Abstract:

Objective To observe the proliferation and apoptosis of Jurkat cells，and to discuss the onco⁃lytic effect of RSV on Jurkat cells and its possible mechanism. Refractory or recurrent acute lymphoblastic leukemiais an important role affecting the overall efficacy of children with leukemia. Oncolytic virotherapy is a new biologi⁃cal therapy against tumors in recent years. Multiple oncolytic viruses，such as measel virus and Newcastle virus，have been widely researched in the treatment of leukemia. However，there are few studies in the treatment of leuke⁃mia with respiratory syncytial virus（RSV）. Methods Jurkat cells were infected with RSV. Jurkat cells not infectedwith RSV were set as the blank control group（con）. Cells were collected at different time points（3 h，6 h，12 h，24 h and 48 h）after infection. Respiratory syncytial virus nonstructural protein 2（RSV⁃NS2）and TRAF6 weredetected by qRT⁃PCR . The proliferation of Jurkat cells was evaluated by MTT and clone formation assay，and theapoptosis level was evaluated by FCM. The protein expression of Bcl2 and TRAF6 and NF⁃κB and cleaved Caspase⁃3，8，9 was compared by Western blot. Results After RSV infected Jurkat cells，qRT⁃PCR detected that the expres⁃sion of RSV⁃NS2 began to appear within 3 h after infection，increased significantly at 6 h，then increased in a time⁃dependent manner（P < 0.05），while the expression of TRAF6 decreased with the extension of infection time（P <0.05）. MTT results showed that the proliferation of Jurkat cells decreased significantly from 6 h to 24 h after RSVinfection（P < 0.05）. Clone formation experiment showed that the number of clones of Jurkat cells decreased significantly 12 days after RSV infection（P < 0.05），suggesting that RSV inhibited the proliferation of Jurkatcells. FCM results showed that the apoptosis level of Jurkat cells increased significantly in a time⁃dependent man⁃ner from 12 h to 48 h after RSV infection（P < 0.05）. Western blot analysis revealed that the expression of cleavedcaspase⁃3 and cleaved caspase⁃9 increased significantly after 12 hours of RSV infection，and the expression of Bcl2decreased significantly（P < 0.05），but the expression of cleaved caspase⁃8 did not change significantly. The expres⁃sion of TRAF6 and p⁃NF⁃κB decreased with the extension of infection time（P < 0.05）. Conclusion RSV in⁃hibits the proliferation of Jurkat cells，promotes cell apoptosis and inhibits TRAF6/NF⁃κB pathway，so as to exertthe inhibitory effect on Jurkat cells，revealing that RSV can produce oncolytic effect on hematological tumors.

Key words:

respiratory syncytial virus, Jurkat, TRAF6, NF?κB