FIG 2.

M. tuberculosis infection upregulates TREM2 expression. (A and B) TREM2 mRNA and protein levels of M. tuberculosis-infected THP-1 macrophages (MOI = 10) were assessed by (A) qRT-PCR and (B) Western blotting at the indicated time points. hMDMs were infected with M. tuberculosis (MOI = 10) and at indicated time points postinfection, TREM2 mRNA and protein levels were quantified by (C) qRT-PCR and (D) Western blot. Data shown in panels A and C were analyzed using the 2^−ΔΔCT method, normalized to ACTB as a reference gene, and are expressed as the relative fold change compared to uninfected cells. qPCR data represents the result of three technical replicates (mean ± SD). (E) M. bovis BCG and M. tuberculosis were mock treated or pretreated with gentamicin (150 μg/mL) for 1 h. Bacteria were then used to infect THP-1 macrophages, and TREM2 protein levels were analyzed at day 3. (F) Listeria monocytogenes-infected (MOI = 10) and M. tuberculosis-infected THP-1 macrophages at the indicated time points were analyzed by Western blotting, and vinculin was used as a loading control. (G) THP-1 macrophages were pretreated with the indicated inhibitors for 2 h and 6 h (in the case of SN-011) and subsequently infected with M. tuberculosis (MOI = 10). TREM2 expression was analyzed by Western blotting at 3 days postinfection using vinculin as a loading control. Blots in panels B, D, E, F, and G are representative of three independent biological replicates. The quantification of TREM2 expression is shown below each panel and is reported as normalized expression over vinculin. AU, arbitrary units.