Since macrophages play an important role in the pathology of mycobacterial diseases and cancer, in the present study, selleckchem we evaluated the MIP in live and killed form for macrophage activation potential, compared it with BCG and investigated the underlying mechanisms. High levels of tumour necrosis factor-α, interleukin-12p40 (IL-12p40), IL-6 and nitric oxide were produced by MIP-stimulated macrophages as
compared with BCG-stimulated macrophages. Prominent up-regulation of co-stimulatory molecules CD40, CD80 and CD86 was also observed in response to MIP. Loss of response in MyD88-deficient macrophages showed that both MIP and BCG activate the macrophages in a MyD88-dependent manner. MyD88 signalling pathway culminates in nuclear factor-κB/activator protein-1 (NF-κB/AP-1) activation and higher activation of NF-κB/AP-1 was observed in response to MIP.
With the help of pharmacological inhibitors and Toll-like receptor (TLR) -deficient macrophages, we observed the role of TLR2, TLR4 and intracellular TLRs in MIP-mediated macrophage activation. Stimulation of HEK293 cells expressing TLR2 in homodimeric or heterodimeric learn more form showed that MIP has a distinctly higher level of TLR2 agonist activity compared with BCG. Further experiments suggested that TLR2 ligands are well exposed in MIP whereas they are obscured in BCG. Our findings establish the higher macrophage activation potential of MIP compared with BCG and delineate the
underlying mechanism. “
“Eosinophils are multifunctional leukocytes involved in allergic reactions as well as adipose tissue regulation. IL-5 is required for eosinophil survival; however, the in vivo mechanisms of eosinophil regulation are not fully understood. A transgenic (tg) mouse model with il5 promoter-driven EGFP expression was established for detecting the IL-5-producing cells in vivo. Il5-egfp tg mice expressed high levels of EGFP in gonadal adipose tissue (GAT) cells. EGFP+ cells in GAT were mainly group 2 innate lymphoid cells (ILCs). IL-33 preferentially expanded EGFP+ cells and eosinophils in GAT in vivo. EGFP+ ILCs were found to upregulate prg2 mRNA expression in GAT eosinophils. These results demonstrate that ILCs activate eosinophils in GAT. Phosphoribosylglycinamide formyltransferase The blockage of IL-33Rα, οn the other hand, did not impair EGFP+ ILC numbers but did impair eosinophil numbers in vivo. GAT eosinophils expressed IL-33Rα, and IL-33 expanded eosinophil numbers in CD90+ cell-depleted mice. IL-33 was further observed to induce the expression of retnla and epx mRNA in eosinophils. These findings demonstrate that IL-33 directly activates eosinophils in GAT, and together with our other findings described above, our findings show that IL-33 has dual pathways via which it activates eosinophils in vivo: a direct activation pathway and a group 2 ILC-mediated pathway. This article is protected by copyright.