Abstract
BackgroundPseudomonas aeruginosa (PA) is one of the most common bacteria that causes lung infection in hospital. The aim of our study is to explore the role and action mechanism of NK cells in lung PA infection.MethodsIn this present study, 2.5 × 108 CFU/mouse PA was injected into murine trachea to make lung PA infection mouse model. Anti-asialo GM1 was used to inhibit NK cell. The percentage of NK cells was ensured by flow cytometry, and the M1- and M2-polarized macrophages were determined by flow cytometry, qRT-PCR, and ELISA assay. Besides, H&E staining was performed to ensure the pathological changes in lung tissues. Transmission electron microscopy and western blot were carried out to identify the exosome.ResultsHere, in the mouse model of PA lung infection, NK cell depletion caused M2 polarization of lung macrophage, and exacerbated PA-induced lung injury. Next, our data shown that M2 macrophage polarization was enhanced when the generation of NK cell-derived exosome was blocked in the co-culture system of NK cells and macrophages. Subsequently, we demonstrated that NK cells promoted M1 macrophage polarization both in PA-infected macrophage and the mouse model of PA lung infection, and attenuated lung injury through exosome.ConclusionOverall, our data proved that NK cell may improve PA-induced lung injury through promoting M1 lung macrophage polarization by secreting exosome. Our results provide a new idea for the treatment of PA lung infection.
Highlights
Pseudomonas aeruginosa (PA) is one of the most common bacteria that causes lung infection in hospital
M2 macrophage polarization was promoted in the mouse model of PA lung infection after natural killer (NK) cell was eliminated On the third day after surgery, the bacterial burden in right lung tissues of mice was confirmed by CFU counting
Our data shown that the number of NK cells were significantly reduced in the lung tissues of NK cell-depleted PAinfected mice (Fig. 1b)
Summary
Pseudomonas aeruginosa (PA) is one of the most common bacteria that causes lung infection in hospital. The aim of our study is to explore the role and action mechanism of NK cells in lung PA infection. The percentage of NK cells was ensured by flow cytometry, and the M1- and M2-polarized macrophages were determined by flow cytometry, qRT-PCR, and ELISA assay. Pseudomonas aeruginosa (PA) is a Gram-negative bacterium within the hospital environment, and the major cause of nosocomial pneumonia which mainly occurs in the patients with chronic obstructive pulmonary disease and cystic fibrosis, and the immunocompromised [1, 2]. Macrophage is an important component of the immune system in human, and plays a crucial role in immune responses, tissue homeostasis and the occurrence and development of multiple diseases [6, 7]. It was demonstrated that macrophages are plastic, and can be differentiated into two polarization phenotypes, including pro-inflammatory
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
