Effect of infection from Klebsiella on the production of tumor necrosis factor-α in serum and the apoptosis of the thymocytes in mice

Objective To investigate the productive kinetics of tumor necrosis factor α in serum and the relation between TNF α and the apoptosis in thymus of mice with infection induced by Klebsiella . Methods TNF α in serum was measured by ELISA 3, 6, 9, 12, 24 hours after i.p. The morphologic pictures of thymocyte apoptosis was observed by electron microscope. The apoptosis of the thymocytes was stained by TUNEL and was detected with flow cytometric assessment. Results Sepsis was confirmed by microbiology study 3 hours after i.p Klebsiella . The TNF α was in a single peak manner ( P 0.01), and reached its highest level 6 hours after infection, then decreased to baseline at 24 hours. Flow cytometric analysis showed that apoptosis of thymocytes was gradually increased, reaching their peak 24 hours after infection ( P 0.01). Conclusion The data suggest that infection of Klebsiella can initiate inflammatory cytokines response, and induce thymocytes apoptosis in mice. The apoptosis in thymus is not completely mediated by TNF α.