Monocyte recruitment into the lungs in pneumococcal pneumonia.
The recruitment of monocytes into the alveolar spaces is crucial for clearing infections and resolving the inflammatory response. We have previously reported the effect of acute pneumonia on monocyte transport through the bone marrow, and the present study concerns their clearance from the blood and migration into the lung airspaces. Dividing monocytes were labeled with the thymidine analog, 5'-bromo-2'-deoxyuridine (BrdU). Whole blood containing the labeled monocytes (MO(BrdU)) was transfused from either donor rabbits with pneumonia or from uninfected controls into recipients with pneumonia, where they were detected in blood and tissues using a double immunostaining method. The results show that MO(BrdU) from infected animals rapidly disappeared from the circulation (P < 0.05), preferentially sequestered in the infected lung tissue within 1 h (22.0 +/- 3.3% versus 6.0 +/- 0.4%, pneumonic region versus peripheral blood, P < 0.05), and accumulated to a greater degree in pneumonic airspaces than control monocytes 48 h after transfusion (3.9 +/- 0.5% versus 1.1 +/- 0.1%, P < 0.05). We conclude that immature monocytes released from the marrow by pneumonia sequester rapidly in lung microvessels but their migration in pneumonic airspaces is delayed.
McDonald Research Laboratories and iCAPTURE Centre, University of British Columbia, St. Paul's Hospital, 1081 Burrard Street, Vancouver, BC, V6Z 1Y6 Canada.
Yukinobu
Y
Goto
James C
JC
Hogg
Beth
B
Whalen
Chih-Horng
CH
Shih
Hiroshi
H
Ishii
Stephan F
SF
Van Eeden
D000818:Animals; D000963:Antimetabolites / Q000378:metabolism; D001803:Blood Transfusion; D001973:Bromodeoxyuridine / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D007150:Immunohistochemistry; D007958:Leukocyte Count; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D009000:Monocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism* / Q000637:transplantation; D011018:Pneumonia, Pneumococcal / Q000276:immunology* / Q000378:metabolism; D011817:Rabbits
D000963:Antimetabolites; D001973:Bromodeoxyuridine