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Li D, Hodges R, AukrustNaqvi M, Bair J, Bispo PJM, Gilmore MS, Gregory-Ksander M, Dartt DA. Staphylococcus aureus activates NRLP3-dependent IL-1β secretion from human conjunctival goblet cells using α toxin and toll-like receptors 2 and 1. Front Cell Infect Microbiol 2023; 13:1265471. [PMID: 38089811 PMCID: PMC10711068 DOI: 10.3389/fcimb.2023.1265471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 10/30/2023] [Indexed: 12/18/2023] Open
Abstract
We used cultured human conjunctival goblet cells to determine (i) whether the toxigenic S. aureus- induced activation of the epithelial goblet cells requires two signals to activate the NLRP3 inflammasome, (ii) if one signal is mediated by TLR1, TLR2, or TLR6, and (iii) if the S. aureus toxin α toxin is another signal for the activation of the inflammasome and secretion of mature IL-1β. Cultured cells were incubated with siRNA to knock down the different TLRs. After stimulation with toxigenic S. aureus RN6390, pro-IL-1β synthesis, caspase-1 activity, and mature IL-1β secretion were measured. In a separate set of experiments, the cells were incubated with toxigenic S. aureus RN6390 or mutant S. aureus ALC837 that does not express α toxin with or without exogenous α toxin. A gentamicin protection assay was used to determine if intracellular bacteria were active. We conclude that α toxin from toxigenic S. aureus triggers two separate mechanisms required for the activation of the NLRP3 inflammasome and secretion of mature IL-1β. In the first mechanism, α toxin secreted from internalized S. aureus produces a pore, allowing the internalized bacteria and associated pathogen-associated molecular patterns to interact with intracellular TLR2 and, to a lesser extent, TLR1. In the second mechanism, α toxin forms a pore in the plasma membrane, leading to an efflux of cytosolic K+ and influx of Ca2+. We conclude that α toxin by these two different mechanisms triggers the synthesis of pro-IL-1β and NLRP3 components, activation of capase-1, and secretion of mature IL-1β to defend against bacterial infection.
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Affiliation(s)
- Dayu Li
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, United States
- Department of Ophthalmology Harvard Medical School, Boston, MA, United States
| | - Robin Hodges
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, United States
- Department of Ophthalmology Harvard Medical School, Boston, MA, United States
| | - Maria AukrustNaqvi
- Department of Life Sciences and Health Faculty of Health Sciences Oslo Metropolitan University, Oslo, Norway
| | - Jeffrey Bair
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, United States
| | - Paulo J. M. Bispo
- Department of Ophthalmology Harvard Medical School, Boston, MA, United States
- Massachusetts Eye and Ear, Boston, MA, United States
| | - Michael S. Gilmore
- Department of Ophthalmology Harvard Medical School, Boston, MA, United States
- Massachusetts Eye and Ear, Boston, MA, United States
| | - Meredith Gregory-Ksander
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, United States
- Department of Ophthalmology Harvard Medical School, Boston, MA, United States
| | - Darlene A. Dartt
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, United States
- Department of Ophthalmology Harvard Medical School, Boston, MA, United States
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2
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Logeswaran A, Contreras-Ruiz L, Masli S. Conjunctival Goblet Cell Responses to TLR5 Engagement Promote Activation of Local Antigen-Presenting Cells. Front Immunol 2021; 12:716939. [PMID: 34434198 PMCID: PMC8380822 DOI: 10.3389/fimmu.2021.716939] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 07/15/2021] [Indexed: 12/23/2022] Open
Abstract
Conjunctival epithelium forms a barrier between the ocular surface microbial flora and the ocular mucosa. In addition to secreting gel-forming mucins, goblet cells, located in the conjunctival epithelium, help maintain local immune homeostasis by secreting active TGFβ2 and promoting tolerogenic phenotype of dendritic cells in the vicinity. Although dendritic cell subsets, characteristic of mucosal tissues, are found in the conjunctiva, previous studies provided limited information about their location within the tissue. In this study, we examine immunostained conjunctiva explants to determine the location of CD11c-positive dendritic cells in the context of MUC5AC-positive goblet cells. Considering that conjunctival goblet cells are responsive to signaling induced by pathogen recognition receptors, we also assess if their responses to microbial product, flagellin, can contribute to the disruption of ocular mucosal homeostasis that promotes activation of dendritic cells and results in chronic ocular surface inflammation. We find that dendritic cells in the conjunctiva with an increased microbial colonization are located adjacent to goblet cells. While their cell bodies in the stromal layer are immediately below the epithelial layer, several extensions of dendritic cells are projected across the epithelium towards the ocular surface. Such trans-epithelial dendrites are not detectable in healthy ocular mucosa. In response to topically applied flagellin, increased proportion of CD11c-positive cells in the conjunctiva strongly express MHC class II relative to the untreated conjunctiva. This change is accompanied by reduced immunoreactivity to TGFβ-activating Thrombospondin-1 in the conjunctival epithelium. These findings are supported by in vitro observations in primary cultures of goblet cells that respond to the TLR5 stimulation with an increased expression of IL-6 and reduced level of active TGFβ. The observed changes in the conjunctiva after flagellin application correspond with the development of clinical signs of chronic ocular mucosal inflammation including corneal epitheliopathy. Collectively, these findings demonstrate the ability of ocular mucosal dendritic cells to extend trans-epithelial dendrites in response to increased microbial colonization at the ocular surface. Moreover, this study provides key insight into how goblet cell responses to microbial stimuli may contribute to the disruption of ocular mucosal homeostasis and chronic ocular mucosal inflammation.
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Affiliation(s)
- Abiramy Logeswaran
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
| | - Laura Contreras-Ruiz
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
| | - Sharmila Masli
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
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3
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Swift W, Bair JA, Chen W, Li M, Lie S, Li D, Yang M, Shatos MA, Hodges RR, Kolko M, Utheim TP, Scott W, Dartt DA. Povidone iodine treatment is deleterious to human ocular surface conjunctival cells in culture. BMJ Open Ophthalmol 2020; 5:e000545. [PMID: 32995498 PMCID: PMC7497553 DOI: 10.1136/bmjophth-2020-000545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/07/2020] [Accepted: 08/19/2020] [Indexed: 12/27/2022] Open
Abstract
Objective To determine the effect of povidone iodine (PI), an antiseptic commonly used prior to ocular surgery, on viability of mixed populations of conjunctival stratified squamous and goblet cells, purified conjunctival goblet cells and purified conjunctival stromal fibroblasts in primary culture. Methods and analysis Mixed population of epithelial cells (stratified squamous and goblet cells), goblet cells and fibroblasts were grown in culture from pieces of human conjunctiva using either supplemented DMEM/F12 or RPMI. Cell type was evaluated by immunofluorescence microscopy. Cells were treated for 5 min with phosphate-buffered saline (PBS); 0.25%, 2.5%, 5% or 10% PI in PBS; or a positive control of 30% H2O2. Cell viability was determined using Alamar Blue fluorescence and a live/dead kit using calcein/AM and ethidium homodimer-1 (EH-1). Results Mixed populations of epithelial cells, goblet cells and fibroblasts were characterised by immunofluorescence microscopy. As determined with Alamar Blue fluorescence, all concentrations of PI significantly decreased the number of cells from all three preparation types compared with PBS. As determined by calcein/EH-1 viability test, mixed populations of cells and fibroblasts were less sensitive to PI treatment than goblet cells. All concentrations of PI, except for 0.25% used with goblet cells, substantially increased the number of dead cells for all cell populations. The H2O2 control also significantly decreased the number and viability of all three types of cells in both tests. Conclusion We conclude that PI, which is commonly used prior to ocular surgeries, is detrimental to human conjunctival stratified squamous cells, goblet cells and fibroblasts in culture.
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Affiliation(s)
- William Swift
- Schepens Eye Research Institute, Boston, Massachusetts, USA
| | - Jeffrey A Bair
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Wanxue Chen
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Michael Li
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Sole Lie
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Dayu Li
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Menglu Yang
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Marie A Shatos
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Robin R Hodges
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Ophthalmology, Harvard Medical School, Boston, MA, United States
| | | | - Tor P Utheim
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Oslo University Hospital, Oslo, Norway
| | | | - Darlene A Dartt
- Schepens Eye Research Institute, Boston, Massachusetts, USA.,Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Ophthalmology, Harvard Medical School, Boston, MA, United States
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4
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Lim RR, Wieser ME, Ganga RR, Barathi VA, Lakshminarayanan R, Mohan RR, Hainsworth DP, Chaurasia SS. NOD-like Receptors in the Eye: Uncovering Its Role in Diabetic Retinopathy. Int J Mol Sci 2020; 21:E899. [PMID: 32019187 PMCID: PMC7037099 DOI: 10.3390/ijms21030899] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/22/2020] [Accepted: 01/27/2020] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy (DR) is an ocular complication of diabetes mellitus (DM). International Diabetic Federations (IDF) estimates up to 629 million people with DM by the year 2045 worldwide. Nearly 50% of DM patients will show evidence of diabetic-related eye problems. Therapeutic interventions for DR are limited and mostly involve surgical intervention at the late-stages of the disease. The lack of early-stage diagnostic tools and therapies, especially in DR, demands a better understanding of the biological processes involved in the etiology of disease progression. The recent surge in literature associated with NOD-like receptors (NLRs) has gained massive attraction due to their involvement in mediating the innate immune response and perpetuating inflammatory pathways, a central phenomenon found in the pathogenesis of ocular diseases including DR. The NLR family of receptors are expressed in different eye tissues during pathological conditions suggesting their potential roles in dry eye, ocular infection, retinal ischemia, cataract, glaucoma, age-related macular degeneration (AMD), diabetic macular edema (DME) and DR. Our group is interested in studying the critical early components involved in the immune cell infiltration and inflammatory pathways involved in the progression of DR. Recently, we reported that NLRP3 inflammasome might play a pivotal role in the pathogenesis of DR. This comprehensive review summarizes the findings of NLRs expression in the ocular tissues with special emphasis on its presence in the retinal microglia and DR pathogenesis.
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Affiliation(s)
- Rayne R. Lim
- Ocular Immunology and Angiogenesis Lab, University of Missouri, Columbia, MO 652011, USA; (R.R.L.); (M.E.W.); (R.R.M.)
- Department of Biomedical Sciences, University of Missouri, Columbia, MO 652011, USA
- Ophthalmology, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 652011, USA
| | - Margaret E. Wieser
- Ocular Immunology and Angiogenesis Lab, University of Missouri, Columbia, MO 652011, USA; (R.R.L.); (M.E.W.); (R.R.M.)
| | - Rama R. Ganga
- Surgery, University of Missouri, Columbia, MO 652011, USA;
| | | | | | - Rajiv R. Mohan
- Ocular Immunology and Angiogenesis Lab, University of Missouri, Columbia, MO 652011, USA; (R.R.L.); (M.E.W.); (R.R.M.)
- Department of Biomedical Sciences, University of Missouri, Columbia, MO 652011, USA
- Ophthalmology, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 652011, USA
- Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO 652011, USA;
| | - Dean P. Hainsworth
- Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO 652011, USA;
| | - Shyam S. Chaurasia
- Ocular Immunology and Angiogenesis Lab, University of Missouri, Columbia, MO 652011, USA; (R.R.L.); (M.E.W.); (R.R.M.)
- Department of Biomedical Sciences, University of Missouri, Columbia, MO 652011, USA
- Ophthalmology, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 652011, USA
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5
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Pennington MR, Saha A, Painter DF, Gavazzi C, Ismail AM, Zhou X, Chodosh J, Rajaiya J. Disparate Entry of Adenoviruses Dictates Differential Innate Immune Responses on the Ocular Surface. Microorganisms 2019; 7:E351. [PMID: 31540200 PMCID: PMC6780103 DOI: 10.3390/microorganisms7090351] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/08/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022] Open
Abstract
Human adenovirus infection of the ocular surface is associated with severe keratoconjunctivitis and the formation of subepithelial corneal infiltrates, which may persist and impair vision for months to years following infection. Long term pathology persists well beyond the resolution of viral replication, indicating that the prolonged immune response is not virus-mediated. However, it is not clear how these responses are sustained or even initiated following infection. This review discusses recent work from our laboratory and others which demonstrates different entry pathways specific to both adenovirus and cell type. These findings suggest that adenoviruses may stimulate specific pattern recognition receptors in an entry/trafficking-dependent manner, leading to distinct immune responses dependent on the virus/cell type combination. Additional work is needed to understand the specific connections between adenoviral entry and the stimulation of innate immune responses by the various cell types present on the ocular surface.
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Affiliation(s)
- Matthew R Pennington
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - Amrita Saha
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - David F Painter
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - Christina Gavazzi
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - Ashrafali M Ismail
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - Xiaohong Zhou
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - James Chodosh
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - Jaya Rajaiya
- Howe Laboratory, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
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6
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Commensal microflora in human conjunctiva; characteristics of microflora in the patients with chronic ocular graft-versus-host disease. Ocul Surf 2019; 17:265-271. [DOI: 10.1016/j.jtos.2019.02.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/30/2019] [Accepted: 02/05/2019] [Indexed: 11/19/2022]
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7
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Dartt DA, Hodges RR, Serhan CN. Immunoresolvent Resolvin D1 Maintains the Health of the Ocular Surface. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1161:13-25. [PMID: 31562618 PMCID: PMC6859005 DOI: 10.1007/978-3-030-21735-8_3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The present review focuses on the role of one of the D-series resolvins (Rv) RvD1 in the regulation of conjunctival goblet cell secretion and its role in ocular surface health. RvD1 is the most thoroughly studied of the specialized proresolution mediators in the goblet cells. The anterior surface of the eye consists of the cornea (the transparent central area) and the conjunctiva (opaque tissue that surrounds the cornea and lines the eyelids). The secretory mucin MUC5AC produced by the conjunctival goblet cells is protective of the ocular surface and especially helps to maintain clear vision through the cornea. In health, a complex neural reflex stimulates goblet cell secretion to maintain an optimum amount of mucin in the tear film. The specialized pro-resolution mediator, D-series resolvin (RvD1) is present in human tears and induces goblet cell mucin secretion. RvD1 interacts with its receptors ALX/FPR2 and GPR32, activates phospholipases C, D, and A2, as well as the EGFR. This stimulation increases the intracellular [Ca2+] and activates extracellular regulated kinase (ERK) 1/2 to cause mucin secretion into the tear film. This mucin secretion protects the ocular surface from the challenges in the external milieu thus maintaining a healthy interface between the eye and the environment. RvD1 forms a second important mechanism along with activation of a neural reflex pathway to regulate goblet cell mucin secretion and protect the ocular surface in health.
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Affiliation(s)
- Darlene A Dartt
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA.
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
| | - Robin R Hodges
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Charles N Serhan
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
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