Fetal alcohol exposure: effects on immunity of the premature newborn

怀孕期间饮酒仍然是一个重要问题，但其对妊娠不良结局的贡献 早产儿的研究仍然不足。我们以前报道过，大约三分之一的人非常低， 出生体重（VLBW）早产儿暴露于酒精在子宫内，根据母亲的报告。此次曝光 与迟发性脓毒症（LOS）和支气管肺发育不良（BPD）的几率增加有关。在我们 子宫内酒精（ETOH）暴露的动物模型，肺泡巨噬细胞（AM）的免疫反应， 多个物种的新生幼崽中的细菌减少。这些变化包括增加氧化剂 应激和延迟AM成熟，但与抗氧化剂谷胱甘肽（GSH）的治疗得到改善。在 在新生儿肺中，成熟AM的个体发生仍然存在争议，但胎儿单核细胞通过 PU.1对粒细胞/巨噬细胞集落刺激因子（GM-CSF）的应答。宫内酒精暴露 降低GM-CSF，但其对循环单核细胞和不同单核细胞池的影响 肺的发育情况不明。对于适应性免疫应答，抗原呈递依赖于MHC II类分子人白细胞抗原DR（HLA-DR）和免疫抑制的特征在于： 降低抗原呈递细胞如单核细胞或巨噬细胞上的HLA-DR表达。最近， 免疫抑制状态如脓毒症与检查点抑制剂的增加有关 程序性细胞死亡蛋白（PD）-1及其配体PD-L1。在新生小鼠单核细胞和AM中，我们发现， 子宫内ETOH暴露通过增加氧化应激、减少锌和锌而增加免疫抑制 GM-CSF，降低MHC-II表达和增加PD-1/PD-L1。然而，GSH或锌治疗 阻止了这些影响。在插管的极低出生体重婴儿的气管吸出物中，HLA-DR在AM中减少， 发生LOS的婴儿，而发生LOS或BPD的婴儿PD-L1增加。此外，PD- 1和PD-L1的表达在子宫内酒精暴露的VLBW婴儿AM中增加， 未暴露的AM。使用建立的子宫内ETOH小鼠模型加上VLBW新生儿的转化研究， 我们的总体目标是：1）确定子宫内ETOH对先天性和适应性免疫防御的影响， 单核细胞、单核细胞衍生的巨噬细胞（MDM）和AM对抗细菌挑战; 2）确定 减少氧化应激（GSH、GM-CSF和锌）的临床相关干预将改善先天性和 适应性反应; 3）验证乙醇代谢产物脂肪酸乙酯（FAEEs）和磷脂酰乙醇 （PEth）作为VLBW新生儿宫内酒精暴露的生物标志物和4）确定表型加先天性 人单核细胞、MDM和AM样本的适应性防御，这些样本来自有/无胎儿的VLBW新生儿 酒精暴露提高对胎儿酒精暴露的极低出生体重新生儿的识别， 了解它的免疫抑制作用叠加在不成熟的免疫防御有关， 早产对这一脆弱人群及其LOS和BPD风险有重要影响。

Alcohol use during pregnancy continues to be a significant issue but its contribution to adverse outcomes in the premature newborn remains understudied. We previously reported that approximately one in three very low birthweight (VLBW) premature newborns were exposed to alcohol in utero per maternal report. This exposure was linked to an increased odds of late onset sepsis (LOS) and bronchopulmonary dysplasia (BPD). In our animal models of in utero alcohol (ETOH) exposure, alveolar macrophage (AM) immune responses against bacteria were decreased in multiple species of newborn pups. These alterations included increased oxidant stress and delayed AM maturation but were improved by treatment with the antioxidant glutathione (GSH). In the newborn lung, the ontogeny of the mature AM remains controversial but fetal monocytes mature to AM via PU.1 in response to Granulocyte/Macrophage Colony Stimulating Factor (GM-CSF). In utero alcohol exposure decreases GM-CSF but its effects on circulating monocytes and different monocytic cell pools within the developing lung are unknown. For the adaptive immune response, antigen presentation depends on the MHC class II molecule human-leukocyte antigen DR (HLA-DR) and immune depression is characterized by decreased HLA-DR expression on antigen-presenting cells such as monocytes or macrophages. Recently, immune depressed states such as sepsis have been linked to increases in the check point inhibitor programmed cell death protein (PD)-1 and its ligand PD-L1. In neonatal mouse monocytes and AM, we found that in utero ETOH exposure increased immunodepression by increasing oxidant stress, diminishing zinc and GM-CSF, decreasing MHC-II expression, and increasing PD-1/PD-L1. However, GSH or Zinc treatments blocked these effects. In tracheal aspirates of intubated VLBW infants, HLA-DR was diminished in AM from babies who developed LOS while PD-L1 was increased in babies who developed LOS or BPD. In addition, PD- 1 and PD-L1 expressions were increased in AM from VLBW infants with in utero alcohol exposure compared to unexposed AM. Using established in utero ETOH mouse models plus translational studies of VLBW newborns, our overall objectives are to: 1) define in utero ETOH effects on innate and adaptive immune defenses of monocytes, monocyte-derived macrophages (MDM), and AM against bacterial challenges; 2) determine if clinically relevant interventions to diminish oxidant stress (GSH, GM-CSF and Zinc) will improve innate and adaptive responses; 3) validate ethanol metabolites Fatty Acid Ethyl Esters (FAEEs) and phosphatidylethanol (PEth) as biomarkers of in utero alcohol exposure in VLBW newborns and 4) determine phenotype plus innate and adaptive defenses of human monocyte, MDM, and AM samples from VLBW newborns with/without fetal alcohol exposure. Improving identification of VLBW newborns with fetal alcohol exposure and understanding its immunodepressive effects superimposed on immature immune defenses related to prematurity have important implications for this vulnerable population and their risk of LOS and BPD.