TABLE 3.
Isotype distribution of memory B cells in circulation detected by flow cytometry, compared with isotype distribution of ASCs detected by ELISPOT assay after 3 and 6 days of in vitro stimulation (n = 7)
| Cell type | Study day | No. of cells per million PBMCs (mean ± SD) | Mean % ± SD |
||
|---|---|---|---|---|---|
| IgA+ | IgG+ | IgM+ | |||
| CD19+CD27+ memory B cells prior to stimulation, by FACS analysisa | 2 | 20,000 ± 14,000 | 21 ± 10 | 45 ± 8 | 34 ± 14 |
| 30 | 19,000 ± 14,000 | 25 ± 9 | 41 ± 8 | 33 ± 9 | |
| ASCs after 3 days of stimulated culture, by ELISPOT assay | 2 | 7,200 ± 5,900 | 32 ± 20 | 46 ± 22 | 23 ± 15 |
| 30 | 6,500 ± 6,900 | 25 ± 16 | 42 ± 17 | 33 ± 17 | |
| ASCs after 6 days of stimulated culture, by ELISPOT assay | 2 | 43,000 ± 37,000 | 18 ± 8 | 53 ± 15 | 29 ± 11 |
| 30 | 90,000 ± 86,000 | 13 ± 8 | 48 ± 11 | 39 ± 15 | |
a
FACS, fluorescence-activated cell sorter.