HRI is required for infection-induced cytokine expression.

<p>(<b>A</b>) Peritoneal macrophages isolated from <i>Hri</i> +/+ and -/- mice were infected <i>in vitro</i> with either <i>Yersinia pseudotuberculosis</i> (Y.p.) or <i>Listeria monocytogenes</i> (L.m.) for 3 hr. Plotted are the levels of TNFα-encoding transcripts in infected <i>Hri</i> +/+ and -/- cells relative to their respective uninfected control cells. (<b>B</b>) Splenocytes isolated from <i>Hri</i> +/+ and -/- mice were either left uninfected or infected <i>in vitro</i> with L.m. for 5 hrs and then intracellularly stained for TNFα protein. Histrogram displays TNFa levels in macrophages (live, CD11b⁺-gated). The median fluorescence intensities (MFI) of 3 separate experiments is shown (right panel). <i>P</i> values calculated using student <i>t</i> test.