CORNEAL EPITHELIAL-CELL DERIVED THYMOCYTE-ACTIVATING FACTOR (CETAF)

  • 1 January 1982
    • journal article
    • research article
    • Vol. 23  (6) , 757-763
Abstract
Supernatants of a primary rabbit corneal epithelial cell culture and an established corneal cell line (SIRC) were assayed for their ability to enhance mitogen-induced C3H/HeJ mouse thymocyte proliferation. Significant levels of thymocyte-enhancing activity were detected in supernatants from both primary cultures and SIRC. Maximal levels of activity were found after 48-72 h of culture in serum-free medium with 1 .times. 105 cells/ml. When monolayers of SIRC were disrupted, supernatants of these cultures consistently contained levels of activity higher than those of undisrupted control cultures. When supernatants from SIRC cultures (both serum-free and containing > 10% fetal calf serum) were subjected to gel filtration on AcA 54 and Sephacryl S-200, corneal epithelial cell-derived thymocyte-activating factor was eluted as 2 major peaks, between MW 95,000 and 55,000 and MW 30,000 and 15,000. Apparently, corneal epithelial cells, similar to keratinocytes, produce an interleukin 1-like activity lacking species specificity, which enhances the proliferative capacity of thymocytes. Corneal epithelial cells may interact with the immune system through the production of this cytokine.