Interaction of Platelet-Derived Microparticles with a Human B-Lymphoblast Cell Line: A Clue for the Immunologic Function of the Microparticles

Background: Platelets are blood cells with extensive capabilities in hemostasis. They also play a central role in the development of innate and adaptive immune responses. Little information exists about the immunostimulatory role of platelet-derived microparticles (PltMPs). To further elucidate this issue, we conducted this study using the B-lymphoblast cell line 'Daudi' as an available surrogate cell line for peripheral blood B lymphocytes. This cell line does not produce immunoglobulins (Igs) and has low expression of activation markers. Methods: Plt-MPs were isolated from platelet concentrate (PC) using a multi-step centrifugation method. Daudi cells were treated with Plt-MPs in the culture medium while no treatment was given to the control cells. During 5-day co-culture, Daudi cells were evaluated for the Ig production and the expression of the cell surface markers CD86, CD27, and IgD. Results: An increase was observed for the production of IgG and the expression of CD27 and CD86 on Daudi cells in response to Plt-MPs, whereas the IgD level was decreased. The response of Daudi cells was dependent on the concentration of PltMPs and the time of their isolation from PCs during storage. The differences of the variables were significant between the treatment and control groups. Conclusion: PltMPs could induce the activation and differentiation of immortalized cells of B-cell origin. Thus it is conceivable that Plt-MPs may play a significant role as immortalized cell activators in human monoclonal antibody technology in near future. (c) 2017 S. Karger GmbH, Freiburg