Porcine innate and adaptative immune responses to influenza and coronavirus infections
Porcine innate and adaptative immune responses to influenza and coronavirus infections
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DOI：
10.1196/annals.1373.014
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发表时间：
2006-01-01
期刊：
影响因子：
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通讯作者：
Van Reeth, Kristien
中科院分区：
文献类型：
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作者：
Charley, Bernard;Riffault, Sabine;Van Reeth, Kristien
先天免疫反应和适应性免疫反应都有助于控制传染病，包括通过限制人畜共患病从动物宿主向人类传播。猪是人类感染流感病毒的重要动物宿主，也会自然感染冠状病毒，冠状病毒是包括最近出现的严重急性呼吸综合征(SARS)病毒在内的一组重要病毒。因此，猪对流感病毒和冠状病毒的先天免疫反应和适应性免疫反应的研究有助于更好地控制其自然宿主中的这些感染，本文将对此进行简要综述。在感染流感病毒的猪肺分泌物中发现了包括I型干扰素、肿瘤坏死因子-α和白介素6在内的促炎细胞因子，并与临床症状的强度相关，而预先接种流感疫苗则显著减少了攻击时肺内感染病毒和细胞因子的产生，这与临床保护有关。在冠状病毒感染的猪中也发现了I型干扰素的早期产生，包括在粘膜部位。冠状病毒诱导的干扰素涉及病毒糖蛋白和白细胞亚群之间的相互作用，白细胞亚群可能相当于浆细胞样树突状细胞，存在于粘膜和相关的淋巴组织中。鉴于干扰素介导的抗病毒和免疫调节作用，使用干扰素或干扰素诱导剂可能被证明是更好地控制猪流感病毒和冠状病毒感染的有效策略。由于流感和冠状病毒以粘膜表面为目标，适应性免疫反应必须在粘膜部位进行表征。因此，对流感病毒感染或接种的猪的鼻腔和肺部抗体反应进行了分析，这些猪表现出短暂的、但具有潜在保护性的局部IgA和Ig G抗体(Ab)反应。有趣的是，原发流感病毒感染导致肺CD8(+)T细胞和局部淋巴增殖反应的长期增加。感染呼吸道冠状病毒(PRCV)的猪在支气管淋巴结中发现了病毒特异性的抗体分泌细胞，而传染性胃肠炎冠状病毒(TGEV)在肠道组织中诱导了更多的IgA抗体分泌细胞，这说明了抗原给药途径在诱导局部免疫效应机制中的重要性。因此，猪病毒感染为评估免疫参数提供了有价值的模型，这些参数对于控制重要的人畜共患病毒感染的传播非常重要。
Both innate and adaptative immune responses contribute to the control of infectious diseases, including by limiting the spreading of zoonotic diseases from animal reservoirs to humans. Pigs represent an important animal reservoir for influenza virus infection of human populations and are also naturally infected by coronaviruses, an important group of viruses, which includes the recently emerged severe acute respiratory syndrome (SARS) virus. Studies on both innate and adaptative immune responses of pigs to influenza virus and coronaviruses contribute, therefore, to a better control of these infections in their natural hosts and will be briefly reviewed in this article. Pro-inflammatory cytokines, including type I interferon (IFN), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6), were found in lung secretions of influenza virus infected pigs, and correlated with the intensity of clinical signs, whereas prior vaccination against influenza strongly reduced the production of infectious virus and cytokines in the lungs upon challenge, which was associated with clinical protection. An early type I IFN production was also found in coronavirus infected pigs, including at mucosal sites. IFN induction by coronavirus is shown to involve interaction between a viral glycoprotein and a leukocyte subset, likely equivalent to plasmacytoid dendritic cells, present in the mucosae and associated lymphoid tissues. Given the IFN mediated antiviral and immunomodulatory effects, the use of IFN or IFN inducers may prove an efficient strategy for a better control of influenza virus and coronavirus infections in pigs. Because influenza and coronaviruses target mucosal surfaces, adaptative immune responses have to be characterized at mucosal sites. Thus, nasal and pulmonary antibody responses were analyzed in influenza virus infected or vaccinated pigs showing short-lived, but potentially protective local IgA and IgG antibody (Ab) responses. Interestingly, primary influenza virus infection induced long-lived increase of lung CD8(+) T cells and local lymphoproliferative responses. Pigs infected by a respiratory coronavirus (PRCV) showed virus-specific IgG Ab-secreting cells in the bronchial lymph nodes, whereas the transmissible gastroenteritis coronavirus (TGEV) induced more IgA Ab-secreting cells in gut tissues, which illustrates the importance of the route of antigen administration for inducing local immune effector mechanisms. Porcine viral infections provide, therefore, valuable models for evaluating the immune parameters that are important for controlling transmission of important viral zoonotic infections.