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Mesenchymal stem cells derived from human umbilical cord Wharton's jelly (hWJMSCs) became prospective seed cell candidate for tissue engineering and cell-based therapy because of its variety source, easy procurement, robust proliferation, and high purity compared with bone marrow- and adipose-derived MSCs. Such neonatal stem cells can be isolated from a variety of extraembryonic tissues and appear to be more primitive and have greater multi-potentiality than their adult counterparts. In this study, we investigated the immune characters of hWJMSCs and its derived cartilage cells (hWJMSC-Cs) by detecting the expression of major histocompatibility complex I/I(MHC-I/II), costimulatory molecules (CD40, CD80 and CD86) and immune inhibitors including human leukocyte antigen G (HLA-G), indoleamine-2,3-dioxygenase (IDO), and prostaglandin E2 (PGE2). We found that hWJMSCs did not express MHC-II and costimulatory molecules, but moderately expressed MHC-I, and positively expressed immune inhibitors as HLA-G, IDO, PGE2, demonstrating their very low immunogenicity and potential to induce immune tolerance microenvironment in hosts. The results of chondrogenic differentiated hWJMSCs(hWJMSC-Cs) are similar to those of undifferentiated cells, except for the slightly elevated MHC-II and costimulators expression. Additionally, we detected cytokine profile of hWJMSCs through cytokine antibody array and verified by western blot the positive expression of immune suppression-related molecules, HGF, VEGF, TGF, and IL-10. Furthermore, to investigate the in vivo immune response of the cells, hWJMSCs-scaffold constructs were implanted into rabbits and rats, and the result showed that hWJMSCs did not elicit immune rejection in the animals. Their intermediate state between adult and embryonic stem cells makes them an ideal candidate for reprogramming to the pluripotent status. Additional studies are necessary to clarify the potential of hWJMSCs to be used in cartilage and other tissue regeneration and cell-based therapies., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Stem cells derived from umbilical cord Wharton's jelly (WJSCs) are not immunogenic and have immunosuppressive effects. To evaluate the related mechanisms and the effect of transplantation on body immune cells, we examined immune property genes expression in WJSCs and levels of T-lymphocytes subgroups and immunoglobulins (Ig) in heart failure (HF) patients with and without WJSCs transplantation. WJSCs express immune tolerance genes HLA-E, HLA-G and HLA-F and immunomodulation genes VEGF, TGFβ1, HGF, HMOX1, IL1β, IL-6, LIF, LGALS-1/3/8, COX1/2 and PTGE, while they do not express immune response-related genes HLA-DR, HLA-DQ, HLA-DP, CD80, CD86, CD40 and CD40L. No obvious changes of T-lymphocytes subgroups and plasma IgG/IgM were observed in HF patients with WJSCs transplantation. Our results suggest that the immune properties of WJSCs are due to the expression of immune avoidance and immunomodulation genes in the absence of immune response-related genes. WJSCs are secure in immunological aspects when used as seed cells for cardiac repair., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Studies have shown that mesenchymal stem cells (MSCs) have low immunogenicity and immune regulation. Human umbilical cord Wharton's jelly provides a new source for MSCs that are highly proliferative and have multi-differentiation potential. To investigate immunomodulatory effects of human Wharton's jelly cells (WJCs) on lymphocytes, we successfully isolated MSCs from human umbilical cord Wharton's jelly. WJCs expressed MSC markers but low levels of human leukocyte antigen (HLA)-ABC and no HLA-DR. These results indicate that WJCs have low immunogenicity. Both WJCs and their culture supernatant could inhibit the proliferation of phytohemagglutinin-stimulated human peripheral blood lymphocytes and mouse splenocytes. Additionally, WJCs suppressed secretion of transforming growth factor-β1 and interferon-γ by human peripheral blood lymphocytes. We conclude that the immunomodulatory effect of WJCs may be related to direct cell contact and inhibition of cytokine secretion by human peripheral blood lymphocytes., (Copyright © 2011 Elsevier Inc. All rights reserved.)