School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia.
Fish Shellfish Immunol. 2012 May;32(5):732-40. doi: 10.1016/j.fsi.2012.01.022. Epub 2012 Jan 25.
Elevated water temperature can act as a stressor impacting the immune responses of molluscs, potentially increasing their susceptibility to microbial infections. Abalone are commercially important marine molluscs that have recently experienced disease outbreaks caused by a herpesvirus and Vibrio bacteria. Sampling of wild-caught Haliotis rubra showed a significant correlation between water temperature and both antiviral and antibacterial activity, with higher activity in summer than in winter months. However, antibacterial activity was compromised in favour of antiviral activity as the water temperatures peaked in summer. A controlled laboratory experiment was then used to investigate several immune responses of H. rubra, including total haemocyte count (THC), stimulated superoxide anion production (SO), antiviral activity against a model herpesvirus, herpes simplex virus type 1 and antibacterial activity against a representative pathogenic bacterium, Vibrio anguillarum, over one week after raising water temperature from 18 to 21 or 24 °C. THC and SO increased at day 1 and then dropped back to control levels by days 3 and 7. By comparison, the humoural immune parameters showed a delayed response with antibacterial and antiviral activity significantly increasing on days 3 and 7, respectively. Consistent with the field study, antibacterial activity became significantly depressed after prolonged exposure to elevated temperatures. A principal components analysis on the combined immune parameters showed a negative correlation between antiviral and antibacterial activity. SO was positively correlated to THC and neither of these cellular parameters were correlated to the humoural antimicrobial activity. Overall, this study indicates that abalone may have more resilience to viruses than bacterial pathogens under conditions of elevated temperature, such as those predicted under future climate change scenarios.
水温升高会成为应激源，影响贝类的免疫反应，使其更容易受到微生物感染。鲍鱼是具有商业价值的海洋贝类，最近爆发了由疱疹病毒和弧菌引起的疾病。对野生红鲍的采样显示，水温与抗病毒和抗菌活性之间存在显著相关性，夏季的活性高于冬季。然而，随着水温在夏季达到峰值，抗菌活性会受到抑制，转而有利于抗病毒活性。随后，进行了一项受控实验室实验，以研究红鲍的几种免疫反应，包括总血细胞计数（THC）、刺激超氧化物阴离子产生（SO）、针对模型疱疹病毒单纯疱疹病毒 1 的抗病毒活性以及针对代表性致病菌鳗弧菌的抗菌活性。在将水温从 18°C 升高到 21°C 或 24°C 1 周后，检测了这些反应。THC 和 SO 在第 1 天增加，然后在第 3 天和第 7 天降至对照水平。相比之下，体液免疫参数的反应较晚，抗菌和抗病毒活性分别在第 3 天和第 7 天显著增加。与野外研究一致，长时间暴露于高温会导致抗菌活性显著降低。对综合免疫参数进行的主成分分析显示，抗病毒和抗菌活性之间呈负相关。SO 与 THC 呈正相关，而这两个细胞参数均与体液抗菌活性无关。总的来说，这项研究表明，在高温条件下，鲍鱼可能比细菌病原体更能抵抗病毒，例如在未来气候变化情景下预测的那样。
