Expression of Apoptotic Signals Mediated by Different Virulent Classical Swine Fever Virus Infected Pulmonary Alveolar Macrophages and Peripheral Blood Lymphocytes

• Main Authors: Chia-Yu Lin, 林家鈺
• Other Authors: 李維誠
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/34503495732679615291

碩士 === 國立中興大學 === 獸醫病理生物學研究所 === 96 === Infection of classical swine fever virus (CSFV) causes immunosuppression and virus persistence in swine, closely related to the injury of lymphocytes and persistent infection in macrophages. The aim of this study was to investigate the expression of apoptotic signals in pulmonary alveolar macrophages (PAMs) and peripheral blood lymphocytes (PBLs) after infected with different virulence of CSFV. Three different CSFV isolates including the avirulent LPC, low virulent RL06-2, and virulent RL03-5 were used in this study. The disruption of cellular mitochondrial membrane potential, cell membrane integrity, and activation of pan-caspases were analyzed by flow cytometry, and activation of caspase-3 and Akt were detected by Western blotting. The results show that the apoptotic signals of mitochondrial membrane potential disruption and pan-caspases activation were all increased in PAMs infected with CSFV, but the signal of cleaved caspase-3 was not significantly enhanced. In contrast, the anti-apoptotic signal of Akt phosphorylation and its down-stream GSK-3beta of CSFV-infected PAMs were also increased with virulence dependency. However, only RL03-5 infected PAMs had higher cell viability than mock infection and PAMs infected with LPC and RL06-2 CSFV. In contrast, besides RL06-2, increased mitochondrial membrane potential disruption, loss of cell membrane integrity, activation of caspases, and cell viability were less conspicuous in CSFV-infected PBLs than mock infection. Taken these results together, both CSFV infection in PAMs and PBLs initiated apoptotic signals, but the signals may be blocked in the down-stream of caspase effector proteins by the activation of anti-apoptotic signal of phospho-Akt in PAMs, leading to higher cell survival rate in virulent CSFV-infected PAMs. Whether CSFV induces activation of Akt in PBLs, need to be further elucidated.