Marked induction of IL-6, haptoglobin and IFNγ following experimental BRSV infection in young calves
Marked induction of IL-6, haptoglobin and IFNγ following experimental BRSV infection in young calves
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DOI：
10.1016/j.vetimm.2004.09.025
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发表时间：
2005-02-10
影响因子：
1.8
通讯作者：
Heegaard, PMH
中科院分区：
文献类型：
--
作者：
Grell, SN;Tjornehoj, K;Heegaard, PMH
牛呼吸道合胞体病毒（BRSV）在世界范围内已被确认为与犊牛急性呼吸道疾病相关的一种重要病原体。一种感染模型已被开发出来，它能准确反映自然BRSV感染过程中的临床病程以及病理症状的出现和发展。在本研究描述的实验中，犊牛在13 - 21周龄时被感染，并在14周后再次感染。对整个感染期间的血液样本通过酶联免疫吸附测定（ELISA）分析急性期蛋白（触珠蛋白），并通过实时定量逆转录聚合酶链反应（RT - PCR）分析细胞因子白细胞介素 - 2（IL - 2）、白细胞介素 - 4（IL - 4）、白细胞介素 - 6（IL - 6）和干扰素 - γ（IFN - γ）的表达（外周血单个核细胞中的mRNA水平）。在对BRSV的首次感染中，随着临床症状的出现，干扰素 - γ、白细胞介素 - 6和触珠蛋白被显著诱导。干扰素 - γ的反应是双相的，在感染后第1 - 3天有一个早期峰值，在感染后第5 - 8天又有所增加。再次感染也导致干扰素 - γ的诱导，但没有临床症状以及白细胞介素 - 6和触珠蛋白的诱导。这些结果表明，与先天免疫反应相关的早期介质在首次接触病原体时被诱导，但在再次接触（再次感染）时不会被诱导，此时适应性免疫系统可能作为第一道防线发挥作用。（C）2004爱思唯尔公司。版权所有。
Bovine respiratory syncytial virus (BRSV) has been identified worldwide as an important pathogen associated with acute respiratory disease in calves. An infection model has been developed reflecting accurately the clinical course and die, development of pathological signs during a natural BRSV-infection. In the experiments described in the present study, calves were infected at 13-21 weeks of age and reinfected 14 weeks later. Blood samples front the entire infection period were analysed for acute phase protein (haptoglobin) by ELISA and for expression (mRNA level in peripheral blood mononuclear cells) of the cytokines interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6) and interferon-gamma (IFNgamma) by quantitative real-time reverse transcribed polymerase chain reaction (RT-PCR). IFNgamma, interleukin-6 and haptoglobin were markedly induced tot-ether with development of clinical signs in response to the first infection with BRSV The IFNgamma response was biphasic. with an early peak at day 1-3 post infection (p.i.) and a later increase between day 5 and 8 p.i. Reinfection also resulted in an induction of IFNgamma. but without induction of clinical signs, IL-6 and haptoglobin. These results indicate that early mediators connected with the innate responses are induced on a first encounter with the pathogen. but not on a second encounter (reinfection) where the adaptive immune system may act as the first line defence. (C) 2004 Elsevier B.V. All rights reserved.