Wallace H. Coulter Department of Biomedical Engineering, USA; Bioengineering PhD Program, USA; Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA.
Medical Scientist Training Program, USA.
Cells Dev. 2022 Jun;170:203793. doi: 10.1016/j.cdev.2022.203793. Epub 2022 May 29.
Alopecia is a non-specific term for hair loss clinically diagnosed by the hair loss pattern and histological analysis of patient scalp biopsies. The immune-mediated alopecia subtypes, including alopecia areata, lichen planopilaris, frontal fibrosing alopecia, and central centrifugal cicatricial alopecia, are common, significant forms of alopecia subtypes. For example, alopecia areata is the most common autoimmune disease with a lifetime incidence of approximately 2% of the world's population. In this perspective, we discuss major results from studies of immune-mediated alopecia subtypes. These studies suggest the key event in disease onset as the collapse in immune privilege, which alters the hair follicle microenvironment, e.g., upregulation of major histocompatibility complex molecules and increase of cytokine production, and results in immune cell infiltration, inflammatory responses, and damage of hair follicles. We note that previous studies have established that the hair follicle has a complex mechanical microenvironment, which may regulate the function of not only tissue cells but also immune cell infiltrates. This suggests a potential for mechanobiology to contribute to alopecia research by adding new methods, new approaches, and new ways of thinking, which is missing in the existing literature. To fill this a gap in the alopecia research space, we develop a mechanobiological hypothesis that alterations in the hair follicle microenvironment, specifically in the mechanically responsive tissues and cells, partially due to loss of immune privilege, may be contributors to disease pathology. We further focus our discussion on the potential for applying mechanoimmunology to the study of T cell infiltrates in the hair follicle, as they are considered primary contributors to alopecia pathology. To establish the connection between the mechanoimmunological hypothesis and immune-mediated alopecia subtypes, we discuss what is known about the role of T cells in immune-mediated alopecia subtypes, using the most extensively studied AA as our model.
脱发是一种临床上通过脱发模式和患者头皮活检的组织学分析来诊断的非特异性术语。免疫介导的脱发亚型，包括斑秃、扁平苔藓性脱发、额部纤维性脱发和中心性瘢痕性脱发，是常见的、重要的脱发亚型。例如，斑秃是最常见的自身免疫性疾病，其终生发病率约为世界人口的 2%。在这篇观点文章中，我们讨论了免疫介导的脱发亚型研究的主要结果。这些研究表明，疾病发作的关键事件是免疫特权的崩溃，这改变了毛囊微环境，例如主要组织相容性复合体分子的上调和细胞因子产生的增加，并导致免疫细胞浸润、炎症反应和毛囊损伤。我们注意到，先前的研究已经证实，毛囊具有复杂的机械微环境，这不仅可以调节组织细胞的功能，还可以调节免疫细胞浸润的功能。这表明机械生物学有可能通过增加新的方法、新的方法和新的思维方式为脱发研究做出贡献，而这在现有文献中是缺失的。为了填补脱发研究领域的这一空白，我们提出了一个机械生物学假设，即毛囊微环境的改变，特别是在机械反应组织和细胞中的改变，部分是由于免疫特权的丧失，可能是疾病病理的原因之一。我们进一步将讨论重点放在机械免疫学在毛囊 T 细胞浸润研究中的应用潜力上，因为 T 细胞被认为是脱发病理的主要原因之一。为了建立机械免疫假说与免疫介导的脱发亚型之间的联系，我们讨论了 T 细胞在免疫介导的脱发亚型中的已知作用，以最广泛研究的 AA 作为我们的模型。
