Cumulative physiological events influence the inflammatory response of the bovine udder to Escherichia coli infections during the transition period
Cumulative physiological events influence the inflammatory response of the bovine udder to Escherichia coli infections during the transition period
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DOI：
10.3168/jds.2006-696
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发表时间：
2007-01-01
影响因子：
3.5
通讯作者：
Paape, M. J.
中科院分区：
文献类型：
--
作者：
Burvenich, C.;Bannerman, D. D.;Paape, M. J.
分娩时出现的乳腺内大肠菌群感染的比例很高，在哺乳期的前60至70天内发展为以严重炎症体征和脓毒症为特征的疾病。在泌乳牛乳腺中，先天免疫系统在决定这些感染的结果中起着关键作用。自20世纪90年代初以来，与大肠杆菌乳腺炎发病机制有关的牛乳腺先天防御机制的研究显著增加。中性粒细胞是对乳房内感染的先天免疫应答的关键效应细胞，并且它们的功能受到在过渡期期间发生的许多生理事件的影响。当宿主免疫系统的完整性受到使宿主更易感的物理和生理条件的损害时，就会发生寄生虫感染。许多围产期奶牛的先天免疫系统是免疫功能低下的。围产期免疫抑制不太可能是单一生理因素的结果;更有可能的是，几个实体协同作用，对围产期奶牛的许多器官系统的功能产生深远影响。他们的防御系统无法调节先天免疫反应的复杂网络，导致病原体和炎症反应的不完全解决。在过去的30年里，大多数的努力都集中在中性粒细胞渗出，吞噬作用和细菌杀伤。这些功能如何调节大肠杆菌乳腺炎的临床结果，以及它们如何受到激素和代谢的影响一直是深入研究的主题，也是本文的重点。先天免疫的传入（传感）手臂，使主机识别各种各样的病原体，是激烈的研究兴趣的主题，并可能有助于在不同阶段的哺乳期乳房内感染的可变炎症反应。开发新的干预措施，调节炎症反应或有助于消除病原体或两者兼而有之，可能会提供治疗围产期奶牛乳腺炎的治疗前景。
A high proportion of intramammary coliform infections present at parturition develop disease characterized by severe inflammatory signs and sepsis during the first 60 to 70 d of lactation. In the lactating bovine mammary gland, the innate immune system plays a critical role in determining the outcome of these infections. Since the beginning of the 1990s, research has increased significantly on bovine mammary innate defense mechanisms in connection with the pathogenesis of coliform mastitis. Neutrophils are key effector cells of the innate immune response to intramammary infection, and their function is influenced by many physiological events that occur during the transition period. Opportunistic infections occur when the integrity of the host immune system is compromised by physical and physiological conditions that make the host more susceptible. The innate immune system of many periparturient cows is immunocompromised. It is unlikely that periparturient immunosuppression is the result of a single physiological factor; more likely, several entities act in concert, with profound effects on the function of many organ systems of the periparturient dairy cow. Their defense system is unable to modulate the complex network of innate immune responses, leading to incomplete resolution of the pathogen and the inflammatory reaction. During the last 30 yr, most efforts have been focused on neutrophil diapedesis, phagocytosis, and bacterial killing. How these functions modulate the clinical outcome of coliform mastitis, and how they can be influenced by hormones and metabolism has been the subject of intensive research and is the focus of this review. The afferent (sensing) arm of innate immunity, which enables host recognition of a diverse array of pathogens, is the subject of intense research interest and may contribute to the variable inflammatory response to intramammary infections during different stages of lactation. The development of novel interventions that modulate the inflammatory response or contribute to the elimination of the pathogen or both may offer therapeutic promise in the treatment of mastitis in periparturient cows.