ABSTRACT

Neutrophils are the first cells involved in inflammation and pathogen elimination, but they have a short lifespan. So, strategies for enhancing neutrophil lifespan and activities can be useful in many situations such as patients with immunodeficiencies. Previous researches demonstrated that mesenchymal stem cell (MSC) has anti-apoptotic effects on neutrophils. These multipotent cells have immunomodulatory properties and can be isolated from different tissues. MSCs isolated from Wharton’s jelly (WJ-MSCs), a mucosal connective tissue of the umbilical cord, may be better candidates than MSCs obtained from bone marrow or adipose tissue, because WJ-MSCs are younger and protected from damages that are resulted from aging, environmental toxins, and diseases. In addition, they have high proliferative capacity, easier accessibility, and more abundance. It was shown that following in vitro expansion, they are more effective than other sources of MSCs. Cell to cell contact or secretion of soluble factors and exosomes are the main approaches of MSCs in applying their effects. Exosomes and conditioned media (CM) were prepared from WJ-MSCs. Then, neutrophils were isolated and cultured with medium, CM, or exosomes. Then, neutrophil respiratory burst, apoptosis, and phagocytosis capacity were assessed by NBT assay, Annexin V-PI method, and Giemsa staining, respectively. Both treatments improved neutrophil lifespan and phagocytosis. Only MSC-CM could enhance neutrophil respiratory burst. This research demonstrated that MSC-exosomes and CM have protective effects on neutrophil function and lifespan. It can be concluded that MSC mediators can be responsible factors for protective functions of MSCs on neutrophils.

摘要

中性粒细胞是参与炎症和病原体消除的第一个细胞，但它们的寿命很短。因此，增强中性粒细胞寿命和活动的策略在许多情况下（例如患有免疫缺陷的患者）都是有用的。先前的研究表明，间充质干细胞（MSC）对中性粒细胞具有抗凋亡作用。这些多能细胞具有免疫调节特性，可以从不同的组织中分离出来。从脐带的黏膜结缔组织沃顿氏胶 (WJ-MSCs) 中分离出的 MSCs 可能比从骨髓或脂肪组织中获得的 MSCs 更适合，因为 WJ-MSCs 更年轻，并且可以免受老化造成的损害，环境毒素和疾病。此外，它们具有高增殖能力，更容易获得，更丰富。结果表明，在体外扩增后，它们比其他来源的 MSCs 更有效。细胞间接触或分泌可溶性因子和外泌体是MSCs发挥作用的主要途径。外泌体和条件培养基 (CM) 由 WJ-MSC 制备。然后，中性粒细胞被分离并与培养基、CM 或外泌体一起培养。然后，分别通过NBT法、Annexin V-PI法和Giemsa染色法评估中性粒细胞呼吸爆发、细胞凋亡和吞噬能力。两种治疗都改善了中性粒细胞的寿命和吞噬作用。只有MSC-CM可以增强中性粒细胞呼吸爆发。该研究表明，MSC-外泌体和 CM 对中性粒细胞功能和寿命具有保护作用。