Kaurenoic Acid Possesses Leishmanicidal Activity by Triggering a NLRP12/IL-1ß/cNOS/NO Pathway.

Leishmania amazonensis (L. amazonensis) infection can cause severe local and diffuse injuries in humans, a condition clinically known as American cutaneous leishmaniasis (ACL). Currently, the therapeutic approach for ACL is based on Glucantime, which shows high toxicity and poor effectiveness. Therefore, ACL remains a neglected disease with limited options for treatment. Herein, the in vitro antiprotozoal effect and mechanisms of the diterpene kaurenoic acid [ent-kaur-16-en-19-oic acid] (KA) against L. amazonensis were investigated. KA exhibited a direct antileishmanial effect on L. amazonensis promastigotes. Importantly, KA also reduced the intracellular number of amastigote forms and percentage of infected peritoneal macrophages of BALB/c mice. Mechanistically, KA treatment reestablished the production of nitric oxide (NO) in a constitutive NO synthase- (cNOS-) dependent manner, subverting the NO-depleting escape mechanism of L. amazonensis. Furthermore, KA induced increased production of IL-1ß and expression of the inflammasome-activating component NLRP12. These findings demonstrate the leishmanicidal capability of KA against L. amazonensis in macrophage culture by triggering a NLRP12/IL-1ß/cNOS/NO mechanism.

Exploring the antileishmanial activity of N1,N2-disubstituted-benzoylguanidines: synthesis and molecular modeling studies.

In this report, we describe the synthesis and evaluation of nine N1,N2-disubstituted-benzoylguanidines against promastigotes and amastigotes forms of Leishmania amazonensis. The derivatives 2g and 2i showed low IC50 values against promastigote form (90.8 ± 0.05 µM and 68.4 ± 0.03 µM, respectively), low cytotoxicity profile (CC50 396 ± 0.02 µM and 857.9 ± 0.06 µM) for peritoneal macrophages cells and SI of 5.5 and 12.5, respectively. Investigations about the mechanism of action of 2g and 2i showed that both compounds cause mitochondrial depolarization, increase in ROS levels, and generation of autophagic vacuoles on free promastigotes forms. These compounds were also capable of reducing the number of infected macrophages with amastigotes forms (59.5% ± 0.08% and 98.1% ± 0.46%) and the number of amastigotes/macrophages (79.80% ± 0.05% and 96.0% ± 0.16%), through increasing induction of microbicide molecule NO. Additionally, ADMET-Tox in silico predictions showed drug-like features and free of toxicological risks. The molecular docking studies with arginase and gp63 showed that relevant intermolecular interactions could explain the experimental results. Therefore, these results reinforce that benzoylguanidines could be a starting scaffold for the search for new antileishmanial drugs.Communicated by Ramaswamy H. Sarma.

Antileishmanial Activity of 4,8-Dimethoxynaphthalenyl Chalcones on Leishmania amazonensis.

Leishmaniasis is a neglected tropical disease caused by Leishmania species. Available therapeutic options have several limitations. The drive to develop new, more potent, and selective antileishmanial agents is thus a major goal. Herein we report the synthesis and the biological activity evaluation against promastigote and amastigote forms of Leishmania amazonensis of nine 4,8-dimethoxynaphthalenyl chalcones. Compound ((E)-1-(4,8-dimethoxynaphthalen-1-yl)-3-(4-nitrophenyl)prop-2-en-1-one), 4f, was the most promising with an IC50 = 3.3 ± 0.34 µM (promastigotes), a low cytotoxicity profile (CC50 = 372.9 ± 0.04 µM), and a high selectivity index (SI = 112.6). Furthermore, 4f induced several morphological and ultrastructural changes in the free promastigote forms, loss of plasma membrane integrity, and increased reactive oxygen species (ROS). An in silico analysis of drug-likeness and ADME parameters suggested high oral bioavailability and intestinal absorption. Compound 4f reduced the number of infected macrophages and the number of amastigotes per macrophage, with an IC50 value of 18.5 ± 1.19 µM. Molecular docking studies with targets, ARG and TR, showed that compound 4f had more hydrogen bond interactions with the ARG enzyme, indicating a more stable protein-ligand binding. These results suggest that 4,8-dimethoxynaphthalenyl chalcones are worthy of further study as potential antileishmanial drugs.

Experimental chemotherapy in paracoccidioidomycosis using ruthenium NO donor.

Paracoccidioidomycosis (PCM) is a granulomatous disease caused by a dimorphic fungus, Paracoccidioides brasiliensis (Pb). To determine the influence of nitric oxide (NO) on this disease, we tested cis-[Ru(bpy)2(NO)SO3](PF6), ruthenium nitrosyl, which releases NO when activated by biological reducing agents, in BALB/c mice infected intravenously with Pb 18 isolate. In a previous study by our group, the fungicidal activity of ruthenium nitrosyl was evaluated in a mouse model of acute PCM, by measuring the immune cellular response (DTH), histopathological characteristics of the granulomatous lesions (and numbers), cytokines, and NO production. We found that cis-[Ru(bpy)2(NO)SO3](PF6)-treated mice were more resistant to infection, since they exhibited higher survival when compared with the control group. Furthermore, we observed a decreased influx of inflammatory cells in the lung and liver tissue of treated mice, possibly because of a minor reduction in fungal cell numbers. Moreover, an increased production of IL-10 and a decrease in TNF-α levels were detected in lung tissues of infected mice treated with cis-[Ru(bpy)2(NO)SO3](PF6). Immunohistochemistry showed that there was no difference in the number of VEGF- expressing cells. The animals treated with cis-[Ru(bpy)2(NO)SO3](PF6) showed high NO levels at 40 days after infection. These results show that NO is effectively involved in the mechanism that regulates the immune response in lung of Pb-infected mice. These data suggest that NO is a resistance factor during paracoccidioidomycosis by controlling fungal proliferation, influencing cytokine production, and consequently moderating the development of a strong inflammatory response.

Epstein-Barr virus (EBV) microRNAs: involvement in cancer pathogenesis and immunopathology.

The Epstein-Barr virus (EBV), which infects over 90% of adults, appears to have evolved to exploit the normal biology of B-cell development in order to persist as a life-long asymptomatic infection. However, EBV can contribute to oncogenesis. It has become evident that alterations in the expression of microRNAs (miRNAs) from the host cell and EBV can also contribute to cancer pathogenesis. MicroRNAs function by inhibiting translation of select groups of mRNA transcripts containing imperfect annealing sequences in their 3' untranslated regions (3' UTRs) and less frequently through other regions of the transcript. A number of studies have demonstrated that profiles of miRNA expression could establish phenotypic signatures of different cancer types where viruses have been evolved with highly sophisticated gene silencing machinery to disturb the host-immune response. Based on current review, it is possible that a specific virus miRNA may be involved in cancer pathogenesis.

Perfil clínico de pacientes com diagnóstico de tuberculose atendidos no Hospital Universitário de Londrina, Paraná / Clinical profile of patients diagnosed with tuberculosis treated at the University Hospital of Londrina, Paraná

O objetivo deste estudo consistiu em analisar o perfil clínico de pacientes positivos para tuberculose através de um estudo epidemiológico, descritivo e retrospectivo, com base em dados secundários contidos em prontuários dos pacientes atendidos no Hospital Universitário de Londrina compreendendo de janeiro de 2010 a dezembro de 2014. Dos prontuários disponíveis para a análise no momento de estudo 86 casos eram positivos para tuberculose, sendo a maioria do sexo masculino (65/76%) com faixa etária compreendida entre 2 e 91 anos. Os principais sinais clínicos apresentados foram tosse (50/58%), febre (45/52%) e perda de peso (34/40%). Em relação à forma clinica, 58/67% dos pacientes apresentaram a forma pulmonar, e 28/33% a forma não pulmonar. Casos positivos para tuberculose em associação com HIV/AIDS corresponderam a 32/37%. Também foram relatados hábitos prejudiciais dos pacientes nos quais 30/34% eram tabagistas, 20/23% usuários de drogas e 14/16% etilistas. Diante da escassez de dados publicados referentes à tuberculose na nossa região e sua relevância para a saúde pública, nosso estudo contribui com os aspectos epidemiológicos principalmente em relação ao elevado número de casos de coinfecção com Vírus da Imunodeficiência Humana e pacientes com evolução a óbito, auxiliando assim, o desenvolvimento e implementação de campanhas ou projetos que visem o diagnóstico e tratamento precoce.

The objective of this study was to analyze the clinical profile of patients positive for tuberculosis through an epidemiological study, descriptive and retrospective, based on secondary data contained in medical records of patients that attended the Hospital Universitário de Londrina comprising from January 2010 to December 2014. From the medical records available for analysis at the moment of study 86 cases were positive for tuberculosis, being the majority male (65/76%) with age group comprised between 2 to 91 years. The main symptoms presented were cough (50/58%), fever (45/52%) and weight loss (34/40%). Regarding the clinical form, 58/67% of the patients presented the pulmonary form, and 28/33% the non-pulmonary form. Positive cases for tuberculosis in association with HIV/AIDS corresponded to 32/37%. Harmful habits were also reported in patients in which 30/34% were smokers, 20/23% drug users and 14/16% were alcoholics. Against scarcity of published data referring to tuberculosis in our region and its relevance to public health, our study contributes to the epidemiological aspects mainly in relation to the high number of cases of coinfection with Human Immunodeficiency Virus and patients with evolution to death, assisting the development and implementation of campaigns or projects aimed at early diagnosis and treatment.

The effects of nitric oxide on the immune response during giardiasis.

Nitric oxide (NO) is a free radical synthesized from L-arginine by different isoforms NO-synthases. NO possesses multiple and complex biological functions. NO is an important mediator of homeostasis, and changes in its generation or actions can contribute or not to pathological states. The knowledge of effects of NO has been not only important to our understanding of immune response, but also to new tools for research and treatment of various diseases. Knowing the importance of NO as inflammatory mediator in diverse infectious diseases, we decided to develop a revision that shows the participation/effect of this mediator in immune response induced against Giardia spp. Several studies already demonstrated the participation of NO with microbicidal and microbiostatic activity in giardiasis. On the other hand, some works report that Giardia spp. inhibit NO production by consuming the intermediate metabolite arginine. In fact, studies in vitro showed that G. lamblia infection of human intestinal epithelial cells had reduced NO production. This occurs due to limited offer of the crucial substrate arginine (essential aminoacid for NO production), consequently reducing NO production. Therefore, the balance between giardial arginine consumption and epithelial NO production could contribute to the variability of the duration and severity of infections by this ubiquitous parasite.

Detection of Lsr2 gene of Mycobacterium leprae in nasal mucus

In the present study, nasal mucus from patients with leprosy were analyzed by PCR using specific primers for Lsr2 gene of Mycobacterium leprae. The presence of Lsr2 gene in the nasal mucus was detected in 25.80% of patients with paucibacillari leprosy, and 23.07% of contacts. Despite the absence of clinical features in the contact individuals, it was possible to detect the presence of Lsr2 gene in the nasal mucus of these individuals. Therefore, PCR detection of M. leprae targeting Lsr2 gene using nasal mucus samples could contribute to early diagnosis of leprosy.

Interações entre candida albicans e hospedeiro / Interactions between candida albicans and host

Candida albicans pode causar graves infecções em pacientes que estão imunocomprometidos por doenças, por cirurgias ou por terapia imunossupressiva. Os altos níveis de morbidade e mortalidade resultantes de infecções em pacientes hospitalizados mostraram que C. albicans tornou-se um patógeno humano de grande relevância clínica. Mesmo o sistema imune sendo o principal fator que define a transição do fungo de comensal para patogênico, fatores de virulência expressos por C. albicans, tais como adesinas, mudança fenotípica, comportamento dimórfico, e secreção de enzimas hidrolíticas, podem contribuir para a persistência da colonização, assim como o desenvolvimento de episódios sintomáticos. A defesa do hospedeiro compreende ingestão e eliminação do fungo por células fagocíticas que possuem vários receptores, como o Toll-4, dectina-1 associado a receptores tipo Toll-2 e receptores de manose. A interleucina-10 (IL-10) produzida por fagócitos determina a susceptibilidade do hospedeiro a infecção fúngica, enquanto a IL-10 produzida por células T reguladoras é responsável pelo comensalismo. Em contraste, a produção de fator de necrose tumoral- α (TNF-α), interleucina –1 β (lL-1 β), (IL-6), (Il-12) e IL-17 conferem imunidade protetora. O interferon-γ (IFN- γ) produzido por células natural “killer” e células Th1 estimula a migração de fagócitos e maior eficácia na destruição do fungo. Nas células epiteliais de mucosas os receptores NOD-like e defensinas-β citoplasmáticos evitam a translocação de C. albicans da microbiota para os tecidos os quais são modulados por citocinas IL-1 β,IL-17 e IL-22.

Candida albicans can cause grave infections in patients who are immunocompromised by diseases, by surgery, or by immunesupresive therapy. The high levels of morbidity and mortality resulting from those infections in hospitalized patients show that C. albicans became a prominent human pathogen. Although the host immune system is the major factor balancing the transition from commensalisms to pathogenicity, several virulence attributes expressed by C. albicans, such as adhesion factors, phenotypic switching, dimorphic behavior, and secretion of hydrolytic enzymes, might contribute to the persistence of colonization as well as the development of symptomatic episodes. Host defense against candidiasis relies mainly on the ingestion and elimination of C. albicans by phagocytic cells, which present receptors Toll-like 4, dectin–1 associated to receptors Toll-like2 and mannose receptors. The cytokine IL-10 (IL-10) produced by phagocytes has a crucial role on susceptibility of host fungal infection, whereas IL-10 produced by regulatory T cells is mainly responsible by commensalisms. In contrast, productions of tumour necrosis factor - α (TNF-α), interleukin–1 β (lL-1 β), (IL-6) and (Il-12) provided protective cell–mediated immunity. The interferon-γ produced by natural killer and TH1 cells stimulates migration of phagocytes and major efficacy on destruction of fungi. In epithelial cells from mucosas the NOD-like receptors and defensins-β cytoplasmatic prevent the translocation of C. albicans from microbiota to tissues, which are modulated by IL-1 β, Il-17 and Il-22 cytokines.

Ação do extrato de própolis na Leishmaniose / Propolis extract action in Leishmaniasis

A leishmaniose causa mortalidade e morbidade em mais de 80 países e caracteriza-se como uma doença parasitária com diversas manifestações, por isso constitui um sério problema de saúde pública. No Novo Mundo ocorre a Leishmaniose Visceral (LV) e Leishmaniose Tegumentar Americana (LTA). A LTA é considerada uma enfermidade polimórfica, espectral da pele e das mucosas, agrupada em diferentes formas clínicas: a leishmaniose cutânea, a cutaneomucosa e a cutânea difusa. A Organização Mundial da Saúde recomenda os antimoniais pentavalentes como drogas de primeira escolha no tratamento da leishmaniose. Entretanto, devido aos efeitos indesejados dessas drogas, tem sido proposto o estudo para o desenvolvimento de novos fármacos para seu tratamento. Assim, tem-se investigado o uso da própolis, visto que está relacionada a muitas atividades biológicas, como antibacteriana, antifúngica, antiulcerativa, antiviral, antiprotozoária, antiinflamatória, hepatoprotetora, antioxidante, antitumoral, entre outras. Estudos recentes mostraram que a própolis verde ativa macrófagos e estimula os linfócitos B a produzirem anticorpos. A própolis tem demonstrado potencial atividade leishmanicida, por diminuir o diâmetro das lesões, causar alterações morfológicas nas formas promastigotas ou ainda por melhorar a resposta imunológica frente às Leishmanias, ativando macrófagos.Portanto, o objetivo deste trabalho foi relatar as principais atividades leishmanicidas da própolis, por meio de pesquisa bibliográfica eletrônica no PubMed e Scielo durante o ano de 2009. .

Leishmaniasis is a public health problem causing morbidity and mortality in over 80 countries and features a parasitic disease with several manifestations. In the New World occur Visceral Leishmaniasis (VL) and American Cutaneous Leishmaniasis (ACL). The ACL is considered a disease polymorphic of skin and mucous membranes, grouped in different clinical forms: cutaneous leishmaniasis in the skin and mucosa and diffuse cutaneous, and the evolution of this disease is closely related to the mechanisms of escape of the protozoan Leishmania from the immune response, allowing the development of the disease and consequently the onset of clinical manifestations known. The World Health Organization recommends the pentavalent antimony as the first choice drugs. However, they usually give unsatisfactory results, requiring the development of new and affordable drugs for its treatment. It has been investigated that use of propolis it is related to exhibit several biological activities such as antibacterial, antifungal,anti-ulcer agents, antiviral, anti-protozoan, anti-inflammatory, hepatoprotective, antioxidant, antitumor, among others. Recent studies have shown that green propolis active macrophages and stimulates lymphocytes B to produce antibodies. It was also reported that propolis shows a potential antileishmanial activity by reducing the diameter of the lesions, avoiding complications of the lesions by bacteria or by improving the immune response against the Leishmania through macrophages activation. The aim of this work was related the main activities leishmanicida using propolis, by searched the electronic literature PubMed and Scielo during the year 2009..

Participação de células T regulatórias (Tregs) na imunopatogênese da infecção pelo vírus da imunodeficiência humana 1 (HIV-1) / Regulatory T cells participation in the infection immunopathogenesis by the Human Immunodeficiency Vírus

A sobrevivência de pacientes infectados pelo vírus da imunodeficiência humana (HIV-1) é relacionada à prevenção e ao tratamento eficaz de infecções oportunistas. É conhecido que os principais parâmetros para avaliar a progressão da doença causada pelo HIV-1 são contagem de células T CD4+ e carga viral do HIV-1. Células T regulatórias têm sido foco de intensas investigações dentro do sistema imunológico como também na patogênese de diversas doenças. Sabe-se que as células T reguladoras (Tregs) CD4+CD25+FoxP3+ atuam na modulação da ativação imune, funcionando como mediadores críticos da homeostasia imune e da auto-tolerância. Além disso, recentes estudos têm demonstrado que as células Tregs não se limitam à prevenção de auto-imunidade, mas são importantes no controle todas as formas de respostas imunes no contexto de inflamação, infecção, alergia, transplantes e imunidade tumoral. Muitos autores têm identificado as Tregs como células efetoras benéficas no contexto da AIDS, porém há discordância. Tregs podem sustentar importante função na imunopatologia da infecção pelo HIV devido a atividade supressora sobre ativação celular e função efetora. Neste contexto, esta revisão aborda os aspectos moleculares e imunológicos das Tregs no sistema HIV.

The survival of patients infected with human immunodeficiency virus (HIV-1) is related to the prevention and effective treatment of opportunistic infections. It is known that the main parameters to evaluate the progression of disease caused by HIV-1 is the counting of CD4 + T cells and viral load of HIV-1. Regulatory T cells has been considered the focus of intense research within the immune system as well as in the pathogenesis of several diseases. Natural regulatory T cells (Tregs) CD4+CD25+ act in the modulation of immune activation, functioning as critical mediators of immune homeostasis and self-tolerance. Furthermore, recent studies has shown that the function of Tregs cells is not limited to the prevention of autoimmunity, but is also important to control all forms of immune responses in the context of inflammation, infection, allergy, transplantation and tumor immunity. Many authors have identified Tregs as beneficial effector cells in the context of AIDS, but other researchers disagree. Tregs can exert an important role in the immunopathology of HIV infection due to the suppressor activity on cellular activation and effector function. Thus, this review discusses the molecular and immunological aspects of Tregs in the HIV system.

The effects of nitric oxide on the immune response during giardiasis

Nitric oxide (NO) is a free radical synthesized from L-arginine by different isoforms NO-synthases. NO possesses multiple and complex biological functions. NO is an important mediator of homeostasis, and changes in its generation or actions can contribute or not to pathological states. The knowledge of effects of NO has been not only important to our understanding of immune response, but also to new tools for research and treatment of various diseases. Knowing the importance of NO as inflammatory mediator in diverse infectious diseases, we decided to develop a revision that shows the participation/effect of this mediator in immune response induced against Giardia spp. Several studies already demonstrated the participation of NO with microbicidal and microbiostatic activity in giardiasis. On the other hand, some works report that Giardia spp. inhibit NO production by consuming the intermediate metabolite arginine. In fact, studies in vitro showed that G. lamblia infection of human intestinal epithelial cells had reduced NO production. This occurs due to limited offer of the crucial substrate arginine (essential aminoacid for NO production), consequently reducing NO production. Therefore, the balance between giardial arginine consumption and epithelial NO production could contribute to the variability of the duration and severity of infections by this ubiquitous parasite.

Resposta imune a Candida albicans / Immune response to Candida albicans

Candida albicans causa infecções na pele, cavidade oral e esôfago, trato gastrointestinal, vagina e sistema vascular de humanos. As infecções ocorrem em hospedeiros imunocomprometidos ou pacientes debilitados. Acima de 90 por cento dos pacientes HIV+ sofrem de candidíase de mucosas ao menos uma vez no decorrer da doença. A severidade e cronicidade da candidíase oral em pacientes com AIDS são atribuídas, principalmente, à imunodeficiência induzida pelo HIV nos indivíduos afetados, a saber, perda de funções de célula T auxiliar e redução do número de linfócitos T CD4. Na colonização de mucosase infecções sistêmicas de camundongos por este fungo, células Th1 medeiam a proteção dependente de fagócitos, cujas citocinas mais importantes são IL-2, IFN-γ e IL-12, TNF-α. Ao contrario, produção de citocinas inibidoras tais como, IL-4 e IL-10 por células Th2 estão associadas à desativação de fagócitos e à progressão da doença. Possivelmente, o crescimento de formas filamentosas está melhor adaptado para evadir das células do sistema imune, enquanto a forma de levedura pode ser o modo de proliferação em tecidos infectados. Pela produção discriminativa de IL-12 em resposta a levedura e de IL-4 a hifa, as células dendríticas adquirem a capacidade para induzir a diferenciação de células TCD4 para o fenótipo Th1 ou Th2.

Candida albicans causes infections of the skin, oral cavity and esophagus, gastrointestinal tract, vaginaand vascular system. Most infections occur in immunocompromised hosts or debilitated patients. Morethan 90 percent of HIV positive patients suffer from mucosal candidiasis at least once in the course of thisdisease. The overall severity and chronicity of oral candidiasis in patients with AIDS are mainly attributedto the HIV-induced immune deficiency in the affected individuals, namely, the loss of T-helper cells andreduction in the number of CD4+ T lymphocytes. In mucosal colonization and systemic infections ofmice by this fungus, Th1 cells mediate phagocyte-dependent protection, whose most important cytokinesare IL-2, IFN-γ, TNF-α and IL-12. In contrast, production of inhibitory cytokines such as IL-4 and IL-10 by Th2 cells are associated with disactivation of phagocytes and disease progression. Possibly, thegrowth of filamentous forms is better adapted to evade the cells of the immune system, whereas theyeast form may be the mode of proliferation in infected tissues. By the discriminative production of IL-12 or IL-4 in response to the yeast or filamentous forms respectively, dendritic cells acquire the capacityof inducing the differentiation of CD4+ cells towards the Th1 or Th2 phenotypes.Keywords: Candida albicans. Immune response. Systemic infection.

Ocorrência de anticorpos IgG anti-Toxoplasma gondii em alunos do Ensino Médio do município de São Jerônimo da Serra-PR, Brasil / Occurrence of anti-Toxoplasma gondii IgG antibodies in students of High School of São Jerônimo da Serra city-PR, Brazil

O Toxoplasma gondii é um protozoário intracelular obrigatório, possui distribuição geográfica mundial e alta prevalência sorológica em humanos e animais. A toxoplasmose adquirida é, na maioria das vezes, branda ou assintomática porém, em aproximadamente 15% dos casos pode-se desenvolver a forma ocular. O objetivo deste trabalho foi investigar a prevalência de anticorpos IgGanti-Toxoplasma em escolares do Ensino Médio, residentes no Município de São Jerônimo da Serra - PR. A pesquisa de anticorpos foi realizada pela técnica de Imunofluorescência Indireta (IFI). Não houve diferença estatisticamente significativa na prevalência da infecçãoentre os sexos. Os resultados demonstram que em São Jerônimo da Serra a prevalência da toxoplasmose é elevada entre os adolescentes, em ambos os sexos. Os alunos soropositivos devem ser submetidos a exames oftalmológicos periódicos devido ao risco de desenvolverem coriorretinite. Medidas de controle e prevenção devem ser adotadas no município para diminuir a transmissão e evitar os casos mais graves...