Influence of CK2 protein kinase activity on the interaction between Trypanosoma cruzi and its vertebrate and invertebrate hosts.

Chagas disease, endemic from Latin America, is caused by Trypanosoma cruzi and is transmitted by triatomine feces. This parasite undergoes complex morphological changes through its life cycle, promoted by significant changes in signal transduction pathways. The activity of protein kinase CK2 has been described in trypanosomatids. Using a specific peptide and radioactive ATP, we identified CK2 activity on the cellular surface and the cytoplasmic content in Trypanosoma cruzi, apart from the secreted form. Dephosphorylated casein promoted an increase of 48% in the secreted CK2 activity. Total extract of peritoneal macrophages from BALB/c and inactivated human serum promoted an increase of 67% and 36%, respectively, in this activity. The protein secreted by parasites was purified by HPLC and had shown compatibility with the catalytic subunit of mammalian CK2. Incubation of the parasites with CK2 inhibitors, added to the culture medium, prevented their growth. The opposite was observed when CK2 activators were used. Results of interaction between Trypanosoma cruzi and the gut of the vector have revealed that, in the presence of CK2 inhibitors, there is a reduction in the association rate. A similar inhibition profile was seen in the Trypanosoma cruzi-macrophages interaction, confirming the importance of this enzyme in the life cycle of this protozoan.

High levels of pro-inflammatory SARS-CoV-2-specific biomarkers revealed by in vitro whole blood cytokine release assay (CRA) in recovered and long-COVID-19 patients.

BACKGROUND: Cytokines induced by SARS-CoV-2 infection play a crucial role in the pathophysiology of COVID-19 and hyperinflammatory responses have been associated with poor clinical outcomes, with progression to severe conditions or long-term subacute complications named as long-COVID-19. METHODS: In this cross-sectional study, we aimed to evaluate a set of antigen-specific inflammatory cytokines in blood from recovered COVID-19 individuals or who suffered a post-acute phase of SARS-CoV-2 infection compared to healthy individuals with no history of COVID-19 exposition or infection. Interferon-gamma (IFN-γ), IFN-γ-induced protein 10 (IP-10), tumor necrosis factor (TNF), IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, and IL-17A were quantified by multiplex cytometric bead assay and enzyme-linked immunosorbent assay after stimulation of whole blood with recombinant Spike protein from SARS-CoV-2. Additionally, all participants have evaluated for anti-(S) protein-specific IgG antibodies. Clinical specimens were collected within two months of COVID-19 diagnosis. RESULTS: A total of 47 individuals were enrolled in the study, a median age of 43 years (IQR = 14.5), grouped into healthy individuals with no history of infection or exposure to SARS-CoV-2 (unexposed group; N = 21); and patients from the Health Complex of the Rio de Janeiro State University (UERJ), Brazil, who were SARS-CoV-2 positive by RT-PCR (COVID-19 group)-categorized as recovered COVID-19 (N = 11) or long-COVID-19 (N = 15). All COVID-19 patients presented at least one signal or symptom during the first two weeks of infection. Six patients were hospitalized and required invasive mechanical ventilation. Our results showed that COVID-19 patients had significantly higher levels of IFN-γ, TNF, IL-1ß, IL-2, IL-6, IL-8, and IP-10 than the unexposed group. The long-COVID-19 group has presented significantly high levels of IL-1ß and IL-6 compared to unexposed individuals, but not from recovered COVID-19. A principal-component analysis demonstrated 84.3% of the total variance of inflammatory-SARS-CoV-2 response in the first two components, and it was possible to stratify IL-6, TNF, IL-1ß, IL-10, and IL-2 as the top-five cytokines which are candidates to discriminate COVID-19 group (including long-COVID-19 subgroup) and healthy unexposed individuals. CONCLUSION: We revealed important S protein-specific differential biomarkers in individuals affected by COVID-19, bringing new insights into the inflammatory status or SARS-CoV-2 exposition determination.

Low doses of 3-phenyl-lawsone or meglumine antimoniate delivery by tattooing route are successful in reducing parasite load in cutaneous lesions of Leishmania (Viannia) braziliensis-infected hamsters.

Current therapeutic ways adopted for the treatment of leishmaniasis are toxic and expensive including parasite resistance is a growing problem. Given this scenario, it is urgent to explore treatment alternatives for leishmaniasis. The aim of this study was to evaluate the effect of 3-phenyl-lawsone (3-PL) naphthoquinone on Leishmania (Viannia) braziliensis infection, both in vitro and in vivo, using two local routes of administration: subcutaneous (higher dose) and tattoo (lower dose). In vitro 3-PL showed low toxicity for macrophages (CC50 >3200 µM/48h) and activity against intracellular amastigotes (IC50 = 193 ± 19 µM/48h) and promastigotes (IC50 = 116 ± 26 µM/72h), in which induced increased ROS generation. Additionally, 3-PL up-regulated the production of cytokines such as tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1), interleukin-6 (IL-6) and IL-10 in infected macrophages. However, the anti-amastigote action was independent of nitric oxide production. Treatment of hamsters infected with L. (V.) braziliensis from one week after infection with 3-PL by subcutaneous (25 µg/Kg) or tattooing (2.5 µg/Kg) route, during 3 weeks (3 times/week) or 2 weeks (2 times/week) significantly decreased the parasite load (p<0.001) in the lesion. The reduction of parasite load by 3-PL treatment was comparable to reference drug meglumine antimoniate administered by the same routes (subcutaneous 1mg/Kg and tattoo 0.1mg/Kg). In addition, treatment started from five weeks after infection with 3-PL per tattoo also decreased the parasite load. These results show the anti-leishmanial effect of 3-PL against L. (V.) braziliensis and its efficacy by subcutaneous (higher dose) and tattoo (lower dose) routes. In addition, this study shows that drug delivery by tattooing the lesion allows the use of lower doses than the conventional subcutaneous route, which may support the development of a new therapeutic strategy that can be adopted for leishmaniasis.

Vivências de violência no quotidiano de mulheres consumidoras de drogas / Experiences of violence in the daily life of female drug users / Experiencias de violencia en la vida cotidiana de las mujeres consumidoras de drogas

Resumo Enquadramento: O uso de drogas por mulheres é permeado por diversas situações de violência que se repercutem no quotidiano por meio da exclusão e da marginalização das consumidoras. Objetivo: Identificar como a violência está presente no quotidiano de mulheres consumidoras de drogas. Metodologia: Estudo do tipo qualitativo, descritivo e exploratório, desenvolvido com 20 mulheres consumidoras de drogas assistidas num centro de atenção psicossocial álcool e drogas. A colheita de dados foi efetuada por meio de entrevista aberta, e os dados analisados conforme a análise de conteúdo temática. Resultados: O quotidiano de mulheres consumidoras de drogas está associado à violência pelos parceiros, bem como exposição ao risco de violência, à vulnerabilidade e à criminalidade decorrente da presença em cenas de consumo e de tráfico. Conclusão: Existe uma necessidade de desenvolvimento de ações educativas e políticas públicas eficientes que promovam a segurança, reduzam riscos de exposição e atendam às necessidades destas mulheres.

Abstract Background: Women who use drugs experience several situations of violence that impact their daily life through their exclusion and marginalization. Objective: To understand how violence is present in the daily life of women who use drugs. Methodology: A qualitative, descriptive, and exploratory study was conducted with 20 women who use drugs receiving care at a Psychosocial Care Center for Alcohol and Drugs. Data were collected through an open interview and analyzed using the Thematic Content Analysis method. Results: The daily life of these women is associated with partner violence and exposure to the risk of violence, vulnerability, and criminality due to their presence in spaces of drug use and trafficking. Conclusion: Efficient educational interventions and public policies should be designed to promote women's safety, reduce their exposure to these risks, and meet their needs.

Resumen Marco contextual: El consumo de drogas por parte de las mujeres está impregnado de diversas situaciones de violencia que repercuten en la vida cotidiana a través de la exclusión y la marginación de las consumidoras. Objetivo: Identificar cómo la violencia está presente en la vida cotidiana de las mujeres consumidoras de drogas. Metodología: Estudio cualitativo, descriptivo y exploratorio, desarrollado con 20 mujeres consumidoras de drogas atendidas en un centro de atención psicosocial de alcohol y drogas. La recogida de datos se llevó a cabo mediante una entrevista abierta, y los datos se analizaron según el análisis de contenido temático. Resultados: La vida cotidiana de las mujeres consumidoras de drogas está asociada a la violencia de pareja, así como a la exposición al riesgo de violencia, vulnerabilidad y criminalidad derivada de su presencia en los escenarios de consumo y tráfico de drogas. Conclusión: Es necesario desarrollar acciones educativas y políticas públicas eficientes que promuevan la seguridad, reduzcan los riesgos de exposición y satisfagan las necesidades de estas mujeres.

Cortisol Reactivity to a physical stressor in Patients with Depression and Alzheimer's disease.

Some prevalent mental disorders in the elderly, such as Alzheimer's disease (AD) and major depression disorder (MDD), are associated with chronic stress and consequently with possible dysregulation of hypothalamic-pituitary-adrenal (HPA) axis and cortisol levels in basal conditions or in the reactivity of an acute stressor. However, evidence of cortisol behavior after a physical stressor in patients with AD and MDD is scarce. Objective: This study aimed to investigate the cortisol reactivity to a single session of physical exercise in patients with MDD and AD and compare it to healthy control (HC) older individuals. Methods: HC individuals (n=10) and elderly with clinical diagnostic of MDD (n=08) and AD (n=13) were submitted to a single bout of aerobic exercise in a treadmill during 30 minutes of moderate intensity. Salivary cortisol was collected before and after acute stressor. A repeated-measure analysis of variance (ANOVA), spearman correlation, and linear regression were performed. Results: The repeated-measure ANOVA revealed no interaction for cortisol on the moment×group [F(2.000, 28.000)=1.285; p=0.293] and no effect for group (F=0.323; p=0.727). However, a significant effect for moment [F(1.000, 28.000)=4.930; p=0.035] was found, with a decreased cortisol levels in postexercise for all groups. The effect size (ES) of cortisol reduction was small for patients with MDD (d=0.402) and trivial for patients with AD (d=0.166) and HC group (d=0.090). Conclusions: All participants show a decreased cortisol reactivity to a physical stressor, which can be associated with an impairment in coping with an acute stressor.

A doença de Alzheimer (DA) e o transtorno depressivo maior (TDM) são transtornos que acometem idosos e estão associadas ao estresse crônico e à desregulação do eixo hipotálamo-hipófise-adrenal (HPA), que repercute em alterações nos níveis de cortisol (basal e reatividade). Objetivo: Investigar a reatividade do cortisol em uma única sessão de exercício físico em pacientes com TDM e com DA e compará-la com a de idosos saudáveis. Métodos: Indivíduos controle saudáveis (n=10) e idosos com diagnóstico clínico de TDM (n=08) e DA (n=13) foram submetidos a uma única sessão de exercício aeróbio em esteira rolante, durante 30 minutos, em intensidade moderada. O cortisol salivar foi coletado antes e depois do estressor agudo. Na estatística, foram realizadas as análises de variância (ANOVA) de medidas repetidas, correlação de spearman e regressão linear. Resultados: Não foi encontrada interação para momento x grupo [F (2.000, 28.000)=1.285; p=0,293] e tampouco efeito para o grupo (F=0,323; p=0,727). Todavia, foi observado efeito significativo para o momento [F(1,000, 28,000)=4,930; p=0,035], mostrando diminuição dos níveis de cortisol no pós-exercício para todos os grupos. O tamanho do efeito (TE) foi considerado pequeno para o grupo TDM (d=0,402) e trivial para o DA (d=0,166) e o saudável (d=0,090). Conclusões: Todos os participantes apresentaram diminuição da reatividade do cortisol a um estressor físico, o que pode estar associado a um comprometimento no enfrentamento de um estressor agudo.

Flaxseed added to the diet of Alpine goats affects the nutrients intake and blood parameters.

The flaxseed is a nutraceutical food used as a source of α-linolenic acid, which can bring benefits to the health of mammals. This study was carried out to examine the effect of flaxseed inclusion in the diets on the intake of nutrients, body weight, and blood parameters of Alpine goats. Twenty-one adult females with an initial average weight of 41.06 ± 1.84 kg were used in a completely randomized design, with four experimental treatments (0, 5, 10, and 15% of flaxseed in the total diet) and five replications per treatment. The intake of the dry matter presented a decreasing linear effect (P < 0.001), with a reduction of 53.5% between the control diet (0% of flaxseed) and 15% of flaxseed, but no effect was observed on weight gain (P > 0.05). Inclusion of flaxseed from 0 to 15% linearly decreased the intakes of organic matter, crude protein, non-fibrous carbohydrates, and neutral detergent fiber, but increased the ether extract intake (P < 0.001). Regarding plasma concentration traits, increasing the flaxseed levels from 0 to 15% had linear positive effect on LDL, VLDL, and triglycerides (P < 0.05), but no effect on cholesterol, HDL, glucose, creatinine, and urea (P > 0.05). The inclusion of flaxseed in the diet for 80 days changes the nutrients intake and blood parameters but shows no impact on body weight. However, further studies are required to determine the impact of flaxseed on the goat's health in the long term since there has been an increase in the concentration of triglycerides, LDL, and VLDL.

Therapeutic effect of oral quercetin in hamsters infected with Leishmania Viannia braziliensis.

Leishmaniasis is a parasitic disease caused by several species of intracellular protozoa of the genus Leishmania that present manifestations ranging from cutaneous ulcers to the fatal visceral form. Leishmania Viannia braziliensis is an important species associated with American tegumentary leishmaniasis and the main agent in Brazil, with variable sensitivity to available drugs. The search for new therapeutic alternatives to treat leishmaniasis is an urgent need, especially for endemic countries. Not only is quercetin well known for its antioxidant activity in radical scavenging but also several other biological effects are described, including anti-inflammatory, antimicrobial, and pro-oxidant activities. This study aimed to investigate the flavonoid quercetin's therapeutic potential in L. (V.) braziliensis infection. Quercetin showed antiamastigote (IC50 of 21 ± 2.5 µM) and antipromastigote (25 ± 0.7 µM) activities and a selectivity index of 22. The treatment of uninfected or L. (V.) braziliensis-infected macrophages with quercetin increased reactive oxygen species (ROS)/H202 generation without altering Nitric Oxide (NO) production. Oral treatment with quercetin of infected hamsters, starting at 1 week of infection for 8 weeks, reduced the lesion thickness (p > 0.01) and parasite load (p > 0.001). The results of this study suggest that the antiamastigote activity of the flavonoid quercetin in vitro is associated, at least in part, with the modulation of ROS production by macrophages. The efficacy of oral quercetin treatment in hamsters infected with L. (V.) braziliensis was presented for the first time and shows its promising therapeutic potential.

Anti-Leishmania braziliensis activity of 1,10-phenanthroline-5,6-dione and its Cu(II) and Ag(I) complexes.

Leishmaniasis, included in the priority list of the WHO, remains as a neglected disease caused by parasites of the Leishmania genus. There is no vaccine available for human leishmaniasis, and the current treatment is based on old drugs that cause serious side effects. Herein, we initially studied the cellular distribution of the virulence factor gp63, the major metallopeptidase, in a virulent strain of Leishmania braziliensis, and then we measured the inhibitory effects of 1,10-phenanthroline-5,6-dione (phendione), and its metal complexes, [Cu(phendione)3](ClO4)2.4H2O and [Ag(phendione)2]ClO4, on both cellular and extracellular metallopeptidases produced by promastigotes. The action of the three compounds on parasite viability and on parasite-macrophage interaction was also determined. Gp63 molecules were detected in several parasite compartments, including the cytoplasm, the membrane lining the cell body and flagellum, and in the flagellar pocket, which explains the presence of gp63 in the culture medium. The test compounds inhibited parasite metallopeptidases in a typical dose-dependent manner, and they also caused a significant and irreversible inhibition of parasite motility. Moreover, the pre-treatment of promastigotes with the test compounds induced a decrease in the association index with macrophages. Collectively, phendione and its Cu(II) and Ag(I) complexes are excellent prototypes for the development of new anti-L. braziliensis drugs.

Uso de EPI's pelos profissionais de saúde da atenção básica de um município de Goiás / Use of PPE by primary care health professionals in a municipality of Goiás

Objetivo: compreender o entendimento dos profissionais de saúde básica de um município de Goiás, no que se refere a utilização dos Equipamentos de Proteção Individual, focado nos Técnicos de Enfermagem e Enfermeiros dos postos de saúde. Método: foram elaborados questionários sobre a mesma abordagem para esses profissionais, refletindo na parcialidade de retorno dos questionários entregues, embora não influenciou no estudo pretendido, por se tratar de uma pesquisa por amostragem. Resultados: Foram submetidos ao estudo por meio deste recurso, 13 (treze) Técnicos de Enfermagem e 20 (vinte) Enfermeiros. Diante do recurso utilizado, seguiu-se a pesquisa a luz de autores que abordam o tema em estudo. Conclusão: embora pareça lógico, algumas intervenções precisam ser feitas no sentido de melhorar o uso dos EPIs em meio aos profissionais que constituem o sistema de saúde desde um município até a configuração nacional, pois o entendimento é que o todo se constitui por unidades.

Objective: to know the understanding of basic health professionals in a city of Goias state, regarding the use of Personal Protective Equipment, focused on Nursing Technicians and Nurses in health posts. Method: questionnaires were elaborated on the same approach for these professionals, reflecting on the partial return of the questionnaires delivered, although it did not influence the intended study, as it was a sample survey. Results: Through this resource, 13 (thirteen) Nursing Technicians and 20 (twenty) Nurses were submitted to the study. Given the resource used, the research followed the light of authors addressing the subject under study. Conclusion: although it seems logical, some interventions need to be made in order to improve the use of PPE among professionals who constitute the system. from a municipality to the national configuration, because the understanding is that the whole is constituted by units.

Immunomodulation From Moderate Exercise Promotes Control of Experimental Cutaneous Leishmaniasis.

Physical exercise has been described as an important tool in the prevention and treatment of numerous diseases as it promotes a range of responses and adaptations in several biological systems, including the immune system. Studies on the effect of exercise on the immune system could play a critical role in improving public health. Current literature suggests that moderate intensity exercise can modulate the Th1/Th2 dichotomy directing the immune system to a Th1 cellular immune response, which favors the resolution of infections caused by intracellular microorganisms. Leishmaniasis is a group of diseases presenting a wide spectrum of clinical manifestations that range from self-limiting lesions to visceral injuries whose severity can lead to death. The etiological agents responsible for this group of diseases are protozoa of the genus Leishmania. Infections by the parasite Leishmania major in mice (Balb/c) provide a prototype model for the polarization of CD4+ T cell responses of both Th1 (resistance) or Th2 (susceptibility), which determines the progression of infections. The aim of this study was to evaluate the effect of exercise on the development of L. major experimental infections by scanning the pattern of immune response caused by exercise. Groups of Balb/c mice infected with L. major were divided into groups that preformed a physical exercise of swimming three times a week or were sedentary along with treatment or not with the reference drug, meglumine antimoniate. Animals in groups submitted to physical exercise did not appear to develop lesions and presented a significantly lower parasite load independent of drug treatment. They also showed a positive delayed hypersensitivity response to a specific Leishmania antigen compared to control animals. The IFN-γ/IL-4 and IFN-γ/IL10 ratios in trained animals were clearly tilted to a Th1 response in lymph node cells. These data suggest that moderate intensity exercise is able to modulate the Th1 response that provides a protective effect against the development of leishmanial lesions.

Designed mono- and di-covalent inhibitors trap modeled functional motions for Trypanosoma cruzi proline racemase in crystallography.

Chagas disease, caused by Trypanosoma cruzi, affects millions of people in South America and no satisfactory therapy exists, especially for its life threatening chronic phase. We targeted the Proline Racemase of T. cruzi, which is present in all stages of the parasite life cycle, to discover new inhibitors against this disease. The first published crystal structures of the enzyme revealed that the catalytic site is too small to allow any relevant drug design. In previous work, to break through the chemical space afforded to virtual screening and drug design, we generated intermediate models between the open (ligand free) and closed (ligand bound) forms of the enzyme. In the present work, we co-crystallized the enzyme with the selected inhibitors and found that they were covalently bound to the catalytic cysteine residues in the active site, thus explaining why these compounds act as irreversible inhibitors. These results led us to the design of a novel, more potent specific inhibitor, NG-P27. Co-crystallization of this new inhibitor with the enzyme allowed us to confirm the predicted protein functional motions and further characterize the chemical mechanism. Hence, the catalytic Cys300 sulfur atom of the enzyme attacks the C2 carbon of the inhibitor in a coupled, regiospecific-stereospecific Michael reaction with trans-addition of a proton on the C3 carbon. Strikingly, the six different conformations of the catalytic site in the crystal structures reported in this work had key similarities to our intermediate models previously generated by inference of the protein functional motions. These crystal structures span a conformational interval covering roughly the first quarter of the opening mechanism, demonstrating the relevance of modeling approaches to break through chemical space in drug design.

CK2 Secreted by Leishmania braziliensis Mediates Macrophage Association Invasion: A Comparative Study between Virulent and Avirulent Promastigotes.

CK2 is a protein kinase distributed in different compartments of Leishmania braziliensis: an externally oriented ecto-CK2, an intracellular CK2, and a secreted CK2. This latter form is constitutively secreted from the parasite (CsCK2), but such secretion may be highly enhanced by the association of specific molecules, including enzyme substrates, which lead to a higher enzymatic activity, called inductively secreted CK2 (IsCK2). Here, we examined the influence of secreted CK2 (sCK2) activity on the infectivity of a virulent L. braziliensis strain. The virulent strain presented 121-fold higher total CK2 activity than those found in an avirulent strain. The use of specific CK2 inhibitors (TBB, DRB, or heparin) inhibited virulent parasite growth, whereas no effect was observed in the avirulent parasites. When these inhibitors were added to the interaction assays between the virulent L. braziliensis strain and macrophages, association index was drastically inhibited. Polyamines enhanced sCK2 activity and increased the association index between parasites and macrophages. Finally, sCK2 and the supernatant of the virulent strain increased the association index between the avirulent strain and macrophages, which was inhibited by TBB. Thus, the kinase enzyme CK2 seems to be important to invasion mechanisms of L. braziliensis.

The Dialogue of the Host-Parasite Relationship: Leishmania spp. and Trypanosoma cruzi Infection.

The intracellular protozoa Leishmania spp. and Trypanosoma cruzi and the causative agents of Leishmaniasis and Chagas disease, respectively, belong to the Trypanosomatidae family. Together, these two neglected tropical diseases affect approximately 25 million people worldwide. Whether the host can control the infection or develops disease depends on the complex interaction between parasite and host. Parasite surface and secreted molecules are involved in triggering specific signaling pathways essential for parasite entry and intracellular survival. The recognition of the parasite antigens by host immune cells generates a specific immune response. Leishmania spp. and T. cruzi have a multifaceted repertoire of strategies to evade or subvert the immune system by interfering with a range of signal transduction pathways in host cells, which causes the inhibition of the protective response and contributes to their persistence in the host. The current therapeutic strategies in leishmaniasis and trypanosomiasis are very limited. Efficacy is variable, toxicity is high, and the emergence of resistance is increasingly common. In this review, we discuss the molecular basis of the host-parasite interaction of Leishmania and Trypanosoma cruzi infection and their mechanisms of subverting the immune response and how this knowledge can be used as a tool for the development of new drugs.

Pterocarpanquinone LQB-118 induces apoptosis in Leishmania (Viannia) braziliensis and controls lesions in infected hamsters.

Previous results demonstrate that the hybrid synthetic pterocarpanquinone LQB-118 presents antileishmanial activity against Leishmania amazonensis in a mouse model. The aim of the present study was to use a hamster model to investigate whether LQB-118 presents antileishmanial activity against Leishmania (Viannia) braziliensis, which is the major Leishmania species related to American tegumentary leishmaniasis. The in vitro antileishmanial activity of LQB-118 on L. braziliensis was tested on the promastigote and intracellular amastigote forms. The cell death induced by LQB-118 in the L. braziliensis promastigotes was analyzed using an annexin V-FITC/PI kit, the oxidative stress was evaluated by 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) and the ATP content by luminescence. In situ labeling of DNA fragments by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to investigate apoptosis in the intracellular amastigotes. L. braziliensis-infected hamsters were treated from the seventh day of infection with LQB-118 administered intralesionally (26 µg/kg/day, three times a week) or orally (4,3 mg/kg/day, five times a week) for eight weeks. LQB-118 was active against the L. braziliensis promastigotes and intracellular amastigotes, producing IC50 (50% inhibitory concentration) values of 3,4±0,1 and 7,5±0,8 µM, respectively. LQB-118 induced promastigote phosphatidylserine externalization accompanied by increased reactive oxygen species production and ATP depletion. Intracellular amastigote DNA fragmentation was also observed, without affecting the viability of macrophages. The treatment of L. braziliensis-infected hamsters with LQB-118, either orally or intralesionally, was effective in the control of lesion size, parasite load and increase intradermal reaction to parasite antigen. Taken together, these results show that the antileishmanial effect of LQB-118 extends to L. braziliensis in the hamster model, involves the induction of parasite apoptosis and shows promising therapeutic option by oral or local routes in leishmaniasis.

Interactions between Leishmania braziliensis and Macrophages Are Dependent on the Cytoskeleton and Myosin Va.

Leishmaniasis is a neglected tropical disease with no effective vaccines. Actin, microtubules and the actin-based molecular motor myosin Va were investigated for their involvement in Leishmania braziliensis macrophage interactions. Results showed a decrease in the association index when macrophages were without F-actin or microtubules regardless of the activation state of the macrophage. In the absence of F-actin, the production of NO in non-activated cells increased, while in activated cells, the production of NO was reduced independent of parasites. The opposite effect of an increased NO production was observed in the absence of microtubules. In activated cells, the loss of cytoskeletal components inhibited the release of IL-10 during parasite interactions. The production of IL-10 also decreased in the absence of actin or microtubules in non-activated macrophages. Only the disruption of actin altered the production of TNF-α in activated macrophages. The expression of myosin Va tail resulted in an acute decrease in the association index between transfected macrophages and L. braziliensis promastigotes. These data reveal the importance of F-actin, microtubules, and myosin-Va suggesting that modulation of the cytoskeleton may be a mechanism used by L. braziliensis to overcome the natural responses of macrophages to establish infections.

Efeito do exercício no sistema imune: resposta, adaptação e sinalização celular / Effect of exercise on immune system: response, adaptation and cell signaling

INTRODUÇÃO: Durante o último século, o homem tornou-se menos ativo fisicamente, adotando hábitos cada vez mais sedentários. Isto promoveu aumento na incidência de doenças crônicas tais como doenças cardiovasculares, diabetes do tipo 2 e síndrome metabólica. A prática de atividade física pode influenciar o estado de higidez alterando estados metabólicos e também o sistema imunológico. OBJETIVO: Revisar na literatura estudos que abordem os efeitos promovidos pelo exercício físico no desenvolvimento da resposta imunológica e suas possíveis vias de transdução de sinais. MÉTODOS: Foram consultadas as bases de dados SciELO e PubMed. RESULTADOS: A literatura disponível mostra que durante a prática de exercício, várias subpopulações de leucócitos são alteradas de acordo com a intensidade e duração da atividade desempenhada. Exercícios de intensidade moderada estimulam uma resposta pró-inflamatória, enquanto aqueles de alta intensidade tendem a promover respostas anti-inflamatórias visando diminuir os danos na musculatura esquelética. Tais alterações são vistas em células apresentadoras de antígeno (como macrófagos e células dendríticas), neutrófilos, células natural killers (NK) e em moléculas de superfície como os receptores do tipo Toll (TLR) e do complexo principal de histocompatibilidade de classe II (MHC II), além das modificações promovidas em todo o repertório de citocinas. CONCLUSÃO: O estado atual do conhecimento permite considerar que as alterações no sistema imune são dependentes dos parâmetros inerentes ao exercício e que para que todas estas alterações ocorram, algumas cascatas de sinalização celular são acionadas, dando origem a um complexo processo de fosforilação/desfosforilação que culmina em ativação de fatores de transcrição, tradução de RNAm, síntese proteica e proliferação celular.

INTRODUCTION: Over the last century, people have become less active, adopting more sedentary habits. This scenario has increased the incidence of chronic diseases such as cardiovascular diseases, type 2 diabetes and metabolic syndrome. The practice of physical activities can influence healthiness by altering the metabolic state and also the immune system. OBJECTIVE: To review the literature for studies that address the effects promoted by physical exercise on the development of immune responses and the possible signal transduction pathways. METHODS: The SciELO and PubMed data bases were consulted. RESULTS: The available literature shows that during the practice of exercise, various subpopulations of leukocytes are altered in accordance with the intensity and duration of the activity performed. Exercise of moderate intensity stimulates a pro-inflammatory response, while those of high intensity tend to promote anti-inflammatory responses with the purpose to decrease damage to skeletal muscle. Such alterations are observed in cells that present antigens (such as macrophages and dendritic cells), neutrophils, natural killer cells (NK) and in surface molecules like Toll-like receptors (TLR) and major histocompatibility complex class II, as well as the entire repertoire of cytokines. CONCLUSION: The current state of knowledge suggests that the alterations in the immune system are dependent on parameters inherent to exercise and that in order to have all these alterations occurring, some cell signaling cascades are activated, giving rise to a complex process of phosphorylation/dephosphorylation that culminates in the activation of transcription factors, translation of mRNA's, protein synthesis and cell proliferation.

A new experimental culture medium for cultivation of Leishmania amazonensis: its efficacy for the continuous in vitro growth and differentiation of infective promastigote forms.

Parasites from the genus Leishmania cause a variety of disease states in humans and other mammals in tropical and subtropical regions, which include cutaneous, mucocutaneous and visceral leishmaniasis. The elaboration of a culture medium for the in vitro cultivation of Leishmania spp., which promotes the growth and differentiation of the parasites, is an important tool for diagnosis, biochemical, biological and immunological studies in the genus. Herein, we have reported the development of a rapid, inexpensive and reliable monophasic culture medium. The novel medium, designated PBHIL, promoted an excellent parasite growth, generating high quantities of promastigotes with long-term viability, and was able to induce cellular differentiation of L. amazonensis promastigotes to the amastigote-like forms (93%). Additionally, we reported the influence of this novel medium on the biochemical characteristics of L. amazonensis and on the interaction of this parasite parasites with mammalian macrophages.