| Evidence |
the macrophages were grouped by FCN1, SPP1 and FABP4 expression patterns including the FCN1hi group 1, FCN1loSPP1+ group 2, SPP1+ group 3 and FABP4+ group 4 macrophages;Group 1 expressed the peripheral monocyte-like markers S100A8, FCN1 and CD14, and group 2 expressed high levels of the chemokines CCL2, CCL3, CXCL10 and other genes. Both groups had gene expression patterns suggestive of classic M1-like macrophages. Group 3 expressed the immunoregulatory genes A2M, GPR183 and CCL13 and the profibrotic genes TREM2, TGFB1 and SPP1, suggestive of alternative M2-like macrophages, a reparative but profibrotic subset5 . Group 4 expressed the alveolar macrophage (AM) genes FABP4, APOC1, MARCO and genes associated with lipid metabolic functions6 and was enriched in BALFs of controls and moderate cases but not in severe cases |
