Figure 2. Mtb grows within microspheres containing PBMCs and upregulates MMP and cytokine expression.
(A) Mtb proliferates slowly in microspheres with no cells (green line), but progressively in microspheres containing PBMCs (red line), reaching similar luminescence to Middlebrook 7H9 broth culture at 24 days (black line). Blue line, uninfected microspheres. (B) Mtb infection upregulates MMP-1 gene expression and (C) MMP-9 secretion in microspheres. (D) MMP upregulation has a functional effect, causing collagen degradation. DQ Collagen breakdown is higher in Mtb-infected microspheres (red line) than uninfected (blue line). Triangles, microspheres with no PBMCs. (E) Mtb infection increases cellular IFN-γ mRNA accumulation relative to uninfected cells at day four in microspheres (n = 4). (F) Secretion of cytokines by Mtb-infected microspheres (squares) is significantly higher than in microspheres containing uninfected PBMCs (circles). ****p<0.0001 by t-test (B and E) and ANOVA (A, C, D, F).
Figure 2—figure supplement 1. Mtb infection upregulates secretion of multiple growth factors, cytokines and chemokines from microspheres measured by Luminex array.
