Read S E, Williams B R
Clin Invest Med. 1984;7(4):259-62.
The human newborn is particularly susceptible to infections in the neonatal period, due in part to the immaturity and naive state of the immune system. The role of interferon and natural killer cells in host defense in this age group is poorly defined. We have studied natural killer cells and the activation of the interferon system in cord blood. Most newborns (75%) had low natural killer cell activity, and this was unrelated to levels of the intracellular interferon-associated enzyme, 2'-5' oligoadenylate synthetase (2-5A synthetase). Newborn cells responded to interferon in vitro with an increase in natural killer activity, suggesting that this low natural killer cell activity is the result of fewer numbers of effector cells rather than a functional immaturity. Circulating serum interferon was detected in greater than 50% of maternal samples tested; however, this did not correlate with 2-5A synthetase levels in maternal or the corresponding cord blood mononuclear cells. Natural killer cell activity was low in the newborn in spite of activation of the interferon system in 39% of these individuals. This may be an important factor in susceptibility to infections in this period.
人类新生儿在新生儿期特别容易受到感染，部分原因是免疫系统不成熟且处于初始状态。干扰素和自然杀伤细胞在这个年龄组宿主防御中的作用尚不清楚。我们研究了脐血中的自然杀伤细胞和干扰素系统的激活情况。大多数新生儿（75%）的自然杀伤细胞活性较低，这与细胞内干扰素相关酶2'-5'寡腺苷酸合成酶（2-5A合成酶）的水平无关。新生儿细胞在体外对干扰素产生反应，自然杀伤活性增加，这表明这种低自然杀伤细胞活性是效应细胞数量较少的结果，而非功能不成熟。在超过50%检测的母体样本中检测到循环血清干扰素；然而，这与母体或相应脐血单个核细胞中的2-5A合成酶水平无关。尽管这些个体中有39%的人干扰素系统被激活，但新生儿的自然杀伤细胞活性仍然较低。这可能是这个时期易感染的一个重要因素。
