Beck M A, Matthews C C
Department of Nutrition, CB #7220, University of NC at Chapel Hill, Chapel Hill, NC 27599-7220, USA.
Proc Nutr Soc. 2000 Nov;59(4):581-5. doi: 10.1017/s0029665100000823.
Previous work in our laboratory demonstrated that a virus could undergo rapid mutation in a host deficient in Se, leading to a normally avirulent virus acquiring virulence due to genome changes. Once these mutations occur, even a host with adequate Se-nutriture is susceptible to the newly virulent virus. What influence does the deficiency in Se have on the immune response of the host? Infection with myocarditic strains of coxsackievirus induces an inflammatory response in the cardiac tissue. It is this immune response that induces the heart damage, rather than direct viral effects on the heart tissue. Chemokines are chemo-attractant molecules that are secreted during an infection in order to attract immune cells to the site of the injury, and have been found to be important for the development of coxsackievirus-induced myocarditis. We found that a deficiency in Se influences the expression of mRNA for the chemokine monocyte chemo-attractant protein-1, which may have implications for the development of myocarditis in the Se-deficient host. Expression of mRNA for interferon-gamma was also greatly decreased in the Se-deficient animal. Thus, a deficiency in Se can have profound effects on the host as well as on the virus itself. How the alteration of the immune response of the Se-deficient animal affects the development of the virulent genotype remains to be answered.
我们实验室之前的研究表明，病毒在缺硒宿主中可能会迅速发生突变，导致原本无毒力的病毒因基因组变化而获得毒力。一旦发生这些突变，即使是硒营养充足的宿主也易受新出现的有毒力病毒的感染。硒缺乏对宿主的免疫反应有何影响？感染柯萨奇病毒的心肌炎毒株会在心脏组织中引发炎症反应。正是这种免疫反应导致了心脏损伤，而非病毒对心脏组织的直接作用。趋化因子是在感染期间分泌的化学吸引分子，目的是将免疫细胞吸引到损伤部位，并且已发现其对柯萨奇病毒诱导的心肌炎的发展很重要。我们发现，硒缺乏会影响趋化因子单核细胞趋化蛋白-1的mRNA表达，这可能与缺硒宿主中心肌炎的发展有关。在缺硒动物中，γ-干扰素的mRNA表达也大幅下降。因此，硒缺乏会对宿主以及病毒本身产生深远影响。缺硒动物免疫反应的改变如何影响有毒力基因型的发展仍有待解答。
