HEAT-SHOCK PROTEIN EXPRESSION IN HUMAN CONJUNCTIVA

Purpose. To examine the distribution of human heat shock proteins (HSPs) HSP90, inducible HSP70 (iHSP70), constitutive and inducible HSP70 (cHSP70), HSP65, and human HSP27 in conjunctival biopsy specimens of ocular cicatricial pemphigoid (OCP), atopic keratoconjunctivitis, and healthy persons with cataract. Methods. Using an immunoperoxidase technique, conjunctival biopsy specimens from ten patients with ocular cicatricial pemphigoid, ten patients with atopic keratoconjunctivitis and ten healthy persons undergoing cataract surgery were analyzed with a panel of monoclonal antibodies directed against human HSPs. Results. Large amounts of HSP90 and HSP27, and lesser amounts of cHSP70, iHSP70, and HSP65 were present in atopic keratoconjunctivitis and normal epithelium; less of these proteins were seen in OCP conjunctival epithelium. In atopic keratoconjunctivitis and normal tissue the substantia propria contained a few HSP-positive cells, and the vascular endothelium was consistently negative for all of the HSPs. In sharp contrast, OCP stroma contained large numbers of cells staining for HSP27, HSP90, and iHSP70, and the vasculature was strongly positive, particularly for HSP90, cHSP70, and HSP27. Conclusion. These results indicate that normal and atopic keratoconjunctivitis epithelia express HSP90 and HSP27 and some form of HSP65 and HSP70. The differences between normal, atopic keratoconjunctivitis, and OCP stromal staining suggest an upregulated expression of HSP90, cHSP70, and HSP27 at the site of inflammation in OCP, the stroma, from cytokine release. The striking presence of HSP in the conjunctival vascular endothelium from OCP patients suggests a previously unappreciated role of the vasculature in OCP.