Abstract
Purpose :
Previously, we used a contact lens wearing murine model to show that lens wear was associated with corneal para-inflammation involving CD11c+ cells (24 h) and Ly6G+ cells (5-6 days). Recently, we showed transient receptor potential (TRP) ion-channels associated with corneal nerves were involved in corneal CD45+ and CD11c+ cell responses that correlated with protection against bacterial colonization. Here, we explored the role of TRP nociceptors in contact lens-mediated parainflammation.
Methods :
Contact lenses were fitted onto one eye of C57BL/6 wild-type (WT) or double or single gene-knockout mice in TRPA1V1(-/-), TRPA1(-/-) or TRPV1(-/-). Contralateral eyes were used as controls. After 24 h or 6 days of lens wear, lenses were removed, and mice euthanized. Freshly enucleated eyes were fixed in ice-cold methanol or 2 % paraformaldehyde and corneal expression of MHC Class II+ cells or Ly6G+ cells detected using antibody labeling and imaging. Student’s t-test and One-way ANOVA were used for statistical analysis and P < 0.05 considered significant.
Results :
Lens-wearing corneas of WT mice showed a significant increase in MHC Class-II+ cells after 24 h, and in Ly6G+ cells after 6 days, vs. non-lens wearing controls (P < 0.0001, Student’s t-test). Corneas remained free of visible pathology. Lens-wearing corneas of all TRP gene-knockout mice showed a significant increase in MHC Class-II+ cells at 24 h vs. respective baseline controls (P < 0.0001, Student’s t-test). Non-lens wearing corneas of each TRP gene-knockout mouse showed significant reduction in MHC Class-II+ cells vs. WT at 24 h (P < 0.0001, One-way ANOVA). Corneas of lens-wearing TRP gene-knockout mice each showed a significant reduction in Ly6G+ cell infiltration vs. lens-wearing WT after 6 days (P < 0.0001, One-way ANOVA). Little or no corneal Ly6G+ cells were observed in 6 day non-lens wearing controls.
Conclusions :
TRP nociceptors are required for contact lens-associated corneal para-inflammatory responses involving Ly6G+ cell (neutrophil) infiltrative after 6 days of lens wear, but not the MHC Class-II+ (CD11c+) responses after 24 h of lens wear. TRP nociceptors are involved in modulating baseline levels of corneal MHC-II+ cells. Specific role(s) for TRPA1 or TRPV1 in mediating these corneal phenotypes remains to be determined.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.