Fig. 6

AXL regulates the expression of cytokines via STAT6 in M2 macrophages. A–C mRNA was collected from M2 macrophages polarized from AXL-KO THP-1 and control cells, and the expression of M2 macrophage markers or cytokines/chemokines was examined using qRT-PCR. AXL KO in M2 macrophages derived from THP-1 cells reduced the mRNA expression of CD209, IL13RA, and IL2RG A. AXL KO in M2 macrophages derived from THP-1 cells reduced the expression of the immunosuppressive cytokines/chemokines CCL20, CCL26, EREG, and IL1B B. AXL KO in M2 macrophages derived from THP-1 cells increased the expression of cytokines/chemokines involved in the interferon γ–mediated signaling pathway, such as IFNG, CXCL10, and GBP2, at the gene level C. D and E CM from and lysates of M2 macrophages polarized from AXL-KO THP-1 cells had decreased expression of CCL20, CCL26, and EREG protein D but increased expression of CXCL9 and CXCL10 protein E as determined using ELISA. F The migration of human IBC cells was assessed using a transwell migration assay, with CM collected from control and AXL-KO M2 macrophages with or without the addition of recombinant CCL20, CCL26, and EREG protein, serving as attractants. CCL20, CCL26, and EREG mitigated the inhibitory effect of AXL-KO M2 macrophages on SUM149 and BCX010 cell migration. G qRT-PCR was conducted to measure the mRNA expression level of CCL20, CCL26, and EREG in control, AXL-KO, and AXL-KO + STAT6-overexpressing M2 macrophages. Overexpression of STAT6 mitigated the suppressive effect of AXL KO in M2 macrophages on the expression of CCL20, CCL26, and EREG genes. All experiments were repeated at least three times. Data were summarized as means ± SD. Two-tailed Student t test (A–E) and 1-way analysis of variance followed by Dunnett’s multiple comparison test (F and G) were used to calculate P values. *P < 0.05; **P < 0.01; ***P < 0.001