BACKGROUND The mechanism of resistance to SbIII in Leishmania is complex, multifactorial and involves not only biochemical mechanisms, but also other elements, such as the immune system of the host. OBJECTIVES In this study, putative changes in the immunological profile of human monocytes infected with wild-type (WT) and antimony (SbIII)-resistant Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum lines were evaluated. METHODS Susceptibility assays WT and SbIII-resistant L. braziliensis and L. infantum were performed using lines THP-1 human monocytic lineage. Phagocytic capacity, cytokine profile, intracellular nitric oxide (NO) production and surface carbohydrate residues profile were performed in peripheral blood monocytes by flow cytometry. FINDINGS The phagocytic capacity and intracellular NO production by classical (CD14++CD16-) and proinflammatory (CD14++CD16+) monocytes were higher in the presence of L. infantum lines compared to L. braziliensis lines. The results also highlight proinflammatory monocytes as the cellular subpopulation of major relevance in a phagocytosis event and NO expression. It is important to note that L. infantum induced a proinflammatory cytokine profile characterised by higher levels of TNF-α in culture supernatant than L. braziliensis. Conversely, both Leishmania lines induce high levels of IL-6 in culture supernatant. Analysis of the expression profile of surface carbohydrates showed that L. braziliensis presents 4.3-fold higher expression of galactose(β1,4)N-acetylglucosamine than L. infantum line. Interestingly, the expression level of α-N-acetylgalactosamine residues was 2-fold lower in the SbIII-resistant L. braziliensis line than its counterpart WT line, indicating differences in surface glycoconjugates between these lines. MAIN CONCLUSIONS Our results showed that L. braziliensis and L. infantum induce different innate immune responses and a highly inflammatory profile, which is characteristic of infection by L. infantum, the species associated with visceral disease.

中文翻译：

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婴儿利什曼原虫通过人促炎性单核细胞诱导高吞噬能力和细胞内一氧化氮的产生。

背景技术在利什曼原虫中对SbIII的抗性机制是复杂的，多因素的，不仅涉及生化机制，而且还涉及其他因素，例如宿主的免疫系统。目的在本研究中，评估了被野生型（WT）和锑（SbIII）抗性利​​什曼原虫（Viannia）的巴西利什曼原虫和利什曼原虫（Leishmania）婴儿系感染的人单核细胞的免疫学特征的假定变化。方法使用THP-1系人单核细胞系对WT和SbIII耐药的巴西乳杆菌和婴儿乳杆菌进行药敏试验。通过流式细胞术在外周血单核细胞中进行吞噬能力，​​细胞因子谱，细胞内一氧化氮（NO）产生和表面碳水化合物残留谱。研究结果发现，与巴氏乳杆菌系相比，在巴氏乳杆菌系存在下，经典（CD14 ++ CD16-）和促炎性（CD14 ++ CD16 +）单核细胞的吞噬能力和胞内一氧化氮的产生更高。结果还突出了促炎性单核细胞，因为它与吞噬作用事件和NO表达密切相关。重要的是要注意，婴儿乳杆菌诱导的促炎性细胞因子特征是培养上清液中的TNF-α水平高于巴西乳杆菌。相反，两种利什曼原虫系在培养上清液中诱导高水平的IL-6。分析表面碳水化合物的表达谱表明，巴西乳杆菌的半乳糖（β1,4）N-乙酰氨基葡萄糖表达量比婴儿乳杆菌高4.3倍。有趣的是 在抗SbIII的巴西乳杆菌系中，α-N-乙酰半乳糖胺残基的表达水平比其对应的WT系低2倍，表明这些系之间的表面糖缀合物存在差异。主要结论我们的结果表明，巴西乳杆菌和婴儿乳杆菌可诱导不同的先天免疫反应和高度炎症，这是与内脏疾病有关的婴儿乳杆菌感染的特征。