Acute Lung Inflammation in Klebsiella pneumoniae B5055-Induced Pneumonia and Sepsis in BALB/c Mice: A Comparative Study
- PDF / 552,467 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 63 Downloads / 165 Views
Acute Lung Inflammation in Klebsiella pneumoniae B5055-Induced Pneumonia and Sepsis in BALB/c Mice: A Comparative Study Vijay Kumar1,2,3 and Sanjay Chhibber1
Abstract—Lungs play an important role in the body's defense against a variety of pathogens, but this network of immune system-mediated defense can be deregulated during acute pulmonary infections. The present study compares acute lung inflammation occurring during Klebsiella pneumoniae B5055-induced pneumonia and sepsis in BALB/c mice. Pneumonia was induced by intranasal instillation of bacteria (104 cfu), while sepsis was developed by placing the fibrin-thrombin clot containing known amount of bacteria (102 cfu) into the peritoneal cavity of animals. Mice with sepsis showed 100% mortality within five postinfection days, whereas all the animals with pneumonia survived. In animals suffering from K. pneumoniae B5055-induced pneumonia, all the inflammatory parameters (TNF-α, IL-1α, MPO, MDA, and NO) were found to be maximum till third post-infection day, after that, a decline was observed, whereas in septic animals, all the above-mentioned markers of inflammation kept on increasing. Histopathological study showed presence of alternatively activated alveolar macrophages (or foam cells) in lungs of mice with pneumonia after third post-infection day, which might have contributed to the induction of resolution of inflammation, but no such observation was made in lungs of septic mice. Hence, during pneumonia, controlled activation of macrophages may lead to resolution of inflammation. KEY WORDS: acute lung inflammation; macrophages; neutrophils; sepsis; pneumonia; Klebsiella pneumoniae B5055.
opment of acute lung inflammation/acute lung injury (ALI) or its more severe form called acute respiratory distress syndrome (ARDS). Severe sepsis is an important and common risk factor associated with development of acute lung injury, comprising of 6–42% of ALI [1]. ALI observed during pneumonia and sepsis is associated with high mortality. During ARDS, acute lung injury is responsible for very high mortality rates (34–60%) [2]. Neutrophil infiltration into the lung alveoli along with resultant endothelial cell injury are marked features of ALI [3, 4]. It is likely that neutrophil infiltration in the compartmentalized infection (pneumonia) may be different as compared to the migration of neutrophils into the lungs during systemic inflammation (sepsis). Since no reports are available in literature on this aspect, therefore the present study was conducted to compare the infiltration of lungs with neutrophils and the resultant inflammation arising as a consequence of pathogenic process of pneumonia or sepsis.
INTRODUCTION Lungs are not only involved in gaseous exchange but they also play a very important role in immunemediated defense against a wide variety of inhaled toxicants or pathogenic microorganisms. However, this protective immune-mediated action of lungs gets disintegrated during acute bacterial infections like pneumonia and sepsis. The overwhelming immune response generated during pneu
Data Loading...
