Komatsu Keiko, Miyazaki Dai, Morohoshi Kei, Kuo Chuan-Hui, Kakimaru-Hasegawa Akiko, Komatsu Naoki, Namba Sachiko, Haino Makoto, Matsushima Kouji, Inoue Yoshitsugu
Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, Tottori, Japan.
Curr Eye Res. 2008 Sep;33(9):736-49. doi: 10.1080/02713680802344716.
Herpetic stromal keratitis (HSK) is an immunopathological reaction to herpes simplex virus type 1 (HSV-1) corneal infection. It has been reported that CD4+ cells play the most important role in the pathogenesis of this disease. In this study, we have focused on two chemokine receptors, CCR5 and CXCR3, which are expressed on CD4+ Th1 cells in mice HSK model.
CCR5-deficient (CCR5KO), CXCR3-deficient (CXCR3KO), CCR5/CXCR3 double-deficient (DKO), and wild type (WT) mice (C57/BL6 background) were infected intracorneally with HSV-1 (CHR3 strain). The corneas were examined biomicroscopically, and cryosections of the corneas were examined histologically and immunohistochemically. Real-time RT-PCR and RNase protection assay (RPA) were performed, and the virus titers were measured in excised eyes and trigeminal ganglia (TG).
The HSK clinical severity in DKO mice was significantly lower than that in WT mice, and this was reversed by transfer of cells from the spleen of WT mice to DKO mice. Histologically, the numbers of T cells (CD4+ and CD8+ cells) and neutrophils infiltrating the cornea were significantly fewer in CCR5KO, CXCR3KO, and DKO mice. Transcript levels of immune-related cell surface marker in the eye by RPA were reduced in DKO mice. The expression of I-TAC was significantly increased in the cornea of CCR5KO mice, and MIP-1alpha and MIP-1beta were significantly lower in CXCR3KO mice than in WT mice by RT-PCR. There were no significant differences of virus titers in the eye and TG among any groups of mice except the increase in the TG of DKO mice on day 5 PI.
The suppression of chemotaxis and activation of CD4+ Th1 cells by the lacking of CXCR3 and CCR5 causes a decrease of other infiltrating cells, resulting in a lower severity of HSK. These results suggest that targeting chemokine receptors is a promising way to treat HSK.
疱疹性基质性角膜炎（HSK）是对单纯疱疹病毒1型（HSV-1）角膜感染的一种免疫病理反应。据报道，CD4+细胞在该疾病的发病机制中起最重要作用。在本研究中，我们聚焦于两种趋化因子受体，即CCR5和CXCR3，它们在小鼠HSK模型的CD4+ Th1细胞上表达。
将CCR5缺陷型（CCR5KO）、CXCR3缺陷型（CXCR3KO）、CCR5/CXCR3双缺陷型（DKO）和野生型（WT）小鼠（C57/BL6背景）经角膜内感染HSV-1（CHR3株）。对角膜进行生物显微镜检查，并对角膜冰冻切片进行组织学和免疫组织化学检查。进行实时RT-PCR和核糖核酸酶保护分析（RPA），并在摘除的眼睛和三叉神经节（TG）中测量病毒滴度。
DKO小鼠的HSK临床严重程度显著低于WT小鼠，而将WT小鼠脾脏细胞转移至DKO小鼠可逆转这种情况。组织学上，CCR5KO、CXCR3KO和DKO小鼠角膜中浸润的T细胞（CD4+和CD8+细胞）和中性粒细胞数量显著减少。RPA检测显示，DKO小鼠眼中免疫相关细胞表面标志物的转录水平降低。RT-PCR结果显示，CCR5KO小鼠角膜中I-TAC的表达显著增加，CXCR3KO小鼠角膜中MIP-1α和MIP-1β的表达显著低于WT小鼠。除感染后第5天DKO小鼠的TG中病毒滴度增加外，各小鼠组的眼睛和TG中的病毒滴度无显著差异。
CXCR3和CCR5的缺失对CD4+ Th1细胞趋化性和活化的抑制导致其他浸润细胞减少，从而使HSK的严重程度降低。这些结果表明，靶向趋化因子受体是治疗HSK的一种有前景的方法。
