Peribronchial lymphocyte activation in bleomycin-induced lung injury.
The role of lymphocytes in bleomycin (Bleo)-induced lung injury remains obscure. In normal hamsters, peribronchial lymphatic tissue (PBLT) has been found to contain a large population of T lymphocytes responsive to interleukin 2 (IL-2) but not to IL-4. Lung injury induced by a single intratracheal instillation of Bleo in hamsters has been ameliorated by cyclosporin A (CyA). In the present study, using this model, PBLT-derived lymphocyte function was explored for 28 days after Bleo instillation. Increase in PBLT lymphocytes occurred at five time points investigated, reaching highest values on day +7 (p < 0.0025). Cell proliferation in response to concanavalin A was enhanced, while IL-2 +/- the mitogen had no effect. In contrast to its inactivity in the normal hamster, in the Bleo-injured animal IL-4 alone induced T cell proliferation (p = 0.0077) on day +7. CyA therapy initially suppressed and delayed recovery of the number of lymphocytes and their activation. The results of this study suggest the existence of a vulnerable period in Bleo-induced lung injury and indicate that lymphocytes participate in the pathogenesis of the insult to the tissue. The unresponsiveness to IL-2 and the emergence of cellular response to IL-4 indicate immune deviation in PBLT-derived T cells.
Mallory Institute of Pathology, Boston University School of Medicine, Massachusetts, USA.
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Lossos
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Breuer
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Shriki
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D000818:Animals; D000900:Anti-Bacterial Agents / Q000633:toxicity*; D001761:Bleomycin / Q000633:toxicity*; D001980:Bronchi / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D006224:Cricetinae; D016572:Cyclosporine / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D008208:Lymphatic System / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D008297:Male; D008647:Mesocricetus; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*
D000900:Anti-Bacterial Agents; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D003208:Concanavalin A; D001761:Bleomycin; D015847:Interleukin-4; D016572:Cyclosporine