Skip to main content
. 2011 Sep 15;10(3):248–259. doi: 10.1016/j.chom.2011.08.006

Figure 1.

Figure 1

The Microbial and Host Macrophage Transcriptomes Reflect Free Zinc Overload during M. tuberculosis Infection

(A) RT-qPCR analysis of ctpC and Rv3269 expression during human macrophage infection. Cells were infected for the indicated time. The data shown are means ±SD of ctpC expression, normalized with respect to sigA, in intracellular bacteria, relative to the inoculum (0). The data shown are from an experiment performed in triplicate and were analyzed with Student's t test. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001; the data are representative of four independent biological replicates.

(B) Transcriptional profile analysis. Red-blue density display showing the expression levels of the human metallothionein-encoding genes MT1H, MT1M, MT1X, and MT2A at 4, 18, or 48 hr after M. tuberculosis infection in macrophages, as reported in microarray analysis by Tailleux et al. (Tailleux et al., 2008). Genes are ordered in rows, conditions as columns. The colors indicate the strength of expression, running from red (high levels of expression) to blue (low levels of expression; in arbitrary units).

(C) RT-qPCR analysis of the expression ratio of the genes encoding the metal transcription factor-1 (MTF1), MT1, MT2, and the zinc exporter ZnT1/SLC30A1 in human macrophages during M. tuberculosis infection, relative to uninfected cells (0). After indicated time of infection, total cellular RNA was extracted and analyzed by RT-qPCR. Data are displayed as fold-change relative to expression before infection, and are normalized relative to hprt. Averaged data (mean ±SD from a triplicate experiment) from one representative donor out of four tested are shown.

(D–F) MTF1 localization. (D) MTF1 was immunolocalized (green) in uninfected macrophages (upper panels) and in macrophages infected as in (A) for 24 hr with DsRed-expressing M. tuberculosis (red, lower panels). Cell nuclei are labeled with the fluorescent dye TOPRO-3 (blue). The oblique bars indicate analysis lines as used in (E) to quantify the MTF1 signal. (E) Average MTF1 signal intensity, analyzed as in (D), for 25 cells per condition. (F) MTF1 signal intensity ratio (nucleus/cytoplasm) measured before infection (0) and 2 or 24 hr after infection. Scale white bar, 20 μm. The data shown in (D)–(F) are representative of two independent experiments, and data shown in (E) and (F) represent mean ±SD of values calculated from 40 randomly chosen cells in several fields.