Extracellular vesicles and sleep deprivation.

Sleep is vital in preserving mental and physical well-being by aiding bodily recovery, strengthening the immune system, and regulating hormones. It enhances memory, concentration, and mood regulation, reducing stress and anxiety. Sleep deprivation, a common phenomenon affecting approximately 20% of adults, decreases performance, alertness, and health integrity. Furthermore, it triggers physiological changes, including increased stress hormone levels, leading to various disorders such as hyperglycemia and hypertension. Recent research explores the role of extracellular vesicles (EVs) in sleep-related conditions. EVs, released by cells, play vital roles in intercellular communication and biomarker potential. Studies indicate that sleep deprivation influences EV release, impacting cancer progression, endothelial inflammation, and thrombosis risk. Understanding these mechanisms offers insights into therapeutic interventions. Thus, multidisciplinary approaches are crucial to unraveling the complex interactions between sleep, EVs, and health, providing direction for effective prevention and treatment approaches for sleep disorders and related conditions.

B-1 cell response in immunity against parasites.

The peritoneal cavity has a microenvironment capable of promoting proliferation, differentiation, and activation of the resident cells and recruitment of blood cells through the capillary network involved in the peritoneum. Among the cells found in the peritoneal cavity, B-1 cells are a particular cell type that contains features that are not very well defined. These cells differ from conventional B lymphocytes (B-2) by phenotypic, functional, and molecular characteristics. B-1 cells can produce natural antibodies, migrate to the inflammatory focus, and have the ability to phagocytose pathogens. However, the role of B-1 cells in immunity against parasites is still not completely understood. Several experimental models have demonstrated that B-1 cells can affect the susceptibility or resistance to parasite infections depending on the model and species. Here, we review the literature to provide information on the peculiarities of B-1 lymphocytes as well as their interaction with parasites.

Chronic Sleep Restriction Impairs the Antitumor Immune Response in Mice.

OBJECTIVES: Sleep regulates immune function reciprocally and can affect the parameters that are directly involved in the immune response. Sleep deprivation is considered to be a stress-causing factor and is associated with impaired immune activity. It causes increased glucocorticoid concentrations by activating the hypothalamic-pituitary-adrenal axis; this can lead to a series of disorders that are associated with the prolonged or increased secretion of these hormones. The aim of this study was to evaluate the effects of sleep restriction (SR) on the development of pulmonary experimental metastasis and the modulation of the tumor immune response. METHODS: The SR protocol was accomplished by depriving C57BL/6 male mice of sleep for 18 h/day for 2, 7, 14, and 21 days. The modified multiple-platforms method was used for SR. RESULTS: The results showed that cytotoxic cells (i.e., natural killer [NK] and CD8+ T cells) were reduced in number and regulatory T cells were predominant in the tumor microenvironment. Sleep-restricted mice also exhibited a reduced number of dendritic cells in their lymph nodes, which may have contributed to the ineffective activation of tumor-specific T cells. Peripheral CD4+ and CD8+ T cells were also reduced in the sleep-restricted mice, thus indicating an immunosuppressive status. CONCLUSIONS: Sleep dep-rivation induces failure in the activity of cells that are im-portant to the tumor immune response, both in the tumor microenvironment and on the periphery. This leads to the early onset and increased growth rate of lung metastasis.

In vivo and in vitro phagocytosis of Leishmania (Leishmania) amazonensis promastigotes by B-1 cells.

Leishmaniasis is caused by Leishmania parasites that infect several cell types. The promastigote stage of Leishmania is internalized by phagocytic cells and transformed into the obligate intracellular amastigote form. B-1 cells are a subpopulation of B cells that are able to differentiate in vitro and in vivo into mononuclear phagocyte-like cells with phagocytic properties. B-1 cells use several receptors for phagocytosis, such as the mannose receptor and third complement receptor. Leishmania binds to the same receptors on macrophages. In this study, we demonstrated that phagocytes derived from B-1 cells (B-1 CDP) were able to internalize promastigotes of L. (L.) amazonensis in vitro. The internalized promastigotes differentiated into amastigotes. Our results showed that the phagocytic index was higher in B-1 CDP compared to peritoneal macrophages and bone marrow-derived macrophages. The in vivo phagocytic ability of B-1 cells was also demonstrated. Parasites were detected inside purified B-1 cells after intraperitoneal infection with L. (L.) amazonensis promastigotes. Intraperitoneal stimulation with the parasites led to an increase in both IL-10 and TNF-α. These results highlight the importance of studying B-1 CDP cells as phagocytic cells that can participate and contribute to immunity to parasites.

In silico characterization of hypothetical proteins from Paracoccidioides lutzii.

Nearly 60% of Paracoccidioides lutzii genes encode products annotated as hypothetical or predicted proteins (HPs). In this study, we describe the global detection and functional inference of HPs, using computational methods based on sequence similarity, identification of targeting signals, presence of known protein domains, and use of the Gene Ontology functional classification scheme. Our analysis enabled a high-throughput characterization of predicted cellular localization and presence of protein domains, clustering HPs into different functional categories including metabolism, localization, cell cycle, response to stimulus, and signaling. To investigate P. lutzii HP expression profiles, we used data obtained from the expressed sequence tag database (dbEST). These analyses revealed 2364 HPs expressed in different situations, namely in mycelial and yeast forms, during the transition from mycelium to yeast, and under conditions mimicking infection. Based on this transcriptomic data, we performed a functional enrichment analysis according to the domains present in the HPs expressed in each condition. The most overrepresented functional domains were those involved in the regulation of gene expression, suggesting important and as yet undescribed roles for these HPs in the adaptation of P. lutzii to environmental conditions. In addition, the expression profiles of six randomly selected HPs were analyzed by quantitative real-time polymerase chain reaction in order to verify their expression in the complementary DNA libraries analyzed in this investigation. The approach used in this study should improve functional characterization of P. lutzii HPs.

Gene expression in B-1 cells from lupus-prone mice.

New Zealand Black X New Zealand White F1 [(NZB/NZW)F1] mice develop an autoimmune condition with similarities to human systemic lupus erythematosus (SLE). In this study, we demonstrate that B-1 cells, which have previously been reported to be involved in several autoimmune diseases, have altered gene expression in these mice. RNA was extracted from purified B-1 cells of disease-free C57BL/6 mice and lupus-prone (NZB/NZW)F1 mice. Gene expression was analysed using DNA microarray techniques and validated by real time reverse transcriptase polymerase chain reaction (RT-PCR). In (NZB/NZW)F1 mice, some genes had altered expression patterns compared to disease-free controls. Specifically, the upregulation of Ifitm1, Pvrl2 and Ifi202b and downregulation of Trp53bp1 mRNA were observed in (NZB/NZW)F1 mice. These genes are known to be associated with autoimmune diseases. This pattern of gene expression in B-1 cells could understanding of the pathogenesis of SLE. Thus, it is reasonable to hypothesise that the altered gene expression observed in B-1 cells in our experimental model is important for SLE prognosis and therapy, and these implications are discussed herein.

Impact of sleep restriction in B-1 cells activation and differentiation.

B-1 lymphocytes are a subtype of B cells with functional and phenotypic features that differ from conventional B lymphocytes. These cells are mainly located in mice's pleural and peritoneal cavities and express unconventional B cell surface markers. B-1 cells participate in immunity by producing antibodies, cytokines, and chemokines and physically interacting with other immune cells. In addition, B-1 cells can differentiate into mononuclear phagocyte-like cells and phagocytize several pathogens. However, the activation and differentiation of B-1 cells are not entirely understood. It is known that several factors can influence B-1 cells, such as pathogens components and the immune response. This work aimed to evaluate the influence of chronic stress on B-1 cell activation and differentiation into phagocytes. The experimental sleep restriction was used as a stress model since the sleep alteration alters several immune cells' functions. Thus, mice were submitted to sleep restriction for 21 consecutive days, and the activation and differentiation of B-1 cells were analyzed. Our results demonstrated that B-1 cells initiated the differentiation process into mononuclear phagocytes after the period of sleep restriction. In addition, we detected a significant decrease in lymphoid lineage commitment factors (EBF, E2A, Blnk) (*P < 0.05) and an increase in the G-CSFR gene (related to the myeloid lineage commitment factor) (****P < 0.0001), as compared to control mice no submitted to sleep restriction. An increase in the co-stimulatory molecules CD80 and CD86 (**P < 0.01 and *P < 0.05, respectively) and a higher production of nitric oxide (NO) (*P < 0.05) and reactive oxygen species (ROS) (*P < 0.05) were also observed in B-1 cells from mice submitted to sleep restriction. Nevertheless, B-1 cells from sleep-restricted mice showed a significant reduction in the Toll-like receptors (TLR)-2, -6, and -9, and interleukine-10 (IL-10) cytokine expression (***P < 0.001) as compared to control. Sleep-restricted mice intraperitoneally infected withL. amazonensispromastigotes showed a reduction in the average internalized parasites (*P < 0.05) by B-1 cells. These findings suggest that sleep restriction interferes with B-1 lymphocyte activation and differentiation. In addition, b-1 cells assumed a more myeloid profile but with a lower phagocytic capacity in this stress condition.

Expression analysis of transcription factors in sugarcane during cold stress.

Transcription factors (TF) are a wide class of genes in plants, and these can regulate the expression of other genes in response to various environmental stresses (biotic and abiotic). In the current study, transcription factor activity in sugarcane was examined during cold stress. Initially, RNA transcript reads of two sugarcane cultivars (ROC22 and GT08-1108) under cold stress were downloaded from SRA NCBI database. The reads were aligned into a reference genome and the differential expression analyses were performed with the R/Bioconductor edgeR package. Based on our analyses in the ROC22 cultivar, 963 TF genes were significantly upregulated under cold stress among a total of 5649 upregulated genes, while 293 TF genes were downregulated among a total of 3,289 downregulated genes. In the GT08-1108 cultivar, 974 TF genes were identified among 5,649 upregulated genes and 283 TF genes were found among 3,289 downregulated genes. Most transcription factors were annotated with GO categories related to protein binding, transcription factor binding, DNA-sequence-specific binding, transcription factor complex, transcription factor activity in RNA polymerase II, the activity of nucleic acid binding transcription factor, transcription corepressor activity, sequence-specific regulatory region, the activity of transcription factor of RNA polymerase II, transcription factor cofactor activity, transcription factor activity from plastid promoter, transcription factor activity from RNA polymerase I promoter, polymerase II and RNA polymerase III. The findings of above results will help to identify differentially expressed transcription factors during cold stress. It also provides a comprehensive analysis of the regulation of the transcription activity of many genes. Therefore, this study provides the molecular basis for improving cold tolerance in sugarcane and other economically important grasses.

A new species of Scinax Wagler (Hylidae: Scinaxini) from the tropical forests of Northeastern Brazil.

We describe a new species of the Scinax ruber clade from Northeastern Brazil that occurs in widely separated geographic areas in the Atlantic Forest of southern Bahia state and the Highland Humid Forest of Serra de Baturité, northeast Ceará state. Scinax tropicalia sp. nov. (holotype coordinates: -14.795694°, -39.172645°) is diagnosed from all 75 currently recognize species of the S. ruber clade by bioacoustical and morphological adult traits, such as duration (0.11-0.31 s) and dominant frequency (1.59-1.85 kHz) of the advertisement call, snout shape rounded, nearly rounded, or semi-circular in dorsal view and rounded to slightly protruding in profile, bilobate vocal sac, absence of pectoral glands and spicule-shaped papillary epidermal projections on nuptial pads, and color pattern on the dorsum of body and hidden surfaces of hindlimbs.

A new large canopy-dwelling species of Phyllodytes Wagler, 1930 (Anura, Hylidae) from the Atlantic Forest of the state of Bahia, Northeastern Brazil.

The known diversity of treefrogs of the genus Phyllodytes has rapidly increased in recent years, currently comprising 14 species. Recent field work in the Atlantic Rainforest of the state of Bahia lead to the discovery of a new large species of Phyllodytes which is herein described based on multiple evidence including morphological, acoustical and genetic data. Phyllodytes sp. nov. is one of the largest species within the genus and presents immaculate yellowish dorsum and limbs. The advertisement call of the species is composed of 7-31 notes (half pulsed/pulsatile-half harmonic) with frequency-modulated harmonics. Phyllodytes sp. nov. has a karyotype of 2n = 22 chromosomes, as also found in other species of the genus. Genetic distance values of the 16S mitochondrial rRNA among Phyllodytes sp. nov. and its congeners range between 6.4 to 10.2%. The description of another new species for this state reinforces the need for further taxonomic work with Phyllodytes in this region that has been revealed as a priority area for research and conservation of this genus.

A cell surface 230 kDa protein from murine melanoma involved with tumor malignancy.

Because melanoma incidence has increased at a dramatic rate, it is relevant to identify novel melanoma antigens for diagnosis and develop monoclonal antibodies recognizing such molecules. Some monoclonal antibodies (mAbs), raised against murine melanoma, identify molecules correlated with carcinogenesis. Herein, we describe a murine melanoma-associated 230 kDa molecule, expressed only in tumorigenic cell lines. Moreover, its expression is higher in more metastatic than less metastatic cells. G12F2 mAb, produced against this antigen, inhibited in vitro proliferation of both murine and human melanoma cells and enhanced in vitro complement activity. It also affected in vivo tumor growth and lung metastases formation. This 230kDa molecule represents an important target for experimental melanoma studies and may become a potential diagnostic marker for malignancy as well as a useful tool for immunotherapeutic approaches.

Expression analysis of transcription factors in sugarcane during cold stress / Análise de expressão de fatores de transcrição em cana-de-açúcar sob estresse por frio

Transcription factors (TF) are a wide class of genes in plants, and these can regulate the expression of other genes in response to various environmental stresses (biotic and abiotic). In the current study, transcription factor activity in sugarcane was examined during cold stress. Initially, RNA transcript reads of two sugarcane cultivars (ROC22 and GT08-1108) under cold stress were downloaded from SRA NCBI database. The reads were aligned into a reference genome and the differential expression analyses were performed with the R/Bioconductor edgeR package. Based on our analyses in the ROC22 cultivar, 963 TF genes were significantly upregulated under cold stress among a total of 5649 upregulated genes, while 293 TF genes were downregulated among a total of 3,289 downregulated genes. In the GT08-1108 cultivar, 974 TF genes were identified among 5,649 upregulated genes and 283 TF genes were found among 3,289 downregulated genes. Most transcription factors were annotated with GO categories related to protein binding, transcription factor binding, DNA-sequence-specific binding, transcription factor complex, transcription factor activity in RNA polymerase II, the activity of nucleic acid binding transcription factor, transcription corepressor activity, sequence-specific regulatory region, the activity of transcription factor of RNA polymerase II, transcription factor cofactor activity, transcription factor activity from plastid promoter, transcription factor activity from RNA polymerase I promoter, polymerase II and RNA polymerase III. The findings of above results will help to identify differentially expressed transcription factors during cold stress. It also provides a comprehensive analysis of the regulation of the transcription activity of many genes. Therefore, this study provides the molecular basis for improving cold tolerance in sugarcane and other economically important grasses.

Fatores de transcrição (FT) são uma ampla classe de genes em plantas e podem regular a expressão de outros genes em resposta a vários estresses ambientais (estresses bióticos e abióticos). No presente estudo, a atividade do fator de transcrição na cana-de-açúcar foi examinada durante o estresse pelo frio. Inicialmente, as leituras de transcrição de RNA de duas cultivares de cana-de-açúcar (ROC22 e GT08-1108) sob estresse frio foram baixadas do banco de dados SRA NCBI. As leituras foram alinhadas em um genoma de referência e as análises de expressão diferencial foram realizadas com o pacote R / Bioconductor edgeR. Com base em nossas análises no cultivar ROC22, 963 genes TF foram significativamente regulados positivamente sob estresse pelo frio entre um total de 5.649 genes regulados positivamente, enquanto 293 genes TF foram regulados negativamente entre um total de 3.289 genes regulados negativamente. No cultivar GT08-1108, 974 genes TF foram identificados entre 5.649 genes regulados positivamente e 283 genes TF foram encontrados entre 3.289 genes regulados negativamente. Os fatores de transcrição, em sua maioria, foram anotados com categorias GO relacionadas à ligação de proteína, ligação de fator de transcrição, ligação específica de sequência de DNA, complexo de fator de transcrição, atividade de fator de transcrição em RNA polimerase II, atividade de fator de transcrição de ligação de ácido nucleico, atividade de corepressor de transcrição, sequência específica da região reguladora, atividade do fator de transcrição da RNA polimerase II, atividade do cofator do fator de transcrição, atividade do fator de transcrição do promotor do plastídio, atividade do fator de transcrição do promotor da RNA polimerase I, polimerase II e RNA polimerase III. As descobertas dos resultados acima ajudarão a identificar fatores de transcrição expressos diferencialmente durante o estresse pelo frio. Ele também fornece uma análise abrangente da regulação da atividade [...].

Expression analysis of transcription factors in sugarcane during cold stress

Abstract Transcription factors (TF) are a wide class of genes in plants, and these can regulate the expression of other genes in response to various environmental stresses (biotic and abiotic). In the current study, transcription factor activity in sugarcane was examined during cold stress. Initially, RNA transcript reads of two sugarcane cultivars (ROC22 and GT08-1108) under cold stress were downloaded from SRA NCBI database. The reads were aligned into a reference genome and the differential expression analyses were performed with the R/Bioconductor edgeR package. Based on our analyses in the ROC22 cultivar, 963 TF genes were significantly upregulated under cold stress among a total of 5649 upregulated genes, while 293 TF genes were downregulated among a total of 3,289 downregulated genes. In the GT08-1108 cultivar, 974 TF genes were identified among 5,649 upregulated genes and 283 TF genes were found among 3,289 downregulated genes. Most transcription factors were annotated with GO categories related to protein binding, transcription factor binding, DNA-sequence-specific binding, transcription factor complex, transcription factor activity in RNA polymerase II, the activity of nucleic acid binding transcription factor, transcription corepressor activity, sequence-specific regulatory region, the activity of transcription factor of RNA polymerase II, transcription factor cofactor activity, transcription factor activity from plastid promoter, transcription factor activity from RNA polymerase I promoter, polymerase II and RNA polymerase III. The findings of above results will help to identify differentially expressed transcription factors during cold stress. It also provides a comprehensive analysis of the regulation of the transcription activity of many genes. Therefore, this study provides the molecular basis for improving cold tolerance in sugarcane and other economically important grasses.

Resumo Fatores de transcrição (FT) são uma ampla classe de genes em plantas e podem regular a expressão de outros genes em resposta a vários estresses ambientais (estresses bióticos e abióticos). No presente estudo, a atividade do fator de transcrição na cana-de-açúcar foi examinada durante o estresse pelo frio. Inicialmente, as leituras de transcrição de RNA de duas cultivares de cana-de-açúcar (ROC22 e GT08-1108) sob estresse frio foram baixadas do banco de dados SRA NCBI. As leituras foram alinhadas em um genoma de referência e as análises de expressão diferencial foram realizadas com o pacote R / Bioconductor edgeR. Com base em nossas análises no cultivar ROC22, 963 genes TF foram significativamente regulados positivamente sob estresse pelo frio entre um total de 5.649 genes regulados positivamente, enquanto 293 genes TF foram regulados negativamente entre um total de 3.289 genes regulados negativamente. No cultivar GT08-1108, 974 genes TF foram identificados entre 5.649 genes regulados positivamente e 283 genes TF foram encontrados entre 3.289 genes regulados negativamente. Os fatores de transcrição, em sua maioria, foram anotados com categorias GO relacionadas à ligação de proteína, ligação de fator de transcrição, ligação específica de sequência de DNA, complexo de fator de transcrição, atividade de fator de transcrição em RNA polimerase II, atividade de fator de transcrição de ligação de ácido nucleico, atividade de corepressor de transcrição, sequência específica da região reguladora, atividade do fator de transcrição da RNA polimerase II, atividade do cofator do fator de transcrição, atividade do fator de transcrição do promotor do plastídio, atividade do fator de transcrição do promotor da RNA polimerase I, polimerase II e RNA polimerase III. As descobertas dos resultados acima ajudarão a identificar fatores de transcrição expressos diferencialmente durante o estresse pelo frio. Ele também fornece uma análise abrangente da regulação da atividade de transcrição de muitos genes. Portanto, este estudo fornece base molecular para melhorar a tolerância ao frio em cana-de-açúcar e outras gramíneas economicamente importantes.

Expression analysis of transcription factors in sugarcane during cold stress / Análise de expressão de fatores de transcrição em cana-de-açúcar sob estresse por frio

Abstract Transcription factors (TF) are a wide class of genes in plants, and these can regulate the expression of other genes in response to various environmental stresses (biotic and abiotic). In the current study, transcription factor activity in sugarcane was examined during cold stress. Initially, RNA transcript reads of two sugarcane cultivars (ROC22 and GT08-1108) under cold stress were downloaded from SRA NCBI database. The reads were aligned into a reference genome and the differential expression analyses were performed with the R/Bioconductor edgeR package. Based on our analyses in the ROC22 cultivar, 963 TF genes were significantly upregulated under cold stress among a total of 5649 upregulated genes, while 293 TF genes were downregulated among a total of 3,289 downregulated genes. In the GT08-1108 cultivar, 974 TF genes were identified among 5,649 upregulated genes and 283 TF genes were found among 3,289 downregulated genes. Most transcription factors were annotated with GO categories related to protein binding, transcription factor binding, DNA-sequence-specific binding, transcription factor complex, transcription factor activity in RNA polymerase II, the activity of nucleic acid binding transcription factor, transcription corepressor activity, sequence-specific regulatory region, the activity of transcription factor of RNA polymerase II, transcription factor cofactor activity, transcription factor activity from plastid promoter, transcription factor activity from RNA polymerase I promoter, polymerase II and RNA polymerase III. The findings of above results will help to identify differentially expressed transcription factors during cold stress. It also provides a comprehensive analysis of the regulation of the transcription activity of many genes. Therefore, this study provides the molecular basis for improving cold tolerance in sugarcane and other economically important grasses.

Resumo Fatores de transcrição (FT) são uma ampla classe de genes em plantas e podem regular a expressão de outros genes em resposta a vários estresses ambientais (estresses bióticos e abióticos). No presente estudo, a atividade do fator de transcrição na cana-de-açúcar foi examinada durante o estresse pelo frio. Inicialmente, as leituras de transcrição de RNA de duas cultivares de cana-de-açúcar (ROC22 e GT08-1108) sob estresse frio foram baixadas do banco de dados SRA NCBI. As leituras foram alinhadas em um genoma de referência e as análises de expressão diferencial foram realizadas com o pacote R / Bioconductor edgeR. Com base em nossas análises no cultivar ROC22, 963 genes TF foram significativamente regulados positivamente sob estresse pelo frio entre um total de 5.649 genes regulados positivamente, enquanto 293 genes TF foram regulados negativamente entre um total de 3.289 genes regulados negativamente. No cultivar GT08-1108, 974 genes TF foram identificados entre 5.649 genes regulados positivamente e 283 genes TF foram encontrados entre 3.289 genes regulados negativamente. Os fatores de transcrição, em sua maioria, foram anotados com categorias GO relacionadas à ligação de proteína, ligação de fator de transcrição, ligação específica de sequência de DNA, complexo de fator de transcrição, atividade de fator de transcrição em RNA polimerase II, atividade de fator de transcrição de ligação de ácido nucleico, atividade de corepressor de transcrição, sequência específica da região reguladora, atividade do fator de transcrição da RNA polimerase II, atividade do cofator do fator de transcrição, atividade do fator de transcrição do promotor do plastídio, atividade do fator de transcrição do promotor da RNA polimerase I, polimerase II e RNA polimerase III. As descobertas dos resultados acima ajudarão a identificar fatores de transcrição expressos diferencialmente durante o estresse pelo frio. Ele também fornece uma análise abrangente da regulação da atividade de transcrição de muitos genes. Portanto, este estudo fornece base molecular para melhorar a tolerância ao frio em cana-de-açúcar e outras gramíneas economicamente importantes.

Extracellular Vesicles Released by Leishmania (Leishmania) amazonensis Promote Disease Progression and Induce the Production of Different Cytokines in Macrophages and B-1 Cells.

The extracellular vesicles (EVs) released by Leishmania can contribute to the establishment of infection and host immunomodulation. In this study, we characterized the shedding of EVs from Leishmania (Leishmania) amazonensis promastigotes. This species is the causative agent of cutaneous leishmaniasis, and its role during interactions with bone marrow-derived macrophages (BMDMs) and peritoneal B-1 cells was evaluated. Leishmania amazonensis promastigotes cultivated in vitro at different times and temperatures spontaneously released EVs. EVs were purified using size-exclusion chromatography (SEC) and quantitated by nanoparticle tracking analysis (NTA). NTA revealed that the average size of the EVs was approximately 180 nm, with concentrations ranging from 1.8 × 108 to 2.4 × 109 vesicles/mL. In addition, the presence of LPG and GP63 were detected in EVs obtained at different temperatures. Naïve BMDMs stimulated with EVs exhibited increased IL-10 and IL-6 expression. However, incubating B-1 cells with parasite EVs did not stimulate IL-10 expression but led to an increase in the expression of IL-6 and TNFα. After 7 weeks post-infection, animals infected with L. amazonensis promastigotes in the presence of parasite EVs had significant higher parasite load and a polarization to Th2 response, as compared to the group infected with the parasite alone. This work demonstrated that EVs isolated from L. amazonensis promastigotes were able to stimulate macrophages and B-1 cells to express different types of cytokines. Moreover, the immunomodulatory properties of EVs probably contributed to an increase in parasite burden in mice. These findings suggest that the functionality of L. amazonensis EVs on immune system favor of parasite survival and disease progression.

The axis IL-10/claudin-10 is implicated in the modulation of aggressiveness of melanoma cells by B-1 lymphocytes.

B-1 lymphocytes are known to increase the metastatic potential of B16F10 melanoma cells via the extracellular signal-regulated kinase (ERK) pathway. Since IL-10 is associated with B-1 cells performance, we hypothesized that IL-10 could be implicated in the progression of melanoma. In the present work, we found that the C57BL/6 mice, inoculated with B16F10 cells that were co-cultivated with B-1 lymphocytes from IL-10 knockout mice, developed fewer metastatic nodules than the ones which were injected with the melanoma cells that were cultivated in the presence of wild-type B-1 cells. The impairment of metastatic potential of the B16F10 cells was correlated with low activation of the ERK signaling pathway, supporting the idea that the production of IL-10 by B-1 cells influences the behavior of the tumor. A microarray analysis of the B-1 lymphocytes revealed that IL-10 deficiency is associated with down-regulation of the genes that code for claudin-10, a protein that is involved in cell-to-cell contact and that has been linked to lung adenocarcinoma. In order to determine the impact of claudin-10 in the cross-talk between B-1 lymphocytes and the B16F10 tumor cells, we took advantage of small interfering RNA. The silencing of claudin-10 gene in B-1 lymphocytes inhibited activation of the ERK pathway and abrogated the B-1-induced aggressive behavior of the B16F10 cells. Thus, our findings suggest that the axis IL-10/claudin-10 is a promising target for the development of therapeutic agents against aggressive melanoma.

[Isolation of rabies virus from the insectivorous bat Myotis nigricans]. / Isolamento do vírus rábico de morcego insetívoro Myotis nigricans.

The following is a case study of the natural infection by the rabies virus of an insectiverous bat belonging to the species Myotis nigricans in the municipality of Ribeirão Pires, Greater S. Paulo. Diagnosis was made by means of immunofluorescence and intracerebral innoculation of mice with nervous and intrascapular muscular tissues.

Cross talk between peritoneal macrophages and B-1 cells in vitro.

B-1 cells constitute a distinct B cell population with unique phenotypic and functional characteristics. They represent the main B cell population found in mouse peritoneal and pleural cavities. The communication between B-1 cells and peritoneal macrophages has been previously studied, and the effect this interaction has on macrophages has been previously described. Using an in vitro co-culture model, herein we demonstrated that peritoneal macrophages were able to increase survival rates and to stimulate proliferation of B-1 cells. IL-6 was also found to be important in B-1 cell survival; recombinant IL-6 increases the percentage of viable B-1 cells in culture. Furthermore, molecules involved in the IL-6 signaling pathway, such as STAT-3 and Bcl-2, were highly expressed in B-1 cells after co-culture with peritoneal macrophages. IL-6-deficient peritoneal macrophages were not able to increase B-1 cell survival, confirming the importance of this cytokine. Altogether, our results indicate a novel mechanism in which peritoneal macrophages are able to regulate the B-1 population via IL-6 secretion.

B16 melanoma cells increase B-1 cell survival, IL-10 production and radioresistance in vitro.

B-1 cells can be differentiated from B-2 cells because they are predominantly located in the peritoneal and pleural cavities and have distinct phenotypic patterns and activation properties. The role of both cell populations in cancer progression is still controversial. Previous studies have indicated that direct contact between B-1 cells and B16 melanoma tumor cells (B16) increases the metastatic potential of the tumor cells. However, cellular changes that are induced in B-1 cells during the interaction between these two cell types have not been evaluated. In the present study, it is hypothesized that B-1 cells are modified after their interaction with tumor cells, leading to both increased cell viability and rate of proliferation. Additionally, soluble factors that were secreted by B16 cells were sufficient to augment B-1 cell viability and to modify the production of IL-10 by B-1 cells. Impressively, after direct or indirect contact with the B16 cells, B-1 cells became resistant to radiation-induced cell death. Thus, future studies that assess the importance of concomitant immunity and other conventional therapies in cancer treatment are needed.