Phenotypic and functional traits of peripheral blood mononuclear cells retained by controlled cryopreservation:...

Many immunological experiments would be greatly facilitated if peripheral blood mononuclear cells (PBMC) preserved important functional properties over longer periods of time. Regarding adhesive interactions with endothelial cells, a crucial step of inflammatory processes, this had not been investigated yet. We demonstrate that PBMC subsets subjected to controlled cryopreservation retain their phenotypic traits inasmuch as the proportion of viable T cells, monocytes/macrophages and B cells was comparable with their freshly isolated counterparts. More importantly, we demonstrate for the first time that the procedure does not impede crucial adhesion-mediated dynamic interactions with endothelial cells. Using a flow chamber system, freshly isolated and cryopreserved PBMC showed similar rolling and firm adhesion on TNF-α-activated endothelial cells under shear flow as compared to freshly isolated PBMC from the same donors. Thus, our observation is an important prerequisite for functional studies of leucocyte recruitment when sequential investigations with material from the same patients are required.