Depletion of MCP-1 increases development of herpetic stromal keratitis by innate immune modulation.
Chemokines are important chemoattractant inflammatory molecules, but their interdependent network in disease pathogenesis remains unclear. Studies in mouse models have shown that herpetic stromal keratitis (SK) is produced by the consequence of a tissue-destructive immunoinflammatory reaction involving herpes simplex virus type 1 (HSV) infection. Here we found that ocular HSV infection leads to increased expression of monocyte chemoattractant protein-1 (MCP-1), one of the major chemoattractants for immune cells that express CCR2, in the SK cornea. However, MCP-1 is unlikely to be a chemoattractant for infiltrating Gr-1(+), CD11b(+) cells in SK, as these cells are found to be CCR2 negative. Nevertheless, infection of MCP-1(-/-) mice resulted in more severe SK lesion severity compared with WT mice (P<0.01). We demonstrated that the loss of MCP-1 in the SK cornea caused a significant overexpression of macrophage inflammatory protein-2 (MIP-2) (P<0.01) on days 2 and 4 postinfection and increased infiltration of inflammatory cells (Gr-1-high and CD11b(+)) expressing CXCR2, a receptor for MIP-2, into the cornea. Subsequently, increased infiltration of inflammatory cells accelerated by MIP-2 overexpression might result in the high production of inflammatory molecules, including vascular endothelial growth factor (VEGF) and IL-1beta in SK, as well as CpG oligodeoxynucleotide (ODN)-implanted eyes of MCP-1(-/-) mice. These results indicate that MCP-1 in the SK cornea might regulate the expression of other chemokines, as well as the infiltration of inflammatory cells and control development of SK.
Kim
Bumseok
B
Department of Microbiology and Pathobiology, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996-0845, USA.
Sarangi
Pranita P
PP
Lee
Yunsang
Y
Deshpande Kaistha
Shilpa
S
Lee
Sujin
S
Rouse
Barry T
BT
D000818:Animals; D039481:CD11b Antigen / Q000276:immunology; D018932:Chemokine CCL2 / Q000172:deficiency / Q000276:immunology* / Q000378:metabolism; D054426:Chemokine CXCL2; D018925:Chemokines / Q000096:biosynthesis / Q000276:immunology*; D003315:Cornea / Q000276:immunology / Q000378:metabolism / Q000821:virology; D018899:CpG Islands / Q000276:immunology; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology*; D018259:Herpesvirus 1, Human / Q000276:immunology* / Q000378:metabolism; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000821:virology; D053583:Interleukin-1beta / Q000096:biosynthesis / Q000276:immunology; D016849:Keratitis, Herpetic / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009841:Oligonucleotides / Q000276:immunology / Q000494:pharmacology; D054390:Receptors, CCR2; D019707:Receptors, Chemokine / Q000276:immunology / Q000378:metabolism; D013997:Time Factors
C515334:CCR2 protein, human; D039481:CD11b Antigen; C515335:Ccr2 protein, mouse; D018932:Chemokine CCL2; D054426:Chemokine CXCL2; D018925:Chemokines; C404915:Cxcl2 protein, mouse; C503133:Gr-1 protein, mouse; D053583:Interleukin-1beta; D009841:Oligonucleotides; D054390:Receptors, CCR2; D019707:Receptors, Chemokine