title: [Cloning and biological activities of riboenzymes against major histocompatibility complex class II transactivator].
abstract: 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.
authors.affiliation: Institute of Hematology, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Guo
authors.forename: Ping
authors.initials: P
authors.lastname: Zou
authors.forename: Xu-chun
authors.initials: XC
authors.lastname: Yang
authors.forename: Hua-zhong
authors.initials: HZ
authors.lastname: Lu
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Yi-lin
authors.initials: YL
authors.lastname: Cao
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Hua-hua
authors.initials: HH
authors.lastname: Fan
mesh_terms: 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
chemical_list: C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D016337:RNA, Catalytic; D015534:Trans-Activators