Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, 10032, USA.
Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, 10032, USA.
Semin Immunopathol. 2017 Nov;39(6):593-604. doi: 10.1007/s00281-017-0648-7. Epub 2017 Sep 11.
The immune system in early life is tasked with transitioning from a relatively protected environment to one in which it encounters a wide variety of innocuous antigens and dangerous pathogens. The immaturity of the developing immune system, and particularly the distinct functionality of T lymphocytes in early life, has been implicated in increased susceptibility to infection. Previous work has demonstrated that immune responses in early life are skewed toward limited inflammation and atopy; however, there is mounting evidence that such responses are context- and tissue-dependent. The regulation, differentiation, and maintenance of infant T cell responses, particularly as it relates to tissue compartmentalization, remains poorly understood. How the tissue environment impacts early-life immune responses and whether the development of localized protective immune memory cell subsets are established is an emerging area of research. As infectious diseases affecting the respiratory and digestive tracts are a leading cause of morbidity and mortality worldwide in infants and young children, a deeper understanding of site-specific immunity is essential to addressing these challenges. Here, we review the current paradigms of T cell responses during infancy as they relate to tissue localization and discuss implications for the development of vaccines and therapeutics.
生命早期的免疫系统面临着从相对受保护的环境转变为接触各种无害抗原和危险病原体的环境的任务。发育中免疫系统的不成熟，特别是生命早期 T 淋巴细胞的独特功能，与易感性增加有关。先前的研究表明，生命早期的免疫反应偏向于有限的炎症和过敏反应；然而，越来越多的证据表明，这种反应与上下文和组织有关。婴儿 T 细胞反应的调节、分化和维持，特别是与组织区隔化有关，仍然知之甚少。组织环境如何影响生命早期的免疫反应，以及局部保护性免疫记忆细胞亚群的发展是否建立，是一个新的研究领域。由于影响呼吸道和消化道的传染病是全世界婴儿和幼儿发病率和死亡率的主要原因，因此深入了解特定部位的免疫对于应对这些挑战至关重要。在这里，我们回顾了与组织定位相关的生命早期 T 细胞反应的当前范例，并讨论了其对疫苗和治疗药物开发的影响。
