Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington 98109, USA.
Nat Rev Immunol. 2012 Oct;12(10):687-95. doi: 10.1038/nri3295. Epub 2012 Sep 14.
Host restriction factors are potent, widely expressed intracellular blocks to viral replication that are an important component of the innate immune response to viral infection. However, viruses have evolved mechanisms that antagonize restriction factors. Through evolutionary pressure for both host survival and virus replication, an evolutionary 'arms race' has developed that drives continuous rounds of selection for beneficial mutations in the genes encoding restriction factors and their viral antagonists. Because viruses can evolve faster than their hosts, the innate immune system of modern-day vertebrates is for the most part optimized to defend against ancient viruses, rather than newer viral threats. Thus, the evolutionary history of restriction factors might, in part, explain why humans are susceptible or resistant to the viruses present in the modern world.
宿主限制因子是一种强有力的、广泛表达的细胞内阻止病毒复制的因子，是固有免疫反应抵抗病毒感染的重要组成部分。然而，病毒已经进化出了拮抗限制因子的机制。通过宿主生存和病毒复制的进化压力，一种进化的“军备竞赛”已经形成，促使编码限制因子及其病毒拮抗因子的基因不断进行有益突变的选择。由于病毒的进化速度比宿主快，因此现代脊椎动物的固有免疫系统在很大程度上是为了抵御古老的病毒，而不是针对新出现的病毒威胁进行优化。因此，限制因子的进化历史可能部分解释了为什么人类对现代世界存在的病毒易感性或抗性不同。
