The presence and potential functions of resident plasmacytoid dendritic cells (pDCs) in peripheral tissues is unclear. We report that pDCs constitutively populate naïve corneas and are increased during sterile injuries or acute herpes simplex virus 1 (HSV-1) keratitis. Their local depletion leads to severe clinical disease, nerve loss, viral dissemination to the trigeminal ganglion and draining lymph nodes, and mortality, while their local adoptive transfer limits disease. pDCs are the main source of HSV-1-induced IFN-α in the corneal stroma through TLR9, and they prevent re-programming of regulatory T cells (Tregs) to effector ex-Tregs. Clinical signs of infection are observed in pDC-depleted corneas, but not in pDC-sufficient corneas, following low-dose HSV-1 inoculation, suggesting their critical role in corneal antiviral immunity. Our findings demonstrate a vital role for corneal pDCs in the control of local viral infections.

尚不清楚外周组织中驻留的浆细胞样树突状细胞（pDC）的存在和潜在功能。我们报告说，pDC构成性地构成了幼稚的角膜，并且在无菌性损伤或急性单纯疱疹病毒1（HSV-1）角膜炎期间增加。它们的局部消耗导致严重的临床疾病，神经丧失，病毒扩散至三叉神经节和引流淋巴结以及死亡率，而它们的局部过继转移限制了疾病。pDC是通过TLR9在HSV-1诱导的角膜基质中的IFN-α的主要来源，它们可防止将调节性T细胞（Tregs）重新编程为效应子ex-Treg。在低剂量HSV-1接种后，在耗尽pDC的角膜中观察到了感染的临床体征，但在pDC充足的角膜中未观察到感染的体征，表明它们在角膜抗病毒免疫中起关键作用。