Proteomics of Bronchoalveolar Lavage Fluid Reveals a Lung Oxidative Stress Response in Murine Herpesvirus-68 Infection.

Eric Bortz,Ting-Ting Wu,Parthive Patel,Julian Whitelegge,Ren Sun

doi:10.3390/v10120670

Abstract

Murine herpesvirus-68 (MHV-68) productively infects mouse lungs, exhibiting a complex pathology characteristic of both acute viral infections and chronic respiratory diseases. We sought to discover proteins differentially expressed in bronchoalveolar lavage (BAL) from mice infected with MHV-68. Mice were infected intranasally with MHV-68. After nine days, as the lytic phase of infection resolved, differential BAL proteins were identified by two-dimensional (2D) electrophoresis and mass spectrometry. Of 23 unique proteins, acute phase proteins, vitamin A transport, and oxidative stress response factors Pdx6 and EC-SOD (Sod3) were enriched. Correspondingly, iNOS2 was induced in lung tissue by seven days post-infection. Oxidative stress was partly a direct result of MHV-68 infection, as reactive oxygen species (ROS) were induced in cultured murine NIH3T3 fibroblasts and human lung A549 cells infected with MHV-68. Finally, mice infected with a recombinant MHV-68 co-expressing inflammatory cytokine murine interleukin 6 (IL6) showed exacerbated oxidative stress and soluble type I collagen characteristic of tissue recovery. Thus, oxidative stress appears to be a salient feature of MHV-68 pathogenesis, in part caused by lytic replication of the virus and IL6. Proteins and small molecules in lung oxidative stress networks therefore may provide new therapeutic targets to ameliorate respiratory virus infections.

Highlights

Respiratory virus infections have the potential to cause significant lung pathology including acute respiratory distress syndrome (ARDS)
Recovery and Characterization of bronchoalveolar lavage (BAL) Fluid from Mouse Lungs Infected with murine herpesvirus-68 (MHV-68)
Lytic MHV-68 infection proceeds under conditions of oxidative stress, as we found that treating infected cells with paraquat did not inhibit but rather mildly enhanced red fluorescent protein (RFP)/MHV-68 virus infection (Figure S3)

Summary

Introduction

Respiratory virus infections have the potential to cause significant lung pathology including acute respiratory distress syndrome (ARDS). In addition to the continual burden of disease from respiratory viruses such as influenza types A and B, respiratory syncytial virus (RSV), parainfluenza viruses, adenovirus, recently emerged coronaviruses responsible for Middle East (MERS-CoV) and severe acute (SARS-CoV) respiratory syndromes, H5N1 and H7N9 pathogenic avian influenza viruses, pandemic swine-origin (H1N1) influenza, and human metapneumovirus target the human lungs [1,2,3,4,5,6,7]. Co-morbid, underlying pulmonary medical conditions including asthma, chronic obstructive pulmonary disease (COPD), and tuberculosis (TB) are associated with severe respiratory virus infections [8,9,10,11]. A murine gammaherpesvirus is protective in mice challenged with lethal influenza A virus, suggesting immunomodulatory roles for gammaherpesviruses in the pathogenesis of lung infections [14]. The application of new genomics technologies for understanding respiratory virus infections under isogenic host conditions might yield deeper insight into the pathological changes that occur in virus infection of the mammalian lung, and provide targets for diagnostic biomarkers or therapeutic intervention

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Conclusion