Chagas disease, a neglected tropical disease (NTD) caused by the flagellated protozoan Trypanosoma cruzi (T. cruzi), is a major public health problem. It was initially restricted to Latin America, but it is now expanding globally. Host and pathogen interactions are crucial in the establishment of disease, and since 1970, it has been known that eukaryotic cells release extracellular vesicles (EVs), which in turn have an important role in intercellular communication in physiological and pathological conditions. Our study proposed to characterize and compare circulating EVs isolated from the plasma of chronic Chagas disease (CCD) patients and controls. For this, peripheral blood was collected from patients and controls, and mononuclear cells (PBMCs) were isolated and stimulated with parasite EVs, showing that patient cells released fewer EVs than control cells. Then, after plasma separation followed by EV total shedding enrichment, the samples were subjected to ultracentrifugation to isolate the circulating EVs, which then had their size and concentration characterized by nanoparticle tracking analysis (NTA). This showed that patients had a lower concentration of circulating EVs while there were no differences in size, corroborating the in vitro data. Additionally, circulating EVs were incubated with THP-1 cells (macrophages) that, after the interaction, had their supernatant analyzed by ELISA for cytokine detection. In relation to their ability to induce cytokine production, the CCD patient EVs were able to induce a differential production of IFN-γ and IL-17 in relation to controls, with differences being more evident in earlier/less severe stages of the disease. In summary, a decreased concentration of circulating EVs associated with differential activation of the immunological system in patients with CCD is related to parasite persistence and the establishment of chronic disease. It is also a potential biomarker for monitoring disease progression.

中文翻译：

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南美锥虫病的新生物标志物：从慢性南美锥虫病患者外周血中分离的细胞外囊泡调节人体免疫反应

恰加斯病，一种被忽视的热带病 (NTD)，由鞭毛原生动物克氏锥虫( T. cruzi ) 引起)，是一个重大的公共卫生问题。它最初仅限于拉丁美洲，但现在正在全球扩展。宿主和病原体的相互作用对于疾病的发生至关重要，自 1970 年以来，人们就知道真核细胞会释放细胞外囊泡 (EVs)，而后者又在生理和病理条件下的细胞间通讯中发挥重要作用。我们的研究提议表征和比较从慢性恰加斯病 (CCD) 患者和对照的血浆中分离出来的循环 EV。为此，从患者和对照中收集外周血，分离单核细胞 (PBMC) 并用寄生虫 EV 刺激，表明患者细胞释放的 EV 少于对照细胞。然后，在血浆分离后进行 EV 总脱落富集，对样品进行超速离心以分离循环 EV，然后通过纳米粒子跟踪分析 (NTA) 对其大小和浓度进行表征。这表明患者的循环 EV 浓度较低，而大小没有差异，证实了体外数据。此外，循环 EV 与 THP-1 细胞（巨噬细胞）一起孵育，在相互作用后，通过 ELISA 分析其上清液以检测细胞因子。就其诱导细胞因子产生的能力而言，CCD 患者 EV 能够诱导与对照相比产生差异的 IFN- γ和 IL-17，差异在疾病的早期/较轻的阶段更为明显。总之，与 CCD 患者免疫系统差异激活相关的循环 EV 浓度降低与寄生虫持续存在和慢性疾病的建立有关。它也是监测疾病进展的潜在生物标志物。