TY - JOUR AB - In immunosuppressed hosts, Legionella pneumophila (Lp) infection usually develops into severe pneumonia, which is pathologically characterized by increased vascular permeability and pulmonary edema. At present, mechanisms associated with changes in pulmonary capillary permeability (PCP) and the pathogenesis of pulmonary edema in immunosuppressed hosts with Lp infection are unclear. Therefore, in the present study an animal model of normal and immunosuppressed guinea pigs infected with Lp was established. An isolated perfused lung system was used to investigate the extent of changes in PCP. Pathological and immunofluorescence examinations were performed to explore the mechanism underlying these changes. The results indicated that PCP increased with the highest magnitude in immunosuppressed guinea pigs infected with Lp, with repeated ANOVA indicating synergism between infection and immunosuppression (P=0.0444). Hematoxylin and eosin staining and electron microscopy revealed more severe morphological damages in the lung tissues and pulmonary capillaries of the immunosuppressed animals infected with Lp compared with normal animals infected with Lp. Immunofluorescence analysis showed that immunosuppression reduced the expression of the vascular endothelial cell junction protein VE‑cadherin (P=0.027). Following Lp infection, VE‑cadherin expression was significantly lower in the immunosuppressed guinea pigs compared with their immunocompetent counterparts (P=0.001). These results suggest that immunosuppression combined with Lp infection induces more significant damage to pulmonary capillaries compared with Lp infection alone, resulting in a significantly increased PCP. AD - Department of Respiratory Medicine, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China Department of Respiratory Medicine, Heilongjiang Provincial Hospital, Harbin, Heilongjiang 150036, P.R. China Department of Respiratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China AU - Cai,Xu AU - Yu,Na AU - Ma,Jiangwei AU - Li,Wen‑Yang AU - Xu,Mingtao AU - Li,Erran AU - Zhang,Min AU - Wang,Wei AU - Chen,Yu AU - Kang,Jian DA - 2019/12/01 DO - 10.3892/etm.2019.8102 EP - 4378 IS - 6 JO - Exp Ther Med KW - immunosuppression Legionella pneumophila serogroup 1 pulmonary capillary permeability pulmonary artery pressure isolated lung perfusion PY - 2019 SN - 1792-0981 1792-1015 SP - 4368 ST - Altered pulmonary capillary permeability in immunosuppressed guinea pigs infected with Legionella pneumophila serogroup 1 T2 - Experimental and Therapeutic Medicine TI - Altered pulmonary capillary permeability in immunosuppressed guinea pigs infected with Legionella pneumophila serogroup 1 UR - https://doi.org/10.3892/etm.2019.8102 VL - 18 ER -