Cortisol biosynthesis in the human ocular surface innate immune response.

Innate immune responses have a critical role in regulating sight-threatening ocular surface (OcS) inflammation. While glucocorticoids (GCs) are frequently used to limit tissue damage, the role of intracrine GC (cortisol) bioavailability via 11-beta-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) in OcS defense, remains unresolved. We found that primary human corneal epithelial cells (PHCEC), fibroblasts (PHKF) and allogeneic macrophages (M1, GM-CSF; M2, M-CSF) were capable of generating cortisol (M1>PHKF>M2>PHCEC) but in corneal cells, this was independent of Toll-like receptor (TLR) activation. While PolyI∶C induced maximal cytokine and chemokine production from both PHCEC (IFNγ, CCL2, CCL3, and (CCL4), IL6, CXCL10, CCL5, TNFα) and PHKF (CCL2, IL-6, CXCL10, CCL5), only PHKF cytokines were inhibited by GCs. Both Poly I∶C and LPS challenged-corneal cells induced M1 chemotaxis (greatest LPS-PHKF (250%), but down-regulated M1 11ß-HSD1 activity (30 and 40% respectively). These data were supported by clinical studies demonstrating reduced human tear film cortisol∶cortisone ratios (a biomarker of local 11ß-HSD1 activity) in pseudomonas keratitis (1∶2.9) versus healthy controls (1∶1.3; p<0.05). This contrasted with putative TLR3-mediated OcS disease (Stevens-Johnson Syndrome, Mucous membrane pemphigoid) where an increase in cortisol∶cortisone ratio was observed (113.8∶1; p<0.05). In summary, cortisol biosynthesis in human corneal cells is independent of TLR activation and is likely to afford immunoprotection under physiological conditions. Contribution to ocular mucosal innate responses is dependent on the aetiology of immunological challenge.

Elevation of conjunctival epithelial CD45INTCD11b⁺CD16⁺CD14⁻ neutrophils in ocular Stevens-Johnson syndrome and toxic epidermal necrolysis.

PURPOSE: Ocular complications related to Stevens-Johnson Syndrome (SJS)-Toxic Epidermal Necrolysis (TEN) may persist and progress after resolution of systemic disease. This is thought to be related in part to persistent ocular innate-immune signaling. In this study, our aim was to characterize infiltrative conjunctival cellular profiles during acute (<12 months) and chronic (>12 months) disease. METHODS: Consecutive patients presenting with SJS-TEN over a 12-month period were followed for 1 year. Detailed clinical examination and conjunctival impression cell recovery was analyzed by flow cytometry for the presence of intraepithelial leukocytes and compared with healthy controls (n = 21). RESULTS: Ten patients were recruited of whom six had acute disease and five were classified as TEN (SCORTEN = 1, n = 4). Conjunctival inflammation was graded as absent/mild in a total of nine patients; but despite this, evidence of fornix shrinkage was observed in nine subjects. This inversely correlated with disease duration (P < 0.05). A reduction in percentage of CD8αß(+) T cells compared with controls (80% vs. 57%; P < 0.01) was associated with a corresponding increase in the number/percentage of CD45(INT)CD11b(+)CD16(+)CD14(-) neutrophils (186 vs. 3.4, P < 0.01, 31% vs. 0.8%, P < 0.001). Neutrophils inversely correlated with disease duration (r = -0.71, P = 0.03), yet there was no absolute change in the CD8αß(+) or neutrophil populations during the study period (P = 1.0). CONCLUSIONS: These data highlight that a neutrophilic infiltrate is present in mildly inflamed or clinically quiescent conjunctival mucosa in patients with ocular SJS-TEN, where neutrophil numbers inversely correlate with disease duration. Neutrophil persistence endorses the hypothesis of an unresolved innate-inflammatory process that might account for disease progression.