Figure 5.

Poly I:C-induced CD8 T cell activation is NK1.1⁺ population-independent. (A) Wild type or TLR3^−/− mice were i.p. injected with 1μg SEA with or without 40 μg poly I:C. A day later mice were sacrificed and lung lymphocytes extracted. NK cell activation is defined by upregulation of CD69 surface expression on NK1.1⁺D×5⁺ cells. Data shown are representative of 2 experiments. (B) TLR3^−/− mice were i.p. injected with control or anti-IFNα/β serum before immunization with 1μg SEA and 40 μg poly I:C. On day 1−4 post immunization, mice were bled and frequency of CD69⁺ NK cells analyzed by gating on NK1.1⁺D×5⁺ cells in the peripheral blood lymphocyte population. N=2−5 for each data point. (C) Wild type mice were injected i.p. with control Ig or PK136 antibody to deplete NK1.1⁺ population 18 hours before immunization with 1μg SEA with or without 40 μg poly I:C. On day 5 post immunization, the frequency of NK cells in the spleen were examined by staining for D×5 and CD94 markers. (D) NK1.1⁺ depletion and immunization were carried out as in (C). On day 5-post immunization the frequency of splenic Vβ3⁺ T cells was analyzed by gating on CD8⁺ cells. N=5. (E) One million total splenocytes were restimulated with SEA in the presence of brefeldin A for 5 hours in vitro. Intracellular staining of IFNγ and TNFα was analyzed by gating on CD4⁻Vβ3⁺ T cells. N=5. * P<0.05.