Ethanol effects on pulmonary innate immunity in a murine model of aging

项目摘要 老年人（≥ 65岁）越来越常见的行为是饮酒，其中40%的人饮酒。 每周3天，平均每天1-2杯，被认为是“适度”摄入。尽管老年人通常 虽然饮酒量比年轻人少，但酒精对健康的负面影响在老年人中可能更大 因为新陈代谢缓慢和药物的使用。酒精消费与全身性 炎症和细胞介导的免疫力下降，类似于“炎症老化”的影响，基础免疫力的升高， 炎症状态，其甚至存在于健康的老年个体中。此外，酒精使用和高龄 与其他无害病原体感染的发病率和严重程度增加有关， 肺炎链球菌;然而，酒精对老年人免疫力的影响还有待研究。 研究了肺泡巨噬细胞（AM）是肺内固有的免疫细胞，调节体内平衡 并成为响应肺部病原体而引发炎症的关键效应细胞。巨噬 病原体的刺激导致促分裂原活化蛋白激酶（MAPK）的细胞内活化， NF-κB途径，以及产生化学引诱物以在免疫细胞中募集和激活额外的免疫细胞。 感染部位。我们实验室以前的研究表明，高龄和急性体内乙醇 暴露独立地有助于减少巨噬细胞产生促炎细胞因子 用Toll样受体（TLR）激动剂离体刺激，其抑制p38 MAPK活化。 此外，初步的体内数据表明，适度的，多日的乙醇暴露导致降低 白细胞介素-（Il-）6、肿瘤坏死因子-（Tnf-）α和单核细胞趋化因子C-C基序趋化因子配体 与给予载体的老年小鼠和给予载体的年轻小鼠相比， 小鼠，无论乙醇暴露。鉴于这些发现，我们假设高龄和酒精 暴露可协同抑制小鼠AM中p38 MAPK的活化，导致 促炎介质的产生、吞噬作用受损和/或免疫细胞失调 感染后的恢复。为了验证这一点，在目标1中，我们将研究乙醇和先进燃料的影响。 年龄对MAPK活化和巨噬细胞功能的影响。经过多日的溶剂或乙醇处理后，我们将 调节离体肺泡巨噬细胞中的p38 MAPK表达，并测量吞噬作用和 促炎细胞因子和趋化因子。在目标2中，我们将评估CCL 2在肺免疫中的作用。 用CCL 2重组蛋白和体内S.肺炎感染。期间 在感染过程中，我们将通过体积描记法测量呼吸功能， 通过定量PCR检测负荷。总的来说，这些研究将扩大我们对免疫学的认识。 老年人饮酒的后果，并可能确定治疗目标，以改善 饮酒的老年人感染相关的健康结果。

Project Summary An increasingly common behavior in the elderly ( ≥ 65 years old) is alcohol consumption, with 40% consuming an average of 1-2 drinks/day 3 days a week, considered “moderate” intake. Even though the elderly typically drink less than younger adults do, the negative health effects of alcohol may be more potent in older drinkers due to slower metabolism and medication use. Alcohol consumption correlates with heightened systemic inflammation and reduced cell-mediated immunity, similar to the effects of “inflamm-aging,” the elevated basal inflammatory state which is present even in healthy elderly individuals. Further, alcohol use and advanced age are associated with increased incidence and severity of infection with otherwise innocuous pathogens such as Streptococcus pneumoniae; however, the effects of alcohol on immunity in the elderly have yet to be investigated. Alveolar macrophages (AMs), the resident innate immune cells in the lung, regulate homeostasis and become critical effector cells to initiate inflammation in response to pulmonary pathogens. Macrophage stimulation by pathogens results in intracellular activation of the mitogen-activated protein kinase (MAPK) and NF-κB pathways, and the production of chemoattractants to recruit and activate additional immune cells at the site of infection. Previous studies from our laboratory have shown that advanced age and acute in vivo ethanol exposure independently contribute to decreased production of pro-inflammatory cytokines by macrophages stimulated with Toll-like receptor (TLR) agonists ex vivo, which paralleled suppression of p38 MAPK activation. In addition, preliminary in vivo data show that moderate, multi-day ethanol exposure leads to decreased Interleukin- (Il-) 6, Tumor necrosis factor- (Tnf-) α, and monocyte chemoattractant C-C motif chemokine ligand 2 (Ccl2) gene expression in lung homogenates of aged mice, compared to aged mice given vehicle, and young mice regardless of ethanol exposure. Given these findings, we hypothesize that advanced age and ethanol exposure act synergistically to suppress p38 MAPK activation in murine AMs, leading to decreased production of pro-inflammatory mediators, impaired phagocytosis, and/or dysregulated immune cell recruitment following infection. To test this, in Aim 1, we will examine the impact of ethanol and advanced age on MAPK activation and macrophage function. Following multi-day vehicle or ethanol treatment, we will modulate p38 MAPK expression in alveolar macrophages ex vivo and measure phagocytosis and production of pro-inflammatory cytokines and chemokines. In Aim 2, we will assess the role of CCL2 in pulmonary immune cell recruitment after treatment with CCL2 recombinant protein and in vivo S. pneumoniae infection. During the course of infection, we will measure respiratory function by plethysmography and quantify lung bacterial burden by quantitative PCR. Collectively, these studies will expand our knowledge of the immunological consequences of alcohol consumption in the elderly, and potentially identify therapeutic targets to improve infection-related health outcomes in older adults who consume alcohol.