ABSTRACT
The TIPE( tumor necrosis factor-alpha-induced protein 8-like) family has been recently described as regulators of tu-morigenesis and inflammation .The family consists of four highly homologous members: TNFAIP8 ( tumor necrosis factor-α-induced protein 8), TIPE1 (TNFAIP8L1), TIPE2 (TNFAIP8L2) and TIPE3 (TNFAIP8L3).Although TNFAIP8 family share high degrees of sequence homology , the members have different histological expressions , biological functions and molecular targets .TNFAIP8 shows the functions of inhibiting bacterial infection and promoting tumor migration .As a negative regulator of immunity and inflammation , TIPE2 is also an inhibitor of the oncogenic Ras in some neoplastic diseases .TIPE1 can induce cell apoptosis and inhibit tumor .TIPE3 is the transfer protein of phosphoinositide second messengers and can promote cancer .Emerging studies show TIPE family play important regulatory roles in many diseases;however, specific biological activities and exact molecular mechanisms need to be further elucidated .
ABSTRACT
Objective:To study the role of DR5 in TRAIL apoptotic signal transduction. Methods:BALB/C mice were immunized with recombinant DR5 that contains the full-length extracellular domain of the human DR5. Anti-DR5 mAb was generated by hybridoma. The level of DR5 expression on Jurkat cell line was examined by flow cytometry. The rates of TRAIL-induced apoptosis and anti-DR5 mAb blocking on Jurkat cells were tested by flow cytometry with TRAIL apoptosis kit.Results:The percentage of DR5 expression on Jurkat cells was 94 83%. TRAIL and anti-TRAIL mAb could kill Jurkat cells on dose-dependent, and the killing rate was 90% in the concentration of 50～100 ng/ml. The killing role of TRAIL could be blocked on Jurkat cells pretreated with anti-DR5 mAb. The average percentage of blocking was 90 49%.Conclusion:DR5 plays a very key role in TRAIL induced apoptosis in Jurkat cells.