Lacrimal gland epithelial cells stimulate proliferation in autologous lymphocyte preparations

Autoimmune dacryoadenitis is a frequent cause of lacrimal insufficiency. In order to test hypotheses regarding mechanisms that can trigger this syndro me, we developed a method to obtain a preparation of rabbit lacrimal gland epithelial cells essentially free of immune-system cells. The method relies on controlled digestion to disperse lacrimal acini, and recovers acini by filtration through various sizes of nylon mesh. Purity and integrity of the preparation were established qualitatively using light and electron micros copy. Contamination by immune-system cells was quantitated by immunohistoch emistry using anti-CD18, and -RTLA (rabbit thymic lymphocyte antigen) antib odies. The novel method produced preparations of highly-purified lacrimal g land epithelial cells (pLGEC) with expected morphological characteristics w ith less than 1.5 % of the cells staining for CD18 or RTLA. The method also yielded preparations of lacrimal gland interstitial cells (LGIC) enriched for lymphocytes: in these preparations either CD18 or RTLA were detected on nearly 10% of the cells. pLGEC promoted proliferation in preparations of a utologous splenic lymphocytes (SPL) that was blocked by anti-MHC class II b ut not anti-MHC class I antibodies. This observation, combined with the app arent requirement that pLGEC must contact the autologous lymphocyte prepara tion to promote proliferation, supports the hypothesis the proliferation ar ises from antigen-presentation via MHC class II by pLGEC. (C) 2000 Academic Press.