FIG. 6.

Dose dependency and time course of the proliferative response of B cells to the CpG phosphodiester oligonucleotide derived from B. bovis. B cells purified by negative selection were tested for proliferation in a 3-day assay with medium or 10, 20, and 40 μM concentrations of either the B. bovis RAP-1-derived ISS oligonucleotide TAAAAACGTTAC (solid circles) or the control oligonucleotides TAAAAAGCTTAC (open circles) and TAAAAAQGTTAC (solid triangles) (A). In a different experiment, negatively selected B cells were cultured for either 48 or 72 h and radiolabeled for the last 6 h of culture with medium (solid bars) or 40 μM TAAAAACGTTAC (gray bars) or TAAAAAGCTTAC (striped bars). The CG dinucleotide is indicated with an underscore (B).