Amniotic membrane modulates innate immune response inhibiting PRRs expression and NF-κB nuclear translocation on...

Area of Science:

• Immunology
• Ophthalmology
• Regenerative Medicine

Background:

• Herpetic stromal keratitis involves corneal damage from inflammatory responses to viral antigens.
• Pattern recognition receptors (MDA5, RIG-1, TLR3) recognize viral dsRNA, activating innate immunity and cytokine secretion via NF-κB.
• Amniotic membrane (AM) is known to reduce inflammation, but its effect on these specific innate immune receptors is unclear.

Purpose of the Study:

• To investigate the effect of AM on innate immune receptor expression and NF-κB activation in corneal cells stimulated with viral dsRNA.
• To determine if AM influences the expression of MDA5, RIG-1, and TLR3 in human limbal myofibroblasts (HLM).
• To elucidate the anti-inflammatory mechanisms of AM in the context of viral keratitis.

Main Methods:

• Human limbal myofibroblasts (HLM) were stimulated with poly I:C (a viral dsRNA mimic).
• The effect of AM on cytokine synthesis and secretion was measured.
• Protein expression of MDA5, RIG-1, and TLR3 was assessed in the presence and absence of AM.
• NF-κB nuclear translocation was monitored using immunofluorescence.
• Changes in cadherin expression and cellular morphology were analyzed.

Main Results:

• AM significantly inhibited the synthesis and secretion of pro-inflammatory cytokines in poly I:C-stimulated HLM.
• AM reduced the protein expression of MDA5, RIG-1, and TLR3 in stimulated HLM.
• AM significantly inhibited NF-κB nuclear translocation in stimulated HLM.
• AM altered cadherin localization, affecting myofibroblastic cellular morphology.

Conclusions:

• AM creates an anti-inflammatory microenvironment by inhibiting innate immune receptors and NF-κB activation.
• Inhibiting NF-κB nuclear translocation in infected corneal tissue could mitigate inflammation.
• These findings support the therapeutic use of AM transplantation for herpetic stromal keratitis.