TY - JOUR
T1 - Early production of tumor necrosis factor-α by Gr-1+ cells and its role in the host defense to pneumococcal infection in lungs
AU - Hatta, Masumitsu
AU - Yamamoto, Natsuo
AU - Miyazato, Akiko
AU - Ishii, Naoto
AU - Nakamura, Kiwamu
AU - Inden, Ken
AU - Aoyagi, Tetsuji
AU - Kunishima, Hiroyuki
AU - Hirakata, Yoichi
AU - Suzuki, Kazuo
AU - Kaku, Mitsuo
AU - Kawakami, Kazuyoshi
PY - 2010/3
Y1 - 2010/3
N2 - In this study, we elucidated the role of tumor necrosis factor (TNF)-α in the host defense to pulmonary infection with Streptococcus pneumoniae and defined the cellular source of this cytokine at an early stage of infection. Administration of anti-TNF-α monoclonal antibody (mAb) resulted in the reduced accumulation of neutrophils in bronchoalveolar lavage fluids (BALFs) and severe exacerbation of this infection. In a flow cytometric analysis, the intracellular expression of TNF-α was detected in Gr-1 bright+ and Gr-1dull+ cells during the time intervals postinfection, and F4/80+ cells expressed intracellular TNF-α before Gr-1dull+ cells appeared. The Gr-1bright+ and Gr-1dull+ cells sorted from BALF cells at 24 h were identified as neutrophils and macrophage-like cells, respectively, and the Gr-1 dull+ cells expressing CD11c, partially CD11b and a marginal level of F4/80 secreted TNF-α in in vitro cultures. Finally, deletion of Gr-1 + cells by administration of the specific mAb significantly reduced the concentrations of this cytokine in BALF at 6 and 12 h postinfection, but not the expression of TNF-α in F4/80+ cells. Thus, these results demonstrated that neutrophils, F4/80+ macrophages and Gr-1 dull+ CD11c+ macrophage-like cells played an important role in the production of TNF-α in lungs at an early stage of infection with S. pneumoniae.
AB - In this study, we elucidated the role of tumor necrosis factor (TNF)-α in the host defense to pulmonary infection with Streptococcus pneumoniae and defined the cellular source of this cytokine at an early stage of infection. Administration of anti-TNF-α monoclonal antibody (mAb) resulted in the reduced accumulation of neutrophils in bronchoalveolar lavage fluids (BALFs) and severe exacerbation of this infection. In a flow cytometric analysis, the intracellular expression of TNF-α was detected in Gr-1 bright+ and Gr-1dull+ cells during the time intervals postinfection, and F4/80+ cells expressed intracellular TNF-α before Gr-1dull+ cells appeared. The Gr-1bright+ and Gr-1dull+ cells sorted from BALF cells at 24 h were identified as neutrophils and macrophage-like cells, respectively, and the Gr-1 dull+ cells expressing CD11c, partially CD11b and a marginal level of F4/80 secreted TNF-α in in vitro cultures. Finally, deletion of Gr-1 + cells by administration of the specific mAb significantly reduced the concentrations of this cytokine in BALF at 6 and 12 h postinfection, but not the expression of TNF-α in F4/80+ cells. Thus, these results demonstrated that neutrophils, F4/80+ macrophages and Gr-1 dull+ CD11c+ macrophage-like cells played an important role in the production of TNF-α in lungs at an early stage of infection with S. pneumoniae.
KW - Neutrophils
KW - Pneumococcal infection
KW - TNF-α
UR - http://www.scopus.com/inward/record.url?scp=76349099573&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=76349099573&partnerID=8YFLogxK
U2 - 10.1111/j.1574-695X.2009.00616.x
DO - 10.1111/j.1574-695X.2009.00616.x
M3 - Article
C2 - 19909342
AN - SCOPUS:76349099573
VL - 58
SP - 182
EP - 192
JO - Pathogens and Disease
JF - Pathogens and Disease
SN - 2049-632X
IS - 2
ER -