Objective    To construct human eukaryotic expression system expressing T cell surface molecule CD40L and identify the expression product in SCCL cell line h446.     Methods    The expression vector pcDNA3.1-CD40L was constructed by recombinant DNA technology

then transfected into h446 cell line of SCCL by lipidosome methods

and the expressed membrane protein was identified by flow cytometry.     Results    The pcDNA3.1(+)-CD40L was constructed successfully and the coding region was inserted into the vector correctly. The membrane protein was observed by flow cytometry on transfected h446 cell line of SCCL.     Conclusion    Human CD40L was expressed successfully in eukaryotic system

which is very important in the anti-tumor vaccination study with a recombinant human CD40L in clinic.