These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Adenosine A(2B) receptor deficiency promotes host defenses against gram-negative bacterial pneumonia.
    Author: Barletta KE, Cagnina RE, Burdick MD, Linden J, Mehrad B.
    Journal: Am J Respir Crit Care Med; 2012 Nov 15; 186(10):1044-50. PubMed ID: 22997203.
    Abstract:
    RATIONALE: Activation of the adenosine A(2B) receptor (A(2B)R) promotes antiinflammatory effects in diverse biological settings, but the role of this receptor in antimicrobial host defense in the lung has not been established. Gram-negative bacillary pneumonia is a common and serious illness associated with high morbidity and mortality, the treatment of which is complicated by increasing rates of antibiotic resistance. OBJECTIVES: To test the hypothesis that absence of adenosine A(2B) receptor signaling promotes host defense against bacterial pneumonia. METHODS: We used a model of Klebsiella pneumoniae pneumonia in wild-type mice and mice with targeted deletion of the A(2B)R. Host responses were compared in vivo and leukocyte responses to the bacteria were examined in vitro. MEASUREMENTS AND MAIN RESULTS: A(2B)R(-/-) mice demonstrated enhanced bacterial clearance from the lung and improved survival after infection with K. pneumoniae compared with wild-type controls, an effect that was mediated by bone marrow-derived cells. Leukocyte recruitment to the lungs and expression of inflammatory cytokines did not differ between A(2B)R(-/-) and wild-type mice, but A(2B)R(-/-) neutrophils exhibited sixfold greater bactericidal activity and enhanced production of neutrophil extracellular traps compared with wild-type neutrophils when incubated with K. pneumoniae. Consistent with this finding, bronchoalveolar lavage fluid from A(2B)R(-/-) mice with Klebsiella pneumonia contained more extracellular DNA compared with wild-type mice with pneumonia. CONCLUSIONS: These data suggest that the absence of A(2B)R signaling enhances antimicrobial activity in gram-negative bacterial pneumonia.
    [Abstract] [Full Text] [Related] [New Search]