Division of Experimental Medicine, University of California San Francisco, San Francisco, CA 94110, USA.
J Immunol. 2012 Dec 15;189(12):5841-8. doi: 10.4049/jimmunol.1201679. Epub 2012 Nov 7.
Persistent viral infection is often associated with dysfunctional immune responses against unrelated pathogens. Lymphocytic choriomeningitis virus (LCMV) can establish acute or chronic infections in mice and is widely used as a model for persistent virus infections in humans. Mice infected with LCMV develop a transient defect in Ag-specific immunity against heterologous viral infection. Although it has been proposed that LCMV infection induces an immunosuppressed state within the host, our data show that infected mice successfully clear vaccinia virus through a mechanism that involves CD8(+) T cell-derived IFN-γ. This observation demonstrates that chronic LCMV infection does not impair protective immunity against heterologous viral challenge. Rather, a natural sterilizing immunity is induced following a primary infection that prevents a secondary infection. Our findings suggest a need to re-evaluate current thoughts about the immune suppression that might occur during a persistent infection.
持续性病毒感染通常与针对无关病原体的功能失调的免疫反应有关。淋巴细胞性脉络丛脑膜炎病毒（LCMV）可在小鼠中引发急性或慢性感染，并且被广泛用作人类持续性病毒感染的模型。感染 LCMV 的小鼠会对异源病毒感染产生短暂的抗原特异性免疫缺陷。尽管有人提出 LCMV 感染会在宿主内诱导免疫抑制状态，但我们的数据表明，感染的小鼠通过涉及 CD8(+)T 细胞衍生的 IFN-γ的机制成功清除了牛痘病毒。这一观察结果表明，慢性 LCMV 感染不会损害针对异源病毒挑战的保护性免疫。相反，初次感染后会诱导一种天然的杀菌性免疫，从而阻止二次感染。我们的研究结果表明，有必要重新评估当前关于持续性感染期间可能发生的免疫抑制的观点。
