System for producing embryonic stem cells which markedly reduces the risk of contamination with pathogens

Mar 8 2005

A.C.T. Holdings and Advanced Cell Technology, Inc. (ACT) reported the first derivation of human embryonic stem cells in completely feeder-layer-free and serum-free conditions.

The research, which appears online (ahead of print) in the journal The Lancet, by ACT and its collaborators, describes a system for producing embryonic stem cells which markedly reduces the risk of contamination with pathogens that could be transmitted to patients and the population-at-large.

To-date, all human embryonic stem cell lines have been isolated in contact with either mouse or human cells that may have contaminated the stem cells with viruses or other pathogens. It is therefore likely that the human embryonic stem cell lines authorized for federal research funding under the President's August 9, 2001 policy are therefore unsuitable for use in transplant medicine. "The ability to generate embryonic stem cells without exposure to living cells or serum solves a major problem associated with the use of these cells in future medical therapies," said Robert Lanza, Vice President of Medical & Scientific Development at ACT, and senior author of the study. "There are unique challenges associated with the earliest stages of stem cell derivation. Our study shows that the cell- and serum-free derivation of new embryonic stem cell lines is possible from the beginning."

Although feeder-free systems have been described in the past, they have all been used for the maintenance of previously-established human embryonic stem cell lines that have already been exposed to potential contamination by contact with such animal cells. "The routine culture of existing stem cells is like maintaining a house you live in," said Irina Klimanskaya, Director of Stem Cell Biology at ACT, and first author of the paper. "However, establishing a new cell line is comparable to building a new house on an undeveloped site beginning with only blueprints. Of course, the challenge of establishing stem cell lines in a feeder-free system is even greater than merely building a house. Only those culture systems that ensure the most favorable environment for the growth of stem cells will yield new lines, and our system provided such an environment."

The extracellular-matrix-coated plates used in ACT's study proved remarkably stable, and could be easily sterilized using a variety of conventional treatment and sterilization processes. This work also represents an important step toward a completely animal product-free culture system for the derivation and maintenance of new "clean" embryonic stem cell lines.

Michael D. West, Chairman, President, and Chief Scientific Officer of ACT, and an author on the paper said: "The advance of regenerative medicine from the laboratory bench to the bedside will require steps like these, to guarantee that the life-giving cells are free of any known viruses or pathogens. We hope that public policy will facilitate the exploration of new "clean" cell lines by medical researchers to determine that they are indeed free of potential pathogens, and to fashion new therapies from these cells for currently untreatable diseases."

The researchers of the paper from Advanced Cell Technology, collaborated with scientists from the Department of Pathology and Laboratory Medicine at the University of Wisconsin Medical School, Madison; and the Cytogenetics Laboratory, Wisconsin State Laboratory of Hygiene, Madison, Wisconsin. The paper's other authors are Young Chung of ACT, and Lorraine Meisner and Julie Johnson of the Cytogenetics Laboratory.

A.C.T. Holdings, Inc., a Nevada corporation, is a biotechnology company applying human embryonic stem cell technology in the emerging field of regenerative medicine. The company is currently headquartered in Worcester, Massachusetts. The company intends to establish a research facility in California, where voters last November passed Proposition 71. Often referred to as the "Stem Cell Initiative", Proposition 71 provides $3.0 billion over the next ten years for stem cell research.