BRAZILIAN ARCHIVES OF BIOLOGY AND TECHNOLOGY A N I N T E R N A T I O N A L J O U R N A L Detection of Lsr2 Gene of Mycobacterium leprae in Nasal Mucus

ABSTRACT In the present study, nasal mucus from patients with leprosy were analyzed by PCR using specific primers for Lsr2 gene of Mycobacterium leprae

TRAÇOS IMPRESSOS NO TEMPO: UMA EXPLORAÇÃO HISTÓRICA E BIBLIOGRÁFICA DOS VÍNCULOS ENTRE MEIO AMBIENTE, ASPECTOS CLIMÁTICOS E GEOLÓGICOS

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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

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

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. 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 HI

Atividade leishmanicida de extrato hidroalcoólico de própolis brasileira em Leishmania amazonensis

As leishmanioses são consideradas doenças negligenciadas devido às altas incidências, ampla distribuição geográfica e dificuldade no tratamento sendo incluídas na relação de doenças prioritárias pela Organização Mundial da Saúde. Os tratamentos disponíveis para estas doenças apresentam elevada toxicidade, justificando a busca por fármacos alternativos. Estudos prévios com própolis, resina produzida por abelhas, demonstraram sua atividade antiparasitária e imunomoduladora em diversos modelos experimentais. O objetivo deste trabalho foi avaliar o efeito in vitro do extrato hidroalcoólico de própolis brasileira, coletado na cidade de Botucatu no estado de São Paulo, sobre formas promastigotas de Leishmania amazonensis, bem como analisar seu efeito in vivo sobre a carga parasitária em baço de camundongos susceptíveis à infecção. Assim, formas promastigotas tratadas com extrato hidroalcoólico de própolis brasileira nas concentrações 5, 10, 25, 50 ou 100 µg/mL apresentaram efeito inibitório sobre a proliferação desses parasitos nos tempos de 24, 96 e 168 h. No entanto, as concentrações de 50 e 100 µg/mL mostraram-se mais eficazes quando comparadas ao controle e às demais concentrações em todos os tempos avaliados. Em relação à carga parasitária, após 30 dias de infecção com L. amazonensis, camundongos BALB/c foram tratados diariamente com a própolis (5mg/kg), via oral ou intraperitoneal, durante 60 dias. Posteriormente, o baço destes animais foi coletado para análise da carga parasitária. O tratamento por via oral reduziu 40% da carga parasitária. Desta forma, a amostra de própolis brasileira testada apresentou ação leishmanicida sobre L. amazonensis em cultura e em camundongos infectados com este protozoário

Interactions Between Candida albicans and Host <br> Interações entre Candida albicans e Hospedeiro

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. <p><p> 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