3,605 research outputs found

    Editorial: γδ T Cells in Cancer

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    Since the discovery of γδ T cells, this rare and unique component of the immune system has been recognized for its potential in cancer immunology and immunotherapy. In the mid-1980s, it became clear that a major component of adaptive immune responses is the ability of T cell receptors (TCR) to undergo somatic recombination in order to recognize multiple antigens

    A versatile nanocarrierCubosomes, characterization, and applications

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    The impact of nanotechnology on the exponential growth of several research areas, particularly nanomedicine, is undeniable. The ability to deliver active molecules to the desired site could significantly improve the efficiency of medical treatments. One of the nanocarriers developed which has drawn researchers’ attention are cubosomes, which are nanosized dispersions of lipid bicontinuous cubic phases in water, consisting of a lipidic interior and aqueous domains folded in a cubic lattice. They stand out due to their ability to incorporate hydrophobic, hydrophilic, and amphiphilic compounds, their tortuous internal configuration that provides a sustained release, and the capacity to protect and safely deliver molecules. Several approaches can be taken to prepare this structure, as well as different lipids like monoolein or phytantriol. This review paper describes the different methods to prepare nanocarriers. As it is known, the physicochemical properties of nanocarriers are very important, as they influence their pharmacokinetics and their ability to incorporate and deliver active molecules. Therefore, an extensive characterization is essential to obtain the desired effect. As a result, we have extensively described the most common techniques to characterize cubosomes, particularly nanocarriers. The exceptional properties of the cubosomes make them suitable to be used in several applications in the biomedical field, from cancer therapeutics to imaging, which will be described. Taking in consideration the outstanding properties of cubosomes, their application in several research fields is envisaged.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, by Marie Skłodowska Curie grant (MSCA-RISE; FODIAC; 778388) and by European Regional Development Fund (ERDF) through the Competitiveness factors Operational program—Norte 2020, COMPETE and National Funds through the FCT—under the project AgriFood XXI (NORTE- 01-0145-FEDER-000041). J.L.P. acknowledge the Instituto de Salud Carlos III for a “Sara Borrell” grant (CD19/00250), cofounded by European Social Fund (“El FSE invierte en futuro”). C.J.O.F. acknowledge the FCT for the grant SFRH/149/BD/14199/2019.info:eu-repo/semantics/publishedVersio

    Lutzomyia longipalpis Saliva Triggers Lipid Body Formation and Prostaglandin E2 Production in Murine Macrophages

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    After the injection of saliva into the host's skin by sand flies, a transient erythematous reaction is observed, which is related to an influx of inflammatory cells and the release of various molecules that actively facilitate the blood meal. It is important to understand the specific mechanisms by which sand fly saliva manipulates the host's inflammatory responses. Herein, we report that saliva from Lutzomyia (L.) longipalpis, a widespread Leishmania vector, induces early production of eicosanoids. Intense formation of intracellular organelles called lipid bodies (LBs) was noted within those cells that migrated to the site of saliva injection. In vitro and ex vivo, sand fly saliva was able to induce LB formation and PGE2 release by macrophages. Interestingly, PGE2 production induced by L. longipalpis saliva was dependent on intracellular mechanisms involving phosphorylation of signaling proteins such as PKC-α and ERK-1/2 and subsequent activation of cyclooxygenase-2. Thus, this study provides new insights into the pharmacological properties of sand fly saliva and opens new opportunities for intervening with the induction of the host's inflammatory pathways by L. longipalpis bites

    Granulocyte-Colony Stimulating Factor-Overexpressing Mesenchymal Stem Cells Exhibit Enhanced Immunomodulatory Actions Through the Recruitment of Suppressor Cells in Experimental Chagas Disease Cardiomyopathy

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    Genetic modification of mesenchymal stem cells (MSCs) is a promising strategy to improve their therapeutic effects. Granulocyte-colony stimulating factor (G-CSF) is a growth factor widely used in the clinical practice with known regenerative and immunomodulatory actions, including the mobilization of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Here we evaluated the therapeutic potential of MSCs overexpressing G-CSF (MSC_G-CSF) in a model of inflammatory cardiomyopathy due to chronic Chagas disease. C57BL/6 mice were treated with wild-type MSCs, MSC_G-CSF, or vehicle (saline) 6 months after infection with Trypanosoma cruzi. Transplantation of MSC_G-CSF caused an increase in the number of circulating leukocytes compared to wild-type MSCs. Moreover, G-CSF overexpression caused an increase in migration capacity of MSCs to the hearts of infected mice. Transplantation of either MSCs or MSC_G-CSF improved exercise capacity, when compared to saline-treated chagasic mice. MSC_G-CSF mice, however, were more potent than MSCs in reducing the number of infiltrating leukocytes and fibrosis in the heart. Similarly, MSC_G-CSF-treated mice presented significantly lower levels of inflammatory mediators, such as IFNγ, TNFα, and Tbet, with increased IL-10 production. A marked increase in the percentage of Tregs and MDSCs in the hearts of infected mice was seen after administration of MSC_G-CSF, but not MSCs. Moreover, Tregs were positive for IL-10 in the hearts of T. cruzi-infected mice. In vitro analysis showed that recombinant hG-CSF and conditioned medium of MSC_G-CSF, but not wild-type MSCs, induce chemoattraction of MDSCs in a transwell assay. Finally, MDSCs purified from hearts of MSC_G-CSF transplanted mice inhibited the proliferation of activated splenocytes in a co-culture assay. Our results demonstrate that G-CSF overexpression by MSCs potentiates their immunomodulatory effects in our model of Chagas disease and suggest that mobilization of suppressor cell populations such as Tregs and MDSCs as a promising strategy for the treatment of chronic Chagas disease. Finally, our results reinforce the therapeutic potential of genetic modification of MSCs, aiming at increasing their paracrine actions

    An. Acad. Bras. CiĂŞnc.

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    Abstract Mesenchymal stem cells present clinical potential to recover and regenerate injured tissues in diverse pathologies. The in vitro expansion and characterization of these cells contribute to elucidation of the mechanisms of senescence and strategies involving cell therapies. This study aimed to compare specific characteristics between initial and advanced passages of mesenchymal stem cells derived from adipose tissue and bone marrow. Both cell types were characterized according to immunophenotype, osteogenic differentiation, genomic instability, migration assay, doubling population time and colony forming ability. Our results demonstrated that both cell types were able to maintain an immunophenotypic profile typical of mesenchymal stem cells during increasing passages. Adipose stem cells at initial passage presented greater migration capacity compared to advanced passage cells, and advanced passage cells proliferated faster than initial passage cells. Bone marrow stem cells at early passages presented higher osteogenic potential than advanced. At advanced passages they presented higher colony forming capacity and genetic damage than those at initial passage. These results suggest that mesenchymal stem cells maintained in culture presented characteristics of senescence that should be monitored prior the use in regenerative medicine and cells derived from bone marrow at initial passage have better potential for therapeutic use in bone tissue engineering

    Participation of Dopamine D1 and D2 Receptors in the Rapid-Onset Behavioral Sensitization to Modafinil

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    Studies on the abuse potential of modafinil, a psychostimulant-like drug used to treat narcolepsy, are still controversial. While some studies claim no potential for abuse, increasing evidence suggests that modafinil induces abuse-related effects, including rapid-onset behavioral sensitization (i.e., a type of sensitization that develops within hours from the drug priming administration). The rapid-onset sensitization paradigm is a valuable tool to study the neuroplastic changes that occur quickly after drug administration, and shares neuroadaptations with drug abuse in humans. However, the mechanisms involved in the rapid-onset behavioral sensitization induced by modafinil are uncertain. Our aim was to investigate the possible involvement of dopamine D1 and D2 receptors on acute modafinil-induced hyperlocomotion and on the induction and expression of rapid-onset behavioral sensitization induced by modafinil in male Swiss mice. Treatment with the D1 receptor antagonist SCH 23390 or the D2 receptor antagonist sulpiride attenuated the acute modafinil-induced hyperlocomotion in a dose-dependent manner. Pretreatment with either antagonist before the priming injection of modafinil prevented the development of sensitization in response to a modafinil challenge 4 h later. However, only SCH 23390 decreased the expression of modafinil-induced rapid-onset behavioral sensitization. Taken together, the present findings provide evidence of the participation of D1 and D2 receptors on the development of rapid-onset behavioral sensitization to modafinil, and point to a prominent role of D1 receptors on the expression of this phenomenon

    Uso de redes neurais artificais na predi??o de valores gen?ticos para peso aos 205 dias em bovinos da ra?a Tabapu?.

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    Dados de 19240 animais Tabapu?, provenientes de 152 fazendas localizadas em diversos estados brasileiros, nascidos entre 1976 e 1995, foram utilizados para predi??o do valor gen?tico do peso aos 205 dias de idade (VG_P205) por meio de redes neurais artificiais (RNAs) e usando o algoritmo LM ? Levenberg Marquardt ? para treinamento dos dados de entrada. Por se tratar de rede com aprendizado supervisionado, foram utilizados, como sa?da desejada, os valores gen?ticos preditos pelo BLUP para a caracter?stica P205. Os valores gen?ticos do P205 obtidos pela RNA e os preditos pelo BLUP foram altamente correlacionados. A ordena??o dos valores gen?ticos do P205 oriundos das RNAs e os valores preditos pelo BLUP (VG_P205_RNA) sugeriram que houve varia??o na classifica??o dos animais, indicando riscos no uso de RNAs para avalia??o gen?tica dessa caracter?stica. Inser??es de novos animais necessitam de novo treinamento dos dados, sempre dependentes do BLUP.Data from 19,240 Tabapu? animals from 152 farms located in different states of Brazil, born from 1976 to 1995, were used to predict the genetic value of body weight at 205 days of age (BV_P205) of Tabapu? beef cattle using Artificial Neural Networks (ANN) and LM algorithm - Levenberg Marquardt training for data entry. Due to the use of networks with supervised learning, the predicted breeding values for P205 from BLUP were used as desired output. The breeding values for P205 obtained from RNA and those predicted by BLUP were highly correlated. The ranked breeding values for body weight at 205 days through RNA and those predicted by BLUP (VG_P205_RNA) showed a variation in the classification of animals indicating risks in the use of ANNs procedure for genetic evaluation of this trait. Insertions of new animals require new training data always dependent on BLUP
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