Instituto René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, Brazil.
Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Salvador, Brazil.
Front Cell Infect Microbiol. 2020 Jul 29;10:380. doi: 10.3389/fcimb.2020.00380. eCollection 2020.
infection causes considerable human morbidity and may develop into a deadly visceral form in endemic regions. The parasite infects macrophages where they can replicate intracellularly. Furthermore, they modulate host immune responses by using virulence factors (lipophosphoglycan, glycoprotein-63, and others) that promote survival inside the cells. Extracellular vesicles (EVs) released by parasites are important for cell-cell communication in the proinflammatory milieu modulating the establishment of infection. However, information on the ability of EVs from different species to modulate inflammatory responses is scarce, especially from those species causing different clinical manifestations (visceral vs. cutaneous). The purpose of this study was to compare macrophage activation using EVs from three species from New World including , and . EVs were released from promastigote forms, purified by ultracentrifugation and quantitated by Nanoparticle Tracking Analysis (NTA) prior to murine macrophage exposure. NTA analysis did not show any differences in the EV sizes among the strains. EVs from and failed to induce a pro-inflammatory response. EVs from both WT and LPG-deficient mutant (LPG-KO) did not show any differences in their interaction with macrophages, suggesting that LPG solely was not determinant for activation. On the other hand, EVs from were immunomodulatory inducing NO, TNF-α, IL-6, and IL-10 via TLR4 and TLR2. To determine whether such activation was related to NF-κB p65 translocation, THP-1 macrophage cells were exposed to EVs. In the same way, only EVs from exhibited a highly percentage of cells positive for NF-κB. Our results suggest an important role of EVs in determining the pattern of immune response depending on the parasite species. For , LPG was not determinant for the activation.
感染会导致相当大的人类发病率，并可能在流行地区发展为致命的内脏形式。寄生虫感染巨噬细胞，在巨噬细胞内进行复制。此外，它们通过使用毒力因子（脂磷甘露聚糖、糖蛋白-63 等）来调节宿主免疫反应，从而促进细胞内的存活。寄生虫释放的细胞外囊泡（EVs）对于调节感染建立的促炎环境中的细胞间通讯非常重要。然而，关于不同物种的 EV 调节炎症反应的能力的信息很少，特别是对于引起不同临床表现（内脏与皮肤）的物种。本研究旨在比较来自新世界的三种物种（ 、 和 ）的 EV 对巨噬细胞的激活作用。EV 从前鞭毛体形式释放，通过超速离心纯化，并在暴露于鼠巨噬细胞之前通过纳米颗粒跟踪分析（NTA）定量。NTA 分析未显示不同菌株之间 EV 大小的任何差异。 和 的 EV 未能诱导促炎反应。来自 和 LPG 缺陷型突变体（LPG-KO）的 EV 在与巨噬细胞的相互作用中没有显示出任何差异，这表明 LPG 单独不是激活的决定因素。另一方面，来自 的 EV 通过 TLR4 和 TLR2 诱导 NO、TNF-α、IL-6 和 IL-10 的免疫调节。为了确定这种激活是否与 NF-κB p65 易位有关，用 EV 暴露 THP-1 巨噬细胞。同样，只有 的 EV 显示出高度百分比的 NF-κB 阳性细胞。我们的结果表明，EV 在确定免疫反应模式方面起着重要作用，这取决于寄生虫的种类。对于 ，LPG 不是激活的决定因素。
