REQUIREMENT FOR LYMPHOCYTES AND RESIDENT MACROPHAGES IN LPS-INDUCED PLEURAL EOSINOPHIL ACCUMULATION

Citation
Pt. Bozza et al., REQUIREMENT FOR LYMPHOCYTES AND RESIDENT MACROPHAGES IN LPS-INDUCED PLEURAL EOSINOPHIL ACCUMULATION, Journal of leukocyte biology, 56(2), 1994, pp. 151-158
Citations number
37
Categorie Soggetti
Immunology,Hematology
ISSN journal
07415400
Volume
56
Issue
2
Year of publication
1994
Pages
151 - 158
Database
ISI
SICI code
0741-5400(1994)56:2<151:RFLARM>2.0.ZU;2-9
Abstract
In this study we investigated the involvement of inflammatory cells in the pleural accumulation of eosinophils induced by lipopolysaccharide (LPS). Intrathoracic (i.t.) injection of LPS (250 ng/cavity) into rat s induced a significant eosinophil accumulation that developed within 24 h, was maximal at 48 h, and returned to control values within 120 h . This eosinophil influx was preceded by a huge neutrophil influx with in 4 h and accompanied by a mononuclear cell accumulation between 24 a nd 48 h. Pretreatment with an antineutrophil monoclonal antibody (RP-3 , 2 ml per animal) selectively reduced the number of circulating neutr ophils within 8 h but failed to alter the LPS-induced eosinophilia. Si milarly, platelet depletion with an anti-rat platelet antiserum did no t alter the LPS-induced eosinophil accumulation. Cyclosporine (50 mg/k g, 12 and 2 h before) partially inhibited (51%) the LPS-induced pleura l eosinophilia, whereas the eosinophilia was not changed by prior degr anulation of pleural mast cells with polymyxin B (10 mu g/cavity, 24 h before). Moreover, selective depletion of T lymphocytes using an anti -Thy 1.0 monoclonal antibody significantly inhibited the eosinophilia triggered by LPS. The i.t. injection of liposomes containing dichlorom ethylene diphosphonate significantly reduced (65 %) the number of resi dent macrophages after 5 days. Under this condition, the eosinophil in filtration induced by LPS was completely inhibited. Accordingly, the i .t. injection of supernatant from macrophage monolayers, obtained from the pleural cavities of LPS-injected rats, into naive recipient anima ls led to a twofold increase in the number of pleural eosinophils. In conclusion, our data suggest an important role for resident macrophage s and T lymphocytes in the eosinophil accumulation induced by LPS.