Integrated Analysis Reveals That miR-193b, miR-671, and TREM-1 Correlate With a Good Response to Treatment of Human Localized Cutaneous Leishmaniasis Caused by Leishmania braziliensis.

Localized cutaneous leishmaniasis (LCL) is a chronic disease characterized by ulcerated skin lesion(s) and uncontrolled inflammation. The mechanisms underlying the pathogenesis of LCL are not completely understood, and little is known about posttranscriptional regulation during LCL. MicroRNAs (miRNAs) are non-coding small RNAs that regulate gene expression and can be implicated in the pathogenesis of LCL. We investigated the involvement of miRNAs and their targets genes in human LCL using publicly available transcriptome data sets followed by ex vivo validation. Initial analysis highlighted that miRNA expression is altered during LCL, as patients clustered separately from controls. Joint analysis identified eight high confidence miRNAs that had altered expression (-1.5 ≤ fold change ≥ 1.5; p < 0.05) between cutaneous ulcers and uninfected skin. We found that the expression of miR-193b and miR-671 are greatly associated with their target genes, CD40 and TNFR, indicating the important role of these miRNAs in the expression of genes related to the inflammatory response observed in LCL. In addition, network analysis revealed that miR-193b, miR-671, and TREM1 correlate only in patients who show faster wound healing (up to 59 days) and not in patients who require longer cure times (more than 60 days). Given that these miRNAs are associated with control of inflammation and healing time, our findings reveal that they might influence the pathogenesis and prognosis of LCL.

IFN-beta impairs superoxide-dependent parasite killing in human macrophages: evidence for a deleterious role of SOD1 in cutaneous leishmaniasis.

Type I IFNs (IFN-alpha/beta) have only recently gained considerable attention as immunomodulators in nonviral infectious diseases. IFN-beta has been shown to protect, in a NO-dependent manner, against murine Old World leishmaniasis caused by Leishmania major, but data in New World leishmaniasis are lacking. We found that IFN-beta dose-dependently increases parasite burden in Leishmania amazonensis- as well as Leishmania braziliensis-infected human macrophages, independent of endogenous or exogenous NO. However, IFN-beta significantly reduced superoxide release in Leishmania-infected as well as uninfected human macrophages. This decrease in superoxide production was paralleled by a significant IFN-beta-mediated increase in superoxide dismutase 1 (SOD1) protein levels. Additionally, IFN-beta inhibition of leishmanicidal activity was mimicked by SOD1 and antagonized by either pharmacological or small interfering RNA-mediated inhibition of SOD1. Finally, pronounced SOD1 expression in situ was demonstrated in biopsies from New World cutaneous leishmaniasis patients. These findings reveal a hitherto unknown IFN-beta/SOD1 axis in Leishmania infection and suggest that inhibition of SOD-associated pathways could serve as strategy in the treatment of L. amazonensis as well as L. braziliensis infection, major human pathogens.

Lung granulomas from Mycobacterium tuberculosis/HIV-1 co-infected patients display decreased in situ TNF production.

Tuberculosis/HIV-1 co-infection is responsible for thousands of deaths each year, and previous studies have reported that co-infected individuals display major morphological alterations in tissue granulomas. The purpose of this study was to evaluate immunohistopathological characteristics in lung tissues from pulmonary TB/HIV-1-co-infected individuals. Following autopsy, tuberculosis-positive HIV-1-negative cases displayed granulomas with normal architecture, mainly composed of a mononuclear infiltrate with typical epithelioid, as well as giant cells, and exhibiting caseous necrosis. In contrast, lesions from the TB/HIV-1-co-infected group showed extensive necrosis, poorly formed granulomas, and a marked presence of polymorphonuclear cells. More importantly, TNF staining was greatly reduced in the TB/HIV-1-co-infected individuals. Our data suggest that HIV-1 infection alters the organization of pulmonary granulomas by modulating TNF and, possibly, cell trafficking, leading to an impaired anti-tuberculosis response.

Polymerase chain reaction (PCR) is highly sensitive for diagnosis of mucosal leishmaniasis.

We evaluated the use of polymerase chain reaction (PCR) for diagnosis of mucosal leishmaniasis (ML) in an endemic area in Acre, Brazil, where Leishmania braziliensis is present. Leishmania DNA was detected 34 of 35 cases, yielding a positivity rate of 97.1%, which was higher than the positivity rates for all of the other diagnostic methods studied, namely Montenegro skin test (MST), anti-Leishmania serological testing and microscopic examination of lesion biopsy specimens. These findings have led us to propose guidelines for the diagnosis of ML that use PCR as the principal method of parasitological confirmation of cases.

Estudo morfológico in situ da resposta imuno-inflamatória na tuberculose pulmonar humana / Morfologic in situ study of the immuno-inflamatoryresponse in human pulmonary tuberculosis

O objetivo do estudo é fazer uma correlação morfológica entre as lesões observadas em pacientes com tuberculose pulmonar, Vírus da Imuno-deficiência Humana- contribuindo para o entendimento das interações entre células de defesa, bacilo e citocinas na resposta imuno-inflamatória que se monta, elucidando possíveis variações morfológicas destas lesões e os seus significados funcionais. Foram analisados ao microscópio óptico cortes histológicos de pacientes autopsiados no Hospital Universitário Professor Edgar Santos entre 1995 e 2001 com diagnóstico anátomo patológico de tuberculose pulmonar. O enfoque principal foram os granulomas ou lesões observadas nos cortes histológicos de pulmões dos casos selecionados onde além do Hematoxilina- Eosina e Ziehl-Niels en foram feitas marcações imunohistoquimicas para Interferon gama, Fator de Necrose Tumoral alfa e Fator de Transformação do Crescimento beta. Os casos de cada grupo foram cuidadosamente selecionados excluindo-se aqueles que tivessem outra doença pulmonar que não tuberculose para evitar resultados falso positivos ou falso negativos pela presença de mais de um grande agente etiológico. Os resultados foram analisados por meio de tabelas algorítmicas vista por pelo menos três observadores onde foi feita a análise dos parâmetros morfológicos como a formação e modulação dos granulomas, a arquitetura e composição celular ods mesmos assim como a presença e extensão da necrose. Foi feito uma avaliação das citocinas. Os resultados foram comparados e uma média dos valores foi utilizada no estudo. O grupo Vírus da Imuno-deficiência Humana + mostrou granulomas mal formados , com pouca ou nenhuma modulação, com extensas áreas de necrose e ainda com uma composição celular diferente onde predominam polimorfonucleares. No grupo Vírus da Imuno-defeciência Humana - o padrão de reposta imuno-inflamatória foi diferente sendo observados granulomas bem formados com arquitetura preservada, variável quantidade de necrose e composto predominantemente por células mononucleares e com a presença de células epitelióides e células gigantes. Foram observadas diferenças nos perfis de citocinas nas lesões que fogem ao que está descrito na literatura. Existem padrões morfológicos diferentes para a tuberculose pulmonar humana quando se comparam pacientes Vírus da Imuno-defeciência Humana +/ Vírus da Imuno-deficiência Humana- estas variações intimamente relacionadas ao acordo da imunidade celular destes pacientes.