Conjunctival inflammation induces Langerhans cell migration into the cornea

Area of Science:

• Ophthalmology
• Immunology
• Transplantation Biology

Background:

• Langerhans cells (LCs) absence in corneal epithelium is crucial for corneal allograft acceptance.
• Corneal stimulation induces LC migration, potentially harming graft survival.
• The impact of conjunctival inflammation on LC migration remains unclear.

Purpose of the Study:

• To investigate if conjunctival inflammation induces Langerhans cell migration into the cornea.
• To understand the influence of conjunctival inflammation on the corneal immunological environment.

Main Methods:

• BALB/c mice were divided into four groups: corneal inflammation (positive control), conjunctival inflammation (silk sutures), conjunctival inflammation (nylon sutures), and no inflammation (control).
• Inflammation was induced via sutures in the cornea or conjunctiva.
• LCs in the corneal epithelium were quantified using immunofluorescence assay with anti-Ia antibody 14 days post-suturing.

Main Results:

• Group A (corneal inflammation) showed 29.4 ± 3.8 Ia(+) cells/mm².
• Groups B and C (conjunctival inflammation) showed 7.9 ± 1.2 and 7.8 ± 0.7 Ia(+) cells/mm², respectively.
• All inflamed groups (A, B, C) had significantly more Ia(+) cells than the naive control group (N, 1.6 ± 0.5 cells/mm²; p < 0.005).

Conclusions:

• Conjunctival inflammation, induced by sutures, significantly increases Langerhans cell migration into the cornea.
• Conjunctival inflammation alters the corneal immunological environment.
• These findings suggest conjunctival inflammation may adversely affect orthotopic corneal allograft outcomes.