Splenic T Cell Proliferation 7 and 28 days following pulmonary exposure to CNF, Crocidolite Asbestos or SWCNT. Mice were exposed via pharyngeal aspiration to 120 μg/mouse CNF or Asbestos, or 40 μg/mouse SWCNT. Animals were sacrificed 7 and 28 days post exposure (white and black bars, respectively) and splenic T cell proliferation was evaluated. Means ± SE (n = 6 mice per group). *p < 0.05 vs. control (PBS) exposed mice.