Department of Zoology, School of Biological Sciences, Dr. Hari Singh Gour University, Sagar, India.
Department of Biotechnology, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
Front Immunol. 2018 Apr 5;9:657. doi: 10.3389/fimmu.2018.00657. eCollection 2018.
The role of immune system in various bone pathologies, such as osteoporosis, osteoarthritis, and rheumatoid arthritis is now well established. This had led to the emergence of a modern field of systems biology called as osteoimmunology, an integrated research between fields of immunology and bone biology under one umbrella. Osteoporosis is one of the most common inflammatory bone loss condition with more than 200 million individuals affected worldwide. T helper (Th) cells along with various other immune cells are major players involved in bone homeostasis. In the present review, we specifically discuss the role of various defined T lymphocyte subsets (Th cells comprising Th1, Th2, Th9, Th17, Th22, regulatory T cells, follicular helper T cells, natural killer T cells, γδ T cells, and CD8 T cells) in the pathophysiology of osteoporosis. The study of the specific role of immune system in osteoporosis has now been proposed by our group as "immunoporosis: the immunology of osteoporosis" with special emphasis on the role of various subsets of T lymphocytes. The establishment of this new field had been need of the hour due to the emergence of novel roles of various T cell lymphocytes in accelerated bone loss observed during osteoporosis. Activated T cells either directly or indirectly through the secretion of various cytokines and factors modulate bone health and thereby regulate bone remodeling. Several studies have summarized the role of inflammation in pathogenesis of osteoporosis but very few reports had delineated the precise role of various T cell subsets in the pathobiology of osteoporosis. The present review thus for the first time clearly highlights and summarizes the role of various T lymphocytes in the development and pathophysiology of osteoporosis, giving birth to a new field of biology termed as "immunoporosis". This novel field will thus provide an overview of the nexus between the cellular components of both bone and immune systems, responsible for the observed bone loss in osteoporosis. A molecular insight into the upcoming and novel field of immunoporosis would thus leads to development of innovative approaches for the prevention and treatment of osteoporosis.
免疫系统在各种骨骼病理学中的作用，如骨质疏松症、骨关节炎和类风湿关节炎，现在已经得到了充分的证实。这导致了一个名为骨免疫学的现代系统生物学领域的出现，这是免疫学和骨生物学领域的综合研究。骨质疏松症是最常见的炎症性骨质流失疾病之一，全球有超过 2 亿人受到影响。辅助性 T 细胞（Th 细胞）以及各种其他免疫细胞是参与骨稳态的主要参与者。在本综述中，我们特别讨论了各种定义明确的 T 淋巴细胞亚群（Th 细胞包括 Th1、Th2、Th9、Th17、Th22、调节性 T 细胞、滤泡辅助 T 细胞、自然杀伤 T 细胞、γδ T 细胞和 CD8 T 细胞）在骨质疏松症病理生理学中的作用。我们小组提出了“免疫骨质疏松症：骨质疏松症的免疫学”这一概念，专门研究免疫系统在骨质疏松症中的特定作用，特别强调了各种 T 淋巴细胞亚群的作用。由于在骨质疏松症中观察到各种 T 淋巴细胞亚群在加速骨丢失中发挥的新作用，因此需要建立这个新的领域。活化的 T 细胞无论是直接还是间接通过分泌各种细胞因子和因子来调节骨健康，从而调节骨重塑。许多研究总结了炎症在骨质疏松症发病机制中的作用，但很少有报道详细描述了各种 T 细胞亚群在骨质疏松症病理生物学中的确切作用。因此，本综述首次明确强调并总结了各种 T 淋巴细胞在骨质疏松症的发生和病理生理学中的作用，为生物学领域创造了一个新的领域，称为“免疫骨质疏松症”。这个新领域将提供骨骼和免疫系统细胞成分之间的联系的概述，负责骨质疏松症中观察到的骨丢失。对新兴的免疫骨质疏松症领域的分子研究将为骨质疏松症的预防和治疗方法的发展提供依据。
