Purpose: To develop a mouse model of human dry eye disease (DED) for investigation of sex differences in autoimmune-associated dry eye pathology.
Methods: Ocular surface disease was assessed by quantifying corneal epithelial damage with lissamine green stain in the NOD.H-2h4,IFNγ-/-,CD28-/- (NOD.H-2h4 DKO) mouse model of Sjögren's syndrome (SS). Lacrimal gland function was assessed by tear volume quantification with phenol red thread and lacrimal gland inflammation (i.e., dacryoadenitis) was assessed by quantification of immune cell foci, flow cytometric analysis of immune cell composition, and expression of proinflammatory markers.
Results: The NOD.H-2h4 DKO mouse model of SS exhibits greater age-dependent increases in corneal damage than in NOD.H-2h4 parental mice and demonstrates an earlier disease onset in females compared to males. The severity of ocular surface disease correlates with loss of goblet cell density, increased conjunctivitis, and dacryoadenitis that is more pronounced in NOD.H-2h4 DKO than NOD.H-2h4 mice. B cells dominate lacrimal infiltrates in 16-week-old NOD.H-2h4 and NOD.H-2h4 DKO mice, but T helper cells and macrophages are also present. Lacrimal gland expression of proinflammatory genes, including the P2X7 and P2Y2 purinergic receptors, is greater in NOD.H-2h4 DKO than NOD.H-2h4 mice and correlates with dacryoadenitis.
Conclusions: Our results demonstrate for the first time that autoimmune dry eye disease occurs in both sexes of NOD.H-2h4 DKO and NOD.H-2h4 mice, with earlier onset in female NOD.H-2h4 DKO mice when compared to males of the same strain. This study demonstrates that both NOD.H-2h4 and NOD.H-2h4 DKO mice are novel models that closely resemble SS-related and sex-dependent DED.