Pathogenesis of herpetic stromal keratitis in CCR5- and/or CXCR3-deficient mice.
OBJECTIVE
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.


METHODS
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).


RESULTS
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.


CONCLUSIONS
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.
Komatsu
Keiko
K
Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, Tottori, Japan.
Miyazaki
Dai
D
Morohoshi
Kei
K
Kuo
Chuan-Hui
CH
Kakimaru-Hasegawa
Akiko
A
Komatsu
Naoki
N
Namba
Sachiko
S
Haino
Makoto
M
Matsushima
Kouji
K
Inoue
Yoshitsugu
Y
D019264:Adoptive Transfer; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D054405:Chemokine CCL3 / Q000235:genetics / Q000378:metabolism; D054407:Chemokine CCL4 / Q000235:genetics / Q000378:metabolism; D054371:Chemokine CXCL11 / Q000235:genetics / Q000378:metabolism; D002522:Chlorocebus aethiops; D003319:Corneal Stroma / Q000294:innervation / Q000378:metabolism / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics; D018628:Gene Dosage; D018259:Herpesvirus 1, Human / Q000502:physiology; D007124:Immunoenzyme Techniques; D016849:Keratitis, Herpetic / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009504:Neutrophils / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D019713:Receptors, CCR5 / Q000172:deficiency* / Q000502:physiology; D054367:Receptors, CXCR3 / Q000172:deficiency* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012668:Trigeminal Ganglion / Q000821:virology; D014709:Vero Cells / Q000821:virology
C496534:Ccl3 protein, mouse; C496535:Ccl4 protein, mouse; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D054371:Chemokine CXCL11; C515203:Cxcl11 protein, mouse; C515188:Cxcr3 protein, mouse; D004279:DNA, Viral; D012333:RNA, Messenger; D019713:Receptors, CCR5; D054367:Receptors, CXCR3