phenotypes, are still poorly understood. The role of non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) acting as oncogenes or tumor suppressor genes has been recently highlighted by a plethora of studies in breast cancer. These ncRNAs positively or negatively impact on different signaling pathways that govern the cancer hallmarks associated with bCSC, making them attractive targets for therapy. In this review, we present a current summary of the studies on the pivotal roles of lncRNAs and microRNAs in the regulation of genes associated to stemness of bCSC.
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Neoplasias de la Mama/genética , MicroARNs/genética , Células Madre Neoplásicas/citología , Células Madre Neoplásicas/metabolismo , ARN Largo no Codificante/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Células Madre Neoplásicas/patologíaRESUMEN
Due to their increasing rates of morbidity and mortality, childhood malignancies are considered a global health priority, with acute lymphoblastic leukemias (ALLs) showing the highest incidence worldwide. Control of malignant clone emergence and the subsequent normal-leukemic hematopoietic cell out-competition require antitumor monitoring mechanisms. Investigation of cancer surveillance innate cells may be critical to understand the mechanisms contributing in either disease progression or relapse, and to promote displacement of leukemic hematopoiesis by the normal counterpart. We report here that NK cell production is less and low hematopoietic progenitor numbers contribute to this defect. By investigating the expression of the activation molecule class I restricted T-cell associated molecule (CRTAM) along the hematopoietic lineage differentiation pathway, we have identified lymphoid precursor populations coexpressing CD34, CD56/CD3/CD19, and CRTAM as the earliest developmental stage where activation may take place in specialized niches that display the ligand nectin-like-2. Of note, bone marrow (BM) from patients with ALL revealed high contents of preactivated CD56high NK cells expressing CRTAM and endowed with an exhaustion-like phenotype and the functional capability of producing IL-10 and TGF-ß in vitro. Our findings suggest, for the first time, that the tumor microenvironment in ALL directly contribute to exhaustion of NK cell functions by the CRTAM/Necl-2 interaction, and that the potential regulatory role of exhausted-like NK cells may favor malignant progression at the expense of anti-tumor responses. Phenotypic and functional identity of this unique suppressor-like NK cell population within the leukemic BM would be of special interest for the pathobiology of ALL and development of targeting strategies.
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Médula Ósea/inmunología , Molécula 1 de Adhesión Celular/genética , Proteínas de la Matriz Extracelular/genética , Células Asesinas Naturales/inmunología , Chaperonas Moleculares/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Microambiente Tumoral/inmunología , Antígenos CD/genética , Antígenos CD/inmunología , Médula Ósea/patología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Molécula 1 de Adhesión Celular/inmunología , Diferenciación Celular , Niño , Técnicas de Cocultivo , Citotoxicidad Inmunológica , Proteínas de la Matriz Extracelular/inmunología , Regulación de la Expresión Génica , Humanos , Vigilancia Inmunológica , Inmunofenotipificación , Interleucina-10/genética , Interleucina-10/inmunología , Células K562 , Células Asesinas Naturales/patología , Activación de Linfocitos , Células Madre Mesenquimatosas/inmunología , Células Madre Mesenquimatosas/patología , Chaperonas Moleculares/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Cultivo Primario de Células , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/inmunología , Microambiente Tumoral/genéticaRESUMEN
En 2005 se publicaron recomendaciones para la tipificación de hemopatías malignas en Latinoamérica. Se consideró necesario realizar una reunión nacional para actualizarlas. Se convocaron y reunieron 95 profesionales expertos en el tema para analizar y contrastar alternativas y llegar a un consenso. Se alcanzaron opiniones de consenso en lo relativo a indicaciones, tipos y manejo de muestras, anticuerpos, nomenclatura e informe de resultados para el diagnóstico y seguimiento de las leucemias agudas. Las recomendaciones se describen en este artículo y se hace hincapié en la necesidad de que los laboratorios nacionales se apeguen a ellas.
Recommendations for the typing of hematological malignancies in Latin America were published in 2005. Carrying out a national meeting to update them was deemed necessary. 95 professional experts on the subject were invited in order to analyze and contrast alternatives and reach a consensus. Consensus opinions were reached regarding indications, sample types and processing, antibodies, nomenclature and reporting of results for the diagnosis and monitoring of acute leukemias. This paper describes the recommendations and emphasizes on the need for national laboratories to adhere to them.
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Neoplasias Hematológicas/diagnóstico , Inmunofenotipificación/métodos , Leucemia/diagnóstico , Adhesión a Directriz , Neoplasias Hematológicas/inmunología , Humanos , Laboratorios/normas , América Latina , Leucemia/inmunologíaRESUMEN
Resumen En 2005 se publicaron recomendaciones para la tipificación de hemopatías malignas en Latinoamérica. Se consideró necesario realizar una reunión nacional para actualizarlas. Se convocaron y reunieron 95 profesionales expertos en el tema para analizar y contrastar alternativas y llegar a un consenso. Se alcanzaron opiniones de consenso en lo relativo a indicaciones, tipos y manejo de muestras, anticuerpos, nomenclatura e informe de resultados para el diagnóstico y seguimiento de las leucemias agudas. Las recomendaciones se describen en este artículo y se hace hincapié en la necesidad de que los laboratorios nacionales se apeguen a ellas.
Abstract Recommendations for the typing of hematological malignancies in Latin America were published in 2005. Carrying out a national meeting to update them was deemed necessary. 95 professional experts on the subject were invited in order to analyze and contrast alternatives and reach a consensus. Consensus opinions were reached regarding indications, sample types and processing, antibodies, nomenclature and reporting of results for the diagnosis and monitoring of acute leukemias. This paper describes the recommendations and emphasizes on the need for national laboratories to adhere to them.
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Humanos , Leucemia/diagnóstico , Inmunofenotipificación/métodos , Neoplasias Hematológicas/diagnóstico , Leucemia/inmunología , Neoplasias Hematológicas/inmunología , Adhesión a Directriz , Laboratorios/normas , América LatinaRESUMEN
Cancer is a major cause of death in children worldwide, with B-lineage cell acute lymphoblastic leukemia (B-ALL) being the most frequent childhood malignancy. Relapse, treatment failure and organ infiltration worsen the prognosis, warranting a better understanding of the implicated mechanisms. Cortactin is an actin-binding protein involved in cell adhesion and migration that is overexpressed in many solid tumors and in adult B-cell chronic lymphocytic leukemia. Here, we investigated cortactin expression and potential impact on infiltration and disease prognosis in childhood B-ALL. B-ALL cell lines and precursor cells from bone marrow (BM) and cerebrospinal fluid (CSF) of B-ALL patients indeed overexpressed cortactin. In CXCL12-induced transendothelial migration assays, transmigrated B-ALL cells had highest cortactin expression. In xenotransplantation models, only cortactinhigh-leukemic cells infiltrated lungs, brain, and testis; and they colonized more easily hypoxic BM organoids. Importantly, cortactin-depleted B-ALL cells were significantly less efficient in transendothelial migration, organ infiltration and BM colonization. Clinical data highlighted a significant correlation between high cortactin levels and BM relapse in drug-resistant high-risk B-ALL patients. Our results emphasize the importance of cortactin in B-ALL organ infiltration and BM relapse and its potential as diagnostic tool to identify high-risk patients and optimize their treatments.
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Biomarcadores de Tumor/metabolismo , Neoplasias de la Médula Ósea/patología , Cortactina/metabolismo , Recurrencia Local de Neoplasia/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Migración Transendotelial y Transepitelial , Adolescente , Animales , Apoptosis , Neoplasias de la Médula Ósea/metabolismo , Proliferación Celular , Niño , Preescolar , Femenino , Estudios de Seguimiento , Regulación Neoplásica de la Expresión Génica , Humanos , Lactante , Recién Nacido , Masculino , Ratones , Ratones Desnudos , Recurrencia Local de Neoplasia/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Pronóstico , Tasa de Supervivencia , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND AND AIMS: Childhood acute leukemias (AL) are characterized by the excessive production of malignant precursor cells at the expense of effective blood cell development. The dominance of leukemic cells over normal progenitors may result in either direct suppression of functional hematopoiesis or remodeling of microenvironmental niches, contributing to BM failure and AL-associated mortality. We undertook this study to investigate the contents and functional activity of hematopoietic stem/progenitor cells (HSPC) and their relationship to immune cell production and risk status in AL pediatric patients. METHODS: Multiparametric flow cytometry of BM aspirates was performed to classify AL on the basis of lineage and differentiation stages and to analyze HSPC and immune cell frequencies. Controlled co-culture systems were conducted to evaluate functional lineage potentials of primitive cells. Statistical correlations and inter-group significant differences were established. RESULTS: Among 113 AL BM aspirates, 26.5% corresponded to ProB, 19.5% to PreB and 32% contain ProB and PreB differentiation stages, whereas nearly 9% of the cases were T- and 13% myeloid-lineage leukemias. We identified ProB-ALL as the subtype endowed with the highest relative contents of HSPC, whereas T-ALL and PreB-ALL showed a critically reduced size of both HSC and MLP compartments. Notably, lower cell frequencies of HSPC in ProB-ALL correlated to high-risk prognosis at disease debut. CONCLUSIONS: HSPC abundance at initial diagnosis may aid to predict the clinical course of ALL and to identify high-risk patients. A clearer understanding of their population dynamics and functional properties in the leukemia setting will potentially pave the way for targeted therapies.
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Células de la Médula Ósea/patología , Médula Ósea/patología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Células Madre/patología , Diferenciación Celular , Niño , Técnicas de Cocultivo , Citometría de Flujo , Células Madre Hematopoyéticas/patología , HumanosRESUMEN
Inflammation is the normal immune response of vascularized tissues to damage and bacterial products, for which leukocyte transendothelial migration (TEM) is critical. The effects of cell-to-cell contact seen in both leukocyte and endothelial cells include cytoskeleton rearrangement, and dynamic expression of adhesion molecules and metalloproteinases. TEM induces expression of anti-apoptotic molecules, costimulatory molecules associated with antigen presentation, and pattern recognition receptors (PRR), such as TLR-4, in monocytes. However, little is known about how TLR-4 increment operates in monocytes during an inflammatory response. To understand it better, we used an in vitro model in which monocytes crossed a layer of IL-1ß stimulated Human Umbilical Vein Endothelial Cells (HUVEC). After TEM, monocytes were tested for the secretion of inflammatory cytokines and chemokines, their phenotype (CD14, CD16, TLR-4 expression), and TLR-4 canonical [Nuclear Factor kappa B, (NF-κB) pathway] and non-canonical [p38, extracellular signal-regulated kinases (ERK) 1/2 pathway] signal transduction induced by lipopolysaccharide (LPS). Phagocytosis and bacterial clearance were also measured. There was diminished secretion of LPS-induced inflammatory cytokines (IL-1ß, IL-6, and TNF-α) and higher secretion of chemokines (CXCL8/IL-8 and CCL2/MCP-1) in supernatant of TEM monocytes. These changes were accompanied by increases in TLR-4, CD14 (surfaces expression), p38, and ERK1/2 phosphorylated cytoplasmic forms, without affecting NF-κB activation. It also increased bacterial clearance after TEM by an O2 -independent mechanism. The data suggest that interaction between endothelial cells and monocytes fine-tunes the inflammatory response and promotes bacterial elimination.