FIGURE 1.

Frequency and characteristics of in vitro–transformed CB B cells. CBMC were subjected to in vitro EBV infection and cultured for 3, 7, or 14 d when the characteristics of the CD19⁺ B cell population were assessed by flow cytometry. (A) Gating strategy for CD19⁺ and CD19⁺CD27⁺ cells among live-gated cells. For each time point in (B) frequencies of CD19⁺ cells among live gated cells and in (C) CD19⁺ cell forward (FSC-H) and side scatter (SSC-H) properties are shown. (D) Frequency of CD19⁺CD23⁺ cells and geometric mean fluorescence intensity (GeoMFI) of CD23 on CD19⁺ cells on day 14. (E) For each time point, frequency of CD19⁺CD27⁺ cells is shown. (F) Characteristics of the CD19⁺ population as in (B), (C), and (E) on day 14 using 2×, 1×, 0.5×, or 0.1× the standard volume of EBV-containing supernatant for transformation. CB (n = 2–5) for each independent experiment.