Novel Requirement for Staphylococcal Cell Wall-Anchored Protein SasD in Pulmonary Infection

Author:

Grousd Jennifer A,Riesmeyer Abigail M.,Cooper Vaughn S.ORCID,Bomberger Jennifer M.ORCID,Richardson Anthony R.ORCID,Alcorn John F.

Abstract

AbstractStaphylococcus aureus can complicate preceding viral infections, including influenza virus. A bacterial infection combined with a preceeding viral infection, known as super-infection, leads to worse outcomes compared to single infection. Most of the super-infection literature focuses on the changes in immune responses to bacteria between homeostatic and virally infected lungs. However, it is unclear how much of an influence bacterial virulence factors have in super-infection. Staphylococcal species express a broad range of cell wall-anchored proteins (CWAs) that have roles in host adhesion, nutrient acquisition, and immune evasion. We screened the importance of these CWAs using mutants lacking individual CWAs in vivo in both bacterial pneumonia and influenza super-infection. In bacterial pneumonia, lacking individual CWAs led to varying decreases in bacterial burden, lung damage, and immune infiltration into the lung. However, the presence of a preceding influenza infection partially abrogated the requirement for CWAs. In the screen, we found that the uncharacterized CWA S. aureus surface protein D (SasD) induced changes in both inflammatory and homeostatic lung markers. We further characterized a SasD mutant (sasD A50.1) in the context of pneumonia. Mice infected with sasD A50.1 had decreased bacterial burden, inflammatory responses, and mortalty compared to wildtype S. aureus. Mice also had reduced levels of IL-1β compared with wildtype, likely derived from macrophages. Reductions in IL-1β transcript levels as well as increased macrophage viability implicate altered macrophage cell death pathways. These data identify a novel virulence factor for S. aureus that influences inflammatory signaling within the lung.ImportanceStaphylococcus aureus is a common commensal bacteria that can cause severe infections, such as pneumonia. In the lung, viral infections increase the risk of staphylococcal pneumonia, leading to combined infections known as super-infections. The most common virus associated with S. aureus pneumonia is influenza, and super-infections lead to worse patient outcomes compared to either infection alone. While there is much known about how the immune system differs between healthy and virally infected lungs, the role of bacterial virulence factors in super-infection is less understood. The significance of our research is identifying new bacterial virulence factors that play a role in the initiation of infection and lung injury, which could lead to future therapies to prevent pulmonary single or super-infection with S. aureus.

Publisher

Cold Spring Harbor Laboratory

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3