Fig. 4: Loss of LXN upregulates PD-L2 expression in macrophage and increases polarization towards M2 phenotype.

A BMDMs from WT and LXN KO mice were subjected to RNA-seq. Volcano plot of gene expression changes in LXN KO and WT macrophages. B Heatmap of RNA-seq data showing the up- and downregulation genes in LXN-deficient macrophages (n = 3 mice). C GO analysis of upregulated and downregulated genes suggested the enrichment in the regulation of immune system. D Representative KEGG analysis of macrophage adhesion molecules in T cell receptor signaling pathway. E Relative expression levels of cytokine and chemokine mRNA in WT and LXN KO macrophage were measured by qRT-PCR. n = 3, *P < 0.05, **P < 0.01, ***P < 0.001. F Western blot showed LXN deficiency upregulates the expression PD-L2, PD-L1 and CD163 in macrophages. **P < 0.01, n.s. no significance. G Representative FACS plots and frequencies of PD-L2⁺ populations in F4/80⁺CD11b⁺ cells from WT or LXN-deficient mice. n = 4, ^*P < 0.05. H Representative qRT-PCR analysis of M1 (IL-1β, iNOS) and M2 (Arg1) macrophage markers in RAW264.7 cells transfected with CTL or LXN siRNA after induction of IL-4 (20 ng/ml) or IFN-ɤ+LPS (30 ng/ml+100 ng/ml) for 72 h. n = 3, *P < 0.05, **P < 0.01. n = 3, **P < 0.01. Data are representative of three independent experiments.