<i>M. tuberculosis</i> persists in a non-replicating state inside adipocytes.

<div><p> <b>A.</b> 3T3-L1 mouse (grey bars) and primary human (black bars) adipocytes were infected with <i>M. tuberculosis</i>, clinical isolate MT103, at a MOI of 1.</p> <p>Mycobacterial binding to the cells was measured after 4 h at 4°C in the presence of various inhibitors.</p> <p>Man, yeast mannan; LAM, lipoarabinomannan; pA, polyadenosinic acid; pI, polyinosinic acid; Fuc, fucoidan; PC, PAz-PC, a predominant form of oxidized low-density lipoprotein.</p> <p>Results are expressed as % of the binding without inhibitor (Ø).</p> <p> <b>B.</b> 3T3-L1 adipocytes (grey bars) and pre-adipocytes (black bars) were infected as described in A. in the presence of Fuc or PAz-PC.</p> <p>Mycobacterial binding was assessed and analysed as in A.</p> <p> <b>C.</b> 3T3-L1 pre-adipocytes (black squares) and adipocytes (open squares) were pulsed with <i>M. tuberculosis</i> MT103 at a MOI of 1 for 4 h at 37°C, then chased with fresh medium.</p> <p>Mycobacterial survival, expressed as % of the bacterial load at day 0, was monitored on a 10-day period.</p> <p>The results are standardized as % of the bacterial load at day 0 because of the differential <i>M. tuberculosis</i> binding to adipocytes and pre-adipocytes.</p> <p> <b>D.</b> 3T3-L1 adipocytes were infected as described in C.</p> <p>Viable counts (CFU) were quantified by plating serial dilutions of cell lysates (open bars), and total counts (CEQ) were quantified by qPCR (grey bars).</p> <p> <b>E.</b> 3T3-L1 adipocytes were infected as described in C.</p> <p>In order to kill extra-cellular bacteria cells were pre-incubated with 200 µg/ml amikacin 2 h prior lysis and plating.</p> <p>Results are expressed as % of bacterial load at day 0.</p> <p> <b>F.</b> 3T3-L1 adipocytes and pre-adipocytes were infected as described in C.</p> <p>Cells were treated with 1 µg/ml rifampicin (Rif), 0.1 µg/ml isoniazid (Inh), 25 µg/ml pyrazinamide (Pza) or 5 µg/ml ethambutol (Emb) at day 3, and bacterial loads were quantified at day 5.</p> <p>Results are expressed as % of bacterial load at day 5 in the absence of antibiotics (Ø).</p> <p>In all panels, results are the mean of three independent experiments and bars indicate ± sd.</p> <p>NT, not tested; NS, not significant, and *, p<0.05, as assessed by Mann-Whitney test of median comparison.</p></div