June 2015
Volume 56, Issue 7
Free
ARVO Annual Meeting Abstract  |   June 2015
Protective Role and Mechanism of NLRP3/Caspase-1 Inflammasome Induced IL-33 Production by Corneal Epithelium in Fungal Keratitis
Author Affiliations & Notes
  • Xia Hua
    Ophthalmology, Baylor College of Medicine, Houston, TX
    Cataract, Tianjin Eye Hospital, Tianjin Medical University, Tianjin, China
  • Xiaoyong Yuan
    Ophthalmology, Baylor College of Medicine, Houston, TX
    Cataract, Tianjin Eye Hospital, Tianjin Medical University, Tianjin, China
  • Wei Chi
    Ophthalmology, Baylor College of Medicine, Houston, TX
  • Jin Li
    Ophthalmology, Baylor College of Medicine, Houston, TX
  • Zongduan Zhang
    Ophthalmology, Baylor College of Medicine, Houston, TX
  • Stephen C Pflugfelder
    Ophthalmology, Baylor College of Medicine, Houston, TX
  • De-Quan Li
    Ophthalmology, Baylor College of Medicine, Houston, TX
  • Footnotes
    Commercial Relationships Xia Hua, None; Xiaoyong Yuan, None; Wei Chi, None; Jin Li, None; Zongduan Zhang, None; Stephen Pflugfelder, None; De-Quan Li, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2015, Vol.56, 1881. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Xia Hua, Xiaoyong Yuan, Wei Chi, Jin Li, Zongduan Zhang, Stephen C Pflugfelder, De-Quan Li; Protective Role and Mechanism of NLRP3/Caspase-1 Inflammasome Induced IL-33 Production by Corneal Epithelium in Fungal Keratitis. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):1881.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: To explore the protective role and mechanism of innate immunity by corneal epithelium through NLRP3/caspase-1 inflammasome-induced IL-33 production in response to fungal infection using Candida albicans (C. albicans) infected fungal keratitis (FK) mouse model and in vitro human corneal epithelial cells (HCECs) exposed to heated killed C. albicans (HKCA).

Methods: Fungal keratitis was established in C57BL/6 mice by 106 CFU of C. albicans strain SC5314 isolated from patients. Primary HCECs, established from donor limbal explants, were challenged by HKCA (104-106 cells/ml) with or without prior incubation of inhibitors to NLRP3 (glybenclamide), caspase-1 (z-YVAD fmk) or dectin-1 (laminarin and syk inhibitor). The production and/or activity of NLRP3 inflammasome associated molecules and IL-33 were evaluated by reverse transcription and quantitative real time PCR (RT-qPCR), immunofluorescent staining, caspase activity assays, ELISA and Western blot analysis. FK mice were also treated by recombinant mature form of mouse IL-33 (rmIL-33) to evaluate its efficacy.

Results: The mRNA and protein levles of IL-33 was found to be significantly induced, which accompanied by increased production and activity of NLRP3, ASC, caspase-1, in FK mice compared with the mock mice as controls. The dose-dependent production and activity of NLRP3 inflammasome and IL-33 were also observed in HCECs exposed to HKCA compared to normal control. Glybenclamide inhibited NLRP3 activation, and also blocked the activation of caspase-1. Both inhibitors to NLRP3 or caspase-1 suppressed maturation of IL-33. Interestingly, IL-33 maturation and NLRP3 activation were also suppressed in HCECs exposed to HKCA with pretreated dectin-1 inhibitors (laminarin and syk inhibitor) and NF-ĸB inhibitors (BAY11-7082 and quinazoline). Furthermore, the keratitis was attenuated in severity and recovered rapidly by rmIL-33 subconjunctival injection, while it was exacerbated with treatment of inhibitors to NLRP3 or caspase-1in FK mice.

Conclusions: Our findings reveal a novel mechanism and signaling pathway of innate immunity by corneal epithelium, which produces IL-33 through dectin-1 mediated activation of NLRP3/caspase-1 inflammasome to defense against C. albicans invasion in fungal keratitis. The studies provide new insight in the innate immunity that protects cornea from fungal infection.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×