Suppression of HLA class II expression of cell lines transfected with the mutated CIITA constructs
Objective To explore the depression of MHC class Ⅱ molecules by transfecting the mutated CⅡTA (MHC class Ⅱ transactivator) constructs. Methods Restriction enzymes, PCR technique and synthesized oligonucleotide strand were used to construct three mutants as pcDNA3mCⅡTA2, pcDNA3mCⅡTA3 and pcDNA3mCⅡTA4. All mutants and pcDNA3 vector were transfected into HeLa and Raji cell lines by lipofectamine. RT PCR and flow cytometry were used to determine the changes of the MHC class Ⅱ inducible/constitutive expression. Results Mutants pcDNA3mCⅡTA3 and pcDNA3mCⅡTA4 suppressed the inducible/constitutive expression of MHC class Ⅱ genes. However, pcDNA3 vector and pcDNA3mCⅡTA2 in which the initiation codon ATG was not contained had no effect on the MHC class Ⅱ expression. Conclusion The constructed mutants pcDNA3mCⅡTA3 and pcDNA3mCⅡTA4 suppressed the expression of MHC class Ⅱ genes. [