Department of Veterinary Sciences, College of Agricultural Sciences and Natural Resources, Texas Tech University, Lubbock, TX, 79409, United States.
Department of Veterinary Sciences, College of Agricultural Sciences and Natural Resources, Texas Tech University, Lubbock, TX, 79409, United States; Department of Animal Science, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga, SP, 13635-900, Brazil.
Theriogenology. 2020 Jul 1;150:201-209. doi: 10.1016/j.theriogenology.2020.01.040. Epub 2020 Jan 20.
After parturition, dairy cows rely on an effective innate immune response, through the actions of neutrophils, macrophages, and antimicrobial peptides, to clear the uterus from pathogenic bacteria, such as E. coli, Bacteroides spp, F. necrophorum and T. pyogenes. However, the role of adaptive immunity in the postpartum uterus is less understood. In this review, we explore concepts of mucosal adaptive immunity and discuss recent findings regarding the efficacy of vaccines to reduce metritis in dairy cows. Areas of lymphocytic aggregates are seen throughout the bovine reproductive tract after parturition, but it is unknown if their development is influenced by previous exposure to pathogens or other intrinsic factors. Through the actions of Treg cells and γδ T cells, the uterus is an immune-tolerant environment during pregnancy. After parturition, the dynamics in the endometrial and circulating lymphocytic populations differ among cows that develop uterine diseases and healthy counterparts. However, the functionality of those cells has not yet been determined. It has been hypothesized that cows that fail to switch their uterine environment from an anti-inflammatory state prior to parturition to a pro-inflammatory state after calving are more susceptible to uterine infections. Given the nature of metritis related pathogens and the importance of innate immunity to uterine defense mechanisms, we speculate that an adaptive immunity biased towards a Th1/Th17 cellular response will provide best protection against uterine infections. Few studies have evaluated the efficacy of immunization in reducing the incidence of metritis in dairy cows revealing inconsistent findings.
分娩后，奶牛依靠有效的先天免疫反应，通过中性粒细胞、巨噬细胞和抗菌肽的作用，从子宫中清除大肠杆菌、拟杆菌属、坏死梭杆菌和酿脓链球菌等致病菌。然而，适应性免疫在产后子宫中的作用还不太清楚。在这篇综述中，我们探讨了黏膜适应性免疫的概念，并讨论了最近关于疫苗降低奶牛子宫内膜炎疗效的发现。在分娩后，牛的生殖道内可见到淋巴细胞聚集区，但尚不清楚其发育是否受到先前接触病原体或其他内在因素的影响。通过 Treg 细胞和 γδ T 细胞的作用，子宫在怀孕期间是一个免疫耐受的环境。分娩后，发生子宫疾病的奶牛和健康奶牛的子宫内膜和循环淋巴细胞群的动态变化不同。然而，这些细胞的功能尚未确定。有人假设，在分娩前未能将子宫环境从抗炎状态转变为产后期的促炎状态的奶牛更容易发生子宫感染。鉴于子宫内膜炎相关病原体的性质和先天免疫对子宫防御机制的重要性，我们推测偏向 Th1/Th17 细胞反应的适应性免疫将为子宫感染提供最佳保护。很少有研究评估免疫接种在降低奶牛子宫内膜炎发病率方面的效果，结果不一致。
