[Cloning and biological activities of riboenzymes against major histocompatibility complex class II transactivator].
OBJECTIVE
To investigate the cloning and biological activities of riboenzymes against major histocompatibility complex (MHC) class II transactivator (CIITA) so as to explore the feasibility of using hammerhead riboenzyme to create immune tolerance.


METHODS
Three riboenzymes against MHC CIITA were synthesized and their activities were evaluated in vitro. Rz464, the riboenzyme with a better digestion effect, was inserted into the vector pIRES2-EGFP (then called pRz464). Human B lymphoma cells of Daudi line were cultured and transfected with pRz464 (then called pRz464-D). Cultured Daudi cells transfected with riboenzyme without the ability against CIITA (Rz-D) were used as control group. The expressions of classic MHC CIITA (HLA-DR, DP, and DQ) on the surface of Daudi cells before and after transfection were examined by flow cytometry.


RESULTS
The expressions of HLA-DR, DP, and DQ on the surface of cultured Daudi cells (Rz-D) were 97.9 +/- 0.8%, 94.3 +/- 1.1%, and 54.4 +/- 3.1% respectively. The expressions of HLA-DR, DP, and DQ were inhibited by 88.4%, 83.5%, and 93.4% respectively on the surface of pRz464-D cells.


CONCLUSIONS
The hammerhead riboenzyme Rz464 inhibits the expression of CIITA mRNAs, thus inhibiting the expression of MHC II molecules. It may be used in antigen-specific tolerance induction in allo-transplantation.
Guo
Rong
R
Institute of Hematology, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Zou
Ping
P
Yang
Xu-chun
XC
Lu
Hua-zhong
HZ
Gao
Feng
F
Cao
Yi-lin
YL
Zhang
Min
M
Fan
Hua-hua
HH
D003001:Cloning, Molecular; D015316:Genetic Therapy; D006801:Humans; D007108:Immune Tolerance; D009687:Nuclear Proteins; D016337:RNA, Catalytic / Q000235:genetics* / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000235:genetics; D014162:Transfection
C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D016337:RNA, Catalytic; D015534:Trans-Activators