Growth arrested Swiss mouse embryonic 3T3 cells are used as feeders to support the growth of epidermal keratinocytes and several other target cells. The 3T3 cells have been extensively subcultured owing to their popularity and wide distribution in the world and, as a consequence selective inclusion of variants is a strong possibility in them. Inadvertently selected variants expressing innate re...

Clinical studies with adoptive immunotherapy using allogeneic natural killer (NK) cells showed feasibility, but also limitation regarding the transfused absolute cell numbers. First promising results with peripheral blood mononuclear cells (PBMCs) as feeder cells to improve the final cell number need further optimization and investigation of the unknown controlling mechanism in the cross-talk t...

The optimal maintenance of human embryonic stem cells (hESC) in vitro is generally observed in the presence of a feeder-layer of mouse embryonic fibroblasts in a serum-containing medium. Various approaches are now available to remove the feeder requirement. Today, the best feeder-free system for the maintenance of hESC and induced pluripotent stem (iPS) cells is based on a serum-replacement med...

BACKGROUND Natural killer (NK) cells constantly survey surrounding tissues and remove newly generated cancer cells, independent of cancer antigen recognition. Although there have been a number of attempts to apply NK cells for cancer therapy, clinical application has been somewhat limited because of the difficulty in preparing a sufficient number of NK cells. Therefore, ex vivo NK cell expansio...

Although human pluripotent stem cells (hPSCs) can proliferate robustly on the feeder-free culture system, genetic instability of hPSCs has been reported in such environment. Alternatively, feeder cells enable hPSCs to maintain their pluripotency. The feeder cells are usually grown in a culture medium containing fetal bovine serum (FBS) prior to coculture with hPSCs. The use of FBS might limit t...

The rabbit is a classical experimental animal species. A major limitation in using rabbits for biomedical research is the lack of germ-line-competent rabbit embryonic stem cells (rbESCs). We hypothesized that the use of homologous feeder cells and recombinant rabbit leukemia inhibitory factor (rbLIF) might improve the chance in deriving germ-line-competent rbES cells. In the present study, we e...

PURPOSE To establish a culture technique for human corneal epithelial equivalents that do not require fetal bovine serum (FBS), feeder cells, or bovine pituitary extracts and compare this system with conventional culture medium with FBS and mouse 3T3 fibroblasts. METHODS Human corneal limbal tissue from donor corneas was dissociated on denuded amniotic membranes and then cultured for 3 weeks ...

Mouse 3T3-Swiss albino cells are widely used as feeder cells to culture the human epidermis for the treatment of burns. To minimize the risk of xenoinfection, quality control of the feeder cells is required in the Japanese guidelines on regenerative medicine using feeder cells. We characterized three lots of 3T3-Swiss albino cells that are publicly or commercially available in Japan. One lot, w...

Previous observations obtained from a culture of blastodermal cells on a mouse fibroblast feeder layer (STO) suggested that STO cells provide a factor or factors that facilitate development of avian primordial germ cells (PGC) from dispersed embryo cells. The purpose of the current study was to test the hypothesis that soluble factors produced by STO cells are responsible, at least in part, in ...

Progress in isolating stem cells from tissues, or generating them from adult cells by nuclear transfer, encourages attempts to use stem cells from affected individuals for gene correction and autologous therapy. Current viral vectors are efficient at introducing transgenic sequences but result in random integrations. Gene targeting, in contrast, can directly correct an affected gene, or incorpo...