Mycobacterium leprae-induced Insulin-like Growth Factor I attenuates antimicrobial mechanisms, promoting bacterial survival in macrophages.

Mycobacterium leprae (ML), the etiologic agent of leprosy, can subvert macrophage antimicrobial activity by mechanisms that remain only partially understood. In the present study, the participation of hormone insulin-like growth factor I (IGF-I) in this phenomenum was investigated. Macrophages from the dermal lesions of the disseminated multibacillary lepromatous form (LL) of leprosy expressed higher levels of IGF-I than those from the self-limited paucibacillary tuberculoid form (BT). Higher levels of IGF-I secretion by ML-infected macrophages were confirmed in ex vivo and in vitro studies. Of note, the dampening of IGF-I signaling reverted the capacity of ML-infected human and murine macrophages to produce antimicrobial molecules and promoted bacterial killing. Moreover, IGF-I was shown to inhibit the JAK/STAT1-dependent signaling pathways triggered by both mycobacteria and IFN-γ most probably through its capacity to induce the suppressor of cytokine signaling-3 (SOCS3). Finally, these in vitro findings were corroborated by in vivo observations in which higher SOCS3 expression and lower phosphorylation of STAT1 levels were found in LL versus BT dermal lesions. Altogether, our data strongly suggest that IGF-I contributes to the maintenance of a functional program in infected macrophages that suits ML persistence in the host, reinforcing a key role for IGF-I in leprosy pathogenesis.

Estudo colaborativo nacional para o estabelecimento do material de referência de trabalho da vacina contra sarampo, caxumba e rubéola: evolução para a autossuficência na produção nacional da vacina tríplice viral / National collaborative study for establishing the working reference material of the vaccine against measles/mumps and rubella: evolution to the self-sufficiency in the national production of triple viral vaccine

A monografia farmacopeica da vacina tríplice viral (sarampo/caxumba/rubéola) exige a validação de desempenho do ensaio de potência utilizando-se apropriado material de referência (MR). Com o intuito de estabelecer o primeiro MR de trabalho (MRT) nacional para a vacina tríplice viral, foi realizado o estudo colaborativo nacional com a participação de duas únicas instituições que executam o ensaio de potência desta vacina, o Instituto de Tecnologia em Imunobiológicos (Bio-Manguinhos, produtor nacional) e o Instituto Nacional de Controle de Qualidade em Saúde.O material candidato (cMRTBio), preparado pelo produtor, foi avaliado pelos laboratórios participantes utilizando-se as respectivas metodologias in-house de determinação de potência. O cMRTBio foi considerado apropriado como MR in-house por estar em concordância com as especificações recomendadas nas normativas de compêndios, a saber: variações intra- (< 5 %), inter-ensaios (< 10 %) e entre laboratórios (< 10 %) abaixo dos limites aceitáveis; e potência estimada (log10 CCID50/DH) em 3,72 para sarampo, 4,80 para caxumba e 3,70 para rubéola. Este trabalho reflete o compromisso do único produtor nacional da vacina tríplice viral com a saúde pública, descrevendo-se a expansão da tecnologia, o cumprimento às diretrizes internacionais, o cuidado com o controle da qualidade e culminância para a autossuficiência nacional na produção de vacinas.

The pharmacopoeia monograph for the measles/mumps and rubella (MMR) triple vaccine demands to perform the validation of the potency assay by using the suitable reference material (MR). Aiming at establishing the firstwork MR (MRT) for the MMR triple vaccine, a national collaborative study was performed with the participation of the two unique national institutions working on the vaccine potency evaluation test, the Imunobiological Technology Institute (Bio-Manguinhos, national manufacturer) and the National Institute for Quality Control in Health. The candidate product (cMRTBio) prepared by the manufacturer was evaluated by the participant laboratories by employing the respective in-house methodologies for determining the potency. The cMRTBio was considered suitable as in-house MR, according to the specifications based on the normative compendia, being the intra-assay (< 5 %), inter-assay(< 10 %) and between laboratories variations (< 10 %) below the acceptable limits, and the estimate potency(log10 CCID50/DH) in 3.72 for measles, 4.80 for mumps and 3.70 for rubella. This study reflects the commitment of the unique national MMR vaccine producer to the public health, describing the expansion of technology,the compliance with international guidelines and the careful quality control, leading to the national self-sufficiency in the vaccine production.

Deciphering the contribution of lipid droplets in leprosy: multifunctional organelles with roles in Mycobacterium leprae pathogenesis

Leprosy is an infectious disease caused by Mycobacterium leprae that affects the skin and nerves, presenting a singular clinical picture. Across the leprosy spectrum, lepromatous leprosy (LL) exhibits a classical hallmark: the presence of a collection of M. leprae-infected foamy macrophages/Schwann cells characterised by their high lipid content. The significance of this foamy aspect in mycobacterial infections has garnered renewed attention in leprosy due to the recent observation that the foamy aspect represents cells enriched in lipid droplets (LD) (also known as lipid bodies). Here, we discuss the contemporary view of LD as highly regulated organelles with key functions in M. leprae persistence in the LL end of the spectrum. The modern methods of studying this ancient disease have contributed to recent findings that describe M. leprae-triggered LD biogenesis and recruitment as effective mycobacterial intracellular strategies for acquiring lipids, sheltering and/or dampening the immune response and favouring bacterial survival, likely representing a fundamental aspect of M. leprae pathogenesis. The multifaceted functions attributed to the LD in leprosy may contribute to the development of new strategies for adjunctive anti-leprosy therapies.

Isolation and characterization of azotobacter strains from brazilian soils

Thirty-eight Azotobacter spp strains isolated from Brasilian soils were characterized for the foollowing properties : utilization of different carbon sources, diffusible pigment production, melanin production, sodium-dependent growth, siderophore production, streptomycin resistance and antibiotic-like substances production. Four strains were identified : one as A. armeniacus and three as A. paspali.