Immunohistochemical detection of hematopoietic stem cells and induced pluripotent stem cells

© Fraunhofer ITEM

Immunohistochemical analysis of teratoma sections. IHC staining for CD34+ and CD31+ cells, representing hemogenic endothelium (A; scale bar 50 µm). Exemplary result of IHC for hCD90, hCD34 and human nuclei in a teratoma section, arrows indicate CD34+/CD90+ cells (B; scale bar 20 µm).

A core area of our research in the field of biodistribution of cell therapies is immunohistochemical detection of hematopoietic stem cells and induced pluripotent stem cells in tissues and whole-organ slices of laboratory animals, even if the number of cells distributed throughout the body is low. For this purpose, a broad spectrum of antibodies is established at Fraunhofer ITEM. In view of safety aspects and registration, histopathology and immunohistochemistry are performed under GLP conditions.

A risk of stem cell therapies is the formation of teratomas. These  germ cell tumors can be induced by injection of pluripotent stem cells into immunodeficient mice. During tumor growth, the injected stem cells differentiate into cell types from all three germ layers, reflecting embryonic development to a certain degree. With the broad range of methods we have at our disposal, teratoma formation can be assessed as an endpoint in toxicology studies.