PRODUCTION OF INTERLEUKIN-6 AND INTERLEUKIN-8 BY HUMAN MAMMARY-GLAND EPITHELIAL-CELLS

The production of transforming growth factor-beta2 (TGF-beta2), interl eukin-1beta (IL-1beta), IL-6, IL-8, and tumor necrosis factor-alpha (T NF-alpha) by spontaneously immortalized human mammary gland epithelial cells of non-malignant origin and the effect of prolactin upon the pr oduction of those cytokines were investigated. Cells were cultured on plastic with epithelial growth factor, insulin, and hydrocortisone. Cy tokines were quantified by enzyme-immunoassays. The cells produced IL- 6 and IL-8, but no detectable TGF-beta2, IL-1beta, or TNF-alpha. Altho ugh prolactin enhanced the uptake of [H-3]thymidine, it did not alter the production of cytokines/interleukins. Because of the marked produc tion of IL-8 by mammary epithelium and a past report of TGF activity i n human milk, those agents were quantified in human milk. The mean +/- S.D. concentrations of IL-8 and TGF-beta2 in human milk obtained in t he first 3 days of lactation were 3684 +/- 2910 and 130 +/- 108 pg/ml, respectively. Thus, IL-8 and TGF-beta2 are normal constituents in hum an milk, and human mammary gland epithelium may be responsible for pro ducing some of the IL-6 and IL-8 in human milk.