Figure 3.

Key figure. Potential sequence of events in tuberculosis (TB) granuloma progression identified by gene co-expression analysis.

Unbiased analysis of RNA-sequencing data identified a seven-gene cluster unique to TB lymph nodes compared with the non-infectious granulomatous disease, sarcoidosis. Several of these genes have previously been implicated in TB pathogenesis. Considering their function together leads to a proposed sequence of events starting with excessive monocyte recruitment, which are then epigenetically reprogrammed to propagate inflammation, ultimately leading to excessive matrix metalloproteinase-1 (MMP1) expression, which causes matrix destruction. Part of figure created with BioRender (www.BioRender.com). Abbreviations: CCL, C-C motif chemokine ligand; FAM124A, family with sequence similarity 124 member A; OLR1, oxidised low-density lipoprotein receptor 1; SLC11A1, solute carrier family 11 member 1.