Poorly Cross-Linked Peptidoglycan in MRSA Due to mecA Induction Activates the Inflammasome and Exacerbates Immunopathology.
Poorly Cross-Linked Peptidoglycan in MRSA Due to mecA Induction Activates the Inflammasome and Exacerbates Immunopathology.
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DOI：
10.1016/j.chom.2015.10.011
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发表时间：
2015-11-11
影响因子：
30.3
通讯作者：
Liu GY
中科院分区：
文献类型：
--
作者：
Müller S;Wolf AJ;Iliev ID;Berg BL;Underhill DM;Liu GY
Methicillin-resistant S. aureus (MRSA) is a leading health problem. Compared to methicillin-sensitive S. aureus, MRSA infections are associated with greater morbidity and mortality but the mechanisms underlying MRSA pathogenicity are unclear. Here we show that the protein conferring β-lactam antibiotic resistance, penicillin-binding protein 2A (encoded by the mecA gene), directly contributes to pathogenicity during MRSA infection. MecA induction leads to a reduction in peptidoglycan cross-linking that allows for enhanced degradation and detection by phagocytes, resulting in robust IL-1β production. Peptidoglycan isolated from β-lactam-challenged MRSA strongly induces the NLRP3 inflammasome in macrophages but these effects are lost upon peptidoglycan solubilization. Mutant MRSA bacteria with naturally-occurring short peptidoglycan cross-links induce high IL-1β levels in vitro, and cause increased pathology in vivo. β-lactam treatment of MRSA skin infection exacerbates immunopathology, which is IL-1-dependent. Thus, antibiotic-induced expression of mecA during MRSA skin infection contributes to immunopathology by altering peptidoglycan structure.
