Ex vivo evaluation of PBMNCs collected with a new cell separator

BACKGROUND: This study reports on an evaluation of the ability of a cell se parator (Amicus, Baxter Healthcare) and the integral MNC computer software program to collect a variety of MNC subsets. The collection efficiency (CE) of the Amicus for these MNC subsets was compared to that of another cell s eparator (CS-3000 Plus, Baxter). The collected MNCs were also assayed ex vi vo to determine if these cells remained functional. STUDY DESIGN AND METHODS: Healthy volunteer blood donors were recruited to provid e PBMNCs for the isolation of CD3+, CD4+, CD8+, CD19+, NK, and gamma delta cells and monocytes. Cells were collected with an Amicus (test arm; n = 16 ) or a CS-3000 Plus (control arm; n = 11) cell separator. Cells were counte d on a flow cytometer and CEs were calculated. For functional studies, the Amicus-collected MNC data were compared to CS-3000 Plus historical data. Fu nctional studies performed included surface antigen expression assays (CD8), proliferation assays (CD4+ and CD8+ cells), NK cytotoxicity assays for K 562 and HUVE cells, and E-selectin induction on endothelial cells through N K+ contact dependency. Dendritic cells (DCs) were generated from CD34+ cell s collected on the Amicus, positively selected by the use of antibody-bound , magnetic bead technology, and then cultured ex vivo with a combination of growth factors to generate the DCs. RESULTS: CEs were higher on the Amicus than on the CS-3000 Plus for CD3+ (6 8 vs. 54%), CD4+ (70 vs. 56%), CD8+ (68 vs. 52%), and CD19+ (60 vs. 48%) ce lls (p <0.05). For the two separators, CEs were equivalent for monocytes, N K+, and gamma delta+ cells. The Amicus separator collected significantly fe wer platelets than did the CS-3000 Plus (p<0.00001). CD4+, CD8+, and NK cel ls proliferated normally. NK cells appropriately stimulated E-selectin expr ession on endothelial cells. Culture-generated DCs obtained by using Amicus -collected CD34+ cells expressed appropriate cell surface markers. CONCLUSION: The Amicus separator is acceptable for the collection of PBMNC subsets. The device collects CD3+, CD4+, CD8+, and CD19+ T- and B-cell subs ets with greater efficiency and collects MNCs with significantly fewer cont aminating platelets than does the CS-3000 Plus. Cells collected on the Amic us are suitable for use in a variety of research and clinical immunobiologi c studies.