Figure 2.

Induction of IL-4 responsiveness following tgD-CD154 binding to bovine B cells. Supernatants from (a) mock-transfected, (b) pSLIAtgD-transfected, or (c) pSLIAtgD-CD154-transfected Cos-7 cells were incubated with bovine B cells. Bound protein was detected with a gD-specific mAb cocktail, followed by FITC-conjugated goat anti-mouse immunoglobulin. (d) Triplicate cultures of bovine B cells (4 × 10⁴ cells/well) were incubated with medium or with pSLIAtgD- or pSLIAtgD-CD154 transfected Cos-7 cell supernatants. Cultures were incubated for 72 hr with either 100 μl/well of 10 ng/ml recombinant human IL-4 (+IL-4) or medium (–IL-4). Cell proliferation was detected by adding methyl-[³H]thymidine during the last 18 hr of culture. Data are shown as average c.p.m. + SEM for triplicate cultures.