Characteristics of hematopoietic stem cells of umbilical cord blood

Umbilical cord blood is a rich source of hematopoietic stem cells (HSCs) and was collected from the placenta and cord. It is an alternative to bone marrow transplantation. HSCs present in cord blood are more primitive than their counterparts in bone marrow or peripheral blood. HSCs can be effectively developed into different cell lines with using proper cytokine combination. This process is used in medicine, especially in hematology.

The totipotent stem cells will become the pluripotent cells in the embryonic. After that, pluripotent cells are transformed into tissue stem cells and called multipotent cells. These cells are division into two progenies: A multipotential hematopoietic stem cell (HSC) and hematopoietic progenitor cell (HPC).

The morphology of cord blood hematopoietic cells

The morphology of human HSC is similar in appearance to a small cell with a narrow hem cytoplasm. It has the ability to intense proliferation and self-renewal and the ability to multiline differentiation. HSC resemble lymphocytes. They are non-adherent, and rounded, with a rounded nucleus and low cytoplasm-to-nucleus ratio. Thus, HSCs cannot be isolated as a pure population, it is not possible to identify them in a microscope.

Surface markers’ expressing on cord blood hematopoietic cells

The classical marker of human HSC is CD34 It is used to isolate HSC for reconstitution of patients who are haematologically incompetent as a result of chemotherapy or disease.

The surface marker-CD34 antigen, was only used to determine the hematopoietic cells. Nevertheless, most cells with CD34 antigen expression of bone marrow or umbilical cord blood. It is a transmembrane glycoprotein of approximately 104–120 kDa. Therefore, its function is associated with the occurrence of transmembrane signaling. CD34 antigen is involved in the regulation of hematopoietic stem cell’s adhesion to the stroma. In addition, many markers belong to the cluster of differentiation series, like: CD34 + , CD38 - , CD90 + , and CD45 - ,,,. (Fig. 1)

Fig.1: Surface markers of cord blood hematopoietic cells (http://stemcellassays.com)

Ref: Anna Hordyjewska et al., 2015. Cytotechnology: DOI 10.1007/s10616-014-9796-y

Nguyen Van Tinh, PhD