Figure 2.

In vitro exposure to perfluorooctane sulfonate induces dose-dependent CD4⁺ and CD8⁺ T cell division in the dolphin. Percentage of (A) CD4⁺ and (B) CD8⁺ T cells divided as determined by carboxyfluorescein succinimidyl ester dilution at 2 and 4 days post-culture with 0 µg ml⁻¹ (open circles), 0.5 µg ml⁻¹ (gray triangles) and 5.0 µg ml⁻¹ (dark diamonds) perfluorooctane sulfonate. *P ≤ 0.001.