Cytokine responses in gnotobiotic pigs after infection with virulent or attenuated human rotavirus
Cytokine responses in gnotobiotic pigs after infection with virulent or attenuated human rotavirus
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DOI：
10.1128/jvi.80.1.372-382.2006
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发表时间：
2006-01-01
影响因子：
5.4
通讯作者：
Saif, LJ
中科院分区：
文献类型：
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作者：
Azevedo, MSP;Yuan, L;Saif, LJ
为了解细胞因子在轮状病毒感染中的作用，我们采用酶联免疫吸附试验检测了新生猪血清和肠道内容物中肿瘤坏死因子-α(TNF-α)和白介素6(IL-6)(促炎因子)、IL-12(Th1诱导剂)、γ-干扰素(Th1)、IL-4和IL-10(Th2)和转化生长因子-β(Th3)的动态变化，以及ELISPOT法检测回肠、脾和血液中单核细胞(CSC)对IL-12、IFN-γ、IL-4和IL-10的反应。猪接受人轮状病毒(HRV)强毒株Wa P1a[8]G1株(VirHRV)、减毒Wa HRV(AttHRV)或模拟(对照组)。在VirHRV组中，血清中的肿瘤坏死因子-α水平较早达到峰值，并保持在较高水平，而在AttHRV组中，则在较晚时达到峰值。在免疫后第1天，VirHRV组血清IL-6水平显著升高，而在两组接种后第3天，两组的血清IL-6水平均显著升高。在包括对照组在内的所有猪的血清中都检测到了IL-12，在两个HRV感染组中都有显著升高的峰值，表明IL-12在诱导对轮状病毒感染的免疫反应中起到了作用。在感染AttHRV的猪中，血清和肠道内容物中只有低和短暂的干扰素-伽马反应，而在感染病毒的猪中，干扰素-伽马反应显著增加和延长。这与病毒引起的腹泻和病毒血症不谋而合。VirHRV组回肠分泌干扰素-γ的细胞数显著高于对照组。两组回肠IL-4 CSCs数量均显著高于对照组。与AttHRV组中较低的水平相比，VirHRV组的血清中IL-10水平明显较高。然而，AttHRV组回肠和脾中IL-10 CSCs的数量明显高于VirHRV组，提示AttHRV诱导的Th2反应的启动延迟。与AttHRV感染或对照组相比，VirHRV感染后血清中干扰素-γ和IL-10的反应率显著升高。这些数据表明，轮状病毒感染期间Th1/Th2反应平衡，与AttHRV相比，VirHRV感染后早期细胞因子水平更高。绘制轮状病毒感染后细胞因子反应的动力学和模式图对于诱导HRV疫苗的保护性免疫具有重要意义。更高的保护率可能与更平衡的Th1和Th2型反应有关，但由VirHRV触发的更高的早期干扰素-γ(Th1)和促炎细胞因子的诱导也可能在VirHRV诱导的更高的肠道免疫球蛋白A应答和保护率中发挥重要作用。
To understand the role of cytokines during rotavirus infection, we assessed the kinetics of tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) (proinflammatory), IL-12 (Th1 inducer), gamma interferon (IFN-gamma) (Th1), IL-4 and IL-10 (Th2), and transforming growth factor beta (Th3) cytokine responses by enzyme-linked immunosorbent assay in serum and intestinal contents of neonatal gnotobiotic pigs and IL-12, IFN-gamma, IL-4, and IL-10 cytokine-secreting cell (CSC) responses of mononuclear cells from ileum, spleen, and blood by ELISPOT. Pigs received the virulent Wa P1A [8] G1 strain of human rotavirus (HRV) (VirHRV), attenuated Wa HRV (AttHRV), or mock (controls). The TNF-alpha levels peaked earlier and remained elevated in serum of the VirHRV group but peaked later in the AttHRV group. In serum, IL-6 was significantly elevated at postinoculation day (PID) 1 in the VirHRV group and at PID 3 in both HRV groups. The IL-12 was detected in serum of all pigs including controls with significantly elevated peaks in both HRV-infected groups, indicating a role for IL-12 in the induction of immune responses to rotavirus infection. Only low and transient IFN-gamma responses occurred in serum and intestinal contents of the AttHRV-infected pigs, compared to significantly higher and prolonged IFN-gamma responses in the VirHRV-infected pigs. This observation coincides with the diarrhea and viremia induced by VirHRV. The number of IFN-gamma-secreting cells was significantly higher in the ileum of the VirHRV group than in that of the controls. The number of IL-4 CSCs was significantly higher in ileum of both HRV groups than in that of the controls. Significantly higher levels of IL-10 in the serum occurred early in the VirHRV group, compared to lower levels in the AttHRV group. However, the number of IL-10 CSCs was significantly higher later in ileum and spleen of the AttHRV than in the VirHRV group, suggesting a delayed initiation of a Th2 response induced by AttHRV. A significantly higher percentage of pigs had IFN-gamma and IL-10 responses in serum after VirHRV infection than after AttHRV infection or in controls. These data indicate a balanced Th1/Th2 response during rotavirus infection, with higher cytokine levels early after infection with VirHRV compared to that with AttHRV. Mapping the kinetics and patterns of cytokine responses after rotavirus infection has important implications for induction of protective immunity by HRV vaccines. Higher protection rates may be associated with more balanced Th1- and Th2-type responses, but induction of higher earlier IFN-gamma (Th1) and proinflammatory cytokines triggered by VirHRV may also play an important role in the higher intestinal immunoglobulin A responses and protection rates induced by VirHRV.