Abscopal Effect, Extracellular Vesicles and Their Immunotherapeutic Potential in Cancer Treatment.

The communication between tumor cells and the microenvironment plays a fundamental role in the development, growth and further immune escape of the tumor. This communication is partially regulated by extracellular vesicles which can direct the behavior of surrounding cells. In recent years, it has been proposed that this feature could be applied as a potential treatment against cancer, since several studies have shown that tumors treated with radiotherapy can elicit a strong enough immune response to eliminate distant metastasis; this phenomenon is called the abscopal effect. The mechanism behind this effect may include the release of extracellular vesicles loaded with damage-associated molecular patterns and tumor-derived antigens which activates an antigen-specific immune response. This review will focus on the recent discoveries in cancer cell communications via extracellular vesicles and their implication in tumor development, as well as their potential use as an immunotherapeutic treatment against cancer.

Double CD4/CD8-Positive, Nonpoikilodermic Mycosis Fungoides Expressing CD56 in a Young Man.

ABSTRACT: We report a case of mycosis fungoides (MF) in an 18-year-old man whose neoplastic T cells expressed CD4, CD8, and CD56, with no evidence of TCR-delta or Epstein-Barr virus (EBER) expression. Clinically, neither hypopigmentation nor hyperpigmentation nor poikilodermatous skin lesions were present, and the lesions subsided with oral corticoids and retinoids and environmental solar ultraviolet exposure. Our case represents the oldest patient reported so far with nonpoikilodermatous, CD8/CD56 MF and adds to the phenotypic diversity of MF in the pediatric population. This distinct phenotype does not seem to be linked to a more aggressive course than the classic CD-4 positive one.

Lactate-Loaded Nanoparticles Induce Glioma Cytotoxicity and Increase the Survival of Rats Bearing Malignant Glioma Brain Tumor.

A glioblastoma is an aggressive form of a malignant glial-derived tumor with a poor prognosis despite multimodal therapy approaches. Lactate has a preponderant role in the tumor microenvironment, playing an immunoregulatory role as well as being a carbon source for tumor growth. Lactate homeostasis depends on the proper functioning of intracellular lactate regulation systems, such as transporters and enzymes involved in its synthesis and degradation, with evidence that an intracellular lactate overload generates metabolic stress on tumor cells and tumor cell death. We propose that the delivery of a lactate overload carried in nanoparticles, allowing the intracellular release of lactate, would compromise the survival of tumor cells. We synthesized and characterized silica and titania nanoparticles loaded with lactate to evaluate the cellular uptake, metabolic activity, pH modification, and cytotoxicity on C6 cells under normoxia and chemical hypoxia, and, finally, determined the survival of an orthotopic malignant glioma model after in situ administration. A dose-dependent reduction in metabolic activity of treated cells under normoxia was found, but not under hypoxia, independent of glucose concentration. Lactated-loaded silica nanoparticles were highly cytotoxic (58.1% of dead cells) and generated significant supernatant acidification. In vivo, lactate-loaded silica nanoparticles significantly increased the median survival time of malignant glioma-bearing rats (p = 0.005) when administered in situ. These findings indicate that lactate-loaded silica nanoparticles are cytotoxic on glioma cells in vitro and in vivo.

Surgical correction of juvenile idiopathic scoliosis. our patients' perception of their quality of life / Correção cirúrgica da escoliose idiopática juvenil - percepção de nossos pacientes sobre sua qualidade de vida / Corrección quirúrgica de escoliosis idiopática juvenil - percepción de nuestros pacientes sobre su calidad de vida

ABSTRACT Objective: To report the results of our patients who underwent scoliosis correction surgery in relation to their quality of life. Introduction: Juvenile idiopathic scoliosis affects between 1 and 3% of the population during puberty. Treatment will be conservative in most cases. The goal of surgical treatment is to improve coronal and sagittal alignment. The SRS 22 questionnaire is a useful tool for assessing quality of life in these patients. Methods: A retrospective study of 22 patients submitted to corrective surgery for juvenile idiopathic scoliosis between October 2017 and January 2020 was conducted. All of them had curves greater than 45 degrees managed through instrumentation and arthrodesis. Post-surgical quality of life was assessed using the SRS 22 questionnaire. Results: The average age of our patients at the time of the intervention was 15.5 years with a predominance of female patients. The application of the SRS 22 questionnaire generated the following mean scores: pain 4.6, function 4.3, self-image 4.41, mental health 4.89, and satisfaction 5.0. Conclusions: The development of surgical techniques has allowed good results to be achieved in the treatment of scoliosis. The evaluation of our patients using the SRS 22 questionnaire reflects a good quality of life in the 5 parameters evaluated. The main limitations of this study were the small sample size and its retrospective nature. Level of Evidence III; Retrospective, longitudinal, descriptive, observational study.

RESUMO Objetivo: Relatar os resultados de nossos pacientes operados para correção de escoliose com relação à sua qualidade de vida. Introdução: A escoliose idiopática juvenil afeta entre 1% e 3% da população durante a puberdade. O tratamento será conservador na maioria dos casos. O tratamento cirúrgico terá como objetivo melhorar o alinhamento coronal e sagital. O questionário SRS 22 é uma ferramenta útil para avaliar a qualidade de vida desses pacientes. Métodos: Foi realizado um estudo retrospectivo de 22 pacientes operados entre outubro de 2017 e janeiro de 2020 devido à escoliose idiopática juvenil. Todos tinham curvas superiores a 45 graus tratadas com instrumentação e artrodese. A qualidade de vida pós-operatória foi avaliada por meio do questionário SRS-22. Resultados: A média de idade dos nossos pacientes no momento da intervenção foi 15,5 anos, com predominância do sexo feminino. A aplicação do questionário SRS-22 gerou os seguintes escores médios: dor 4,6; função 4,3; autoimagem 4,41; saúde mental 4,89 e satisfação 5,0. Conclusões: O desenvolvimento das técnicas cirúrgicas permitiu obter bons resultados no tratamento da escoliose. A avaliação de nossos pacientes por intermédio do questionário SRS 22 reflete boa qualidade de vida nos cinco parâmetros avaliados. As principais limitações deste estudo foram o pequeno tamanho da amostra e seu caráter retrospectivo. Nível de Evidência III; Estudo retrospectivo, longitudinal, descritivo, observacional.

RESUMEN Objetivo: Reportar los resultados de nuestros pacientes operados para corrección de escoliosis en relación a su calidad de vida. Introducción: La escoliosis idiopática juvenil afecta entre el 1% y 3% de la población durante la pubertad. El tratamiento será, en la mayoría, de los casos conservador. El tratamiento quirúrgico tendrá como objetivo mejorar la alineación coronal y sagital. El cuestionario SRS 22 es una herramienta útil para la valoración de la calidad de vida en estos pacientes. Métodos: Se realizó un estudio retrospectivo de 22 pacientes intervenidos entre octubre de 2017 y enero de 2020 debido a la escoliosis idiopática juvenil. Todos tenían curvas mayores de 45 grados manejadas mediante instrumentación y artrodesis. Se realizó la evaluación de la calidad de vida posquirúrgica mediante el cuestionario SRS-22. Resultados: La edad promedio de nuestros pacientes en el momento de la intervención fue de 15,5 años con predominio de pacientes del sexo femenino. La aplicación del cuestionario SRS-22 generó las siguientes puntuaciones medias: dolor 4,6; función 4,3; autoimagen 4,41; salud mental 4,89 y satisfacción 5,0. Conclusiones: El desarrollo de las técnicas quirúrgicas ha permitido obtener buenos resultados en el tratamiento de la escoliosis. La evaluación de nuestros pacientes mediante el cuestionario SRS 22 refleja una buena calidad de vida en los 5 parámetros evaluados. Las limitaciones principales de este estudio han sido el pequeño tamaño de la muestra y su carácter retrospectivo. Nivel de Evidencia III; Estudio retrospectivo, longitudinal, descriptivo, observacional.

Prevalence and characteristics of upper lumbar disc herniations in our practice: a retrospective analysis / Prevalência e características das hérnias lombares superiores em nosso meio: análise retrospectiva / Prevalencia y características de las hernias lumbares altas en nuestro medio: analisis retrospectivo

ABSTRACT Introduction: Upper lumbar disc herniations (ULDH) are considered infrequent injuries (1-11%). They present, most often in older adults, with special clinical features that make diagnosis and therapeutic decision-making difficult. The prevalence, location, and management of these herniations and the medical history of our patients were analyzed. Methods: Sex, age, injury level, previous surgery, and patient treatment data from July 2018 to May 2021 were collected retrospectively. During this period, 179 patients underwent surgery, 33 of whom patients presented ULDH. Results: Thirty-three patients were included in the study (18 male and 15 female). Ages ranged from 39 to 85 years, with a predominance of elderly patients. The levels operated were L1-L2 in seven patients, L2-L3 in ten patients, L3-L4 in fourteen patients, and surgery in two levels (L2-L3, L3-L4) in two patients. In our practice, microdiscectomy is the preferred approach and was performed in all cases, with the addition of fusion in four of the 33 patients. Finally, a history of low lumbar disc herniation (LLDH) surgery was found in 16 patients. Conclusions: In our population, ULDHs are a rare entity with lower prevalence at the higher lumbar levels. They occur more frequently in elderly patients and clinical presentation can vary, which is a challenge for surgeons. In older adults, the development of lumbar kyphosis due to vertebral wedging is considered a risk factor for the development of ULDH. Surgical management by microdiscectomy is considered a technique with good results for this pathology. Level of Evidence III; Retrospective, longitudinal, descriptive, observational study.

RESUMO Introdução: As hérnias de disco lombares altas (ULDH) são consideradas lesões infrequentes (1% a 11%). Ocorrem principalmente em idosos com características clínicas especiais que dificultam o diagnóstico e a decisão terapêutica. A prevalência, localização, o tratamento e a história de nossos pacientes foram analisados. Métodos: Dados sobre sexo, idade, nível das lesões, história cirúrgica e tratamento de nossos pacientes foram coletados retrospectivamente de julho de 2018 a maio de 2021. Nesse período, 179 pacientes foram operados, dos quais 33 apresentavam ULDH. Resultados: Trinta e três pacientes foram incluídos neste estudo, sendo 18 homens e 15 mulheres. A faixa etária variou de 39 a 85 anos, predominando os pacientes idosos. Os níveis operados foram L1-L2 em sete pacientes, L2-L3 em dez pacientes, L3-L4 em catorze pacientes e cirurgia em 2 níveis (L2-L3, L3-L4) em dois pacientes. Em nosso meio, a microdiscectomia é o tratamento de escolha, que foi realizado em todos os casos, adicionando fusão em 4 dos 33 pacientes. Finalmente, encontrou-se o antecedente de cirurgia de hérnia de disco lombar baixa (LLDH) em 16 pacientes. Conclusões: Em nosso meio, a ULDH é uma entidade rara e com menor prevalência em níveis lombares mais altos. Ocorrem com maior frequência em idosos e seu quadro clínico pode ser variado, o que representa um desafio para o cirurgião. Em idosos, o desenvolvimento de cifose lombar devido ao acunhamento vertebral é considerado um fator de risco para o desenvolvimento de ULDH. A cirurgia de microdiscectomia é considerada uma técnica com bons resultados nessa patologia. Nível de Evidência III; Estudo retrospectivo, transversal, descritivo, observacional.

RESUMEN Introducción: Las hernias discales lumbares altas (ULDH) son consideradas lesiones infrecuentes (1-11%). Se presentan principalmente en adultos mayores con características clínicas especiales que dificultan su diagnóstico y decisión terapéutica. La prevalencia, localización, manejo y antecedentes de nuestros pacientes fueron analizados. Métodos: Los datos con respecto a sexo, edad, nivel de lesión, antecedentes quirúrgicos y manejo de nuestros pacientes fueron recolectados retrospectivamente desde julio del 2018 hasta mayo del 2021. Durante este periodo 179 pacientes fueron operados, de los cuales 33 presentaron ULDH. Resultados: Treinta y tres pacientes fueron incluidos en éste estudio, de los cuales 18 eran hombres y 15 mujeres. Los rangos de edad variaron entre 39 y 85 años, predominando pacientes de la tercera edad. Los niveles intervenidos fueron L1-L2 en siete pacientes, L2-L3 en diez pacientes, L3-L4 en catorce pacientes y cirugía en 2 niveles (L2-L3, L3-L4) en dos pacientes. En nuestro medio, la microdiscectomía es el manejo preferido, el cual se realizó en todos los casos, agregando fusión en 4 de los 33 pacientes. Finalmente se encontró antecedente de cirugía por hernias discales lumbares bajas (LLDH) en 16 pacientes. Conclusiones: En nuestro medio, las ULDH son una entidad rara con menor prevalencia en niveles lumbares más altos. Se presentan con mayor frecuencia en personas de edad avanzada y su cuadro clínico puede ser variado, lo cual representa un reto para cirujano. En adultos mayores el desarrollo de cifosis lumbar por acuñamientos vertebrales se considera un factor de riesgo para el desarrollo de ULDH. El manejo quirúrgico mediante microdiscectomía se considera una técnica con buenos resultados en ésta patología. Nivel de Evidencia III; Estudio retrospectivo, transversal, descriptivo, observacional.

Associations between carabid beetles and fungi in the light of 200 years of published literature.

Describing and conserving ecological interactions woven into ecosystems is one of the great challenges of the 21st century. Here, we present a unique dataset compiling the biotic interactions between two ecologically and economically important taxa: ground beetles (Coleoptera: Carabidae) and fungi. The resulting dataset contains the carabid-fungus associations collected from 392 scientific publications, 129 countries, mostly from the Palearctic region, published over a period of 200 years. With an updated taxonomy to match the currently accepted nomenclature, 3,378 unique associations among 5,564 records were identified between 1,776 carabid and 676 fungal taxa. Ectoparasitic Laboulbeniales were the most frequent fungal group associated with carabids, especially with Trechinae. The proportion of entomopathogens was low. Three different formats of the data have been provided along with an interactive data digest platform for analytical purposes. Our database summarizes the current knowledge on biotic interactions between insects and fungi, while offering a valuable resource to test large-scale hypotheses on those interactions.

The Role of Tricarboxylic Acid Cycle Metabolites in Viral Infections.

Host cell metabolism is essential for the viral replication cycle and, therefore, for productive infection. Energy (ATP) is required for the receptor-mediated attachment of viral particles to susceptible cells and for their entry into the cytoplasm. Host cells must synthesize an array of biomolecules and engage in intracellular trafficking processes to enable viruses to complete their replication cycle. The tricarboxylic acid (TCA) cycle has a key role in ATP production as well as in the synthesis of the biomolecules needed for viral replication. The final assembly and budding process of enveloped viruses, for instance, require lipids, and the TCA cycle provides the precursor (citrate) for fatty acid synthesis (FAS). Viral infections may induce host inflammation and TCA cycle metabolic intermediates participate in this process, notably citrate and succinate. On the other hand, viral infections may promote the synthesis of itaconate from TCA cis-aconitate. Itaconate harbors anti-inflammatory, anti-oxidant, and anti-microbial properties. Fumarate is another TCA cycle intermediate with immunoregulatory properties, and its derivatives such as dimethyl fumarate (DMF) are therapeutic candidates for the contention of virus-induced hyper-inflammation and oxidative stress. The TCA cycle is at the core of viral infection and replication as well as viral pathogenesis and anti-viral immunity. This review highlights the role of the TCA cycle in viral infections and explores recent advances in the fast-moving field of virometabolism.

Mitochondrial Signature in Human Monocytes and Resistance to Infection in C. elegans During Fumarate-Induced Innate Immune Training.

Monocytes can develop immunological memory, a functional characteristic widely recognized as innate immune training, to distinguish it from memory in adaptive immune cells. Upon a secondary immune challenge, either homologous or heterologous, trained monocytes/macrophages exhibit a more robust production of pro-inflammatory cytokines, such as IL-1ß, IL-6, and TNF-α, than untrained monocytes. Candida albicans, ß-glucan, and BCG are all inducers of monocyte training and recent metabolic profiling analyses have revealed that training induction is dependent on glycolysis, glutaminolysis, and the cholesterol synthesis pathway, along with fumarate accumulation; interestingly, fumarate itself can induce training. Since fumarate is produced by the tricarboxylic acid (TCA) cycle within mitochondria, we asked whether extra-mitochondrial fumarate has an effect on mitochondrial function. Results showed that the addition of fumarate to monocytes induces mitochondrial Ca2+ uptake, fusion, and increased membrane potential (Δψm), while mitochondrial cristae became closer to each other, suggesting that immediate (from minutes to hours) mitochondrial activation plays a role in the induction phase of innate immune training of monocytes. To establish whether fumarate induces similar mitochondrial changes in vivo in a multicellular organism, effects of fumarate supplementation were tested in the nematode worm Caenorhabditis elegans. This induced mitochondrial fusion in both muscle and intestinal cells and also increased resistance to infection of the pharynx with E. coli. Together, these findings contribute to defining a mitochondrial signature associated with the induction of innate immune training by fumarate treatment, and to the understanding of whole organism infection resistance.

Mitochondria: An Integrative Hub Coordinating Circadian Rhythms, Metabolism, the Microbiome, and Immunity.

There is currently some understanding of the mechanisms that underpin the interactions between circadian rhythmicity and immunity, metabolism and immune response, and circadian rhythmicity and metabolism. In addition, a wealth of studies have led to the conclusion that the commensal microbiota (mainly bacteria) within the intestine contributes to host homeostasis by regulating circadian rhythmicity, metabolism, and the immune system. Experimental studies on how these four biological domains interact with each other have mainly focused on any two of those domains at a time and only occasionally on three. However, a systematic analysis of how these four domains concurrently interact with each other seems to be missing. We have analyzed current evidence that signposts a role for mitochondria as a key hub that supports and integrates activity across all four domains, circadian clocks, metabolic pathways, the intestinal microbiota, and the immune system, coordinating their integration and crosstalk. This work will hopefully provide a new perspective for both hypothesis-building and more systematic experimental approaches.

Malignant Glioma Therapy by Vaccination with Irradiated C6 Cell-Derived Microvesicles Promotes an Antitumoral Immune Response.

Glioblastoma is the most common and malignant tumor of the CNS, with a mean survival of 14 months after diagnosis. Its unfavorable prognosis reveals the need for novel therapies. It is known that radiation can induce a systemic antitumor effect. Tumor cells produce and release microvesicles in response to cell damage such as radiation. Microvesicles contain a plethora of bioactive molecules, including antigens involved in modulation of the immune response. In this study, we characterized and evaluated irradiated C6 cell-derived microvesicles as a therapeutic vaccination in C6 malignant glioma. Cultured C6 glioma cells were irradiated with a single dose of 50 Gy to obtain the microvesicles. Subcutaneous implantation of C6 cells was performed when the tumor reached 2 cm in diameter, and non-irradiated and irradiated C6 cell-derived microvesicles were administered subcutaneously. Tumor growth, apoptosis, and immunophenotypes were determined. Reduction of tumor volume (more than 50%) was observed in the group treated with irradiated C6 cell-derived microvesicles compared with the control (p = 0.03). The percentages of infiltrative helper, cytotoxic, and regulatory T lymphocytes as well as apoptotic cells were increased in tumors from immunized rats compared with controls. These findings make microvesicle-based vaccination a promising immunotherapeutic approach against glioblastoma.

Virus Control of Cell Metabolism for Replication and Evasion of Host Immune Responses.

Over the last decade, there has been significant advances in the understanding of the cross-talk between metabolism and immune responses. It is now evident that immune cell effector function strongly depends on the metabolic pathway in which cells are engaged in at a particular point in time, the activation conditions, and the cell microenvironment. It is also clear that some metabolic intermediates have signaling as well as effector properties and, hence, topics such as immunometabolism, metabolic reprograming, and metabolic symbiosis (among others) have emerged. Viruses completely rely on their host's cell energy and molecular machinery to enter, multiply, and exit for a new round of infection. This review explores how viruses mimic, exploit or interfere with host cell metabolic pathways and how, in doing so, they may evade immune responses. It offers a brief outline of key metabolic pathways, mitochondrial function and metabolism-related signaling pathways, followed by examples of the mechanisms by which several viral proteins regulate host cell metabolic activity.

The First Complete Genome Sequence of a Novel Tetrastichus brontispae RNA Virus-1 (TbRV-1).

The complete sequence of a novel RNA virus isolated from Tetrastichus brontispae (TbRV-1) was determined to be 12,239 nucleotides in length with five non-overlapping, linearly arranged coding sequences (CDS), potentially encoding nucleoproteins, hypothetical proteins, matrix proteins, glycoproteins, and RNA-dependent RNA polymerases. Sequence analysis indicated that the RNA-dependent RNA polymerase of TbRV-1 shares a 65% nucleotide and 67% amino acid sequence identity with Hubei dimarhabdovirus 2, suggesting that TbRV-1 is a member of the dimarhabdovirus supergroup. This corresponded to the result of the phylogenetic analysis. The affiliation of TbRV-1 with members of the family Rhabdoviridae was further validated by similar transcription termination motifs (GGAACUUUUUUU) to the Drosophila sigmavirus. The prevalence of TbRV-1 in all tissues suggested that the virus was constitutive of, and not specific to, any wasp tissue. To our knowledge, this is the first report on the complete genome sequence of a dimarhabdovirus in parasitoids.

Anti-Inflammatory and Anti-Fibrotic Effects of Human Amniotic Membrane Mesenchymal Stem Cells and Their Potential in Corneal Repair.

Acute ocular chemical burns are ophthalmic emergencies requiring immediate diagnosis and treatment as they may lead to permanent impairment of vision. The clinical manifestations of such burns are produced by exacerbated innate immune response via the infiltration of inflammatory cells and activation of stromal fibroblasts. New therapies are emerging that are dedicated to repair mechanisms that improve the ocular surface after damage; for example, transplantation of stem cells (SC) has been successfully reported for this purpose. The pursuit of easily accessible, noninvasive procedures to obtain SC has led researchers to focus on human tissues such as amniotic membrane. Human amniotic mesenchymal SC (hAM-MSC) inhibits proinflammatory and fibrotic processes in different diseases. hAM-MSC expresses low levels of classical MHC-I and they do not express MHC-II, making them suitable for regenerative medicine. The aim of this study was to evaluate the effect of intracameral injection of hAM-MSC on the clinical manifestations, the infiltration of inflammatory cells, and the activation of stromal fibroblasts in a corneal alkali-burn model. We also determined the in vitro effect of hAM-MSC conditioned medium (CM) on α-SMA+ human limbal myofibroblast (HLM) frequency and on release of neutrophil extracellular traps (NETs). Our results show that intracameral hAM-MSC injection reduces neovascularization, opacity, stromal inflammatory cell infiltrate, and stromal α-SMA+ cells in our model. Moreover, in in vitro assays, CM from hAM-MSC decreased the quantity of α-SMA+ HLM and the release of NETs. These results suggest that intracameral hAM-MSC injection induces an anti-inflammatory and anti-fibrotic environment that promotes corneal wound healing. Stem Cells Translational Medicine 2018;7:906-917.

Lactate Contribution to the Tumor Microenvironment: Mechanisms, Effects on Immune Cells and Therapeutic Relevance.

Malignant transformation of cells leads to enhanced glucose uptake and the conversion of a larger fraction of pyruvate into lactate, even under normoxic conditions; this phenomenon of aerobic glycolysis is largely known as the Warburg effect. This metabolic reprograming serves to generate biosynthetic precursors, thus facilitating the survival of rapidly proliferating malignant cells. Extracellular lactate directs the metabolic reprograming of tumor cells, thereby serving as an additional selective pressure. Besides tumor cells, stromal cells are another source of lactate production in the tumor microenvironment, whose role in both tumor growth and the antitumor immune response is the subject of intense research. In this review, we provide an integral perspective of the relationship between lactate and the overall tumor microenvironment, from lactate structure to metabolic pathways for its synthesis, receptors, signaling pathways, lactate-producing cells, lactate-responding cells, and how all contribute to the tumor outcome. We discuss the role of lactate as an immunosuppressor molecule that contributes to tumor evasion and we explore the possibility of targeting lactate metabolism for cancer treatment, as well as of using lactate as a prognostic biomarker.

RB mutation and RAS overexpression induce resistance to NK cell-mediated cytotoxicity in glioma cells.

Several theories aim to explain the malignant transformation of cells, including the mutation of tumor suppressors and proto-oncogenes. Deletion of Rb (a tumor suppressor), overexpression of mutated Ras (a proto-oncogene), or both, are sufficient for in vitro gliomagenesis, and these genetic traits are associated with their proliferative capacity. An emerging hallmark of cancer is the ability of tumor cells to evade the immune system. Whether specific mutations are related with this, remains to be analyzed. To address this issue, three transformed glioma cell lines were obtained (Rb(-/-), Ras(V12), and Rb(-/-)/Ras(V12)) by in vitro retroviral transformation of astrocytes, as previously reported. In addition, Ras(V12) and Rb(-/-)/Ras(V12) transformed cells were injected into SCID mice and after tumor growth two stable glioma cell lines were derived. All these cells were characterized in terms of Rb and Ras gene expression, morphology, proliferative capacity, expression of MHC I, Rae1δ, and Rae1αßγδε, mult1, H60a, H60b, H60c, as ligands for NK cell receptors, and their susceptibility to NK cell-mediated cytotoxicity. Our results show that transformation of astrocytes (Rb loss, Ras overexpression, or both) induced phenotypical and functional changes associated with resistance to NK cell-mediated cytotoxicity. Moreover, the transfer of cell lines of transformed astrocytes into SCID mice increased resistance to NK cell-mediated cytotoxicity, thus suggesting that specific changes in a tumor suppressor (Rb) and a proto-oncogene (Ras) are enough to confer resistance to NK cell-mediated cytotoxicity in glioma cells and therefore provide some insight into the ability of tumor cells to evade immune responses.

Varias teorías pretenden explicar la transformación maligna de las células, como es la mutación de genes supresores de tumor y proto-oncogenes. La deleción de Rb (un supresor de tumor), la sobreexpresión de Ras mutado (un proto-oncogén), o ambos, son suficientes para desarrollar gliomagénesis in vitro, y estas características genéticas se asocian con su alta tasa de proliferación. Un rasgo distintivo del cáncer es la capacidad de las células tumorales para evadir el sistema inmune. Por lo que en este estudio analizamos si las mutaciones específicas están relacionadas con la evasión de la respuesta inmune. Para abordar esta cuestión, tres líneas celulares de glioma transformadas se obtuvieron (Rb−/−, RasV12, y Rb−/−/RasV12) mediante transformación retroviral de astrocitos in vitro, reportado anteriormente. Además, las células transformadas RasV12 y Rb−/−/RasV12 fueron inyectadas en ratones SCID y después del crecimiento del tumor se obtuvieron dos líneas celulares de glioma estables. En todas las células se determinaron la expresión génica Rb y Ras, morfología, capacidad de proliferación, expresión de MHC I, Rae1δ, and Rae1αßγδε, mult1, H60a, H60b, H60c, como ligandos para receptores de células NK, y su susceptibilidad a la citotoxicidad mediada por células NK. Nuestros resultados muestran que la transformación de los astrocitos (pérdida de Rb, la sobreexpresión de Ras, o ambos) indujo cambios fenotípicos y funcionales asociados con la resistencia a la citotoxicidad mediada por células NK. Además, la transferencia de astrocitos transformados dentro de ratones SCID aumento la resistencia a la citotoxicidad mediada por células NK, lo que se sugiere que los cambios específicos en un supresor de tumores (Rb) y un proto-oncogén (Ras) son suficientes para conferir resistencia a la citotoxicidad mediada por células NK en células de glioma y, por tanto, proporcionar una idea de la capacidad de las células tumorales para evadir la respuesta inmune.

Metabolic requirements for neutrophil extracellular traps formation.

As part of the innate immune response, neutrophils are at the forefront of defence against infection, resolution of inflammation and wound healing. They are the most abundant leucocytes in the peripheral blood, have a short lifespan and an estimated turnover of 10(10) to 10(11) cells per day. Neutrophils efficiently clear microbial infections by phagocytosis and by oxygen-dependent and oxygen-independent mechanisms. In 2004, a new neutrophil anti-microbial mechanism was described, the release of neutrophil extracellular traps (NETs) composed of DNA, histones and anti-microbial peptides. Several microorganisms, bacterial products, as well as pharmacological stimuli such as PMA, were shown to induce NETs. Neutrophils contain relatively few mitochondria, and derive most of their energy from glycolysis. In this scenario we aimed to analyse some of the metabolic requirements for NET formation. Here it is shown that NETs formation is strictly dependent on glucose and to a lesser extent on glutamine, that Glut-1, glucose uptake, and glycolysis rate increase upon PMA stimulation, and that NET formation is inhibited by the glycolysis inhibitor, 2-deoxy-glucose, and to a lesser extent by the ATP synthase inhibitor oligomycin. Moreover, when neutrophils were exposed to PMA in glucose-free medium for 3 hr, they lost their characteristic polymorphic nuclei but did not release NETs. However, if glucose (but not pyruvate) was added at this time, NET release took place within minutes, suggesting that NET formation could be metabolically divided into two phases; the first, independent from exogenous glucose (chromatin decondensation) and, the second (NET release), strictly dependent on exogenous glucose and glycolysis.

RNA interference: a new strategy in the evolutionary arms race between human control strategies and insect pests.

The relationship between humans and the insect pests of cultivated plants may be considered to be an indirect coevolutionary process, i.e., an arms race. Over time, humans have developed several strategies to minimize the negative impacts of insects on agricultural production. However, insects have made adaptive responses via the evolution of resistance to insecticides, and more recently against Bacillus thuriengiensis. Thus, we need to continuously invest resources in the development of new strategies for crop protection. Recent advances in genomics have demonstrated the possibility of a new weapon or strategy in this war, i.e., gene silencing, which involves blocking the expression of specific genes via mRNA inactivation. In the last decade, several studies have demonstrated the effectiveness of this strategy in the control of different species of insects. However, several technical difficulties need to be overcome to transform this potential into reality, such as the selection of target genes, the concentration of dsRNA, the nucleotide sequence of the dsRNA, the length of dsRNA, persistence in the insect body, and the life stage of the target species where gene silencing is most efficient. This study analyzes several aspects related to the use of gene silencing in pest control and it includes an overview of the inactivation process, as well as the problems that need to be resolved to transform gene silencing into an effective pest control method.

The interplay between pathogen-associated and danger-associated molecular patterns: an inflammatory code in cancer?

There is increasing evidence of a close link between inflammation and cancer, and at the core of inflammation there are both pathogen-associated molecular patterns (PAMPs) and danger (or damage)-associated molecular patterns (DAMPs). Microorganisms harbor molecules structurally conserved within groups called PAMPs that are recognized by specific receptors present on immune cells, such as monocytes and dendritic cells (DCs); these are the pattern recognition receptors (PRRs). Activation through different PRRs leads to production of pro-inflammatory cytokines. A robust immune response also requires the presence of endogenous molecules that pose 'danger' to self-tissues and are produced by damaged or stressed cells; these are the DAMPs, which act also as inducers of inflammation. PAMPs and DAMPs are each recognized by a limited set of receptors that in number probably do not exceed 100. PAMPs and DAMPs interact with each other, and a single PRR can bind to a PAMP as well as a DAMP. Within this framework, we propose that PAMPs and DAMPs act in synchrony, modifying the activation threshold of one another. Thus, the range of PAMP-DAMP partnerships defines the course of inflammation, in a predictable manner, in an 'inflammatory code'. The definition of relevant PAMP-DAMP complexes is important for the understanding of inflammatory disorders in general, and of cancer in particular. Here, we review relevant findings that support the notion of a PAMP-DAMP-based inflammatory code, with emphasis on cancer immunology and immunotherapy.