细菌脂多糖处理对斑马鱼免疫球蛋白亚型表达水平的影响

Effect of Lipopolysaccharide Treatment on Expression of Ig Isotypes In Zebrafish

以20μg/mL的细菌脂多糖溶液对斑马鱼进行浸泡处理24h,用实时荧光定量PCR技术分析斑马鱼IgM、IgD和IgZ基因表达水平的变化。对照组斑马鱼中IgD和IgZ的表达水平相当,且均低于IgM,说明IgM可能具有更重要的生物学作用。细菌脂多糖处理后,斑马鱼3种Ig亚型的表达水平均表现出先升后降趋势,而且均在12h达到最高值。然而,IgM和IgZ的升高幅度显著高于IgD,而且IgM和IgZ在处理24h后表达水平仍然显著高于对照组,说明IgM和IgZ在鱼类病原防御中具有更重要的免疫作用。另外,IgM对细菌脂多糖处理的应答速度比IgZ更快,说明体液免疫系统能够更快地对细菌脂多糖处理作出有效应答,而黏膜免疫系统则反应较慢。

The healthy zebrafish were immersed in 20μg/mL LPS solution for 24 h, and the expressions of IgM, IgD and IgZ were analyzed by real-time fluorescent quantitative PCR. In the control group, the expression levels of IgZ and IgD were similar, lower than that of IgM, indicating a possible heighted role for the IgM isotype. After LPS challenge, the expression of all Ig isotypes was significantly increased with a peak in 12 h. However, the increase range of IgM and IgZ significantly exceeded that of. IgD, and their expression remained higher level than that in the control until 24h, indicating that IgM and IgZ played more important immunological role in response to antigen invasion. Moreover, IgM up-regulated its expression a bit more rapidly than IgZ did, hinting at the clue that the humoral immune system might respond to LPS challenge a bit faster than the mucosal immune system.