IL-33 alleviates corneal nerve damage in herpes simplex keratitis

Area of Science:

• Ophthalmology
• Immunology
• Neuroscience

Background:

• Herpes simplex keratitis (HSK), caused by herpes simplex virus type 1 (HSV-1), is a major global cause of corneal blindness.
• HSK leads to irreversible corneal nerve damage, resulting in vision loss and decreased corneal sensitivity.
• The role of Interleukin-33 (IL-33) in HSK-associated nerve damage and its mechanisms are not well understood.

Purpose of the Study:

• To investigate the effects of IL-33 on HSK severity and corneal nerve damage in a mouse model.
• To elucidate the mechanisms by which IL-33 influences neuroprotective factor production in corneal epithelial cells.
• To explore IL-33's role in regulating macrophage polarization for neuroprotection.

Main Methods:

• Evaluation of IL-33 effects in a mouse model of HSK.
• In vitro investigation of IL-33's impact on neuroprotective factor production in HSV-1 infected corneal epithelial cells (HCE-Ts).
• In vitro co-culture experiments to study IL-33's role in macrophage polarization.

Main Results:

• IL-33 significantly reduced HSK severity and protected corneal nerves in the HSK mouse model.
• IL-33 enhanced the production of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in corneal epithelial cells via the GSK3β/β-catenin pathway.
• IL-33 promoted M2 macrophage polarization through the JAK2/STAT6 pathway, reducing inflammation and neuronal apoptosis.

Conclusions:

• IL-33 exhibits significant neuroprotective effects in herpes simplex keratitis.
• IL-33's mechanisms involve promoting neurotrophic factors and M2 macrophage polarization.
• These findings provide novel insights into potential therapeutic strategies for HSK.