Antibodies to Stem Cell Antigens

Stem cells have the remarkable potential to develop into many different cell types in the body. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.

Human embryonic stem cells, that are typically harvested from 5-7 day embryos, can potentially develop into all type of cells, and they are pursued intensively towards the goal of regenerative medicine. Human embyonic stem cell science faces intense political and ethical scrutiny, and current U.S. federal policy prohibits funding of studies carried out on stem cell lines established after August 9, 2001. However, a number of U.S. states are attempting to set up funding mechanisms for stem cell research that circumvent federal restrictions, and California has recently established the California Institute of Regenerative Medicine which administers $3 billion in public funding for human embryonic stem cell research at California universities and research institutions.

Recently, a new type of stem cell has been isolated and characterized from a number of solid and liquid tumors. These tumor stem cells are a rare population of tumor cells that can reconstitute a new tumor with all the cell types represented in the tumor of origin. These tumor stem cells are putatively responsible for the transplantability and metastatic properties of tumors. The cells are capable of self renewal and asymmetric cell division, as are normal adult and embryonic stem cells. The isolation of such tumor stem cells is important to more completely understand the progression of malignant disease, as well as to the development of improved specific therapies for cancer.

Stem cells are usually characterized by expression of stem cell specific markers known as stem cell antigens. Some of these antigens reappear in certain cancers, for example, PSA or alpha-fetoprotein are well established markers for prostate and liver cancer respectively. More relevant to pluripotent human embryonic stem cells are markers SSEA-3, SSEA-4, TRA-1-60, and TRA-1-81. These antigens are glycans carried by globo-series glycolipids or pericellular matrix proteoglycans. Antibodies to stem cells are typically generated by immunization of with stem cells, stem cell lines, or blastocyst-stage embryos and screening for monoclonal antibodies that bind to the stem cell but not to further differentiated progeny of this stem cell. When the molecular structure of the antigen is known, more direct, antigen-specific strategies for antibody development can be followed.

Antibody Solutions
Tel: 888-843-1069 Fax: 650-938-4390 E-mail: