Role of T-lymphocytes in the resolution of endotoxin-induced lung injury.
An acute neutrophilic lung injury was compared in Balb/c normal and nu/nu (nude) mice to assess the role of T lymphocytes in the resolution of acute pulmonary neutrophilic inflammation following the administration of endotoxin. Maximal neutrophilic infiltration occurred on day 1 post-endotoxin treatment and declined to near normal levels by day 5. In contrast, the percentage of lymphocytes in the bronchoalveolar lavage (BAL) fluid increased from 1.8% on day 1 post-endotoxin to greater than 11% on days three and five, during which time neutrophil resolution was occurring. On days 1-5 after endotoxin administration, approximately 40% of the CD4 lymphocytes expressed the cell surface activation marker, CD69. Despite being CD69+, CD4 cells did not express the high affinity IL-2 receptor chain, CD25, to any significant extent on any of the days studied. To assess the contribution of T cells to the rate of clearance of neutrophils from the BAL, normal and nude Balb/c mice were compared for the percentage of neutrophils following nasal administration of endotoxin. Endotoxin-treated nude mice did not demonstrate significant differences in either the total white blood cell counts or in the clearance of neutrophils from the BAL, as compared to normal Balb/c mice. These data indicate that the influx of activated T cells during the resolution of neutrophilic pneumonitis does not contribute to the rate of neutrophil clearance during acute lung injury.
Morris
P E
PE
Division of Pulmonary and Critical Care Medicine, College of Medicine, University of Kentucky, Lexington 40536-0084, USA.
Glass
J
J
Cross
R
R
Cohen
D A
DA
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002465:Cell Movement; D004731:Endotoxins / Q000633:toxicity*; D008168:Lung / Q000187:drug effects / Q000276:immunology*; D055370:Lung Injury; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology; D011014:Pneumonia / Q000209:etiology / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
D004731:Endotoxins