Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center School of Medicine, New Orleans, LA 70112, USA; Department of Genetics, Louisiana State University Health Sciences Center School of Medicine, New Orleans, LA 70112, USA.
Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center School of Medicine, New Orleans, LA 70112, USA.
Cell Immunol. 2021 Apr;362:104302. doi: 10.1016/j.cellimm.2021.104302. Epub 2021 Feb 4.
MDSC are a heterogeneous population of immature myeloid cells that are released by biological stress such as tissue damage and inflammation. Conventionally, MDSC are known for their detrimental role in chronic inflammation and neoplastic conditions. However, their intrinsic functions in immunoregulation, wound healing, and angiogenesis are intended to protect from over-reactive immune responses, maintenance of immunotolerance, tissue repair, and homeostasis. Paradoxically, under certain conditions, MDSC can impair protective immune responses and exacerbate the disease. The transition from protective to harmful MDSC is most likely driven by environmental and epigenetic mechanisms induced by prolonged exposure to unresolved inflammatory triggers. Here, we review several examples of the dual impact of MDSC in conditions such as maternal-fetal tolerance, self-antigens immunotolerance, obesity-associated cancer, sepsis and trauma. Moreover, we also highlighted the evidence indicating that MDSC have a role in COVID-19 pathophysiology. Finally, we have summarized the evidence indicating epigenetic mechanisms associated with MDSC function.
髓系来源抑制细胞（MDSC）是一类异质性未成熟髓系细胞，由组织损伤和炎症等生物应激释放。传统上，MDSC 因其在慢性炎症和肿瘤性疾病中的有害作用而被人们熟知。然而，其在免疫调节、伤口愈合和血管生成中的固有功能旨在防止过度的免疫反应、维持免疫耐受、组织修复和体内平衡。矛盾的是，在某些情况下，MDSC 会损害保护性免疫反应并加重疾病。从保护性 MDSC 向有害 MDSC 的转变很可能是由长期暴露于未解决的炎症触发因素所诱导的环境和表观遗传机制驱动的。在这里，我们回顾了 MDSC 在母体-胎儿耐受、自身抗原免疫耐受、肥胖相关癌症、脓毒症和创伤等情况下的双重作用的几个例子。此外，我们还强调了表明 MDSC 在 COVID-19 病理生理学中具有作用的证据。最后，我们总结了表明与 MDSC 功能相关的表观遗传机制的证据。
