Experimental Infectious Diseases and Cancer Research, Division of Infectious Diseases and Hospital Epidemiology.
J Infect Dis. 2014 Jan 15;209(2):255-64. doi: 10.1093/infdis/jit428. Epub 2013 Aug 9.
Epstein-Barr virus (EBV) infects >90% of the human population within the first 2 decades of life and establishes reversible latent infection in B cells. The stimuli that lead to switching from latent to lytic EBV infection in vivo are still elusive. Group A streptococci (GAS) are a common cause of bacterial pharyngotonsillitis in children and adolescents and colonize the tonsils and pharynx of up to 20% of healthy children. Thus, concomitant presence of EBV and GAS in the same individual is frequent. Here, we show that EBV carriers who are colonized with GAS shed EBV particles in higher numbers in their saliva, compared with EBV carriers not colonized with GAS. Messenger RNA levels of the master lytic regulatory EBV gene BZLF1 were more frequently detected in tonsils from EBV carriers colonized with GAS than from EBV carriers not colonized. Heat-killed GAS, potentially mimicking GAS colonization, elicited lytic EBV in latently infected lymphoblastoid cell lines (LCLs) partially via Toll-like receptor 2 triggering, as did purified GAS peptidoglycan. Thus, colonization by GAS might benefit EBV by increasing the EBV load in saliva and thereby enhancing the likelihood of EBV spread to other hosts.
EBV 病毒（EBV）在生命的头 20 年内感染了超过 90%的人类，并在 B 细胞中建立了可逆的潜伏感染。导致体内潜伏 EBV 感染向裂解感染转变的刺激因素仍不清楚。A 组链球菌（GAS）是儿童和青少年细菌性咽扁桃体炎的常见病因，并定植于多达 20%健康儿童的扁桃体和咽部。因此，同一人体内同时存在 EBV 和 GAS 是很常见的。在这里，我们发现与未定植 GAS 的 EBV 携带者相比，定植 GAS 的 EBV 携带者的唾液中 EBV 颗粒的脱落数量更多。与未定植 GAS 的 EBV 携带者相比，定植 GAS 的 EBV 携带者的扁桃体中 EBV 裂解调节基因 BZLF1 的信使 RNA 水平更频繁地被检测到。热灭活的 GAS，可能模拟 GAS 定植，通过 Toll 样受体 2 触发，部分引发潜伏感染的淋巴母细胞系（LCL）中的裂解 EBV，纯化的 GAS 肽聚糖也有同样效果。因此，GAS 的定植可能通过增加唾液中的 EBV 载量使 EBV 受益，从而增加 EBV 传播给其他宿主的可能性。
