Extended Data Fig. 3: Cell survival and IgG secretion of encapsulated mouse bone marrow plasma cells over time.
(a) Cell viability of encapsulated and non-encapsulated cells after incubation in culture medium for different time periods. Viability was analyzed by flow cytometry (gated on single cells or single beads/CD138+/live; gating strategy in Supplementary Fig. 2). (b) Detection of IgG in the culture supernatant of encapsulated (red) and nonencapsulated cells (dark gray) by ELISA at different time points. The dashed line indicates the sensitivity of the assay (absorbance corresponding to 1.56 ng/mL IgG). The solid lines denote the mean of two technical replicates. (c) IgG1 secretion of encapsulated and non-encapsulated cells over time was analyzed by flow cytometry. To determine the extent of cross-contamination between beads, the IgG1 signal of plasma cells (CD138+) was compared to the signal of empty beads or cells that lack the plasma cell marker (CD138−; gating strategy in Supplementary Fig. 3). The numbers in the top right corner indicate the percentage of IgG+ events in the CD138+ (red) and CD138− (blue) populations (IgG+ gate indicated by a gray line). The number in the bottom right corner indicates the percentage of ‘true positives’ (percentage of IgG+ events originating from CD138+ based on the sum of IgG+ events from both CD138+ and CD138− populations). The plots show a minimum of 10,019 (CD138−) and 2,533 (CD138+) events at 2% contour level. (d) Time course of ASC IgG secretion and background based on c. Left axis: percentage of IgG1-positive events in the CD138+ (red diamonds) and CD138− (blue diamonds) populations for each analyzed time point. Right axis (gray diamonds): percentage of events in the IgG1 gate that originate from CD138+ and not from CD138−.
