CD20-LV and CD19ds-LV induce minimal activation of resting primary human B lymphocytes.

<p>(<b>A</b>) Freshly isolated primary human B lymphocytes were left untransduced or were incubated with CD20-LV, CD19ds-LV or VSVG-LV at an MOI of 1.5–2 or with CD20-VLP at the same HIV p24 value as CD20-LV. As positive control, B lymphocytes were activated with a cytokine cocktail consisting of 50 ng/ml IL-2, 300 ng/ml CD40Ligand, 10 ng/ml IL-4 and 10 ng/ml IL-10. Forty-eight hours later, the cell surface expression of the activation markers CD69 and CD71 was determined by FACS analysis using appropriate antibodies. Mean values of CD69⁺ and CD71⁺ cells, respectively, of four different donors and SEM are shown. *, ***, and ****indicate <i>P</i><0.05, <i>P</i><0.001 and <i>P</i><0.0001 versus untransduced cells, respectively. Data were analyzed by two-way ANOVA. (<b>B</b>) Freshly isolated primary human B lymphocytes were transduced by CD20-LV (MOI 3), CD19ds-LV (MOI 3) or MV-LV (MOI 5) vectors or remained untransduced. As positive control, B lymphocytes were activated with the same cytokine cocktail as described for (A). Forty-eight hours later, cell cycle progression was monitored by simultaneously visualizing the RNA (pyronin-Y) and DNA (7-AAD) content of the B lymphocytes by FACS analysis. The percentages of cells in G0, G1b or S/G2/M phase of the cell cycle are indicated. One representative experiment out of four independent experiments is shown.