Figure 4.

The effects of TLR2 agonist exposure are mediated by non-autonomous TLR2 signaling in both radioresistant and radiosensitive populations. Chimeric mice were generated by transplanting WT bone marrow into WT recipients (WT→WT), Tlr2^−/− bone marrow into WT recipients (Tlr2^−/−→WT) and WT bone marrow into Tlr2^−/− recipients (WT→Tlr2^−/−). After allowing time for engraftment (11 weeks), mice were treated with PAM₃CSK₄ (100 μg intraperitoneally (i.p.) q48 h × 3 doses). Shown are KSL SLAM frequency in the bone marrow (a) and KSL SLAM cells per spleen (b), as determined by flow cytometry, in chimeric mice and in constitutional Tlr2^−/− controls. (c) Spleen cells from chimeric mice and constitutional Tlr2^−/− controls were plated in complete methylcellulose media and myeloid colony formation was scored after 7 days of growth at 37 °C (n=3–4 mice per group). For all panels, error bars represent mean±s.e.m., and P-values were determined by the two-tailed Student's t-test.