Leib David A, Alexander Diane E, Cox Douglas, Yin Jiyi, Ferguson Thomas A
Department of Microbiology and Immunology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
J Virol. 2009 Dec;83(23):12164-71. doi: 10.1128/JVI.01676-09. Epub 2009 Sep 16.
Autophagy is an important component of host innate and adaptive immunity to viruses. It is critical for the degradation of intracellular pathogens and for promoting antigen presentation. Herpes simplex virus type 1 (HSV-1) infection induces an autophagy response, but this response is antagonized by the HSV-1 neurovirulence gene product, ICP34.5. This is due, in part, to its interaction with the essential autophagy protein Beclin 1 (Atg6) via the Beclin-binding domain (BBD) of ICP34.5. Using a recombinant virus lacking the BBD, we examined pathogenesis and immune responses using mouse models of infection. The BBD-deficient virus (Delta68H) replicated equivalently to its marker-rescued counterpart (Delta68HR) at early times but was cleared more rapidly than Delta68HR from all tissues at late times following corneal infection. In addition, the infection of the cornea with Delta68H induced less ocular disease than Delta68HR. These results suggested that Delta68H was attenuated due to its failure to control adaptive rather than innate immunity. In support of this idea, Delta68H stimulated a significantly stronger CD4(+) T-cell-mediated delayed-type hypersensitivity response and resulted in significantly more production of gamma interferon and interleukin-2 from HSV-specific CD4(+) T cells than Delta68HR. Taken together, these data suggest a role for the BBD of ICP34.5 in precluding autophagy-mediated class II antigen presentation, thereby enhancing the virulence and pathogenesis of HSV-1.
自噬是宿主对病毒先天性和适应性免疫的重要组成部分。它对于细胞内病原体的降解以及促进抗原呈递至关重要。单纯疱疹病毒1型(HSV-1)感染会诱导自噬反应,但这种反应会被HSV-1神经毒力基因产物ICP34.5所拮抗。部分原因是它通过ICP34.5的Beclin结合域(BBD)与必需的自噬蛋白Beclin 1(Atg6)相互作用。我们使用一种缺乏BBD的重组病毒,通过小鼠感染模型研究了其发病机制和免疫反应。缺乏BBD的病毒(Delta68H)在早期与标记物拯救的对应病毒(Delta68HR)复制情况相当,但在角膜感染后的晚期,它比Delta68HR从所有组织中清除得更快。此外,Delta68H感染角膜引起的眼部疾病比Delta68HR少。这些结果表明,Delta68H减毒是由于其无法控制适应性免疫而非先天性免疫。支持这一观点的是,Delta68H刺激了明显更强的CD4(+) T细胞介导的迟发型超敏反应,并且与Delta68HR相比,HSV特异性CD4(+) T细胞产生的γ干扰素和白细胞介素-2明显更多。综上所述,这些数据表明ICP34.5的BBD在阻止自噬介导的II类抗原呈递中发挥作用,从而增强了HSV-1的毒力和发病机制。