Mesenchymal stem cells do not suppress lymphoblastic leukemic cell line proliferation.
BACKGROUND
Several studies have demonstrated the immunosuppresive effects of mesenchymal stem cells (MSCs) in allogeneic or mitogenic interactions. Cell-cell contact inhibition and secretion of suppressive soluble factors have been suggested in this regard.


OBJECTIVE
To investigate if adipose derived MSCs could inhibit Jurkat lymphoblastic leukemia T cell proliferation during coculture.


METHODS
Adherent cells with the ability of cellular growth were isolated from normal adipose tissues. Initial characterization of growing cells by flow cytometry suggested their mesenchymal stem cell characteristics. Cells were maintained in culture and used during third to fifth culture passages. Jurkat or allogeneic peripheral blood mononuclear cells (PBMCs) were labeled with carboxy fluorescein diacetate succinimidyl ester and cocultured with increasing doses of MSCs or MSC culture supernatant. Proliferation of PBMCs or Jurkat cells under these conditions was assessed by flow cytometry after 2 and 3 days of coculture, respectively.


RESULTS
Results showed the expression of CD105, CD166 and CD44, and the absence of CD45, CD34 and CD14 on the surface of MSC like cells. Moreover, initial differentiation studies showed the potential of cell differentiation into hepatocytes. Comparison of Jurkat cell proliferation in the presence and absence of MSCs showed no significant difference, with 70% of cells displaying signs of at least one cell division. Similarly, the highest concentration of MSC culture supernatant (50% vol/vol) had no significant effect on Jurkat cell proliferation (p>0.6). The same MSC lots significantly suppressed the allogeneic PHA activated PBMCs under similar culture conditions.


CONCLUSIONS
Using Jurkat cells as a model of leukemia T cells, our results indicated an uncertainty about the suppressive effect of MSCs and their inhibitory metabolites on tumor or leukemia cell proliferation. Additional systematic studies with MSCs of different sources are needed to fully characterize the immunological properties of MSCs before planning clinical applications.
Mousavi Niri
Neda
N
Department of Immunology, Shiraz University of Medical, Sciences, Shiraz, Iran.
Jaberipour
Mansooreh
M
Razmkhah
Mahboobeh
M
Ghaderi
Abbas
A
Habibagahi
Mojtaba
M
D000273:Adipose Tissue / Q000166:cytology; D015703:Antigens, CD / Q000378:metabolism; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D000071063:Endoglin; D005326:Fetal Proteins / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D016130:Immunophenotyping; D019169:Jurkat Cells; D015458:Leukemia, T-Cell / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D020410:Activated-Leukocyte Cell Adhesion Molecule
D015703:Antigens, CD; D015816:Cell Adhesion Molecules, Neuronal; D000071063:Endoglin; D005326:Fetal Proteins; D018960:Hyaluronan Receptors; D011956:Receptors, Cell Surface; C105613:ALCAM protein, human; D020410:Activated-Leukocyte Cell Adhesion Molecule; C497483:CD44 protein, human; C064206:ENG protein, human