Figure 5

SEB induces activation of the JNK pathway specifically in responding T cells in vivo. WT mice were injected with 50 μg SEB or PBS i.v. and sacrificed after 1 hr. Spleen and lymph nodes were harvested and analyzed for the presence of phosphorylated c-jun in the Vβ8⁺ and Vβ6⁺ T cell populations. a) Spleen: (i) phosphorylation of c-jun in Vβ6⁺ T cells from PBS injected mice. (ii) phosphorylation of c-jun in Vβ6⁺ T cells from SEB injected mice. (iii) phosphorylation of c-jun in Vβ8⁺ T cells from the same PBS injected mice in (i). (iv) phosphorylation c-jun in Vβ8⁺ T cells from the same SEB injected mice in (ii). b) Lymph Node: (i) phosphorylation of c-jun in Vβ6⁺ T cells from PBS injected mice. (ii) phosphorylation of c-jun in Vβ6⁺ T cells from SEB injected mice. (iii) phosphorylation of c-jun in Vβ8⁺ T cells from the same PBS injected mice in (i). (iv) phosphorylation c-jun in Vβ8⁺ T cells from the same SEB injected mice in (ii). Arrow points to the population of cells responding to SEB stimulation by activation of the JNK pathway by inducing c-jun phosphorylation.