Previous reports have demonstrated the growth of undifferentiated human embryonic stem (HES) cells on mouse embryonic fibroblast (MEF) feeders and on
laminin- or
Matrigel-coated
plastic surfaces supplemented with MEF-
conditioned medium. These xenosupport systems run the risk of cross-transfer of animal pathogens from the animal feeder, matrix, or
conditioned medium to the HES cells, thus compromising later clinical application. Here we show that human fetal and adult fibroblast feeders support prolonged undifferentiated HES cell growth of existing cell lines and are superior to cell-free matrices (
collagen I, human extracellular matrix,
Matrigel, and
laminin) supplemented with human or MEF feeder-
conditioned medium. Additionally, we report the derivation and establishment of a new HES cell line in completely animal-free conditions. Like HES cells cultured on MEF feeders, the HES cells grown on human feeders had normal karyotypes, tested positive for
alkaline phosphatase activity, expressed Oct-4 and cell surface markers including
SSEA-3,
SSEA-4, Tra 1-60, and GCTM-2, formed
teratomas in severely combined immunodeficient (SCID) mice, and retained all key morphological characteristics. Human feeder#150;supported HES cells should provide a safer alternative to existing HES cell lines in therapeutic applications.