The Department of Biomedicine

BBB Seminar: Roland Jacobs

Suppression of NK cell effector functions by umbilical-cord derived mesenchymal stem cells

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NB! Tuesday, June 18, 13.00

Roland Jacobs
Department of Clinical Immunology and Rheumatology, Hannover Medical University, Germany

Mesenchymal stem cells (MSCs) are being increasingly considered to be used as biological immunosuppressants in bone marrow transplantation (BMT). In the early reconstitution phase following BMT, natural killer (NK) cells represent the major lymphocyte population in peripheral blood. Therefore, it becomes imperative to understand the MSC-NK cell functional interplay as it might profoundly influence the outcome of transplantation. To date, MSC-NK cell interaction studies have largely focussed on bone marrow-derived MSCs (BM-MSCs). Umbilical cord derived (UC)-MSCs are lucrative as an alternative source of therapeutic MSCs. Thus, we studied the interaction of UC-MSCs with unstimulated allogeneic NK cells. Maximal suppression of NK cell cytotoxicity was found to be mediated by Prostaglandin-E2 released upon direct contact between NK cells and the UC-MSCs. Decrease in the IFN-γ producing potential of NK cells upon IL-12/IL-18 stimulation was caused entirely by soluble factors elaborated by the unprimed MSCs. Thus, UC-MSCs potently suppress different functional activities of NK cells by using distinct mechanisms.

Host: Martha Chekenya Enger, Department of Biomedicine