Tonsil-derived stem cells as a new source of adult stem cells

Abstract

Located near the oropharynx, the tonsils are the primary mucosal immune organ. Tonsil tissue is a promising alternative source for the high-yield isolation of adult stem cells, and recent studies have reported the identification and isolation of tonsil-derived stem cells (T-SCs) from waste surgical tissue following tonsillectomies in relatively young donors (i.e., under 10 years old). As such, T-SCs offer several advantages, including superior proliferation and a shorter doubling time compared to bone marrow-derived mesenchymal stem cells (MSCs). T-SCs also exhibit multi-lineage differentiation, including mesodermal, endodermal (e.g., hepatocytes and parathyroid-like cells), and even ectodermal cells (e.g., Schwann cells). To this end, numbers of researchers have evaluated the practical use of T-SCs as an alternative source of autologous or allogenic MSCs. In this review, we summarize the details of T-SC isolation and identification and provide an overview of their application in cell therapy and regenerative medicine.

Keywords: Cell therapy; Differentiation; Ectoderm; Endoderm; Mesoderm; Stem cell; Tonsil-derived stem cell.

Figure 1

Possible reason enables diversity in tonsil-derived stem cells differentiation; constitutive features of tonsil. Zygote has most powerful differentiation potential (totipotent). It was able to differentiate to all human anatomies and to become human body. Embryonic stem cells (ESCs) are derived from the inner cell mass of the early embryo. ESCs also has great developmental potential and was able to differentiate to all cell lineages of an organism except for extraembryonic tissues (pluripotent). It is well known that ectodermal or endodermal differentiation is often difficult to achieve with mesenchymal stem cells isolated from bone marrow and adipose tissue (multipotent). Tonsil tissues consist of two different origin tissues; epithelial cells from endoderm origin and lymphoid tissues from mesoderm origin.

Figure 2

Differentiation potential of tonsil-derived stem cells. The multi-potency of the tonsil-derived stem cells (T-SCs) is confirmed in many studies. Under the proper conditions and signals (box), T-SCs can be differentiated into non-mesenchymal lineage, such as ectodermal differentiation (neurons, and Schwann-like cells) and endodermal cells (parathyroid like cells, islet cells and hepatocytes). T-MSCs: Tonsil- mesenchymal stem cells.