Human milk plays an important role in the child’s immune system. The human milk oligosaccharides (HMOs) may affect breast-fed infants both locally and systemically. In the present study, HMOs were separated, characterized and investigated for the immunomodulatory effects on RAW264.7 macrophages and its underlying molecular mechanisms. Our results revealed that HMO-7, one of the neutral HMOs fractions can significantly induce the production of nitric oxide (NO) and PGE2 via up-regulating nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) expression. Additionally, HMO-7 was found to stimulate the release of ROS, TNF-α and cytokines including IL-1β, IL-2, IL-6 and IL-10 in RAW264.7 macrophages. Further study showed that macrophage activated by HMO-7 involved in nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathways. Our study provides additional evidence that HMOs are the functional components in human milk and that HMOs may have the potential application in healthcare industry.

人乳在孩子的免疫系统中起着重要作用。人乳低聚糖（HMO）可能会局部和全身地影响母乳喂养的婴儿。在本研究中，对HMO进行了分离，表征和研究，以研究其对RAW264.7巨噬细胞的免疫调节作用及其潜在的分子机制。我们的结果表明，HMO-7是中性HMO组分之一，它可以通过上调一氧化氮合酶（iNOS）和环氧合酶2（COX-2）的表达显着诱导一氧化氮（NO）和PGE2的产生。另外，发现HMO-7在RAW264.7巨噬细胞中刺激ROS，TNF-α和包括IL-1β，IL-2，IL-6和IL-10在内的细胞因子的释放。进一步的研究表明，HMO-7激活的巨噬细胞参与了核因子（NF）-κB和有丝分裂原激活的蛋白激酶（MAPK）信号通路。我们的研究提供了更多的证据，证明HMO是人乳中的功能成分，并且HMO可能在医疗保健行业中具有潜在的应用。