MyD88 contribution to ocular surface homeostasis.
The cornea must maintain homeostasis, enabling rapid response to injury and microbial insult, to protect the eye from insult and infection. Toll-like receptors (TLRs) are critical to this innate immune response through the recognition and response to pathogens. Myeloid differentiation primary respon...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2017-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0182153 |
| _version_ | 1819040397463126016 |
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| author | Rose Y Reins Justin Courson Carolina Lema Rachel L Redfern |
| author_facet | Rose Y Reins Justin Courson Carolina Lema Rachel L Redfern |
| author_sort | Rose Y Reins |
| collection | DOAJ |
| description | The cornea must maintain homeostasis, enabling rapid response to injury and microbial insult, to protect the eye from insult and infection. Toll-like receptors (TLRs) are critical to this innate immune response through the recognition and response to pathogens. Myeloid differentiation primary response (MyD88) is a key signaling molecule necessary for Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R)-mediated immune defense and has been shown to be necessary for corneal defense during infection. Here, we examined the intrinsic role of TLR signaling in ocular surface tissues by determining baseline levels of inflammatory mediators, the response to mechanical stimuli, and corneal infection in MyD88-deficient mice (MyD88-/-). In addition, cytokine, chemokine, and matrix metalloproteinase (MMP) expression was determined in ocular surface cells exposed to a panel of TLR agonists. Compared to wild-type (WT) animals, MyD88-/- mice expressed lower MMP-9 levels in the cornea and conjunctiva. Corneal IL-1α, TNFα, and conjunctival IL-1α, IL-2, IL-6, and IL-9 levels were also significantly reduced. Additionally, CXCL1 and RANTES expression was lower in both MyD88-/- tissues compared to WT and IL-1R-/- mice. Interestingly, MyD88-/- mice had lower corneal sensitivities (1.01±0.31 gm/mm2) than both WT (0.59±0.16 gm/mm2) and IL-1R-/- (0.52±0.08 gm/mm2). Following Pseudomonas aeruginosa challenge, MyD88-/- mice had better clinical scores (0.5±0.0) compared to IL-1R-/- (1.5±0.6) and WT (2.3±0.3) animals, but had significantly more corneal bacterial isolates. However, no signs of infection were detected in inoculated uninjured corneas from either MyD88 or IL-1R-deficient mice. This work furthers our understanding of the importance of TLR signaling in corneal defense and immune homeostasis, showing that a lack of MyD88 may compromise the baseline innate response to insult. |
| first_indexed | 2024-12-21T09:08:27Z |
| format | Article |
| id | doaj.art-8e9488e1f7954ace9b15624788a71738 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-21T09:08:27Z |
| publishDate | 2017-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-8e9488e1f7954ace9b15624788a717382022-12-21T19:09:17ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-01128e018215310.1371/journal.pone.0182153MyD88 contribution to ocular surface homeostasis.Rose Y ReinsJustin CoursonCarolina LemaRachel L RedfernThe cornea must maintain homeostasis, enabling rapid response to injury and microbial insult, to protect the eye from insult and infection. Toll-like receptors (TLRs) are critical to this innate immune response through the recognition and response to pathogens. Myeloid differentiation primary response (MyD88) is a key signaling molecule necessary for Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R)-mediated immune defense and has been shown to be necessary for corneal defense during infection. Here, we examined the intrinsic role of TLR signaling in ocular surface tissues by determining baseline levels of inflammatory mediators, the response to mechanical stimuli, and corneal infection in MyD88-deficient mice (MyD88-/-). In addition, cytokine, chemokine, and matrix metalloproteinase (MMP) expression was determined in ocular surface cells exposed to a panel of TLR agonists. Compared to wild-type (WT) animals, MyD88-/- mice expressed lower MMP-9 levels in the cornea and conjunctiva. Corneal IL-1α, TNFα, and conjunctival IL-1α, IL-2, IL-6, and IL-9 levels were also significantly reduced. Additionally, CXCL1 and RANTES expression was lower in both MyD88-/- tissues compared to WT and IL-1R-/- mice. Interestingly, MyD88-/- mice had lower corneal sensitivities (1.01±0.31 gm/mm2) than both WT (0.59±0.16 gm/mm2) and IL-1R-/- (0.52±0.08 gm/mm2). Following Pseudomonas aeruginosa challenge, MyD88-/- mice had better clinical scores (0.5±0.0) compared to IL-1R-/- (1.5±0.6) and WT (2.3±0.3) animals, but had significantly more corneal bacterial isolates. However, no signs of infection were detected in inoculated uninjured corneas from either MyD88 or IL-1R-deficient mice. This work furthers our understanding of the importance of TLR signaling in corneal defense and immune homeostasis, showing that a lack of MyD88 may compromise the baseline innate response to insult.https://doi.org/10.1371/journal.pone.0182153 |
| spellingShingle | Rose Y Reins Justin Courson Carolina Lema Rachel L Redfern MyD88 contribution to ocular surface homeostasis. PLoS ONE |
| title | MyD88 contribution to ocular surface homeostasis. |
| title_full | MyD88 contribution to ocular surface homeostasis. |
| title_fullStr | MyD88 contribution to ocular surface homeostasis. |
| title_full_unstemmed | MyD88 contribution to ocular surface homeostasis. |
| title_short | MyD88 contribution to ocular surface homeostasis. |
| title_sort | myd88 contribution to ocular surface homeostasis |
| url | https://doi.org/10.1371/journal.pone.0182153 |
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