Fig. 6: M. tuberculosis isolate 6C4 evades macrophage cytosolic surveillance pathways. | Nature Communications

Fig. 6: M. tuberculosis isolate 6C4 evades macrophage cytosolic surveillance pathways.

From: Mycobacterium tuberculosis associated with severe tuberculosis evades cytosolic surveillance systems and modulates IL-1β production

Fig. 6

a Heatmap representing the expression of genes associated with the cGAS pathway in non-infected BMDMs (NI; yellow) and BMDMs infected with M. tuberculosis isolate 4I2 (dark red) or M. tuberculosis isolate 6C4 (blue). z-scores are color coded as shown. C57BL/6 WT BMDMs were generated and infected with b M. tuberculosis isolates 4I2 (solid bars) or 6C4 (open bars) or c with M. tuberculosis isolate 4I2 in the absence (0) or presence of different doses of the cGAS inhibitor RU521. Six hours post-infection, the cell cultures were lysed, RNA extracted, converted to cDNA, and subjected to real-time PCR to quantify the expression of the indicated genes. d C57BL/6 WT or AIM2 deficient (-/-) BMDMs were generated and infected with M. tuberculosis isolates 4I2 (solid bars) or 6C4 (open bars). Infection of C57BL/6 WT BMDMs in the absence (-) or presence (+) of (e) a K+ channel inhibitor (glybenclamide; 25 µg mL–1), f a cathepsin B (CatB) inhibitor (ZRLR; 10 µM) or g a phagocytosis inhibitor (cytochalasin D; 5 µM). h–i C57BL/6 WT BMDMs were generated and infected with live or rifampicin (RIF)-treated M. tuberculosis isolates 4I2 (solid bars) or 6C4 (open bars). d–h Twenty-four hours post-infection, the culture supernatants were harvested and the amount of IL-1β quantified by ELISA. i Six hours post-infection the cell cultures were lysed, RNA extracted, converted to cDNA, and subjected to real-time PCR to quantify the expression of Ifnb. Represented is the mean ± SEM of triplicate wells from one experiment representative of two (b, c, g); from two (d, e, h) or one (f, i) independent experiments. c Represented is the % of inhibition for the expression of each gene in BMDMs infected with M. tuberculosis isolate 4I2 in the presence of RU.521 relatively to those infected in the absence of the cGAS inhibitor. An MOI of 2 was used for all infections. Statistical analysis was performed using two-tailed unpaired Student’s t-test (*p < 0.05; **p < 0.01; ***p < 0.001; and ****p < 0.0001).

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