TLR2-Dependent Signaling for IL-15 Production Is Essential for the Homeostasis of Intestinal Intraepithelial Lymphocytes

Figure 3

Alterations in IEL activation, proliferation, apoptosis, and cytokine mRNA expression after TLR2 knockout. (a) The surface expression of CD69 on IELs was detected by flow cytometry. (b) TLR2^−/− and wild-type mice were injected with BrdU twice per day. After 24 h, BrdU incorporation in the indicated IEL subsets was analyzed by flow cytometry. (c) Intestinal IELs were examined through flow cytometry for CD45 and apoptosis markers (FITC-Annexin V and PI). In the apoptosis map, FITC-Annexin V+/PI+ indicates late apoptosis, FITC-Annexin V+/PI− indicates early apoptosis, and FITC-Annexin V−/PI− indicates live cells. (d) Changes in the small intestinal IEL-derived cytokine mRNA measured using real-time RT-PCR. The results were expressed as the ratio of the number of copies of the gene of interest to the number of copies of the β-actin gene. Five mice per group. Representative of three experiments. ; .

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