Multianalyte Microphysiometry of Macrophage Responses to Phorbol Myristate Acetate, Lipopolysaccharide, and Lipoarabinomannan

作者：Kimmel Danielle W; Meschievitz Mika E; Hiatt Leslie A; Cliffel David E^*

来源：Electroanalysis, 2013, 25(7): 1706-1712.

DOI：10.1002/elan.201300121

• Oxidative burst
• Gram-negative
• Mycobacterium
• Interferon-

This study examined the hypothesis that mycobacterial antigens generate different metabolic responses in macrophages as compared to gram-negative effectors and macrophage activators. To this end, we utilized platinum electrodes and a light addressable potentiometric sensor to observe dynamic electrochemical changes in metabolic flux, as well as extracellular acidification. While phorbol myristate acetate (PMA) is commonly used to study macrophage activation, the concentration used to create this physiological response varies. The response of RAW-264.7 macrophages is concentration-dependent, where the metabolic response to high concentrations of PMA decreases suggesting deactivation. The gram-negative effector, lipopolysaccharide (LPS), was seen to promote oxygen production which was used to produce a delayed onset of oxidative burst. Pre-incubation with interferon- (IFN-) allowed a synergistic effect between IFN- and LPS, allowing immediate initiation of oxidative burst. These studies exhibited a stark contrast with lipoarabinomannan (LAM), an antigenic glycolipid component associated with the bacterial genus Mycobacterium. The presence of LAM effectively inhibits any metabolic response preventing consumption of glucose and oxygen for the promotion of oxidative burst and to ensure pathogenic proliferation. This study demonstrates for the first time the immediate inhibitory metabolic effects LAM has on macrophages, suggesting implications for future intervention studies with Mycobacterium tuberculosis.

• 出版日期2013-7