In this study, we examined the effect of deletion on macrophages in methicillin-resistant (MRSA) infection. MRSA-infected mice were employed for the experiments, and RAW264.7 cells were stimulated with MRSA for the experiments. Macrophage polarization was determined by flow cytometry and quantitative real-time PCR; macrophage phagocytosis was assessed by flow cytometry and laser scanning confocal microscopy; cell apoptosis was assessed by flow cytometry and western blotting. deletion markedly elevated macrophage phagocytosis and M2 macrophages in MRSA infection, which was accompanied by elevated expression of and and reduced expression of , tumor necrosis factor-α (, and deletion also inhibited macrophage apoptosis in MRSA infection, which was manifested by elevated B-cell lymphoma 2 (BCL-2) protein level and reduced protein levels of cleaved cysteine protease 3 (CASPASE-3) and BCL2-Associated X (BAX). Both the and experiments further showed the activation of phosphoinositide 3-kinase (PI3K)/AKT (also known as protein kinase B, PKB) signaling pathway in MRSA infection and that the regulation of expression may be dependent on Toll-like receptor (TLR) 2/PI3K pathway. The above results showed that deletion exhibited a protective role against MRSA infection by promoting M2 polarization and phagocytosis of macrophages and the regulation of partly owing to the activation of TLR2/PI3K pathway, proposing a novel therapeutic strategy for MRSA-infected pneumonia.
