The fetal immune system is distinguishable from the adult immune system by a higher degree of tolerance to foreign antigens. This tolerance is important for fetal development within the ‘foreign’ maternal environment, and during birth when barrier surfaces are first colonized by microbiota. Immune responses against the wave of newly colonizing microbiota would cause massive damage to barrier tissues, so neonates need suppressed immune responses and instead rely on maternal antibodies for protection. It is becoming clear that the early-life establishment of tolerance could impact immune homeostasis and predisposition to autoimmune diseases throughout life. However, it is not well understood how and when perinatal tolerogenic immune responses switch towards adult-like effector immune responses. Here, we present a new report on the differences between cells from perinatal umbilical cord blood (UCB) and adult peripheral blood mononuclear cells (PBMC), which give mechanistic insights into fetal tolerogenic responses.

中文翻译：

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教学容忍度：不同的细胞相互作用使健康成熟

胎儿免疫系统与成人免疫系统的区别在于对外来抗原的耐受性更高。这种耐受性对于“外来”母体环境中的胎儿发育以及出生期间屏障表面首次被微生物群定植时的发育非常重要。针对新定植微生物群的免疫反应会对屏障组织造成巨大损害，因此新生儿需要抑制免疫反应，而是依靠母体抗体进行保护。越来越清楚的是，早期建立的耐受性可能会影响整个生命过程中的免疫稳态和自身免疫性疾病的易感性。然而，目前尚不清楚围产期耐受性免疫反应如何以及何时转变为成人样效应免疫反应。这里，