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McClellan SA, Wright R, Muhammed F, Hazlett LD. Impact of Airborne Exposure to PM 10 Increases Susceptibility to P. aeruginosa Infection. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2024; 21:722. [PMID: 38928968 PMCID: PMC11203766 DOI: 10.3390/ijerph21060722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024]
Abstract
The effects of exposure to airborne particulate matter with a size of 10 μm or less (PM10) on C57BL/6 mouse corneas, their response to Pseudomonas aeruginosa (PA) infection, and the protective effects of SKQ1 were determined. C57BL/6 mouse corneas receiving PBS or SKQ1 were exposed to control (air) or PM10 for 2 weeks, infected, and the disease was documented by clinical score, PMN quantitation, bacterial plate count, RT-PCR and Western blot. PBS-treated, PM10-exposed corneas did not differ at 1 day postinfection (dpi), but exhibited earlier (3 dpi) corneal thinning compared to controls. By 3 dpi, PM10 significantly increased corneal mRNA levels of several pro-inflammatory cytokines, but decreased IL-10, NQO1, GR1, GPX4, and Nrf2 over control. SKQ1 reversed these effects and Western blot selectively confirmed the RT-PCR results. PM10 resulted in higher viable bacterial plate counts at 1 and 3 dpi, but SKQ1 reduced them at 3 dpi. PM10 significantly increased MPO in the cornea at 3 dpi and was reduced by SKQ1. SKQ1, used as an adjunctive treatment to moxifloxacin, was not significantly different from moxifloxacin alone. Exposure to PM10 increased the susceptibility of C57BL/6 to PA infection; SKQ1 significantly reversed these effects, but was not effective as an adjunctive treatment.
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Affiliation(s)
| | | | | | - Linda D. Hazlett
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (S.A.M.); (R.W.); (F.M.)
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Wu J, Wang W, Yuan F, Zheng J, Zhang W, Guo H, Wang L, Dai C, Han F, Wu X, Gao J. CXCL16 exacerbates Pseudomonas aeruginosa keratitis by promoting neutrophil activation. Int Immunopharmacol 2024; 127:111375. [PMID: 38154213 DOI: 10.1016/j.intimp.2023.111375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 12/04/2023] [Accepted: 12/11/2023] [Indexed: 12/30/2023]
Abstract
Pseudomonas aeruginosa (PA) keratitis is a major cause of blindness characterized by corneal inflammation. In a murine model of PA keratitis, we assessed the detrimental effects of CXC chemokine ligand 16 (CXCL16). Quantitative PCR (qPCR), western blotting (WB) and immunofluorescence were used to measure the expression and localization of CXCL16 and its receptor, CXC chemokine receptor 6 (CXCR6). Clinical scores, plate counting, and hematoxylin-eosin staining were used to assess infection severity and its exacerbation by CXCL16. Immunofluorescence, myeloperoxidase assays, and flow cytometry were used to detect neutrophil activity and colocalization with CXCR6. WB and immunofluorescence were used to measure levels of reactive oxygen species (ROS) and matrix metalloproteinases (MMPs). These methods also were used to measure the activation of downstream NF-κB signaling and its positive feedback on CXCL16 expression. ELISA, flow cytometry, and qPCR were used to measure the expression of CXCL2 and T helper 17 (Th17) cell-related genes. CXCL16 and CXCR6 expression was increased in infected corneas. Topical application of CXCL16 exacerbated keratitis by increasing corneal bacterial load and promoting neutrophil infiltration, whereas neutralizing antibody against CXCL16 had the opposite effect. CXCL16 also increased ROS and MMP levels. This neutrophil activation may be caused by its positive feedback with the NF-κB pathway and the upregulation of CXCL2 and Th17 cell related-genes. These data suggest that CXCL16 is an attractive therapeutic target for PA keratitis.
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Affiliation(s)
- Jiayin Wu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China; Department of Ophthalmology, Liaocheng People's Hospital, Shandong University, Liaocheng, Shandong 252000, China
| | - Wentao Wang
- Department of Surgery, Liaocheng Tumor Hospital, Liaocheng, Shandong 252000, China
| | - Fengjiao Yuan
- Joint Laboratory for Translational Medicine Research, Liaocheng People's Hospital, Shandong University, Liaocheng, Shandong 252000, China
| | - Juan Zheng
- Joint Laboratory for Translational Medicine Research, Liaocheng People's Hospital, Shandong University, Liaocheng, Shandong 252000, China
| | - Weihua Zhang
- Department of Ophthalmology, Liaocheng People's Hospital, Shandong University, Liaocheng, Shandong 252000, China
| | - Hui Guo
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China
| | - Leyi Wang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China
| | - Chenyang Dai
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China
| | - Fang Han
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China
| | - Xinyi Wu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, China
| | - Jianlu Gao
- Department of Ophthalmology, Liaocheng People's Hospital, Shandong University, Liaocheng, Shandong 252000, China.
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Wu J, Gao J, Yi L, Gao N, Wang L, Zhu J, Dai C, Sun L, Guo H, Yu FSX, Wu X. Protective effects of resolvin D1 in Pseudomonas aeruginosa keratitis. Mol Immunol 2023; 158:35-42. [PMID: 37104999 DOI: 10.1016/j.molimm.2023.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 03/31/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023]
Abstract
PURPOSE Here, we explored the protective effects of resolvin D1 (RvD1) in Pseudomonas aeruginosa (PA) keratitis. METHODS C57BL/6 (B6) mice were used as an animal model of PA keratitis. Plate counting and clinical scores were used to assess the severity of the infection and the therapeutic effects of RvD1 in the model. Myeloperoxidase assay was used to detect neutrophil infiltration and activity. Quantitative PCR (qPCR) was used to examine the expression of proflammatory and anti-inflammatory mediators. Immunofluorescence staining and qPCR were performed to identify macrophage polarization. RESULTS RvD1 treatment alleviated PA keratitis severity by decreasing corneal bacterial load and inhibiting neutrophil infiltration in the mouse model. Furthermore, RvD1 treatment decreased mRNA levels of TNF-α, IFN-γ, IL-1β, CXCL1, and S100A8/9 while increasing those of IL-1RA, IL-10, and TGF-β1. RvD1 treatment also reduced the aggregation of M1 macrophages and increased that of M2 macrophages. RvD1 provided an auxiliary effect in gatifloxacin-treated mice with PA keratitis. CONCLUSION Based on these findings, RvD1 may improve the prognosis of PA keratitis by inhibiting neutrophil recruitment and activity, dampening the inflammatory response, and promoting M2 macrophage polarization. Thus, RvD1 may be a potential complementary therapy for PA keratitis.
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Affiliation(s)
- Jiayin Wu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250014, China; Department of Ophthalmology, Liaocheng People's Hospital, Liaocheng, Shandong 252000, China
| | - Jianlu Gao
- Department of Ophthalmology, Liaocheng People's Hospital, Liaocheng, Shandong 252000, China
| | - Lili Yi
- Joint Laboratory for Translational Medicine Research, Liaocheng People's Hospital, Liaocheng 252000, China
| | - Nan Gao
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Leyi Wang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250014, China
| | - Jing Zhu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250014, China
| | - Chenyang Dai
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250014, China
| | - Lin Sun
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250014, China
| | - Hui Guo
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250014, China
| | - Fu-Shin X Yu
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Xinyi Wu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong 250014, China.
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Somayajulu M, McClellan SA, Bessert DA, Pitchaikannu A, Hazlett LD. Ocular Effects of Glycyrrhizin at Acidic and Neutral pH. Front Cell Infect Microbiol 2022; 11:782063. [PMID: 35127554 PMCID: PMC8814321 DOI: 10.3389/fcimb.2021.782063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/09/2021] [Indexed: 12/01/2022] Open
Abstract
Purpose To test the effects of acidic vs. neutral pH glycyrrhizin (GLY) on the unwounded and wounded normal mouse cornea and after infection with Pseudomonas aeruginosa isolates KEI 1025 and multidrug-resistant MDR9. Methods Acidic or neutral GLY vs. phosphate-buffered saline (PBS) was topically applied to normal or wounded corneas of C57BL/6 mice. In unwounded corneas, goblet cells and corneal nerves were stained and quantitated. After wounding, corneas were fluorescein stained and photographed using a slit lamp. Mice also were infected with KEI 1025 or MDR9 and the protective effects of GLY pH evaluated comparatively. Results In the unwounded cornea, application of acidic or neutral GLY vs. PBS reduced the number of bulbar conjunctival goblet cells but did not alter corneal nerve density. Similar application of GLY to scarified corneas delayed wound closure. After KEI 1025 infection, none of the GLY vs. PBS-treated corneas perforated; GLY treatment also decreased plate count (neutral pH more effective) and reduced MPO and several cytokines. Similarly, for MDR9, GLY at either pH was protective and also enhanced the effects of moxifloxacin to which MDR9 is resistant. Conclusion Acidic or neutral pH GLY decreased goblet cell number but had no effect on nerve density. After corneal wounding, GLY at either pH (1) delayed wound closure and, (2) after infection, decreased keratitis when used alone or in combination with moxifloxacin. Neutral pH did not alter the therapeutic effect of GLY and would be preferred if used clinically.
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Me R, Gao N, Zhang Y, Lee PSY, Wang J, Liu T, Standiford TJ, Mi QS, Yu FSX. IL-36α Enhances Host Defense against Pseudomonas aeruginosa Keratitis in C57BL/6 Mouse Corneas. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 207:2868-2877. [PMID: 34686582 PMCID: PMC8612993 DOI: 10.4049/jimmunol.2001246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 09/21/2021] [Indexed: 12/13/2022]
Abstract
The IL-36 cytokines are known to play various roles in mediating the immune response to infection in a tissue- and pathogen-dependent manner. The present study seeks to investigate the role of IL-36R signaling in C57BL/6 mouse corneas in response to Pseudomonas aeruginosa infection. IL-36α-/-, IL-36γ-/-, and IL-36R-/- mice had significantly more severe keratitis than wild-type mice. At six hours postinfection, IL-36α pretreatment augmented P. aeruginosa-induced expression of IL-1Ra, IL-36γ, LCN2, and S100A8/A9. At one day postinfection, exogenous IL-36α suppressed, whereas IL-36α deficiency promoted, the expression of IL-1β. At three days postinfection, exogenous IL-36α suppressed Th1 but promoted Th2 immune response. IL-36α stimulated the infiltration of IL-22-expressing immune cells, and IL-22 neutralization resulted in more severe keratitis. IL-36α alone stimulated dendritic cell infiltration in B6 mouse corneas. Taken together, our study suggests that IL-36R signaling plays a protective role in the pathogenesis of P. aeruginosa keratitis by promoting the innate immune defense, Th2, and/or Th22/IL-22 immune responses. Exogenous IL-36α might be a potential therapy for improving the outcome of P. aeruginosa keratitis.
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Affiliation(s)
- Rao Me
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI
| | - Nan Gao
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI
| | - Yangyang Zhang
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI
| | - Patrick S Y Lee
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI
| | - Jie Wang
- Center for Cutaneous Biology and Immunology, Department of Dermatology and Immunology Program, Henry Ford Cancer Institute, Henry Ford Health System, Detroit, MI; and
| | - Tingting Liu
- Center for Cutaneous Biology and Immunology, Department of Dermatology and Immunology Program, Henry Ford Cancer Institute, Henry Ford Health System, Detroit, MI; and
| | - Theodore J Standiford
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI
| | - Qing-Sheng Mi
- Center for Cutaneous Biology and Immunology, Department of Dermatology and Immunology Program, Henry Ford Cancer Institute, Henry Ford Health System, Detroit, MI; and
| | - Fu-Shin X Yu
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI;
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McClellan S, Pitchaikannu A, Wright R, Bessert D, Iulianelli M, Hazlett LD, Xu S. Prophylactic Knockdown of the miR-183/96/182 Cluster Ameliorates Pseudomonas aeruginosa-Induced Keratitis. Invest Ophthalmol Vis Sci 2021; 62:14. [PMID: 34919120 PMCID: PMC8684302 DOI: 10.1167/iovs.62.15.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Previously, we demonstrated that miR-183/96/182 cluster (miR-183C) knockout mice exhibit decreased severity of Pseudomonas aeruginosa (PA)-induced keratitis. This study tests the hypothesis that prophylactic knockdown of miR-183C ameliorates PA keratitis indicative of a therapeutic potential. Methods Eight-week-old miR-183C wild-type and C57BL/6J inbred mice were used. Locked nucleic acid-modified anti-miR-183C or negative control oligoribonucleotides with scrambled sequences (NC ORNs) were injected subconjunctivally 1 day before and then topically applied once daily for 5 days post-infection (dpi) (strain 19660). Corneal disease was graded at 1, 3, and 5 dpi. Corneas were harvested for RT-PCR, ELISA, immunofluorescence (IF), myeloperoxidase and plate count assays, and flow cytometry. Corneal nerve density was evaluated in flatmounted corneas by IF staining with anti-β-III tubulin antibody. Results Anti-miR-183C downregulated miR-183C in the cornea. It resulted in an increase in IL-1β at 1 dpi, which was decreased at 5 dpi; fewer polymorphonuclear leukocytes (PMNs) at 5 dpi; lower viable bacterial plate count at both 1 and 5 dpi; increased percentages of MHCII+ macrophages (Mϕ) and dendritic cells (DCs), consistent with enhanced activation/maturation; and decreased severity of PA keratitis. Anti-miR-183C treatment in the cornea of naïve mice resulted in a transient reduction of corneal nerve density, which was fully recovered one week after the last anti-miR application. miR-183C targets repulsive axon-guidance receptor molecule Neuropilin 1, which may mediate the effect of anti-miR-183C on corneal nerve regression. Conclusions Prophylactic miR-183C knockdown is protective against PA keratitis through its regulation of innate immunity, corneal innervation, and neuroimmune interactions.
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Affiliation(s)
- Sharon McClellan
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Ahalya Pitchaikannu
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Robert Wright
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Denise Bessert
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Mason Iulianelli
- Departments of Biological Sciences and Public Health, College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan, United States
| | - Linda D Hazlett
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Shunbin Xu
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
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The Rcs Stress Response System Regulator GumB Modulates Serratia marcescens-Induced Inflammation and Bacterial Proliferation in a Rabbit Keratitis Model and Cytotoxicity In Vitro. Infect Immun 2021; 89:e0011121. [PMID: 33820815 DOI: 10.1128/iai.00111-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In this study, we tested the hypothesis that the conserved bacterial IgaA-family protein, GumB, mediates microbial pathogenesis associated with Serratia marcescens ocular infections through regulation of the Rcs stress response system. The role of the Rcs system and bacterial stress response systems for microbial keratitis is not known, and the role of IgaA proteins in mammalian pathogenesis models has only been tested with partial-function allele variants of Salmonella. Here, we observed that an Rcs-activated gumB mutant had a >50-fold reduction in proliferation compared to the wild type within rabbit corneas at 48 h and demonstrated a notable reduction in inflammation based on inflammatory signs, including the absence of hypopyons, and proinflammatory markers measured at the RNA and protein levels. The gumB mutant phenotypes could be complemented by wild-type gumB on a plasmid. We observed that bacteria with an inactivated Rcs stress response system induced high levels of ocular inflammation and restored corneal virulence to the gumB mutant. The high virulence of the ΔrcsB mutant was dependent upon the ShlA cytolysin transporter ShlB. Similar results were found for testing the cytotoxic effects of wild-type and mutant bacteria on a human corneal epithelial cell line in vitro. Together, these data indicate that GumB regulates virulence factor production through the Rcs system, and this overall stress response system is a key mediator of a bacterium's ability to induce vision-threatening keratitis.
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Chen Z, Ceballos-Francisco D, Guardiola FA, Huang D, Esteban MÁ. Skin wound healing in gilthead seabream (Sparus aurata L.) fed diets supplemented with arginine. FISH & SHELLFISH IMMUNOLOGY 2020; 104:347-358. [PMID: 32544556 DOI: 10.1016/j.fsi.2020.06.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/03/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Dietary administration of arginine on the wound healing process of gilthead seabream was studied. Two replicates of fish (n = 8) were fed with either a commercial diet [control diet (CON), no arginine added] and the CON diet supplemented with 1% arginine (ARG1) or with 2% arginine (ARG2) for 30 days. Afterward, half of the fish were sampled while the other half were injured and continued to be fed the same diet for an extra week. Results by image analysis showed that the wound closure rate was significantly improved in fish that were fed the ARG1 diet, compared with those in the CON group. After seven days of wound healing, the aminotransferase and creatine kinase levels in the serum and the protease and peroxidase activities in the skin mucus were down-regulated, while the immunoglobulin M level in the skin mucus was up-regulated in the ARG1 group after wounding and in the CON group before wounding. Compared with the CON diet, the ARG1 diet remarkedly depressed the gene expression of mpo, il-8, and tnf-α, and enhanced the gene expression of tgf-β1, igf-1, pcna, krt2, mmp9, fn1α, and colIα and the antioxidant enzyme cat in the skin tissues after wounding. Furthermore, compared with both the ARG1 and the CON groups, negative effects of the ARG2 diet on wound healing were demonstrated. In conclusion, a 1% arginine supplementation facilitates skin wound healing and prevents a systemic inflammation reaction by alleviating the inflammatory response and enhancing the re-epithelialization and ECM biosynthesis in skin wound sites.
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Affiliation(s)
- Zhichu Chen
- Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus of International Excellence, Campus Mare Nostrum, University of Murcia, 30100, Murcia, Spain
| | - Diana Ceballos-Francisco
- Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus of International Excellence, Campus Mare Nostrum, University of Murcia, 30100, Murcia, Spain
| | - Francisco A Guardiola
- Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus of International Excellence, Campus Mare Nostrum, University of Murcia, 30100, Murcia, Spain
| | - Dong Huang
- The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture) & the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, PR China
| | - M Ángeles Esteban
- Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus of International Excellence, Campus Mare Nostrum, University of Murcia, 30100, Murcia, Spain.
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Gao N, Me R, Dai C, Yu FSX. ISG15 Acts as a Mediator of Innate Immune Response to Pseudomonas aeruginosa Infection in C57BL/6J Mouse Corneas. Invest Ophthalmol Vis Sci 2020; 61:26. [PMID: 32416603 PMCID: PMC7405721 DOI: 10.1167/iovs.61.5.26] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/30/2020] [Indexed: 01/04/2023] Open
Abstract
Purpose IFN-stimulated gene (ISG) 15 is a type 1 IFN-induced protein and known to modify target proteins in a manner similar to ubiquitylation (protein conjugation by ISG15 is termed ISGylation). We sought to determine the role of ISG15 and its underlying mechanisms in corneal innate immune defense against Pseudomonas aeruginosa keratitis. Methods ISG15 expression in cultured human corneal epithelial cells (HCECs) and mouse corneas was determined by PCR and Western blot analysis. Gene knockout mice were used to define the role of ISG15 signaling in controlling the severity of P. aeruginosa keratitis, which was assessed with photographing, clinical scoring, bacterial counting, myeloperoxidase assay, and quantitative PCR determination of cytokine expression. Integrin LFA-1 inhibitor was used to assess its involvement of ISG15 signaling in P. aeruginosa-infected corneas. Results Heat-killed P. aeruginosa induced ISG15 expression in cultured HCECs and accumulation in the conditioned media. Isg15 deficiency accelerated keratitis progress, suppressed IFNγ and CXCL10, and promoted IL-1β while exhibiting no effects on IFNα expression. Moreover, exogenous ISG15 protected the corneas of wild-type mice from P. aeruginosa infection while markedly reducing the severity of P. aeruginosa keratitis in type 1 IFN-receptor knockout mice. Exogenous ISG15 increased bacteriostatic activity of B6 mouse corneal homogenates, and inhibition of LFA-1 exacerbated the severity of and abolished protective effects of ISG15 on P. aeruginosa keratitis. Conclusions Type 1 INF-induced ISG15 regulates the innate immune response and greatly reduces the susceptibility of B6 mouse corneas to P. aeruginosa infection in an LFA-1-dependent manner.
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Benton AH, Jackson MD, Wong SM, Dees JL, Akerley BJ, Marquart ME. A Transcriptional Activator of Ascorbic Acid Transport in Streptococcus pneumoniae Is Required for Optimal Growth in Endophthalmitis in a Strain-Dependent Manner. Microorganisms 2019; 7:microorganisms7090290. [PMID: 31450542 PMCID: PMC6780617 DOI: 10.3390/microorganisms7090290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/18/2019] [Accepted: 08/21/2019] [Indexed: 11/16/2022] Open
Abstract
Streptococcus pneumoniae is among the top causes of bacterial endophthalmitis, an infectious disease of the intraocular fluids. The mechanisms by which S. pneumoniae grows and thrives in the intraocular cavity are not well understood. We used a bacterial genome-wide assessment tool (transposon insertion site sequencing) to determine genes essential for S. pneumoniae growth in vitreous humor. The results indicated that an ascorbic acid (AA) transport system subunit was important for growth. We created an isogenic gene deletion mutant of the AA transcriptional activator, ulaR2, in 2 strains of S. pneumoniae. Growth curve analysis indicated that ulaR2 deletion caused attenuated growth in vitro for both strains. However, in vivo vitreous humor infection in rabbits with either strain determined that ulaR2 was necessary for growth in one strain but not the other. These results demonstrate that ulaR2 may be important for fitness during S. pneumoniae endophthalmitis depending on the background of the strain.
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Affiliation(s)
- Angela H Benton
- University of Mississippi Medical Center, Jackson, MS 39216, USA
- Current affiliation: Virginia Tech, Blacksburg, VA 24061, USA
| | | | - Sandy M Wong
- University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Justine L Dees
- University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Brian J Akerley
- University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Mary E Marquart
- University of Mississippi Medical Center, Jackson, MS 39216, USA.
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Hazlett LD, Ekanayaka SA, McClellan SA, Francis R. Glycyrrhizin Use for Multi-Drug Resistant Pseudomonas aeruginosa: In Vitro and In Vivo Studies. Invest Ophthalmol Vis Sci 2019; 60:2978-2989. [PMID: 31311033 PMCID: PMC6944246 DOI: 10.1167/iovs.19-27200] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 06/14/2019] [Indexed: 02/07/2023] Open
Abstract
Purpose Our purpose was to test glycyrrhizin (GLY) effects and ciprofloxacin interactions on multidrug resistant (MDR) isolates of Pseudomonas aeruginosa in vitro and in vivo in a mouse model of keratitis. Methods A Hardy-disk tested antibiotic sensitivity of isolates MDR9 (nonocular) and B1045 (ocular). GLY MIC (both isolates) and ciprofloxacin was determined spectrophotometrically. A live/dead assay using confocal microscopy and plate count, tested GLY effects on bacterial permeabilization/viability. Proteomics profiled bacterial efflux pumps (MDR9 vs. PAO1); RT-PCR comparatively tested GLY effects on their mRNA expression levels. The activity of efflux pumps was tested using ethidium bromide (EB); and scanning electron microscopy (SEM) visualized the effects of GLY treatment of bacteria. A combination of GLY and ciprofloxacin was tested in C57BL/6 mice (begun 18 hours after infection) and disease scored, photographed and MPO and plate counts done. Results MDR9 was resistant to 6/12 and B1045 to 7/12 antibiotics (both to ciprofloxacin). MIC GLY for MDR9 was 40 mg/mL and 15 mg/mL for B1045. Ciprofloxacin MIC (32 μg/mL) was reduced 2-fold to 16 μg/mL when ciprofloxacin and GLY were combined. GLY altered bacterial membrane permeability and reduced viability. Proteomics revealed increased efflux pumps in MDR9 versus PAO1; GLY reduced their mRNA expression levels and EB suggested decreased activity. In C57BL/6 mice, treatment with GLY and ciprofloxacin versus ciprofloxacin, significantly reduced clinical scores, plate count, and MPO. Conclusions GLY decreases MDR by: altering bacterial parameters, including viability and efflux pump activity. In vivo, it increases the effectiveness of ciprofloxacin, reducing ocular disease, plate count, and MPO activity.
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MESH Headings
- Animals
- Anti-Bacterial Agents/therapeutic use
- Anti-Inflammatory Agents/therapeutic use
- Ciprofloxacin/therapeutic use
- Corneal Ulcer/drug therapy
- Corneal Ulcer/microbiology
- Drug Resistance, Multiple, Bacterial/drug effects
- Drug Therapy, Combination
- Eye Infections, Bacterial/drug therapy
- Eye Infections, Bacterial/microbiology
- Female
- Glycyrrhizic Acid/therapeutic use
- Mice
- Mice, Inbred C57BL
- Microbial Sensitivity Tests
- Microscopy, Confocal
- Microscopy, Electron, Scanning
- Pseudomonas Infections/drug therapy
- Pseudomonas Infections/microbiology
- Pseudomonas aeruginosa/drug effects
- Pseudomonas aeruginosa/metabolism
- Pseudomonas aeruginosa/ultrastructure
- RNA, Bacterial/genetics
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
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Affiliation(s)
- Linda D. Hazlett
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Sandamali A. Ekanayaka
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Sharon A. McClellan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Rebecca Francis
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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12
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Mahin Samadi P, Gerami P, Elmi A, Khanaki K, Faezi S. Pseudomonas aeruginosa keratitis: passive immunotherapy with antibodies raised against divalent flagellin. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2019; 22:58-64. [PMID: 30944709 PMCID: PMC6437458 DOI: 10.22038/ijbms.2018.31499.7643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Objective(s): Pseudomonas aeruginosa infections such as keratitis are considered among the major health problems worldwide due to the complexity of pathogenesis and antibiotic resistance crisis, thus, finding new effective approaches for prevention and treatment of the infections seem to be still vital. In this report, we aimed to investigate the therapeutic effects of topical administration of the antibodies against type a and b-flagellin (FLA and FLB) in Pseudomonas keratitis model of infection in mice. Materials and Methods: Scratched corneas of mice were treated with approximately 107 CFUs/eye of PAK and/or PAO1 strains of P. aeruginosa. Specific IgG to FLA, FLB or divalent flagellin were topically applied to the infected corneas for 20 min, 24, and 36 hr post-infection. The bacterial burden and myeloperoxidase activity (as a marker for polymorphonuclears (PMNs) infiltration) were determined in the corneas. The biological activity of the anti-FLA and FLB IgG was evaluated in vitro by opsonophagocytosis test. Results: Compared to other treated corneas, divalent anti-flagellin IgG treatment showed a significant decrease in the bacterial CFUs and myeloperoxidase activity in the infected corneas (P<0.05). Results of opsonophagocytosis revealed that the specific antibodies raised against FLA and FLB had more potent opsonic killing activity on their homologous strains as compared with control group (P<0.05). Conclusion: It appears that in P. aeruginosa keratitis, topical administration of the combined antibodies likely via decreasing the bacterial load, and PMNs infiltration as well as increasing opsonophagocytosis could lead to dramatic improvement of the infected corneas.
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Affiliation(s)
- Pariya Mahin Samadi
- Department of Microbiology, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran, Iran
| | - Parmida Gerami
- Department of Microbiology, Biology Research Center, Zanjan Branch, Islamic Azad University, Zanjan, Iran
| | - Ali Elmi
- Medical Biotechnology Research Center, School of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Korosh Khanaki
- Medical Biotechnology Research Center, School of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Sobhan Faezi
- Medical Biotechnology Research Center, School of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
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Carion TW, Kracht D, Strand E, David E, McWhirter C, Ebrahim AS, Berger EA. VIP modulates the ALX/FPR2 receptor axis toward inflammation resolution in a mouse model of bacterial keratitis. Prostaglandins Other Lipid Mediat 2019; 140:18-25. [PMID: 30529189 PMCID: PMC6326851 DOI: 10.1016/j.prostaglandins.2018.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/03/2018] [Accepted: 12/03/2018] [Indexed: 10/27/2022]
Abstract
Vasoactive intestinal peptide (VIP) has been shown to regulate corneal inflammation. Formyl peptide receptor 2 (FPR2) is a transmembrane protein belonging to the GPCR family. Ligands include pro-resolving lipids, lipoxin A4 (LXA4) and resolvin D1 (RvD1). The current study focuses on the effect of VIP regarding the FPR2 receptor axis in improving disease outcome in a mouse model of bacterial keratitis. Infection was induced in C57BL/6 (B6) mice using P. aeruginosa (PA) ATCC 19660. Mice received topical treatment (VIP or PBS) 3× daily after infection. Mean clinical scores, bacterial plate counts, Griess and myeloperoxidase (MPO) assays indicate that topical VIP effectively abrogates the disease response. Findings also reveal that VIP influences FPR2 pathway activation independent of archetypal VIP receptors. Exploring the immunoresolving role of FPR2, its ligand RvD1 and related enzymes (5-LOX, 12/15-LOX), our results suggest a mechanism by which VIP treatment influences the disease response in bacterial keratitis, which could offer a therapeutic point of intervention for enhancing this pro-resolving circuit.
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Affiliation(s)
- Thomas W Carion
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - David Kracht
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Eliisa Strand
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Edwin David
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Cody McWhirter
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Abdul Shukkur Ebrahim
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Elizabeth A Berger
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, United States.
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Ekanayaka SA, McClellan SA, Peng X, Barrett RP, Francis R, Hazlett LD. HMGB1 Antagonist, Box A, Reduces TLR4, RAGE, and Inflammatory Cytokines in the Cornea of P. aeruginosa-Infected Mice. J Ocul Pharmacol Ther 2018; 34:659-669. [PMID: 30407111 PMCID: PMC6302910 DOI: 10.1089/jop.2018.0073] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/20/2018] [Indexed: 12/12/2022] Open
Abstract
PURPOSE High mobility group box 1 (HMGB1) contributes to adverse disease outcome in Pseudomonas aeruginosa keratitis. This study tests Box A, an HMGB1 antagonist, in a model of the disease. METHODS C57BL/6 mice (B6) were injected subconjunctivally (1 day before infection) with Box A or phosphate-buffered saline (PBS), infected with P. aeruginosa strain ATCC 19660, and injected intraperitoneally with Box A or PBS at 1 and 3 days postinfection (p.i.). Clinical scores, photographs with a slit lamp camera, real-time polymerase chain reaction (RT-PCR), western blot, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), myeloperoxidase (MPO), and bacterial plate count were used to assess disease outcome. In separate experiments, the therapeutic potential of Box A was tested as described above, but with treatment begun at 6 h p.i. RESULTS Box A versus PBS prophylactic treatment significantly reduced clinical scores, MPO activity, bacterial load, and expression of TLR4, RAGE, IL-1β, CXCL2, and TNF-α in the infected cornea. Box A blocked co-localization of HMGB1/TLR4 in infiltrated cells in the stroma at 3 and 5 days p.i., but only at 5 days p.i. for HMGB1/RAGE. Box A versus PBS therapeutic treatment significantly reduced clinical scores, MPO activity, bacterial load, and protein levels of IL-1β, CXCL2, and IL-6 in the infected cornea. CONCLUSION Overall, Box A lessens the severity of Pseudomonas keratitis in mice by decreasing expression of TLR4, RAGE (their interaction with HMGB1), IL-1β, CXCL2 (decreasing neutrophil infiltrate), and bacterial plate count when given prophylactically. Therapeutic treatment was not as effective at reducing opacity (disease), but shared similar features with pretreatment of the mice.
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Affiliation(s)
- Sandamali A. Ekanayaka
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Sharon A. McClellan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Xudong Peng
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ronald P. Barrett
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Rebecca Francis
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Linda D. Hazlett
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
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15
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Thymosin Beta-4 and Ciprofloxacin Adjunctive Therapy Improves Pseudomonas aeruginosa-Induced Keratitis. Cells 2018; 7:cells7100145. [PMID: 30241380 PMCID: PMC6210523 DOI: 10.3390/cells7100145] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/12/2018] [Accepted: 09/18/2018] [Indexed: 01/19/2023] Open
Abstract
With increasing multidrug resistance and contraindication for corticosteroid use, the goal of this study was to develop thymosin beta-4 (Tβ4) as an adjunctive therapy to antibiotics for the treatment of bacterial keratitis that effectively promotes enhanced wound healing, host defense, and inflammation resolution. Disease outcome was assessed by clinical score, slit lamp photography, and histopathology. Cytokine profile, bacterial load, PMN infiltration, and Griess and reactive oxygen species (ROS) levels were determined. Adjunct Tβ4 treatment resulted in a significant improvement compared to PBS, Tβ4, and most remarkably, ciprofloxacin, correlating with changes in mediators of inflammation and wound healing. Collectively, these data provide evidence that wound healing is an essential aspect in the development of new therapies to treat corneal infection. Use of adjunctive Tβ4 provides a more efficacious approach for bacterial keratitis by addressing both the infectious pathogen and deleterious host response.
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16
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Ekanayaka SA, McClellan SA, Barrett RP, Hazlett LD. Topical Glycyrrhizin Is Therapeutic for Pseudomonas aeruginosa Keratitis. J Ocul Pharmacol Ther 2018; 34:239-249. [PMID: 29236588 PMCID: PMC5899296 DOI: 10.1089/jop.2017.0094] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/09/2017] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Glycyrrhizin (GLY), an inhibitor of high-mobility group box 1 (HMGB1) protects prophylactically against Pseudomonas aeruginosa keratitis. However, the therapeutic potential of GLY to enhance an antibiotic has not been tested and is our purpose. METHODS C57BL/6 mice (B6) were infected with a clinical isolate (KEI 1025) of P. aeruginosa and treated topically at 6 h postinfection (p.i.) with GLY or phosphate-buffered saline (PBS). Clinical scores, photography with a slit lamp, enzyme-linked immunosorbent assay, myeloperoxidase assay, bacterial plate counts, histopathology, reactive oxygen/nitrogen species (ROS/RNS) assays, and in vitro macrophage (Mφ) stimulation assays were used to assess effects of GLY treatment. In separate similar experiments, the ability of GLY to bioenhance the antibiotic, tobramycin (TOB), was assessed. RESULTS In vivo, GLY versus PBS topical treatment began at 6 h p.i., improved disease outcome by significantly reducing clinical scores, proinflammatory proteins (HMGB1, RAGE, TLR4, TNF-α, and CXCL2), neutrophil infiltrate, bacterial load, ROS/RNS, and nitric oxide. In vitro, GLY downregulated iNOS and COX-2 expression (mRNA) in both mouse and human (THP-1) Mφ. At 6 and 24 h p.i., treatment with GLY enhanced the effects of TOB compared with TOB alone by significantly reducing corneal bacterial load and/or protein levels of cytokines CXCL2 and IL-1β. CONCLUSIONS Data provide evidence that GLY is not only therapeutic for Pseudomonas keratitis through its ability to reduce HMGB1, bacterial load, and oxidative damage but also through its bioenhancement of an antibiotic, even when treatment is initiated at 24 h after infection.
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Affiliation(s)
- Sandamali A Ekanayaka
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine , Detroit, Michigan
| | - Sharon A McClellan
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine , Detroit, Michigan
| | - Ronald P Barrett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine , Detroit, Michigan
| | - Linda D Hazlett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine , Detroit, Michigan
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McClellan SA, Jerome A, Suvas S, Hazlett LD. NLRC4 regulates caspase-1 and IL-1beta production in a CD11blowLy6Glow population of cells required for resistance to Pseudomonas aeruginosa keratitis. PLoS One 2017; 12:e0185718. [PMID: 28961278 PMCID: PMC5621704 DOI: 10.1371/journal.pone.0185718] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 09/18/2017] [Indexed: 11/18/2022] Open
Abstract
Psbetaeudomonas (P.) aeruginosa infection of the cornea in BALB/c mice does not result in perforation and the mice have been classified as resistant. However, regulation of this response via inflammasome activation remained untested. Therefore, BALB/c mice were infected with P. aeruginosa ATCC strain 19660 and NLRP3 and NLRC4 protein tested by ELISA. Since NLRC4 vs NLRP3 protein levels were significantly higher in the corneas of BALB/c at 1 and 5 days postinfection we used silencing to knockdown NLRC4. Silencing NLRC4 vs scrambled siRNA treatment exacerbated disease in BALB/c mice, reduced myeloperoxidase levels and elevated bacterial plate counts at 5 days postinfection. It also increased pro IL-1beta, but reduced total protein for IL-1beta and IL-18 at 5 days postinfection. Flow cytometry to identify cells affected by silencing, showed reduced caspase-1 levels in a CD11blowLy6Glow population of cells, (but not PMN or macrophages) from the infected cornea of siNLRC4 treated mice that produced less mature IL-1beta. These data provide evidence that the NLRC4 inflammasome contributes to resistance through regulation of caspase-1, IL-1beta and IL-18 in a CD11blowLy6Glow population of cells.
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Affiliation(s)
- Sharon A. McClellan
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Andrew Jerome
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Susmit Suvas
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, United States of America
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Linda D. Hazlett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, United States of America
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, United States of America
- * E-mail:
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18
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Ekanayaka SA, McClellan SA, Barrett RP, Kharotia S, Hazlett LD. Glycyrrhizin Reduces HMGB1 and Bacterial Load in Pseudomonas aeruginosa Keratitis. Invest Ophthalmol Vis Sci 2017; 57:5799-5809. [PMID: 27792814 PMCID: PMC5089214 DOI: 10.1167/iovs.16-20103] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Purpose High mobility group box 1 (HMGB1) contributes to poor disease outcome in Pseudomonas aeruginosa keratitis. This study tests the prophylactic effect of treatment with HMGB1 inhibitors, glycyrrhizin (GLY) and its derivative, carbenoxolone (CBX), for Pseudomonas keratitis. Methods We treated C57BL/6 (B6) mice subconjunctivally with GLY or CBX, infected with a noncytotoxic clinical isolate (KEI 1025) or a cytotoxic strain (ATCC 19660) of P. aeruginosa, and injected intraperitoneally with either agent. Clinical score, photography with a slit lamp, real-time RT-PCR, ELISA, myeloperoxidase (MPO) assay, bacterial plate count, histopathology, and absorbance assays were used to assess treatment efficacy and bacteriostatic activity. Results After KEI 1025 infection, GLY treatment reduced HMGB1 (mRNA and protein levels) and improved disease outcome with significant reduction in mRNA levels of IL-1β, TLR4, CXCL2, and IL-12; protein expression (IL-1β, CXCL2); neutrophil infiltrate; and bacterial load. Treatment with GLY enhanced antimicrobial proteins, including CRAMP and mBD2, but not mBD3. Glycyrrhizin also reduced clinical scores and improved disease outcome in corneas infected with strain 19660. However, neither HMGB1 mRNA or protein levels were reduced, but rather, CXCL2 expression (mRNA and protein), neutrophil infiltrate, and bacterial load were reduced statistically. Treatment with GLY initiated 6 hours after infection reduced plate count; GLY also was bacteriostatic for KEI 1025 and ATCC 19660. Conclusions Glycyrrhizin reduces HMGB1 and is protective against P. aeruginosa-induced keratitis with a clinical isolate that is noncytotoxic. It was similar, but less effective when used after infection with a cytotoxic strain, which did not reduce HMGB1.
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Affiliation(s)
- Sandamali A Ekanayaka
- Department of Anatomy & Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Sharon A McClellan
- Department of Anatomy & Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ronald P Barrett
- Department of Anatomy & Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Shikhil Kharotia
- Department of Anatomy & Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Linda D Hazlett
- Department of Anatomy & Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
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19
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Exogenous Streptococcus pneumoniae Endophthalmitis in Diabetic Rabbits. Sci Rep 2017; 7:46196. [PMID: 28387365 PMCID: PMC5384200 DOI: 10.1038/srep46196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/10/2017] [Indexed: 12/19/2022] Open
Abstract
Diabetics are at increased risk for eye infections including bacterial endophthalmitis. It is unclear whether the severity of endophthalmitis is greater in these patients due to confounding factors such as pre-existing ocular diseases in some but not others. Therefore, we tested the hypothesis that disease severity and/or bacterial loads would be significantly higher in a Type I diabetic rabbit model of Streptococcus pneumoniae endophthalmitis. Rabbits were treated with alloxan to destroy pancreatic islet cells, or mock-treated with vehicle, and maintained for 10 days before intravitreal infection with S. pneumoniae E353. Clinical scoring of the eyes was performed 24 and 48 hours after infection, followed by euthanasia and vitreous harvest to quantitate bacterial loads. There were no significant differences in clinical scores (P ≥ 0.440) or bacterial loads (P = 0.736), however, 4/12 (33%) of the diabetic rabbits became bacteremic. This finding not only indicates a breakdown in the blood-ocular barrier, but also prompts further investigation into the exploitation of the diabetic eye by the streptococci.
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Dadvand P, Nieuwenhuijsen MJ, Basagaña X, Alvarez-Pedrerol M, Dalmau-Bueno A, Cirach M, Rivas I, Brunekreef B, Querol X, Morgan IG, Sunyer J. Traffic-related air pollution and spectacles use in schoolchildren. PLoS One 2017; 12:e0167046. [PMID: 28369072 PMCID: PMC5378327 DOI: 10.1371/journal.pone.0167046] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 11/06/2016] [Indexed: 12/31/2022] Open
Abstract
Purpose To investigate the association between exposure to traffic-related air pollution and use of spectacles (as a surrogate measure for myopia) in schoolchildren. Methods We analyzed the impact of exposure to NO2 and PM2.5 light absorbance at home (predicted by land-use regression models) and exposure to NO2 and black carbon (BC) at school (measured by monitoring campaigns) on the use of spectacles in a cohort of 2727 schoolchildren (7–10 years old) in Barcelona (2012–2015). We conducted cross-sectional analyses based on lifelong exposure to air pollution and prevalent cases of spectacles at baseline data collection campaign as well as longitudinal analyses based on incident cases of spectacles use and exposure to air pollution during the three-year period between the baseline and last data collection campaigns. Logistic regression models were developed to quantify the association between spectacles use and each of air pollutants adjusted for relevant covariates. Results An interquartile range increase in exposure to NO2 and PM2.5 absorbance at home was respectively associated with odds ratios (95% confidence intervals (CIs)) for spectacles use of 1.16 (1.03, 1.29) and 1.13 (0.99, 1.28) in cross-sectional analyses and 1.15 (1.00, 1.33) and 1.23 (1.03, 1.46) in longitudinal analyses. Similarly, odds ratio (95% CIs) of spectacles use associated with an interquartile range increase in exposures to NO2 and black carbon at school was respectively 1.32 (1.09, 1.59) and 1.13 (0.97, 1.32) in cross-sectional analyses and 1.12 (0.84, 1.50) and 1.27 (1.03, 1.56) in longitudinal analyses. These findings were robust to a range of sensitivity analyses that we conducted. Conclusion We observed increased risk of spectacles use associated with exposure to traffic-related air pollution. These findings require further confirmation by future studies applying more refined outcome measures such as quantified visual acuity and separating different types of refractive errors.
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Affiliation(s)
- Payam Dadvand
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
- * E-mail:
| | - Mark J. Nieuwenhuijsen
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Xavier Basagaña
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Mar Alvarez-Pedrerol
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Albert Dalmau-Bueno
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Marta Cirach
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Ioar Rivas
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), Barcelona, Spain
| | - Bert Brunekreef
- Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, Utrecht, The Netherlands
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Xavier Querol
- Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), Barcelona, Spain
| | - Ian G. Morgan
- ARC Centre of Excellence in Vision Science, Research School of Biology, College of Medicine, Biology and Environment, Australian National University, Canberra, Australia
- Department of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jordi Sunyer
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain
- IMIM-Parc Salut Mar, Spain
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Ross BX, Gao N, Cui X, Standiford TJ, Xu J, Yu FSX. IL-24 Promotes Pseudomonas aeruginosa Keratitis in C57BL/6 Mouse Corneas. THE JOURNAL OF IMMUNOLOGY 2017; 198:3536-3547. [PMID: 28330899 DOI: 10.4049/jimmunol.1602087] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/27/2017] [Indexed: 01/28/2023]
Abstract
The aim of this study was to elucidate the expression and functions of IL-24 in C57BL/6 mouse corneas in response to Pseudomonas aeruginosa infection. Among IL-20R cytokines, only IL-24 was induced at both mRNA and protein levels by infection at early time points. The upregulation of IL-24 was dampened by flagellin pretreatment, which protects the corneas from microbial infection. Time course studies revealed bimodal early and later peaks of IL-24 expression, a pattern shared with suppressor of cytokine signaling (SOCS)3 but not IL-1β or IL-6. Silencing of IL-24 enhanced S100A8/A9 expression and suppressed SOCS3, IL-1β, IL-1RN, and matrix metalloproteinase 13 expression at 6 h postinfection. Downregulation of the IL-24 signaling pathway significantly reduced the severity of keratitis, whereas rIL-24 exacerbated P. aeruginosa-mediated tissue destruction. In vitro, rIL-1β induced the expression of SOCS3, IL-24, IL-1β, and IL-6 in primary cultured human corneal epithelial cells. rIL-24, alternatively, stimulated the expression of SOCS3, but not the others. In conclusion, IL-24 promotes P. aeruginosa keratitis through the suppression of early protective mucosal immunity, culminating in increased severity of P. aeruginosa keratitis.
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Affiliation(s)
- Bing X Ross
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201.,Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201
| | - Nan Gao
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201.,Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201
| | - Xinhan Cui
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201.,Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201.,Eye and Ear, Nose, and Throat Hospital of Fudan University, Xuhui District, Shanghai 200031, China; and
| | - Theodore J Standiford
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109
| | - Jianjiang Xu
- Eye and Ear, Nose, and Throat Hospital of Fudan University, Xuhui District, Shanghai 200031, China; and
| | - Fu-Shin X Yu
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201; .,Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201
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Methods for In Vivo/Ex Vivo Analysis of Antimicrobial Peptides in Bacterial Keratitis: siRNA Knockdown, Colony Counts, Myeloperoxidase, Immunostaining, and RT-PCR Assays. Methods Mol Biol 2016. [PMID: 28013522 DOI: 10.1007/978-1-4939-6737-7_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Antimicrobial peptides (AMPs) are essential components of the innate immune response. They have direct killing ability as well as immunomodulatory functions. Here, we describe techniques to identify specific AMPs involved in the protection against microbial keratitis, a vision threatening infection of the cornea of the eye which is the most serious complication of contact lens wear. Specifically we detail the use of siRNA technology to temporarily knockdown AMP expression at the murine ocular surface in vivo and then describe ex vivo assays to determine the level of bacteria, relative number of neutrophils, and levels of cytokines, chemokines, and AMPs in infected corneas.
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McClellan SA, Ekanayaka SA, Li C, Jiang X, Barrett RP, Hazlett LD. Thrombomodulin Protects Against Bacterial Keratitis, Is Anti-Inflammatory, but Not Angiogenic. Invest Ophthalmol Vis Sci 2016; 56:8091-100. [PMID: 26720461 DOI: 10.1167/iovs.15-18393] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Thrombomodulin (TM) is a multidomain, transmembrane protein with anti-inflammatory properties. Thrombomodulin domain (D) 1 is lectin-like, interacting with Lewis Y antigen on lipopolysaccharide, and with HMGB1, while TMD23 is associated with angiogenic and anti-inflammatory functions. Thus, we tested if TM is protective against Pseudomonas aeruginosa keratitis and whether it enhanced corneal vascularity. METHODS Eyes of C57BL/6 (B6) mice were injected with recombinant TM (rTM), rTMD1, or PBS subconjunctivally before and intraperitoneally after infection with P. aeruginosa. Clinical scores, photography with a slit lamp, RT-PCR, ELISA, myeloperoxidase (MPO) assay, viable bacterial plate counts, and India ink perfusion were used to assess the disease response and corneal vascularity (rTM only). RESULTS Recombinant TM versus PBS treatment reduced clinical scores and corneal opacity. Corneal mRNA levels for HMGB1 were unchanged, but proinflammatory molecules IL-1β, CXCL2, NF-κB, TLR4, and RAGE were decreased; anti-inflammatory molecules SIGIRR and ST2 were increased. ELISA confirmed the mRNA data for HMGB1, IL-1β, and CXCL2 proteins. Both neutrophil influx and viable bacterial plate counts also were decreased after rTM treatment. Protein levels for angiogenic molecules VEGF, VEGFR-1, and VEGFR-2 were measured at 5 days post infection and were not different or reduced significantly after rTM treatment. Further, perfusion with India ink revealed similar vessel ingrowth between the two groups. Similar studies were performed with rTMD1, but disease severity, mRNA, proteins, MPO, and plate counts were not changed from controls. CONCLUSIONS These data provide evidence that rTM treatment is protective against bacterial keratitis, does not reduce HMGB1, and is not angiogenic.
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Muraleedharan CK, McClellan SA, Barrett RP, Li C, Montenegro D, Carion T, Berger E, Hazlett LD, Xu S. Inactivation of the miR-183/96/182 Cluster Decreases the Severity of Pseudomonas aeruginosa-Induced Keratitis. Invest Ophthalmol Vis Sci 2016; 57:1506-17. [PMID: 27035623 PMCID: PMC4819431 DOI: 10.1167/iovs.16-19134] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 02/20/2016] [Indexed: 12/19/2022] Open
Abstract
PURPOSE The microRNA-183/96/182 cluster (miR-183/96/182) plays important roles in sensory organs. Because the cornea is replete with sensory innervation, we hypothesized that miR-183/96/182 modulates the corneal response to bacterial infection through regulation of neuroimmune interactions. METHODS Eight-week-old miR-183/96/182 knockout (ko) mice and their wild-type littermates (wt) were used. The central cornea of anesthetized mice was scarred and infected with Pseudomonas aeruginosa (PA), strain 19660. Corneal disease was graded at 1, 3, and 5 days postinfection (dpi). Corneal RNA was harvested for quantitative RT-PCR. Polymorphonuclear neutrophils (PMN) were enumerated by myeloperoxidase assays; the number of viable bacteria was determined by plate counts, and ELISA assays were performed to determine cytokine protein levels. A macrophage (Mϕ) cell line and elicited peritoneal PMN were used for in vitro functional assays. RESULTS MicroRNA-183/96/182 is expressed in the cornea, and in Mϕ and PMN of both mice and humans. Inactivation of miR-183/96/182 resulted in decreased corneal nerve density compared with wt mice. Overexpression of miR-183/96/182 in Mϕ decreased, whereas knockdown or inactivation of miR-183/96/182 in Mϕ and PMN increased their capacity for phagocytosis and intracellular killing of PA. In PA-infected corneas, ko mice showed decreased proinflammatory neuropeptides such as substance P and chemoattractant molecules, MIP-2, MCP1, and ICAM1; decreased number of PMN at 1 and 5 dpi; increased viable bacterial load at 1 dpi, but decreased at 5 dpi; and markedly decreased corneal disease. CONCLUSIONS MicroRNA-183/96/182 modulates the corneal response to bacterial infection through its regulation of corneal innervation and innate immunity.
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Affiliation(s)
- Chithra K. Muraleedharan
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University, School of Medicine, Detroit, Michigan, United States
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Sharon A. McClellan
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Ronald P. Barrett
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Cui Li
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Daniel Montenegro
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Thomas Carion
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Elizabeth Berger
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University, School of Medicine, Detroit, Michigan, United States
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Linda D. Hazlett
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University, School of Medicine, Detroit, Michigan, United States
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
| | - Shunbin Xu
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University, School of Medicine, Detroit, Michigan, United States
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States
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Carion TW, McWhirter CR, Grewal DK, Berger EA. Efficacy of VIP as Treatment for Bacteria-Induced Keratitis Against Multiple Pseudomonas aeruginosa Strains. Invest Ophthalmol Vis Sci 2016; 56:6932-40. [PMID: 26513498 DOI: 10.1167/iovs.15-17315] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Previous studies have demonstrated the efficacy of vasoactive intestinal peptide (VIP) treatment in regulating inflammation following bacterial keratitis induced by the P. aeruginosa strain 19660. However, in the current study we assessed whether disease outcome is specific to 19660 or if VIP treatment is effective against multiple P. aeruginosa strains. METHODS B6 mice received daily IP injections of VIP from -1 through 5 days post injection (p.i.). Control mice were similarly injected with PBS. Corneal infection was induced using PA 19660, PAO1 or KEI 1025. Disease response was documented and bacterial plate counts and myeloperoxidase assays were performed. Expression of select inflammatory mediators as well as enzymes associated with lipid mediator production was assessed after VIP treatment. KEI 1025 was characterized by cytotoxicity and invasion assays and then confirmed for ExoS/ExoU expression. RESULTS VIP treatment converted the susceptible response to resistant for the three P. aeruginosa strains tested. Disease response was significantly reduced with no corneal perforation. Anti-inflammatory mediators were enhanced after VIP treatment, while pro-inflammatory molecules were reduced compared to controls. Furthermore, VIP reduced inflammatory cell persistence in the cornea after infection with each of the P. aeruginosa strains. CONCLUSIONS VIP treatment is effective at ameliorating disease pathogenesis for multiple P. aeruginosa strains, both cytotoxic and invasive. This study is also the first to indicate a possible role for VIP regarding lipid mediator expression in the eye. In addition, the clinical isolate, KEI 1025, was characterized as an invasive strain. Overall, this study strengthens the preclinical development of VIP as a therapeutic agent for ocular infectious disease.
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Affiliation(s)
- Thomas W Carion
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Cody R McWhirter
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Daiyajot K Grewal
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Elizabeth A Berger
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States 2Department of Ophthalmology, Kresge Eye Institute, Detroit, Michigan, United States
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McClellan S, Jiang X, Barrett R, Hazlett LD. High-mobility group box 1: a novel target for treatment of Pseudomonas aeruginosa keratitis. THE JOURNAL OF IMMUNOLOGY 2015; 194:1776-87. [PMID: 25589066 DOI: 10.4049/jimmunol.1401684] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
High-mobility group box 1 (HMGB1), a prototypic alarmin, mediates the systemic inflammatory response syndrome. Treatment with vasoactive intestinal peptide, an anti-inflammatory neuropeptide, downregulates proinflammatory cytokines and promotes healing in a susceptible (cornea perforates) model of Pseudomonas aeruginosa keratitis, and also significantly downregulates HMGB1 expression. Therefore, we examined targeting HMGB1 for the treatment of P. aeruginosa keratitis to avoid delivery and other issues associated with vasoactive intestinal peptide. For this, HMGB1 was silenced using small interfering RNA, whereas controls were treated with a nonspecific scrambled sequence small interfering RNA. Less disease was seen postinfection in siHMGB1 compared with control mice and was documented by clinical score and photographs with a slit lamp. Real-time RT-PCR and ELISA confirmed HMGB1 knockdown. RT-PCR analysis also revealed reduced mRNA levels of IL-1β, MIP-2, TNF-α, TLR4, and receptor for advanced glycation end products, whereas mRNA levels of anti-inflammatory TLRs single Ig IL-1-related receptor and ST2 were increased significantly. HMGB1 knockdown also decreased IL-1β and MIP-2 proteins, reducing polymorphonuclear cell number in the infected cornea. mRNA and protein levels of CXCL12 and CXCR4, as well as mononuclear cells, were reduced significantly after HMGB1 knockdown. Ab neutralization of HMGB1, infection with a clinical isolate, and recombinant HMGB1 treatment of resistant mice supported the silencing studies. These data provide evidence that silencing HMGB1 promotes better resolution of P. aeruginosa keratitis by decreasing levels of proinflammatory mediators (decreasing polymorphonuclear cell infiltration), increasing anti-inflammatory TLRs, reducing CXCL12 (preventing HMGB1/CXCL12 heterodimer formation), and signaling through CXCR4, reducing monocyte/macrophage infiltration.
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Affiliation(s)
- Sharon McClellan
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201
| | - Xiaoyu Jiang
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201
| | - Ronald Barrett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201
| | - Linda D Hazlett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201
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Li C, McClellan SA, Barrett R, Hazlett LD. Interleukin 17 regulates Mer tyrosine kinase-positive cells in Pseudomonas aeruginosa keratitis. Invest Ophthalmol Vis Sci 2014; 55:6886-900. [PMID: 25298414 DOI: 10.1167/iovs.14-14522] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To determine if IL-17 regulates Mer tyrosine kinase-positive (MerTK+) cells in Pseudomonas aeruginosa keratitis. METHODS Interleukin 17 was tested in normal and infected cornea of susceptible C57BL/6 and resistant BALB/c mice. The latter were treated with recombinant mouse (rm) IL-17; both groups were treated with IL-17 neutralizing antibody. Mice were infected, and clinical score, PCR, ELISA, and myeloperoxidase (MPO) assays tested expression of proinflammatory and anti-inflammatory mediators and polymorphonuclear neutrophilic leukocyte (PMN) infiltrate. Fas and Fas ligand (FasL) protein levels were assessed in both mouse strains, while MerTK+ cells were examined by immunostaining and cell sorting before and after IL-17 neutralization. RESULTS The IL-17 mRNA and protein were higher in C57BL/6 versus BALB/c cornea after infection. The rmIL-17 treatment of BALB/c mice modified proinflammatory and anti-inflammatory mediators, but clinical score and MPO assay revealed no differences. However, only BALB/c mice treated with IL-17 neutralizing antibody showed increased disease, macrophage inflammatory protein (MIP) 2, and MPO levels. Fas and FasL protein levels, elevated earlier in BALB/c versus C57BL/6 mice, correlated with significantly more MerTK+ cells in BALB/c cornea at 3 days after infection. Neutralization of IL-17 in C57BL/6 mice elevated MerTK+ cells, while similar treatment of BALB/c mice significantly decreased them. CONCLUSIONS These data provide evidence that IL-17 expression is higher in C57BL/6 versus BALB/c cornea after infection and that the latter group has more MerTK+ cells. Exogenous rmIL-17 failed to shift the disease response in resistant mice, but its neutralization resulted in worsened disease and reduced MerTK+ cells. Neutralization of IL-17 in C57BL/6 mice increased MerTK+ cells but did not dramatically shift the disease response.
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Affiliation(s)
- Cui Li
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Sharon A McClellan
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ronald Barrett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Linda D Hazlett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
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Berger EA, McClellan SA, Vistisen KS, Hazlett LD. HIF-1α is essential for effective PMN bacterial killing, antimicrobial peptide production and apoptosis in Pseudomonas aeruginosa keratitis. PLoS Pathog 2013; 9:e1003457. [PMID: 23874197 PMCID: PMC3715414 DOI: 10.1371/journal.ppat.1003457] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 05/08/2013] [Indexed: 12/28/2022] Open
Abstract
Hypoxia-inducible factor (HIF)-1α, is a transcription factor that controls energy metabolism and angiogenesis under hypoxic conditions, and a potent regulator of innate immunity. The studies described herein examined the role of HIF-1α in disease resolution in BALB/c (resistant, cornea heals) mice after ocular infection with Pseudomonas (P.) aeruginosa. Furthermore, the current studies focused on the neutrophil (PMN), the predominant cell infiltrate in keratitis. Using both siRNA and an antagonist (17-DMAG), the role of HIF-1α was assessed in P. aeruginosa-infected BALB/c mice. Clinical score and slit lamp photography indicated HIF-1α inhibition exacerbated disease and corneal destruction. Real time RT-PCR, immunohistochemistry, ELISA, Greiss and MPO assays, bacterial load, intracellular killing, phagocytosis and apoptosis assays further tested the regulatory role of HIF-1α. Despite increased pro-inflammatory cytokine expression and increased MPO levels after knocking down HIF-1α expression, in vivo studies revealed a decrease in NO production and higher bacterial load. In vitro studies using PMN provided evidence that although inhibition of HIF-1α did not affect phagocytosis, both bacterial killing and apoptosis were significantly affected, as was production of antimicrobial peptides. Overall, data provide evidence that inhibition of HIF-1α converts a normally resistant disease response to susceptible (corneal thinning and perforation) after induction of bacterial keratitis. Although this inhibition does not appear to affect PMN transmigration or phagocytosis, both in vivo and in vitro approaches indicate that the transcriptional factor is essential for effective bacterial killing, apoptosis and antimicrobial peptide production.
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Affiliation(s)
- Elizabeth A. Berger
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Sharon A. McClellan
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Kerry S. Vistisen
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Linda D. Hazlett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
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Sun M, Zhu M, Chen K, Nie X, Deng Q, Hazlett LD, Wu Y, Li M, Wu M, Huang X. TREM-2 promotes host resistance against Pseudomonas aeruginosa infection by suppressing corneal inflammation via a PI3K/Akt signaling pathway. Invest Ophthalmol Vis Sci 2013; 54:3451-62. [PMID: 23611998 PMCID: PMC3658264 DOI: 10.1167/iovs.12-10938] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 04/17/2013] [Indexed: 01/08/2023] Open
Abstract
PURPOSE To explore the role of triggering receptor expressed on myeloid cells 2 (TREM-2) in Pseudomonas aeruginosa (PA) keratitis. METHODS BALB/c mice were routinely infected with PA and evaluated at various postinfection time points for corneal expression of TREM-2, by real-time PCR, Western blot, and flow cytometry. Next, BALB/c and C57BL/6 mice were respectively treated with TREM-2 siRNA or agonistic anti-TREM-2 antibody, to determine the role of TREM-2 in PA keratitis. Bacterial load and neutrophil infiltration were tested by plate count and myeloperoxidase assay, respectively. Th1-/Th2-type and proinflammatory cytokine expression were tested by real-time PCR and ELISA after in vivo and in vitro silencing of TREM-2. Moreover, phosphorylated Akt levels were tested by Western blot in murine macrophages after treatment with agonistic anti-TREM-2 antibody. mRNA levels of proinflammatory cytokines were examined in murine macrophages after TREM-2 activation and lipopolysaccharide stimulation, following pretreatment with inhibitors for PI3K or Akt, to determine whether PI3K/Akt is required in TREM-2-mediated immune modulation. In addition, BALB/c mice were treated with wortmannin and analyzed for bacterial load and proinflammatory cytokine expression. RESULTS TREM-2 expression was elevated in the infected BALB/c corneas at 3 or 5 days postinfection. Silencing of TREM-2 accelerated disease progression by enhancing bacterial load and corneal inflammation, whereas activation of TREM-2 promoted host resistance to PA keratitis. PI3K/Akt signaling is required in the TREM-2-mediated immune modulation, and inhibition of PI3K resulted in worsened disease after PA corneal infection. CONCLUSIONS TREM-2 promoted host resistance to PA infection by suppressing corneal inflammation via activation of the PI3K/Akt pathway.
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MESH Headings
- Animals
- Blotting, Western
- Cells, Cultured
- Colony Count, Microbial
- Cytokines/genetics
- Cytokines/metabolism
- Enzyme-Linked Immunosorbent Assay
- Eye Infections, Bacterial/immunology
- Eye Infections, Bacterial/microbiology
- Eye Infections, Bacterial/prevention & control
- Flow Cytometry
- Immunity, Innate
- Keratitis/immunology
- Keratitis/microbiology
- Keratitis/prevention & control
- Macrophages/metabolism
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Neutrophils/physiology
- Phosphatidylinositol 3-Kinases/metabolism
- Proto-Oncogene Proteins c-akt/metabolism
- Pseudomonas Infections/immunology
- Pseudomonas Infections/microbiology
- Pseudomonas Infections/prevention & control
- Pseudomonas aeruginosa/pathogenicity
- RNA, Small Interfering/genetics
- Real-Time Polymerase Chain Reaction
- Receptors, Immunologic/physiology
- Signal Transduction/physiology
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Affiliation(s)
- Mingxia Sun
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Min Zhu
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Ministry of Education, Guangzhou, China
| | - Kang Chen
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Ministry of Education, Guangzhou, China
| | - Xinxin Nie
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Ministry of Education, Guangzhou, China
| | - Qiuchan Deng
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Ministry of Education, Guangzhou, China
| | - Linda D. Hazlett
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, Michigan
| | - Yongjian Wu
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Ministry of Education, Guangzhou, China
| | - Meiyu Li
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Ministry of Education, Guangzhou, China
| | - Minhao Wu
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control, Sun Yat-sen University, Ministry of Education, Guangzhou, China
| | - Xi Huang
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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Foldenauer MEB, McClellan SA, Berger EA, Hazlett LD. Mammalian target of rapamycin regulates IL-10 and resistance to Pseudomonas aeruginosa corneal infection. THE JOURNAL OF IMMUNOLOGY 2013; 190:5649-58. [PMID: 23626014 DOI: 10.4049/jimmunol.1203094] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-10 is important in the resistance response of BALB/c mice to experimental Pseudomonas aeruginosa corneal infection. However, the cellular mechanisms by which this anti-inflammatory cytokine is regulated remain unknown. Because the mammalian target of rapamycin (mTOR) regulates IL-10 in other disease models, the present study tested its role in bacterial keratitis. After infection, corneas of rapamycin versus control-treated BALB/c mice showed worsened disease, and real-time RT-PCR confirmed that mTOR mRNA levels were significantly decreased. Rapamycin treatment also increased clinical score, polymorphonuclear neutrophil (PMN) infiltration (determined by myeloperoxidase assay), and bacterial load, but it diminished PMN bactericidal activity. Inhibition of mTOR also led to elevated mRNA and protein levels of IL-12p40, matrix metalloproteinase 9, and inducible NO synthase, whereas mRNA and protein levels of IL-10, its regulator/effector STAT-3, and suppressor of cytokine signaling 3 (a proinflammatory cytokine regulator) were decreased. Furthermore, mTOR inhibition reduced levels of proapoptotic caspase-3 and increased levels of B cell lymphoma-2 (antiapoptotic), indicative of delayed apoptosis. mTOR inhibition also altered genes related to TLR signaling, including elevation of TLR4, TLR5, and IL-1R1, with decreases in IL-1R-associated kinase 1 and an inhibitor of NF-κB, NF-κB inhibitor-like 1. Rapamycin treatment also increased levels of IFN-γ and CCAAT/enhancer binding protein, β, a gene that regulates expression of preprotachykinin-A (the precursor of substance P). Collectively, these data, as well as a rescue experiment using rIL-10 together with rapamycin, which decreased PMN in cornea, provide concrete evidence that mTOR regulates IL-10 in P. aeruginosa-induced bacterial keratitis and is critical to balancing pro- and anti-inflammatory events, resulting in better disease outcome.
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Affiliation(s)
- Megan E B Foldenauer
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Fukuda K, Ishida W, Uchiyama J, Rashel M, Kato SI, Morita T, Muraoka A, Sumi T, Matsuzaki S, Daibata M, Fukushima A. Pseudomonas aeruginosa keratitis in mice: effects of topical bacteriophage KPP12 administration. PLoS One 2012; 7:e47742. [PMID: 23082205 PMCID: PMC3474789 DOI: 10.1371/journal.pone.0047742] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 09/17/2012] [Indexed: 12/03/2022] Open
Abstract
The therapeutic effects of bacteriophage (phage) KPP12 in Pseudomonas aeruginosa keratitis were investigated in mice. Morphological analysis showed that phage KPP12 is a member of the family Myoviridae, morphotype A1, and DNA sequence analysis revealed that phage KPP12 is similar to PB1-like viruses. Analysis of the phage KPP12 genome did not identify any genes related to drug resistance, pathogenicity or lysogenicity, and so phage KPP12 may be a good candidate for therapeutic. KPP12 showed a broad host range for P. aeruginosa strains isolated from clinical ophthalmic infections. Inoculation of the scarified cornea with P. aeruginosa caused severe keratitis and eventual corneal perforation. Subsequent single-dose administration of KPP12 eye-drops significantly improved disease outcome, and preserved the structural integrity and transparency of the infected cornea. KPP12 treatment resulted in the suppression of neutrophil infiltration and greatly enhanced bacterial clearance in the infected cornea. These results indicate that bacteriophage eye-drops may be a novel adjunctive or alternative therapeutic agent for the treatment of infectious keratitis secondary to antibiotic-resistant bacteria.
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Affiliation(s)
- Ken Fukuda
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi, Japan.
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Tang A, Balzli CL, Caballero AR, McCormick CC, Taylor SD, O'Callaghan RJ. Staphylococcus aureus infection of the rabbit cornea following topical administration. Curr Eye Res 2012; 37:1075-83. [PMID: 22916736 DOI: 10.3109/02713683.2012.716485] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To determine the ability of diverse S. aureus strains to infect the rabbit cornea following topical inoculation, with special emphasis on a strain of unusual virulence. MATERIALS AND METHODS S. aureus strains (5 × 10(5) colony forming units; CFU) were topically applied onto scarified rabbit corneas or 100 CFU were intrastromally injected into rabbit corneas. Eyes were scored by slit lamp examination (SLE) and corneas were cultured to determine the log CFU. Polymorphonuclear leukocytes (PMN) were quantified by myeloperoxidase assays and corneas underwent histopathological analysis. Hemolysin titers of S. aureus strains were determined and S. aureus interactions with rabbit tears or human corneal epithelial cells were investigated. RESULTS All strains injected into the cornea produced high SLE scores and multi-log increases in CFU. Following topical inoculation, four strains produced low SLE scores with no bacterial replication. One strain (UMCR1) topically infected the cornea, causing high SLE scores, extensive PMN infiltration, and multi-log increases in CFU. Histopathologic analysis demonstrated a PMN influx into the UMCR1-infected cornea, destruction of the corneal epithelium, and severe edema. Strain UMCR1 did not demonstrate a high hemolysin titer or resistance to the bactericidal activity of rabbit tears, but did invade human corneal epithelial cells with relatively high efficiency. CONCLUSIONS One S. aureus strain demonstrated the ability to topically infect the rabbit cornea. This strain was previously found to be unique in its ability to infect the anterior chamber and conjunctiva, suggesting that a key mechanism may be employed to overcome the host defenses of these three ocular sites.
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Affiliation(s)
- Aihua Tang
- Department of Microbiology, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Gao N, Kumar A, Guo H, Wu X, Wheater M, Yu FSX. Topical flagellin-mediated innate defense against Candida albicans keratitis. Invest Ophthalmol Vis Sci 2011; 52:3074-82. [PMID: 21310913 DOI: 10.1167/iovs.10-5928] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study was conducted to investigate whether flagellin, the sole ligand of Toll-like receptor-5 (TLR5), induces an innate defense that is sufficient to protect injured corneas from Candida albicans. METHODS Scarified corneas of adult B6, TLR5(-/-), Camp(-/-) (cathelicidin-related antimicrobial peptide), or PMN-depleted mice were pretreated with Pseudomonas aeruginosa flagellin or a mutant and then were inoculated with C. albicans. The corneas were compared for disease progression, cytokine and Camp expression, and PMN infiltration before and after C. albicans infection. Disease progress was recorded by digital photography and clinical scoring, cytokine levels were determined by ELISA, the levels of Camp gene product were assessed by Western blot, and PMN infiltration was measured by MPO determination and immunohistochemistry. RESULTS Topical application of flagellin induced profound protection against Candida keratitis in a TLR5-dependent manner. The improved disease outcome including reduced tissue inflammation and rapid functional recovery can be attributed to a marked decrease in fungal burden at the early stage of C. albicans infection in flagellin-exposed B6 mouse corneas. Although both PMN infiltration and Camp upregulation contributed to corneal innate defense against fungal infection, Camp ablation totally, and PMN depletion partially, abrogated flagellin-induced fungal clearance in B6 mouse corneas. CONCLUSIONS Flagellin induces a strong innate defense and promotes robust resistance to C. albicans infection in the cornea. Topical flagellin or its mimetic may become a new prophylactic agent for preventing contact lens or trauma/injury-associated microbial keratitis.
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Affiliation(s)
- Nan Gao
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan, USA
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TREM-1 amplifies corneal inflammation after Pseudomonas aeruginosa infection by modulating Toll-like receptor signaling and Th1/Th2-type immune responses. Infect Immun 2011; 79:2709-16. [PMID: 21555403 DOI: 10.1128/iai.00144-11] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
As a novel family of cell surface receptors, triggering receptors expressed on myeloid cells (TREMs) play an important role in inflammatory responses. However, the role of TREMs in the ocular immune system remains unknown. In this study, we examined the expression and function of TREM-1 in Pseudomonas aeruginosa keratitis, one of the most common sight-threatening ocular diseases. TREM-1 was significantly increased in human corneas after P. aeruginosa infection. Consistent with TREM-1 expression at the human ocular surface, TREM-1 levels (mRNA and protein) were also elevated in the infected corneas of C57BL/6 (B6) mice at 1, 3, and 5 days postinfection. To determine whether TREM-1 dictates the outcome of P. aeruginosa keratitis in susceptible mice, TREM-1 signaling in B6 mice was blocked with a soluble mTREM-1/Fc fusion protein. The results indicated that blockade of TREM-1 reduced the severity of corneal disease, polymorphonuclear neutrophil infiltration, Th1/proinflammatory cytokine expression and Toll-like receptor (TLR) activation but enhanced the production of Th2 cytokines, murine β-defensin 2 (mBD2), single Ig interleukin-1R-related molecule (SIGIRR), and ST2. Furthermore, we also used agonistic anti-mTREM-1 antibody to activate TREM-1 signaling in B6 mice and found that TREM-1 activation resulted in worsened disease and earlier corneal perforation in infected B6 mouse corneas and elevated production of proinflammatory cytokines and TLR signaling molecules but reduced expression of mBD2, SIGIRR, and ST2. To the best of our knowledge, this study provides the first evidence that TREM-1 functions as an inflammatory amplifier in P. aeruginosa keratitis by modulating TLR signaling and Th1/Th2 responses.
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Yan H, Qi C, Ling S, Li W, Liang L. Lymphatic vessels correlate closely with inflammation index in alkali burned cornea. Curr Eye Res 2010; 35:685-97. [PMID: 20673045 DOI: 10.3109/02713681003793136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To study the relationship between corneal lymphangiogenesis and inflammation in alkali burned corneas. METHODS Rat corneal lymphatic and blood vessels were labeled and distinguished by whole mount immunofluorescence and 5'-nase-alkaline phosphatase (5'-NA-ALP) double enzyme-histochemistry. Then, lymphatic vessel areas (LVA) and lymphatic vessel counting (LVC) were examined. Corneal inflammation was evaluated by inflammation index (IF) grading, histopathology, electron microscope, and polymorphonuclear leukocyte (PMN) infiltration. The relationship between LVC, LVA, IF, and PMN was examined, respectively. In addition, corneal lymphatic vessels of eleven human alkali burned corneas were examined by lymphatic vessel endothelial receptor (LYVE-1) immunohistochemistry. RESULTS Corneal lymphangiogenesis occurred on Day 3, reached the peak at the end of two weeks, and disappeared five weeks after alkaline burns. Both LVA and LVC were strongly and positively correlated with IF after corneal alkaline burns. However, the relationship between LVC and PMN, between LVA and PMN were significant but converse. Among eleven human alkali burned corneas, corneal lymphangiogenesis was present in three corneas. CONCLUSIONS Corneal lymphagiogenesis develops after alkaline burns and correlates closely with corneal inflammation.
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Affiliation(s)
- Hao Yan
- Department of Ophthalmology, Nanshan Hospital of Guangdong Medical College, Shenzhen, PR China
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Hayashi Y, Call MK, Chikama TI, Liu H, Carlson EC, Sun Y, Pearlman E, Funderburgh JL, Babcock G, Liu CY, Ohashi Y, Kao WWY. Lumican is required for neutrophil extravasation following corneal injury and wound healing. J Cell Sci 2010; 123:2987-95. [PMID: 20699360 DOI: 10.1242/jcs.068221] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An important aspect of wound healing is the recruitment of neutrophils to the site of infection or tissue injury. Lumican, an extracellular matrix component belonging to the small leucine rich proteoglycan (SLRP) family, is one of the major keratan sulfate proteoglycans (KSPGs) within the corneal stroma. Increasing evidence indicates that lumican can serve as a regulatory molecule for several cellular processes, including cell proliferation and migration. In the present study, we addressed the role of lumican in the process of extravasation of polymorphonuclear leukocytes (PMNs) during the early inflammatory phase present in the healing of the corneal epithelium following debridement. We used Lum(-/-) mice and a novel transgenic mouse, Lum(-/-),Kera-Lum, which expresses lumican only in the corneal stroma, to assess the role of lumican in PMN extravasation into injured corneas. Our results showed that PMNs did not readily invade injured corneas of Lum(-/-) mice and this defect was rescued by the expression of lumican in the corneas of Lum(-/-),Kera-Lum mice. The presence of lumican in situ facilitates PMN infiltration into the peritoneal cavity in casein-induced inflammation. Our findings are consistent with the notion that in addition to regulating the collagen fibril architecture, lumican acts to aid neutrophil recruitment and invasion following corneal damage and inflammation.
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Affiliation(s)
- Yasuhito Hayashi
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH 45267-0838, USA
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Wu PZJ, Zhu H, Stapleton F, Hume E, Aliwarga Y, Thakur A, Willcox MDP. Effects of α-Toxin-DeficientStaphylococcus aureuson the Production of Peripheral Corneal Ulceration in an Animal Model. Curr Eye Res 2010; 30:63-70. [PMID: 15875366 DOI: 10.1080/02713680490894630] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To examine the role of Staphylococcus aureus alpha-toxin in contact lens-induced peripheral ulceration (CLPU). MATERIALS AND METHODS Proteolytic enzyme, hyaluronidase, alpha-toxin, and beta-toxin production by S. aureus 8325-4 and its alpha-toxin-deficient mutant (S. aureus DU1090) were examined. Using a rabbit model of CLPU, animals were fitted with hydrogel contact lenses colonized by either S. aureus 8325-4 or the mutant strain. The clinical presentation, bacterial cultures, and histology of the ulceration were examined. RESULTS Both strains of S. aureus produced similar levels of caseinase, gelatinase, elastase, hyaluronidase, and beta-toxin. S. aureus DU1090 induced weaker haemolysis of rabbit blood cells than S. aureus 8325-4. Ulceration in the S. aureus DU1090 eye was less frequent and less severe than that caused by S. aureus 8325-4. CONCLUSIONS The enzyme production profile of S. aureus DU1090 was similar to the parent strain. S. aureus strains may produce CLPU-like lesions irrespective of alpha-toxin production, but severe infectious lesions are produced only in the presence of alpha-toxin.
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Affiliation(s)
- Peter Z J Wu
- Vision Cooperative Research Centre and Cornea and Contact Lens Research Unit, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
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Kumar A, Gao N, Standiford TJ, Gallo RL, Yu FSX. Topical flagellin protects the injured corneas from Pseudomonas aeruginosa infection. Microbes Infect 2010; 12:978-89. [PMID: 20601077 DOI: 10.1016/j.micinf.2010.06.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 06/15/2010] [Accepted: 06/17/2010] [Indexed: 10/19/2022]
Abstract
Among bacterial pathogens, Pseudomonas (P.) aeruginosa infection is the most sight threatening. The corneal innate immune responses are key mediators of the host's defense to P. aeruginosa. Using a mouse model of Pseudomonas keratitis, we evaluated the protective effects of topical application of flagellin, a ligand for Toll-Like receptor 5 (TLR5), on the development of Pseudomonas keratitis and elucidated the underlying mechanisms. Topical application of purified flagellin 6 and 24 h prior to P. aeruginosa inoculation on injured mouse corneas significantly attenuated clinical symptoms of P. aeruginosa keratitis, decreased bacterial burden, and suppressed infection induced inflammation in the B6 mouse cornea. Topical application of flagellin on wounded cornea induced PMN infiltration and markedly upregulated cathelicidin-related antimicrobial peptide (CRAMP) expression. In PMN depleted mice, flagellin promoted bacterial clearance in the cornea compared to that of the PBS treated mice, but was unable to prevent corneal perforation and systemic bacterial dissemination and sepses. Deletion of CRAMP increased corneal susceptibility to P. aeruginosa and abolished flagellin-induced protection in B6 mice. Our findings illustrate the profound protective effect of flagellin on the cornea innate defense, a response that can be exploited for prophylactic purposes to prevent contact lens associated Pseudomonas keratitis.
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Affiliation(s)
- Ashok Kumar
- Departments of Ophthalmology and Anatomy & Cell Biology, Kresge Eye Institute, Wayne State University School of Medicine, 4717 St. Antoine, Detroit, MI 48201, USA
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Hazlett LD, McClellan SA, Barrett RP, Huang X, Zhang Y, Wu M, van Rooijen N, Szliter E. IL-33 shifts macrophage polarization, promoting resistance against Pseudomonas aeruginosa keratitis. Invest Ophthalmol Vis Sci 2010; 51:1524-32. [PMID: 19892870 PMCID: PMC2868421 DOI: 10.1167/iovs.09-3983] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 08/21/2009] [Accepted: 10/23/2009] [Indexed: 01/24/2023] Open
Abstract
PURPOSE To determine the role of IL-33 in resistance to Pseudomonas aeruginosa keratitis. METHODS Corneal IL-33 mRNA and protein levels were tested in susceptible C57BL/6 (B6) and resistant BALB/c mice. B6 mice were injected with recombinant mouse IL-33 (rmIL-33) and disease severity, bacterial load, polymorphonuclear neutrophils (PMN) infiltrate, gene expression of inflammatory, and T-helper (Th)1/Th2 cytokines were tested by RT-PCR. IL-33 signaling and macrophage (Mvarphi) polarization also were examined. RESULTS IL-33 mRNA and protein were expressed constitutively in the normal corneas of both groups and were significantly elevated at 1 to 5 days after infection in BALB/c over B6 mice. rmIL-33-treated B6 mice showed less severe disease than did PBS controls and exhibited decreased bacterial load, PMN infiltrate, and corneal mRNA levels for IL-1beta, MIP-2, and TNF-alpha. Th2-type cytokines (IL-4, -5, -10) also were significantly upregulated, and protein levels for TNF-alpha and IL-10 confirmed the mRNA data. To further investigate IL-33 in corneal inflammation, it was overexpressed in Mvarphi (RAW264.7 cells). This significantly increased IL-5 and IL-10, while it decreased IFN-gamma and other pro-inflammatory cytokines. The role of the Mvarphi was further tested in infected rmIL-33 compared with PBS-injected mice. Immunostaining showed that rmIL-33 injection shifted Mvarphi polarization from NO synthase 2 to arginase production. Furthermore, peritoneally elicited cells (B6 mice) treated with lipopolysaccharide and rmIL-33 exhibited elevated ST2 levels and a shift from IL-12 to IL-10 mRNA production. CONCLUSIONS These data provide evidence that IL-33 promotes a Th2-type immune response and reduces inflammation by polarizing the Mvarphi production of anti-inflammatory mediators in the cornea.
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Affiliation(s)
- Linda D Hazlett
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Wu M, McClellan SA, Barrett RP, Zhang Y, Hazlett LD. Beta-defensins 2 and 3 together promote resistance to Pseudomonas aeruginosa keratitis. THE JOURNAL OF IMMUNOLOGY 2010; 183:8054-60. [PMID: 19933858 DOI: 10.4049/jimmunol.0902140] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Defensins play an important role in both innate and adaptive immunity due to their antimicrobial, regulatory, and chemotactic effects. Nonetheless, the role of murine beta-defensins (mBD) 3 and 4, the murine homologs of human beta-defensins (hBD) 2 and 3, remains unknown in Pseudomonas aeruginosa keratitis. This study explored their role in corneal infection and potential synergy with mBD2, a defensin associated with better outcome in this disease. Immunostaining and real-time RT-PCR data demonstrated that mBD3 and mBD4 expression was inducible and differentially regulated in the infected cornea of resistant BALB/c vs susceptible C57BL/6 (B6) mice. Knockdown studies using small interfering RNA treatment indicated that mBD3, but not mBD4, is required in ocular defense. Moreover, in vivo studies demonstrated individual and combined effects of mBD2 and mBD3 that modulate bacterial load, polymorphonuclear neutrophil (PMN) infiltration, and production of IFN-gamma, MIP-2, IL-1beta, TNF-alpha, inducible NO synthase (iNOS), TLR2, TLR4, MyD88, and NF-kappaB. Most notably, bacterial load was increased at 5 days postinfection by silencing either mBD2 or mBD3, but it was elevated at both 1 and 5 days postinfection when silencing both defensins. PMN infiltration was increased at 1 day postinfection by silencing both defensins or mBD3, but not mBD2 alone. iNOS expression was elevated by silencing mBD2, but it was reduced after silencing mBD3 or both defensins. Additionally, cell sources of mBD2 (macrophages, PMN and fibroblasts) and mBD3 (PMN) in corneal stroma were identified by dual label immunostaining after infection. Collectively, the data provide evidence that mBD2 and mBD3 together promote resistance against corneal infection.
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Affiliation(s)
- Minhao Wu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Zhou Z, Wu M, Barrett RP, McClellan SA, Zhang Y, Hazlett LD. Role of the Fas pathway in Pseudomonas aeruginosa keratitis. Invest Ophthalmol Vis Sci 2009; 51:2537-47. [PMID: 20019368 DOI: 10.1167/iovs.09-4152] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
PURPOSE The role of the Fas pathway was tested in Pseudomonas aeruginosa-infected mouse cornea by contrasting the responses of FasL(-/-) and wild-type (WT) mice. METHODS TUNEL staining, real-time RT-PCR, immunostaining, and ELISA assay were used. RESULTS Compared with WT (resistant) mice, BALB/c FasL(-/-) exhibited significantly elevated bacterial counts and polymorphonuclear leukocyte numbers at 1 and 3 days postinfection (p.i.) and worse outcomes from disease. Similar bacterial challenges in C57BL/6 FasL(-/-) compared with WT mice also led to worsened disease as evidenced by earlier corneal perforation in the susceptible mouse strain. Intense TUNEL staining of apoptotic cells was seen earlier (1 day vs. 3 days) p.i. in BALB/c WT than in knockout mice, This earlier apoptotic pattern correlated with increased expression of caspases 3, 8, and 9 and BAX and with decreased expression of the antiapoptotic molecule Bcl-2. Furthermore, expression levels of the proinflammatory molecule TNF-alpha and its receptor, MIP-2, inducible nitric oxide synthase (iNOS), and nitrite also were significantly elevated in the infected cornea of BALB/c FasL(-/-) compared with WT mice. In vitro, LPS-stimulated Mphi from BALB/c FasL(-/-) mice expressed significantly less caspase 3 and 9, BAX, and IL-10 and more TNF-alpha, MIP-2, and IL-1beta than did cells from WT mice. CONCLUSIONS Fas-FasL interaction in the cornea balances the host innate immune response to improve disease outcome by promoting earlier apoptosis and regulating proinflammatory cytokines/chemokines and nitric oxide (nitrite) production. Dysregulation of this interaction contributes to bystander tissue damage, enhancing nutrients for bacterial growth and worsened disease outcome after P. aeruginosa infection.
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Affiliation(s)
- Zimei Zhou
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Karim MJ, Bhattacherjee P, Biswas S, Paterson CA. Anti-Inflammatory Effects of Lipoxins on Lipopolysaccharide-Induced Uveitis in Rats. J Ocul Pharmacol Ther 2009; 25:483-6. [DOI: 10.1089/jop.2008.0134] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Md. Jahurul Karim
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky
| | - Parimal Bhattacherjee
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky
| | - Sumana Biswas
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky
| | - Christopher A. Paterson
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky
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McClellan SA, Lighvani S, Hazlett LD. IFN-γ: Regulation of Nitric Oxide in theP. aeruginosa-Infected Cornea. Ocul Immunol Inflamm 2009; 14:21-8. [PMID: 16507487 DOI: 10.1080/09273940500545650] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE BALB/c mice are resistant to Pseudomonas aeruginosa (P. aeruginosa) keratitis and bacterial killing/stasis requires nitric oxide (NO). NO regulation in the cornea is unknown and was tested in this model. METHODS Nitrite detection, IFN-gamma-knockout mice, TNF-alpha neutralization, ELISA, aminoguanidine (AG) treatment, MPO, and plate counts were done. RESULTS Evidence shows (i) without IFN-gamma, nitrite levels are elevated, (ii) neutralization of TNF-alpha does not change nitrite levels, and (iii) absence of IFN-alpha and reduced NO synergistically increases disease progress and upregulates pro-inflammatory cytokines, PMN number, and bacterial load. CONCLUSION IFN-gamma regulates NO levels, and synergistic interaction between the two regulates disease outcome in resistant mice.
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Affiliation(s)
- Sharon A McClellan
- Department of Anatomy & Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Törngren L, Rolfsen W, Lundgren B. PGE2and leucocyte levels in aqueous humor after lens extraction and intraocular lens implantation. Ocul Immunol Inflamm 2009; 1:151-8. [DOI: 10.3109/09273949309086552] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Mahlberg K, Uusitalo R, Uusitalo H, Palkama A, Tallberg T. Suppression of experimental autoimmune uveitis in guinea-pigs by inhibition of phospholipase A2. Acta Ophthalmol 2009; 182:166-8. [PMID: 2837053 DOI: 10.1111/j.1755-3768.1987.tb02621.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Retinal S-antigen mixed with complete Freund's adjuvant was used to induce experimental autoimmune uveitis (EAU) in guinea-pigs. Guinea-pigs receiving no treatment, was compared with test animals which received topically and systemically administered KLM-583B, a phospholipase A2 (PLA2) inhibitor, or subcutaneous (sub. cut) and topical corticosteroid treatment, as well as a test group which received cyclosporin A suc. cut. The best clinical suppression of EAU was obtained in the group treated suc. cut with KLM-538B. Steroids also suppressed the inflammation in the eyes but was not as effective as KLM-583B or cyclosporine A. PLA 2 activity in the aqueous humour and the myeloperoxidase (MPO) levels measured from iris-ciliary body were significantly lower in the groups treated suc. cut. with KLM-583B or cyclosporin A. Guinea-pigs treated suc. cut. with KLM-583B and cyclosporin A had the lowest antiserum titres to retinal S-antigen.
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Affiliation(s)
- K Mahlberg
- Department of Ophthalmology, Helsinki University, Central Hospital, Finland
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Mahlberg K, Uusitalo R, Lehtosalo J, Uusitalo H, Tallberg T, Tykkä H. The effect of topically applied ethylenediamine tetra-acetic acid (EDTA) and cyclosporine (CsA) on eccentric corneal allograft survival in rabbits. Acta Ophthalmol 2009. [DOI: 10.1111/j.1755-3768.1990.tb01946.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wu M, McClellan SA, Barrett RP, Hazlett LD. Beta-defensin-2 promotes resistance against infection with P. aeruginosa. THE JOURNAL OF IMMUNOLOGY 2009; 182:1609-16. [PMID: 19155510 DOI: 10.4049/jimmunol.182.3.1609] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Corneal infection with Pseudomonas aeruginosa results in corneal perforation in susceptible C57BL/6 (B6) mice, but not in resistant BALB/c mice. To explore the role of two important defensins, murine beta-defensin-1 (mBD1) and mBD2, in the ocular immune defense system, their mRNA and protein expression levels were tested by real-time RT-PCR and Western blot, respectively. mRNA, protein, and immunostaining data demonstrated that both mBD1 and mBD2 were constitutively expressed in normal BALB/c and B6 corneas, and they were disparately up-regulated in BALB/c (more) vs B6 (less) corneas after infection. To determine whether either defensin played a role in host resistance, BALB/c mice were treated with either mBD1 or mBD2 small interfering RNA by subconjunctival injection together with topical application. Increased corneal opacity and worsened disease were displayed after knockdown of mBD2 but not of mBD1. mBD2 silencing also increased bacterial counts and polymorphonuclear neutrophil infiltration in BALB/c corneas. Real-time RT-PCR data further demonstrated that mBD2, not mBD1, differentially modulated mRNA expression of proinflammatory cytokines/molecules such as IFN-gamma, MIP-2, IL-1beta, TNF-alpha, IL-6, and inducible NO synthase; TLR signaling molecules, including TLR2, TLR4, TLR9, and MyD88; and the transcription factor NF-kappaB. Additionally, in vivo studies indicated that mBD2 silencing enhanced corneal nitrite levels and NF-kappaB activation. Collectively, the data provide evidence that mBD2, but not mBD1, is required for host resistance against P. aeruginosa-induced corneal infection.
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Affiliation(s)
- Minhao Wu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Kumar A, Hazlett LD, Yu FSX. Flagellin suppresses the inflammatory response and enhances bacterial clearance in a murine model of Pseudomonas aeruginosa keratitis. Infect Immun 2008; 76:89-96. [PMID: 17938214 PMCID: PMC2223647 DOI: 10.1128/iai.01232-07] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 10/03/2007] [Indexed: 12/31/2022] Open
Abstract
Pseudomonas aeruginosa is a common organism associated with bacterial keratitis, especially in extended-wear contact lens users. In the present study, we determined that pretreatment of cultured human corneal epithelial cells with flagellin isolated from the P. aeruginosa PAO1 strain attenuated cytokine production when the cells were challenged with a cytotoxic strain (ATCC 19660), suggesting a potential use of bacterial flagellin to downregulate infection-associated inflammation in vivo. Administration of flagellin via the subconjunctival and intraperitoneal routes 24 h prior to Pseudomonas inoculation significantly improved the disease outcome, preserved structural integrity and transparency, and thus maintained vision in otherwise perforated corneas of C57BL/6 (B6) mice. The flagellin pretreatment resulted in suppression of polymorphonuclear leukocyte infiltration at a late stage of infection but not at an early stage of infection, decreased the expression of proinflammatory cytokine genes (genes encoding interleukin-1beta [IL-1beta], macrophage inflammatory protein 2, IL-12, and gamma interferon), and greatly enhanced bacterial clearance in the corneas of B6 mice probably through induced expression of the cathelicidin-related antimicrobial peptide and inducible nitric oxide synthase. This is the first report that describes the protective mechanisms induced by a Toll-like receptor agonist that not only curbs the host inflammatory response but also eliminates invading bacteria in the B6 mouse cornea.
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Affiliation(s)
- Ashok Kumar
- Kresge Eye Institute/Department of Ophthalmo, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Huang LC, Reins RY, Gallo RL, McDermott AM. Cathelicidin-deficient (Cnlp -/- ) mice show increased susceptibility to Pseudomonas aeruginosa keratitis. Invest Ophthalmol Vis Sci 2007; 48:4498-508. [PMID: 17898271 PMCID: PMC4234056 DOI: 10.1167/iovs.07-0274] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To examine the clinical progression and innate immune responses during Pseudomonas aeruginosa (PA) keratitis in cathelicidin-deficient (KO) mice. METHODS PA (ATCC 19660) keratitis was induced in KO mice and wild-type (WT) littermates generated on a 129/SVJ background. Clinical score and histopathology were used to monitor the progression of infection at postinfection (PI) days 1, 3, 7, 14, and 21. Mouse corneas were harvested for viable bacteria quantitation, and myeloperoxidase (MPO) assays were performed to determine the number of infiltrating neutrophils. ELISA was used to quantitate interleukin (IL)-1beta, IL-6, macrophage inflammatory peptide (MIP)-2, keratinocyte-derived chemokine (KC), tumor necrosis factor (TNF)-alpha, and vascular endothelial growth factor (VEGF) levels in the corneas. RESULTS WT mice were resistant (cornea healed), whereas KO mice showed increased susceptibility (corneas failed to recover by 21 days or perforated) to PA infection. Clinical scores were significantly elevated in the infected corneas of KO mice versus WT mice at 7, 14, and 21 days PI. Absence of cathelicidin resulted in significantly delayed clearance of PA in the cornea and an increased number of infiltrating neutrophils at 1, 3, 7, and 14 days PI. KO mice also exhibited differential expression of protein levels for IL-1beta, IL-6, MIP-2, KC, TNF-alpha, and VEGF up to day 21 PI compared with the WT mice. CONCLUSIONS Cathelicidin-deficient mice showed considerable susceptibility to PA keratitis. The present study demonstrates direct in vivo evidence that endogenous expression of cathelicidin provides defense against corneal PA infection indicating its importance in host innate immunity at the ocular surface.
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Affiliation(s)
- Ling C. Huang
- University of Houston, College of Optometry, Houston, Texas
| | - Rose Y. Reins
- University of Houston, College of Optometry, Houston, Texas
| | - Richard L. Gallo
- Department of Medicine, University of California-San Diego, San Diego, California
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Hazlett LD, Li Q, Liu J, McClellan S, Du W, Barrett RP. NKT cells are critical to initiate an inflammatory response after Pseudomonas aeruginosa ocular infection in susceptible mice. THE JOURNAL OF IMMUNOLOGY 2007; 179:1138-46. [PMID: 17617607 DOI: 10.4049/jimmunol.179.2.1138] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD4(+) T cells produce IFN-gamma contributing to corneal perforation in C57BL/6 (B6) mice after Pseudomonas aeruginosa infection. To determine the role of NK and NKT cells, infected corneas of B6 mice were dual immunolabeled. Initially, more NKT than NK cells were detected, but as disease progressed, NK cells increased, while NKT cells decreased. Therefore, B6 mice were depleted of NK/NKT cells with anti-asialo GM1 or anti-NK1.1 Ab. Either treatment accelerated time to perforation, increased bacterial load and polymorphonuclear neutrophils, but decreased IFN-gamma and IL-12p40 mRNA expression vs controls. Next, RAG-1 knockout (-/-; no T/NKT cells), B6.TCR Jalpha281(-/-) (NKT cell deficient), alpha-galactosylceramide (alphaGalCer) (anergized NKT cells) injected and IL-12p40(-/-) vs B6 controls were tested. IFN-gamma mRNA was undetectable in RAG-1(-/-)- and alphaGalCer-treated mice at 5 h and was significantly reduced vs controls at 1 day postinfection. It also was reduced significantly in B6.TCR Jalpha281(-/-), alphaGalCer-treated, and IL-12p40(-/-) (activated CD4(+) T cells also reduced) vs control mice at 5 days postinfection. In vitro studies tested whether endotoxin (LPS) stimulated Langerhans cells and macrophages (Mphi; from B6 mice) provided signals to activate NKT cells. LPS up-regulated mRNA expression for IL-12p40, costimulatory molecules CD80 and CD86, NF-kappaB, and CD1d, and addition of rIFN-gamma potentiated Mphi CD1d levels. Together, these data suggest that Langerhans cell/Mphi recognition of microbial LPS regulates IL-12p40 (and CD1d) driven IFN-gamma production by NKT cells, that IFN-gamma is required to optimally activate NK cells to produce IFN-gamma, and that depletion of both NKT/NK cells results in earlier corneal perforation.
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Affiliation(s)
- Linda D Hazlett
- Department of Anatomy and Cell Biology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
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