Transforming growth factor beta in human milk and some infant formula are biologically active in HT‐2 cells

Abstract

Transforming growth factor beta (TGFβ) of human milk (HM) is thought to play an important role in maintaining appropriate immune function in infants. In the present study we assessed and compared total and TGFβ2 specific activity in HM and infant formulas (IF) in HT‐2 cells. This bioassay is used to study regulation of T‐cell growth by TGFβ inhibiting the S‐phase progression of HT‐2 cells stimulated with IL‐4. Mature HM were sampled from mothers in the US and Mexico, while IF samples (Enfamil® LIPIL®/A+®) were obtained from US, China, Mexico, Thailand, and the Philippines from the manufacturer. HM inhibited cell growth in a dose‐dependent manner. HM at a concentration of TGFβ equivalent to that found of Enfamil (4900 ± 1400 pg/ml) exhibited a 2‐folds higher total bioactivity, which may be explained in part by additional functional factors in HM that also inhibit cell proliferation, differences in physiochemical properties of the milks, or potential matrix effects. TGFβ related activity in HM did not differ between US and Mexican mothers; similarly TGFβ related activity in IF did not vary by the manufacturer location. TGFβ2 specific neutralizing antibody decreased activity in IF and HM by 2‐3 folds and 2‐7 folds respectively, suggesting that some, but not all, of the activity is due to TGFβ2. These results demonstrate that both infant formula and HM exerted similar TGFβ related activities in HT‐2 cells. Supported by MJN.