Fig. 4: Rv0884c inhibits IFN-γ production by CD8+ T cells.
a, After co-culturing indicated Mtb strains-infected BMDMs (MOI = 5) and activated TB10Rg3 T cells for 2 h, the percentage of CD69+ TB10Rg3 T cells was measured in TB10Rg3 T cells. b, After co-culturing indicated Mtb strains-infected BMDMs (MOI = 5) and activated TB10Rg3 T cells for 3 days, the expression of IFN-γ was measured using ELISA. c, After 1 day of infection with Mtb strains, BMDMs were co-incubated with activated TB10Rg3 T cells for 3 days and intracellular c.f.u. in BMDMs infected for 1 or 4 days were determined. d–g, C57BL/6 mice were aerosol-infected with ~200 c.f.u. per mouse of Rv0884c_cKDTet with or without ATc, Rv0884c_cKDTet with ATc and d-serine (30 g l−1), Rv0884c_cKDTet+Rv0884c (F108A) with ATc, and Rv0884c_cKDTet+Rv0884c with ATc. After 4 weeks of infection, we assayed: the percentage of CD69+CD8+ T cells (d); the percentage of CD8+IFN-γ+ T cells in CD8+ T cells from lung tissues (e), or from dLNs (f); and CD69 MFI of CD44high CD8+ T cells in CD8+ T cells from lung tissues (g). h, Peptide (TB10.44–11)-pulsed BMDMs were infected with Rv0884c_cKDTet treated with or without ATc for 1 day and then co-cultured with in vitro differentiated CD8+ T cells from spleens of C57BL6 mice or CD4CreIfngfl/fl mice for another 3 days. Bacterial burden was measured 4 days after infection. i–k, CD4CreIfngfl/fl mice were aerosol-infected with ~200 c.f.u. per mouse of Rv0884c_cKDTet with or without ATc for 4 weeks. Histopathology of lung sections from infected mice was assessed via H&E staining (i, top; scale bar, 100 μm), acid-fast staining (i, bottom; scale bar, 20 μm), histology score (j) and bacterial load (k). Data in a–k represent one experiment with at least three independent biological replicates. Results are shown as mean ± s.e.m. Two-way ANOVA with Tukey’s multiple comparisons test (c), one-way ANOVA with Tukey’s multiple comparisons test (a,b,d–g) and two-tailed unpaired Student’s t-test (h,j,k) were used for statistical analysis.
