TLR-9 Plays a Role in Mycobacterium leprae-Induced Innate Immune Activation of A549 Alveolar Epithelial Cells.

The respiratory tract is considered the main port of entry of Mycobacterium leprae, the causative agent of leprosy. However, the great majority of individuals exposed to the leprosy bacillus will never manifest the disease due to their capacity to develop protective immunity. Besides acting as a physical barrier, airway epithelium cells are recognized as key players by initiating a local innate immune response that orchestrates subsequent adaptive immunity to control airborne infections. However, to date, studies exploring the interaction of M. leprae with the respiratory epithelium have been scarce. In this work, the capacity of M. leprae to immune activate human alveolar epithelial cells was investigated, demonstrating that M. leprae-infected A549 cells secrete significantly increased IL-8 that is dependent on NF-κB activation. M. leprae was also able to induce IL-8 production in human primary nasal epithelial cells. M. leprae-treated A549 cells also showed higher expression levels of human ß-defensin-2 (hßD-2), MCP-1, MHC-II and the co-stimulatory molecule CD80. Furthermore, the TLR-9 antagonist inhibited both the secretion of IL-8 and NF-κB activation in response to M. leprae, indicating that bacterial DNA sensing by this Toll-like receptor constitutes an important innate immune pathway activated by the pathogen. Finally, evidence is presented suggesting that extracellular DNA molecules anchored to Hlp, a histone-like protein present on the M. leprae surface, constitute major TLR-9 ligands triggering this pathway. The ability of M. leprae to immune activate respiratory epithelial cells herein demonstrated may represent a very early event during infection that could possibly be essential to the generation of a protective response.

TLR-9 Plays a Role in Mycobacterium leprae-Induced Innate Immune Activation of A549 Alveolar Epithelial Cells

The respiratory tract is considered the main port of entry of Mycobacterium leprae, the causative agent of leprosy. However, the great majority of individuals exposed to the leprosy bacillus will never manifest the disease due to their capacity to develop protective immunity. Besides acting as a physical barrier, airway epithelium cells are recognized as key players by initiating a local innate immune response that orchestrates subsequent adaptive immunity to control airborne infections. However, to date, studies exploring the interaction of M. leprae with the respiratory epithelium have been scarce. In this work, the capacity of M. leprae to immune activate human alveolar epithelial cells was investigated, demonstrating that M. leprae-infected A549 cells secrete significantly increased IL-8 that is dependent on NF-kB activation. M. leprae was also able to induce IL-8 production in human primary nasal epithelial cells. M. leprae-treated A549 cells also showed higher expression levels of human b-defensin-2 (hbD-2), MCP-1, MHC-II and the co-stimulatory molecule CD80. Furthermore, the TLR-9 antagonist inhibited both the secretion of IL-8 and NF-kB activation in response to M. leprae, indicating that bacterial DNA sensing by this Toll-like receptor constitutes an important innate immune pathway activated by the pathogen. Finally, evidence is presented suggesting that extracellular DNA molecules anchored to Hlp, a histone-like protein present on the M. leprae surface, constitute major TLR-9 ligands triggering this pathway. The ability of M. leprae to immune activate respiratory epithelial cells herein demonstrated may represent a very early event during infection that could possibly be essential to the generation of a protective response.(AU)

Validation of PCR method for mycoplasma detection in the Yellow Fever-vaccine quality control / Validação de método de PCR para detecção de micoplasmasno controle de qualidade da vacina de Febre Amarela

Among the vaccines produced by Bio-Manguinhos, a major centre for manufacturingthe immunobiological products in Latin America, stands out the yellow fever (YF) vaccine.To guarantee the excellence and safety of the YF vaccine, the quality control tests has to be performedthroughout its production. The World Health Organization (WHO) demands the producersto guarantee the absence of Mycoplasma orale, M. pneumoniae, M. gallisepticum and M. synoviaein the biological products. Mycoplasma is a fastidious microorganism, requiring about 35 daysfor attaining the conclusive culturing test. In this study PCR methods were selected for amplifying16S rRNA gene fragments for detecting mycoplasma in the intermediate products of YF vaccine.This standardized methodology was specific and sensitive to detect the low concentrations of mycoplasma in spiked intermediary vaccine products; and the absence of unspecific amplification was also demonstrated. The detection rates ranged from 3.1 to 12.5 colony formingunits and showed 100 % of sensitivity and specificity in the tested samples. The PCR protocol for detecting mycoplasmal DNA in YF vaccine was validated by analysing 286 samples. Bio-Manguinhos produces annually 10,000,000 YF vaccine doses, and this method has been successfully employed, complementing the traditional approach in the mycoplasma detection since 2008.

Dentre as vacinas produzidas por Bio-Manguinhos, um importante centro de produção deimunobiológicos da América Latina, destaca-se a vacina de febre amarela (FA) que é produzidaem ovos embrionados. Para garantir a excelência e a segurança da vacina, testes de controlede qualidade são realizados durante a produção. A Organização Mundial de Saúde (OMS) exigedos produtores a ausência de Mycoplasma orale, M. pneumoniae, M. gallisepticum e M. synoviaeem produtos biológicos. Micoplasmas são micro-organismos fastidiosos, sendo necessários35 dias para que os testes de cultura sejam conclusivos. Neste estudo foram selecionadosmétodos de amplificação de fragmentos do gene 16S rRNA para detecção de micoplasmas emprodutos intermediários da vacina de FA. Esta metodologia padronizada foi capaz de detectarbaixas concentrações de micoplasmas nos produtos intermediários e a ausência de amplificaçãoinespecífica foi demonstrada. O limite de detecção variou entre 3,1 e 12,5 unidades formadorasde colônia; e nas amostras testadas a sensibilidade e a especificidade foram de 100 %. O protocolode PCR para detecção de micoplasmas na vacina foi validado pela análise de 286 amostras.Bio-Manguinhos produz 10.000.000 doses de vacina de febre amarela por ano e, desde 2008,este método tem sido empregado com sucesso, complementando-se a abordagem tradicional.

Validation of PCR method for mycoplasma detection in the Yellow Fever-vaccine quality control / Validação de método de PCR para detecção de micoplasmas no controle de qualidade da vacina de Febre Amarela

Among the vaccines produced by Bio-Manguinhos, a major centre for manufacturing the immunobiological products in Latin America, stands out the yellow fever (YF) vaccine. To guarantee the excellence and safety of the YF vaccine, the quality control tests has to be performed throughout its production. The World Health Organization (WHO) demands the producers to guarantee the absence of Mycoplasma orale, M. pneumoniae, M. gallisepticum and M. synoviae in the biological products. Mycoplasma is a fastidious microorganism, requiring about 35 days for attaining the conclusive culturing test. In this study PCR methods were selected for amplifying 16S rRNA gene fragments for detecting mycoplasma in the intermediate products of YF vaccine. This standardized methodology was specific and sensitive to detect the low concentrations of mycoplasma in spiked intermediary vaccine products; and the absence of unspecific amplification was also demonstrated. The detection rates ranged from 3.1 to 12.5 colony forming units and showed 100 % of sensitivity and specificity in the tested samples. The PCR protocol for detecting mycoplasmal DNA in YF vaccine was validated by analysing 286 samples. Bio-Manguinhos produces annually 10,000,000 YF vaccine doses, and this method has been successfully employed, complementing the traditional approach in the mycoplasma detection since 2008.

Dentre as vacinas produzidas por Bio-Manguinhos, um importante centro de produção de imunobiológicos da América Latina, destaca-se a vacina de febre amarela (FA) que é produzida em ovos embrionados. Para garantir a excelência e a segurança da vacina, testes de controle de qualidade são realizados durante a produção. A Organização Mundial de Saúde (OMS) exige dos produtores a ausência de Mycoplasma orale, M. pneumoniae, M. gallisepticum e M. synoviae em produtos biológicos. Micoplasmas são micro-organismos fastidiosos, sendo necessários 35 dias para que os testes de cultura sejam conclusivos. Neste estudo foram selecionados métodos de amplificação de fragmentos do gene 16S rRNA para detecção de micoplasmas em produtos intermediários da vacina de FA. Esta metodologia padronizada foi capaz de detectar baixas concentrações de micoplasmas nos produtos intermediários e a ausência de amplificação inespecífica foi demonstrada. O limite de detecção variou entre 3,1 e 12,5 unidades formadoras de colônia; e nas amostras testadas a sensibilidade e a especificidade foram de 100 %. O protocolo de PCR para detecção de micoplasmas na vacina foi validado pela análise de 286 amostras. Bio-Manguinhos produz 10.000.000 doses de vacina de febre amarela por ano e, desde 2008, este método tem sido empregado com sucesso, complementando-se a abordagem tradicional.